From: Ash Wilding <ash.j.wild...@gmail.com>
This patch pulls in Linux's atomics helpers for arm32 and arm64, and
their dependencies, as-is.
Note that Linux's arm32 atomics helpers use the READ_ONCE() and
WRITE_ONCE() macros defined in <asm-generic/rwonce.h>, while Linux's
arm64 atomics helpers use __READ_ONCE() and __WRITE_ONCE().
The only difference is that the __* versions skip checking whether the
object being accessed is the same size as a native C type (e.g. char,
int, long, etc). Given the arm32 helpers are using the macros to access
an atomic_t's counter member, which is an int, we can skip this check by
using the __* versions like the arm64 code does.
I mention this here because it forms the first part of my justification
for *not* copying Linux's <linux/compiler_types.h> to Xen; the size
check described above is performed by __native_word() defined in that
header.
The second part of my justification may be more contentious; as you'll
see in the next patch, I intend to drop the __unqual_scalar_typeof()
calls in __READ_ONCE() and __WRITE_ONCE(). This is because the pointer
to the atomic_t's counter member is always a basic (int *) so we don't
need this, and dropping it means we can avoid having to port Linux's
<linux/compiler_types.h>.
If people are against this approach, please bear in mind that the
current version of __unqual_scalar_typeof() in <linux/compiler_types.h>
was actually the reason for Linux upgrading the minimum GCC version
required to 4.9 earlier this year so that they can guarantee C11
_Generic support [1].
So if we do want to take Linux's <linux/compiler_types.h> we'll either
need to:
A) bump up the minimum required version of GCC to 4.9 to match
that required by Linux; in the Xen README we currently state
GCC 4.8 for Arm and GCC 4.1.2_20070115 for x86.
or:
B) mix-and-match an older version of Linux's <linux/compiler_types.h>
with the other headers taken from a newer version of Linux.
Thoughts?
[1] https://lkml.org/lkml/2020/7/8/1308
Signed-off-by: Ash Wilding <ash.j.wild...@gmail.com>
---
xen/include/asm-arm/arm32/atomic.h | 507 +++++++++++++++++++++++
xen/include/asm-arm/arm32/cmpxchg.h | 279 +++++++++++++
xen/include/asm-arm/arm64/atomic.h | 228 ++++++++++
xen/include/asm-arm/arm64/atomic_ll_sc.h | 353 ++++++++++++++++
xen/include/asm-arm/arm64/atomic_lse.h | 419 +++++++++++++++++++
xen/include/asm-arm/arm64/cmpxchg.h | 285 +++++++++++++
xen/include/asm-arm/arm64/lse.h | 48 +++
xen/include/xen/rwonce.h | 90 ++++
8 files changed, 2209 insertions(+)
create mode 100644 xen/include/asm-arm/arm32/atomic.h
create mode 100644 xen/include/asm-arm/arm32/cmpxchg.h
create mode 100644 xen/include/asm-arm/arm64/atomic.h
create mode 100644 xen/include/asm-arm/arm64/atomic_ll_sc.h
create mode 100644 xen/include/asm-arm/arm64/atomic_lse.h
create mode 100644 xen/include/asm-arm/arm64/cmpxchg.h
create mode 100644 xen/include/asm-arm/arm64/lse.h
create mode 100644 xen/include/xen/rwonce.h
diff --git a/xen/include/asm-arm/arm32/atomic.h
b/xen/include/asm-arm/arm32/atomic.h
new file mode 100644
index 0000000000..ac6338dd9b
--- /dev/null
+++ b/xen/include/asm-arm/arm32/atomic.h
@@ -0,0 +1,507 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * arch/arm/include/asm/atomic.h
+ *
+ * Copyright (C) 1996 Russell King.
+ * Copyright (C) 2002 Deep Blue Solutions Ltd.
+ */
+#ifndef __ASM_ARM_ATOMIC_H
+#define __ASM_ARM_ATOMIC_H
+
+#include <linux/compiler.h>
+#include <linux/prefetch.h>
+#include <linux/types.h>
+#include <linux/irqflags.h>
+#include <asm/barrier.h>
+#include <asm/cmpxchg.h>
+
+#ifdef __KERNEL__
+
+/*
+ * On ARM, ordinary assignment (str instruction) doesn't clear the local
+ * strex/ldrex monitor on some implementations. The reason we can use it for
+ * atomic_set() is the clrex or dummy strex done on every exception return.
+ */
+#define atomic_read(v) READ_ONCE((v)->counter)
+#define atomic_set(v,i) WRITE_ONCE(((v)->counter), (i))
+
+#if __LINUX_ARM_ARCH__ >= 6
+
+/*
+ * ARMv6 UP and SMP safe atomic ops. We use load exclusive and
+ * store exclusive to ensure that these are atomic. We may loop
+ * to ensure that the update happens.
+ */
+
+#define ATOMIC_OP(op, c_op, asm_op) \
+static inline void atomic_##op(int i, atomic_t *v) \
+{ \
+ unsigned long tmp; \
+ int result; \
+ \
+ prefetchw(&v->counter); \
+ __asm__ __volatile__("@ atomic_" #op "\n" \
+"1: ldrex %0, [%3]\n" \
+" " #asm_op " %0, %0, %4\n" \
+" strex %1, %0, [%3]\n" \
+" teq %1, #0\n" \
+" bne 1b" \
+ : "=&r" (result), "=&r" (tmp), "+Qo" (v->counter) \
+ : "r" (&v->counter), "Ir" (i) \
+ : "cc"); \
+} \
+
+#define ATOMIC_OP_RETURN(op, c_op, asm_op) \
+static inline int atomic_##op##_return_relaxed(int i, atomic_t *v) \
+{ \
+ unsigned long tmp; \
+ int result; \
+ \
+ prefetchw(&v->counter); \
+ \
+ __asm__ __volatile__("@ atomic_" #op "_return\n" \
+"1: ldrex %0, [%3]\n" \
+" " #asm_op " %0, %0, %4\n" \
+" strex %1, %0, [%3]\n" \
+" teq %1, #0\n" \
+" bne 1b" \
+ : "=&r" (result), "=&r" (tmp), "+Qo" (v->counter) \
+ : "r" (&v->counter), "Ir" (i) \
+ : "cc"); \
+ \
+ return result; \
+}
+
+#define ATOMIC_FETCH_OP(op, c_op, asm_op) \
+static inline int atomic_fetch_##op##_relaxed(int i, atomic_t *v) \
+{ \
+ unsigned long tmp; \
+ int result, val; \
+ \
+ prefetchw(&v->counter); \
+ \
+ __asm__ __volatile__("@ atomic_fetch_" #op "\n" \
+"1: ldrex %0, [%4]\n" \
+" " #asm_op " %1, %0, %5\n" \
+" strex %2, %1, [%4]\n" \
+" teq %2, #0\n" \
+" bne 1b" \
+ : "=&r" (result), "=&r" (val), "=&r" (tmp), "+Qo" (v->counter) \
+ : "r" (&v->counter), "Ir" (i) \
+ : "cc"); \
+ \
+ return result; \
+}
+
+#define atomic_add_return_relaxed atomic_add_return_relaxed
+#define atomic_sub_return_relaxed atomic_sub_return_relaxed
+#define atomic_fetch_add_relaxed atomic_fetch_add_relaxed
+#define atomic_fetch_sub_relaxed atomic_fetch_sub_relaxed
+
+#define atomic_fetch_and_relaxed atomic_fetch_and_relaxed
+#define atomic_fetch_andnot_relaxed atomic_fetch_andnot_relaxed
+#define atomic_fetch_or_relaxed atomic_fetch_or_relaxed
+#define atomic_fetch_xor_relaxed atomic_fetch_xor_relaxed
+
+static inline int atomic_cmpxchg_relaxed(atomic_t *ptr, int old, int new)
+{
+ int oldval;
+ unsigned long res;
+
+ prefetchw(&ptr->counter);
+
+ do {
+ __asm__ __volatile__("@ atomic_cmpxchg\n"
+ "ldrex %1, [%3]\n"
+ "mov %0, #0\n"
+ "teq %1, %4\n"
+ "strexeq %0, %5, [%3]\n"
+ : "=&r" (res), "=&r" (oldval), "+Qo" (ptr->counter)
+ : "r" (&ptr->counter), "Ir" (old), "r" (new)
+ : "cc");
+ } while (res);
+
+ return oldval;
+}
+#define atomic_cmpxchg_relaxed atomic_cmpxchg_relaxed
+
+static inline int atomic_fetch_add_unless(atomic_t *v, int a, int u)
+{
+ int oldval, newval;
+ unsigned long tmp;
+
+ smp_mb();
+ prefetchw(&v->counter);
+
+ __asm__ __volatile__ ("@ atomic_add_unless\n"
+"1: ldrex %0, [%4]\n"
+" teq %0, %5\n"
+" beq 2f\n"
+" add %1, %0, %6\n"
+" strex %2, %1, [%4]\n"
+" teq %2, #0\n"
+" bne 1b\n"
+"2:"
+ : "=&r" (oldval), "=&r" (newval), "=&r" (tmp), "+Qo" (v->counter)
+ : "r" (&v->counter), "r" (u), "r" (a)
+ : "cc");
+
+ if (oldval != u)
+ smp_mb();
+
+ return oldval;
+}
+#define atomic_fetch_add_unless atomic_fetch_add_unless
+
+#else /* ARM_ARCH_6 */
+
+#ifdef CONFIG_SMP
+#error SMP not supported on pre-ARMv6 CPUs
+#endif
+
+#define ATOMIC_OP(op, c_op, asm_op) \
+static inline void atomic_##op(int i, atomic_t *v) \
+{ \
+ unsigned long flags; \
+ \
+ raw_local_irq_save(flags); \
+ v->counter c_op i; \
+ raw_local_irq_restore(flags); \
+} \
+
+#define ATOMIC_OP_RETURN(op, c_op, asm_op) \
+static inline int atomic_##op##_return(int i, atomic_t *v) \
+{ \
+ unsigned long flags; \
+ int val; \
+ \
+ raw_local_irq_save(flags); \
+ v->counter c_op i; \
+ val = v->counter; \
+ raw_local_irq_restore(flags); \
+ \
+ return val; \
+}
+
+#define ATOMIC_FETCH_OP(op, c_op, asm_op) \
+static inline int atomic_fetch_##op(int i, atomic_t *v)
\
+{ \
+ unsigned long flags; \
+ int val; \
+ \
+ raw_local_irq_save(flags); \
+ val = v->counter; \
+ v->counter c_op i; \
+ raw_local_irq_restore(flags); \
+ \
+ return val; \
+}
+
+static inline int atomic_cmpxchg(atomic_t *v, int old, int new)
+{
+ int ret;
+ unsigned long flags;
+
+ raw_local_irq_save(flags);
+ ret = v->counter;
+ if (likely(ret == old))
+ v->counter = new;
+ raw_local_irq_restore(flags);
+
+ return ret;
+}
+
+#define atomic_fetch_andnot atomic_fetch_andnot
+
+#endif /* __LINUX_ARM_ARCH__ */
+
+#define ATOMIC_OPS(op, c_op, asm_op) \
+ ATOMIC_OP(op, c_op, asm_op) \
+ ATOMIC_OP_RETURN(op, c_op, asm_op) \
+ ATOMIC_FETCH_OP(op, c_op, asm_op)
+
+ATOMIC_OPS(add, +=, add)
+ATOMIC_OPS(sub, -=, sub)
+
+#define atomic_andnot atomic_andnot
+
+#undef ATOMIC_OPS
+#define ATOMIC_OPS(op, c_op, asm_op) \
+ ATOMIC_OP(op, c_op, asm_op) \
+ ATOMIC_FETCH_OP(op, c_op, asm_op)
+
+ATOMIC_OPS(and, &=, and)
+ATOMIC_OPS(andnot, &= ~, bic)
+ATOMIC_OPS(or, |=, orr)
+ATOMIC_OPS(xor, ^=, eor)
+
+#undef ATOMIC_OPS
+#undef ATOMIC_FETCH_OP
+#undef ATOMIC_OP_RETURN
+#undef ATOMIC_OP
+
+#define atomic_xchg(v, new) (xchg(&((v)->counter), new))
+
+#ifndef CONFIG_GENERIC_ATOMIC64
+typedef struct {
+ s64 counter;
+} atomic64_t;
+
+#define ATOMIC64_INIT(i) { (i) }
+
+#ifdef CONFIG_ARM_LPAE
+static inline s64 atomic64_read(const atomic64_t *v)
+{
+ s64 result;
+
+ __asm__ __volatile__("@ atomic64_read\n"
+" ldrd %0, %H0, [%1]"
+ : "=&r" (result)
+ : "r" (&v->counter), "Qo" (v->counter)
+ );
+
+ return result;
+}
+
+static inline void atomic64_set(atomic64_t *v, s64 i)
+{
+ __asm__ __volatile__("@ atomic64_set\n"
+" strd %2, %H2, [%1]"
+ : "=Qo" (v->counter)
+ : "r" (&v->counter), "r" (i)
+ );
+}
+#else
+static inline s64 atomic64_read(const atomic64_t *v)
+{
+ s64 result;
+
+ __asm__ __volatile__("@ atomic64_read\n"
+" ldrexd %0, %H0, [%1]"
+ : "=&r" (result)
+ : "r" (&v->counter), "Qo" (v->counter)
+ );
+
+ return result;
+}
+
+static inline void atomic64_set(atomic64_t *v, s64 i)
+{
+ s64 tmp;
+
+ prefetchw(&v->counter);
+ __asm__ __volatile__("@ atomic64_set\n"
+"1: ldrexd %0, %H0, [%2]\n"
+" strexd %0, %3, %H3, [%2]\n"
+" teq %0, #0\n"
+" bne 1b"
+ : "=&r" (tmp), "=Qo" (v->counter)
+ : "r" (&v->counter), "r" (i)
+ : "cc");
+}
+#endif
+
+#define ATOMIC64_OP(op, op1, op2) \
+static inline void atomic64_##op(s64 i, atomic64_t *v) \
+{ \
+ s64 result; \
+ unsigned long tmp; \
+ \
+ prefetchw(&v->counter); \
+ __asm__ __volatile__("@ atomic64_" #op "\n" \
+"1: ldrexd %0, %H0, [%3]\n" \
+" " #op1 " %Q0, %Q0, %Q4\n" \
+" " #op2 " %R0, %R0, %R4\n" \
+" strexd %1, %0, %H0, [%3]\n" \
+" teq %1, #0\n" \
+" bne 1b" \
+ : "=&r" (result), "=&r" (tmp), "+Qo" (v->counter) \
+ : "r" (&v->counter), "r" (i) \
+ : "cc"); \
+} \
+
+#define ATOMIC64_OP_RETURN(op, op1, op2) \
+static inline s64 \
+atomic64_##op##_return_relaxed(s64 i, atomic64_t *v) \
+{ \
+ s64 result; \
+ unsigned long tmp; \
+ \
+ prefetchw(&v->counter); \
+ \
+ __asm__ __volatile__("@ atomic64_" #op "_return\n" \
+"1: ldrexd %0, %H0, [%3]\n" \
+" " #op1 " %Q0, %Q0, %Q4\n" \
+" " #op2 " %R0, %R0, %R4\n" \
+" strexd %1, %0, %H0, [%3]\n" \
+" teq %1, #0\n" \
+" bne 1b" \
+ : "=&r" (result), "=&r" (tmp), "+Qo" (v->counter) \
+ : "r" (&v->counter), "r" (i) \
+ : "cc"); \
+ \
+ return result; \
+}
+
+#define ATOMIC64_FETCH_OP(op, op1, op2)
\
+static inline s64 \
+atomic64_fetch_##op##_relaxed(s64 i, atomic64_t *v) \
+{ \
+ s64 result, val; \
+ unsigned long tmp; \
+ \
+ prefetchw(&v->counter); \
+ \
+ __asm__ __volatile__("@ atomic64_fetch_" #op "\n" \
+"1: ldrexd %0, %H0, [%4]\n" \
+" " #op1 " %Q1, %Q0, %Q5\n" \
+" " #op2 " %R1, %R0, %R5\n" \
+" strexd %2, %1, %H1, [%4]\n" \
+" teq %2, #0\n" \
+" bne 1b" \
+ : "=&r" (result), "=&r" (val), "=&r" (tmp), "+Qo" (v->counter) \
+ : "r" (&v->counter), "r" (i) \
+ : "cc"); \
+ \
+ return result; \
+}
+
+#define ATOMIC64_OPS(op, op1, op2) \
+ ATOMIC64_OP(op, op1, op2) \
+ ATOMIC64_OP_RETURN(op, op1, op2) \
+ ATOMIC64_FETCH_OP(op, op1, op2)
+
+ATOMIC64_OPS(add, adds, adc)
+ATOMIC64_OPS(sub, subs, sbc)
+
+#define atomic64_add_return_relaxed atomic64_add_return_relaxed
+#define atomic64_sub_return_relaxed atomic64_sub_return_relaxed
+#define atomic64_fetch_add_relaxed atomic64_fetch_add_relaxed
+#define atomic64_fetch_sub_relaxed atomic64_fetch_sub_relaxed
+
+#undef ATOMIC64_OPS
+#define ATOMIC64_OPS(op, op1, op2) \
+ ATOMIC64_OP(op, op1, op2) \
+ ATOMIC64_FETCH_OP(op, op1, op2)
+
+#define atomic64_andnot atomic64_andnot
+
+ATOMIC64_OPS(and, and, and)
+ATOMIC64_OPS(andnot, bic, bic)
+ATOMIC64_OPS(or, orr, orr)
+ATOMIC64_OPS(xor, eor, eor)
+
+#define atomic64_fetch_and_relaxed atomic64_fetch_and_relaxed
+#define atomic64_fetch_andnot_relaxed atomic64_fetch_andnot_relaxed
+#define atomic64_fetch_or_relaxed atomic64_fetch_or_relaxed
+#define atomic64_fetch_xor_relaxed atomic64_fetch_xor_relaxed
+
+#undef ATOMIC64_OPS
+#undef ATOMIC64_FETCH_OP
+#undef ATOMIC64_OP_RETURN
+#undef ATOMIC64_OP
+
+static inline s64 atomic64_cmpxchg_relaxed(atomic64_t *ptr, s64 old, s64 new)
+{
+ s64 oldval;
+ unsigned long res;
+
+ prefetchw(&ptr->counter);
+
+ do {
+ __asm__ __volatile__("@ atomic64_cmpxchg\n"
+ "ldrexd %1, %H1, [%3]\n"
+ "mov %0, #0\n"
+ "teq %1, %4\n"
+ "teqeq %H1, %H4\n"
+ "strexdeq %0, %5, %H5, [%3]"
+ : "=&r" (res), "=&r" (oldval), "+Qo" (ptr->counter)
+ : "r" (&ptr->counter), "r" (old), "r" (new)
+ : "cc");
+ } while (res);
+
+ return oldval;
+}
+#define atomic64_cmpxchg_relaxed atomic64_cmpxchg_relaxed
+
+static inline s64 atomic64_xchg_relaxed(atomic64_t *ptr, s64 new)
+{
+ s64 result;
+ unsigned long tmp;
+
+ prefetchw(&ptr->counter);
+
+ __asm__ __volatile__("@ atomic64_xchg\n"
+"1: ldrexd %0, %H0, [%3]\n"
+" strexd %1, %4, %H4, [%3]\n"
+" teq %1, #0\n"
+" bne 1b"
+ : "=&r" (result), "=&r" (tmp), "+Qo" (ptr->counter)
+ : "r" (&ptr->counter), "r" (new)
+ : "cc");
+
+ return result;
+}
+#define atomic64_xchg_relaxed atomic64_xchg_relaxed
+
+static inline s64 atomic64_dec_if_positive(atomic64_t *v)
+{
+ s64 result;
+ unsigned long tmp;
+
+ smp_mb();
+ prefetchw(&v->counter);
+
+ __asm__ __volatile__("@ atomic64_dec_if_positive\n"
+"1: ldrexd %0, %H0, [%3]\n"
+" subs %Q0, %Q0, #1\n"
+" sbc %R0, %R0, #0\n"
+" teq %R0, #0\n"
+" bmi 2f\n"
+" strexd %1, %0, %H0, [%3]\n"
+" teq %1, #0\n"
+" bne 1b\n"
+"2:"
+ : "=&r" (result), "=&r" (tmp), "+Qo" (v->counter)
+ : "r" (&v->counter)
+ : "cc");
+
+ smp_mb();
+
+ return result;
+}
+#define atomic64_dec_if_positive atomic64_dec_if_positive
+
+static inline s64 atomic64_fetch_add_unless(atomic64_t *v, s64 a, s64 u)
+{
+ s64 oldval, newval;
+ unsigned long tmp;
+
+ smp_mb();
+ prefetchw(&v->counter);
+
+ __asm__ __volatile__("@ atomic64_add_unless\n"
+"1: ldrexd %0, %H0, [%4]\n"
+" teq %0, %5\n"
+" teqeq %H0, %H5\n"
+" beq 2f\n"
+" adds %Q1, %Q0, %Q6\n"
+" adc %R1, %R0, %R6\n"
+" strexd %2, %1, %H1, [%4]\n"
+" teq %2, #0\n"
+" bne 1b\n"
+"2:"
+ : "=&r" (oldval), "=&r" (newval), "=&r" (tmp), "+Qo" (v->counter)
+ : "r" (&v->counter), "r" (u), "r" (a)
+ : "cc");
+
+ if (oldval != u)
+ smp_mb();
+
+ return oldval;
+}
+#define atomic64_fetch_add_unless atomic64_fetch_add_unless
+
+#endif /* !CONFIG_GENERIC_ATOMIC64 */
+#endif
+#endif
\ No newline at end of file
diff --git a/xen/include/asm-arm/arm32/cmpxchg.h
b/xen/include/asm-arm/arm32/cmpxchg.h
new file mode 100644
index 0000000000..638ae84afb
--- /dev/null
+++ b/xen/include/asm-arm/arm32/cmpxchg.h
@@ -0,0 +1,279 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ASM_ARM_CMPXCHG_H
+#define __ASM_ARM_CMPXCHG_H
+
+#include <linux/irqflags.h>
+#include <linux/prefetch.h>
+#include <asm/barrier.h>
+
+#if defined(CONFIG_CPU_SA1100) || defined(CONFIG_CPU_SA110)
+/*
+ * On the StrongARM, "swp" is terminally broken since it bypasses the
+ * cache totally. This means that the cache becomes inconsistent, and,
+ * since we use normal loads/stores as well, this is really bad.
+ * Typically, this causes oopsen in filp_close, but could have other,
+ * more disastrous effects. There are two work-arounds:
+ * 1. Disable interrupts and emulate the atomic swap
+ * 2. Clean the cache, perform atomic swap, flush the cache
+ *
+ * We choose (1) since its the "easiest" to achieve here and is not
+ * dependent on the processor type.
+ *
+ * NOTE that this solution won't work on an SMP system, so explcitly
+ * forbid it here.
+ */
+#define swp_is_buggy
+#endif
+
+static inline unsigned long __xchg(unsigned long x, volatile void *ptr, int
size)
+{
+ extern void __bad_xchg(volatile void *, int);
+ unsigned long ret;
+#ifdef swp_is_buggy
+ unsigned long flags;
+#endif
+#if __LINUX_ARM_ARCH__ >= 6
+ unsigned int tmp;
+#endif
+
+ prefetchw((const void *)ptr);
+
+ switch (size) {
+#if __LINUX_ARM_ARCH__ >= 6
+#ifndef CONFIG_CPU_V6 /* MIN ARCH >= V6K */
+ case 1:
+ asm volatile("@ __xchg1\n"
+ "1: ldrexb %0, [%3]\n"
+ " strexb %1, %2, [%3]\n"
+ " teq %1, #0\n"
+ " bne 1b"
+ : "=&r" (ret), "=&r" (tmp)
+ : "r" (x), "r" (ptr)
+ : "memory", "cc");
+ break;
+ case 2:
+ asm volatile("@ __xchg2\n"
+ "1: ldrexh %0, [%3]\n"
+ " strexh %1, %2, [%3]\n"
+ " teq %1, #0\n"
+ " bne 1b"
+ : "=&r" (ret), "=&r" (tmp)
+ : "r" (x), "r" (ptr)
+ : "memory", "cc");
+ break;
+#endif
+ case 4:
+ asm volatile("@ __xchg4\n"
+ "1: ldrex %0, [%3]\n"
+ " strex %1, %2, [%3]\n"
+ " teq %1, #0\n"
+ " bne 1b"
+ : "=&r" (ret), "=&r" (tmp)
+ : "r" (x), "r" (ptr)
+ : "memory", "cc");
+ break;
+#elif defined(swp_is_buggy)
+#ifdef CONFIG_SMP
+#error SMP is not supported on this platform
+#endif
+ case 1:
+ raw_local_irq_save(flags);
+ ret = *(volatile unsigned char *)ptr;
+ *(volatile unsigned char *)ptr = x;
+ raw_local_irq_restore(flags);
+ break;
+
+ case 4:
+ raw_local_irq_save(flags);
+ ret = *(volatile unsigned long *)ptr;
+ *(volatile unsigned long *)ptr = x;
+ raw_local_irq_restore(flags);
+ break;
+#else
+ case 1:
+ asm volatile("@ __xchg1\n"
+ " swpb %0, %1, [%2]"
+ : "=&r" (ret)
+ : "r" (x), "r" (ptr)
+ : "memory", "cc");
+ break;
+ case 4:
+ asm volatile("@ __xchg4\n"
+ " swp %0, %1, [%2]"
+ : "=&r" (ret)
+ : "r" (x), "r" (ptr)
+ : "memory", "cc");
+ break;
+#endif
+ default:
+ /* Cause a link-time error, the xchg() size is not supported */
+ __bad_xchg(ptr, size), ret = 0;
+ break;
+ }
+
+ return ret;
+}
+
+#define xchg_relaxed(ptr, x) ({
\
+ (__typeof__(*(ptr)))__xchg((unsigned long)(x), (ptr), \
+ sizeof(*(ptr))); \
+})
+
+#include <asm-generic/cmpxchg-local.h>
+
+#if __LINUX_ARM_ARCH__ < 6
+/* min ARCH < ARMv6 */
+
+#ifdef CONFIG_SMP
+#error "SMP is not supported on this platform"
+#endif
+
+#define xchg xchg_relaxed
+
+/*
+ * cmpxchg_local and cmpxchg64_local are atomic wrt current CPU. Always make
+ * them available.
+ */
+#define cmpxchg_local(ptr, o, n) ({ \
+ (__typeof(*ptr))__cmpxchg_local_generic((ptr), \
+ (unsigned long)(o), \
+ (unsigned long)(n), \
+ sizeof(*(ptr))); \
+})
+
+#define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n))
+
+#include <asm-generic/cmpxchg.h>
+
+#else /* min ARCH >= ARMv6 */
+
+extern void __bad_cmpxchg(volatile void *ptr, int size);
+
+/*
+ * cmpxchg only support 32-bits operands on ARMv6.
+ */
+
+static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old,
+ unsigned long new, int size)
+{
+ unsigned long oldval, res;
+
+ prefetchw((const void *)ptr);
+
+ switch (size) {
+#ifndef CONFIG_CPU_V6 /* min ARCH >= ARMv6K */
+ case 1:
+ do {
+ asm volatile("@ __cmpxchg1\n"
+ " ldrexb %1, [%2]\n"
+ " mov %0, #0\n"
+ " teq %1, %3\n"
+ " strexbeq %0, %4, [%2]\n"
+ : "=&r" (res), "=&r" (oldval)
+ : "r" (ptr), "Ir" (old), "r" (new)
+ : "memory", "cc");
+ } while (res);
+ break;
+ case 2:
+ do {
+ asm volatile("@ __cmpxchg1\n"
+ " ldrexh %1, [%2]\n"
+ " mov %0, #0\n"
+ " teq %1, %3\n"
+ " strexheq %0, %4, [%2]\n"
+ : "=&r" (res), "=&r" (oldval)
+ : "r" (ptr), "Ir" (old), "r" (new)
+ : "memory", "cc");
+ } while (res);
+ break;
+#endif
+ case 4:
+ do {
+ asm volatile("@ __cmpxchg4\n"
+ " ldrex %1, [%2]\n"
+ " mov %0, #0\n"
+ " teq %1, %3\n"
+ " strexeq %0, %4, [%2]\n"
+ : "=&r" (res), "=&r" (oldval)
+ : "r" (ptr), "Ir" (old), "r" (new)
+ : "memory", "cc");
+ } while (res);
+ break;
+ default:
+ __bad_cmpxchg(ptr, size);
+ oldval = 0;
+ }
+
+ return oldval;
+}
+
+#define cmpxchg_relaxed(ptr,o,n) ({ \
+ (__typeof__(*(ptr)))__cmpxchg((ptr), \
+ (unsigned long)(o), \
+ (unsigned long)(n), \
+ sizeof(*(ptr))); \
+})
+
+static inline unsigned long __cmpxchg_local(volatile void *ptr,
+ unsigned long old,
+ unsigned long new, int size)
+{
+ unsigned long ret;
+
+ switch (size) {
+#ifdef CONFIG_CPU_V6 /* min ARCH == ARMv6 */
+ case 1:
+ case 2:
+ ret = __cmpxchg_local_generic(ptr, old, new, size);
+ break;
+#endif
+ default:
+ ret = __cmpxchg(ptr, old, new, size);
+ }
+
+ return ret;
+}
+
+#define cmpxchg_local(ptr, o, n) ({ \
+ (__typeof(*ptr))__cmpxchg_local((ptr), \
+ (unsigned long)(o), \
+ (unsigned long)(n), \
+ sizeof(*(ptr))); \
+})
+
+static inline unsigned long long __cmpxchg64(unsigned long long *ptr,
+ unsigned long long old,
+ unsigned long long new)
+{
+ unsigned long long oldval;
+ unsigned long res;
+
+ prefetchw(ptr);
+
+ __asm__ __volatile__(
+"1: ldrexd %1, %H1, [%3]\n"
+" teq %1, %4\n"
+" teqeq %H1, %H4\n"
+" bne 2f\n"
+" strexd %0, %5, %H5, [%3]\n"
+" teq %0, #0\n"
+" bne 1b\n"
+"2:"
+ : "=&r" (res), "=&r" (oldval), "+Qo" (*ptr)
+ : "r" (ptr), "r" (old), "r" (new)
+ : "cc");
+
+ return oldval;
+}
+
+#define cmpxchg64_relaxed(ptr, o, n) ({
\
+ (__typeof__(*(ptr)))__cmpxchg64((ptr), \
+ (unsigned long long)(o), \
+ (unsigned long long)(n)); \
+})
+
+#define cmpxchg64_local(ptr, o, n) cmpxchg64_relaxed((ptr), (o), (n))
+
+#endif /* __LINUX_ARM_ARCH__ >= 6 */
+
+#endif /* __ASM_ARM_CMPXCHG_H */
\ No newline at end of file
diff --git a/xen/include/asm-arm/arm64/atomic.h
b/xen/include/asm-arm/arm64/atomic.h
new file mode 100644
index 0000000000..a2eab9f091
--- /dev/null
+++ b/xen/include/asm-arm/arm64/atomic.h
@@ -0,0 +1,228 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Based on arch/arm/include/asm/atomic.h
+ *
+ * Copyright (C) 1996 Russell King.
+ * Copyright (C) 2002 Deep Blue Solutions Ltd.
+ * Copyright (C) 2012 ARM Ltd.
+ */
+#ifndef __ASM_ATOMIC_H
+#define __ASM_ATOMIC_H
+
+#include <linux/compiler.h>
+#include <linux/types.h>
+
+#include <asm/barrier.h>
+#include <asm/cmpxchg.h>
+#include <asm/lse.h>
+
+#define ATOMIC_OP(op) \
+static inline void arch_##op(int i, atomic_t *v) \
+{ \
+ __lse_ll_sc_body(op, i, v); \
+}
+
+ATOMIC_OP(atomic_andnot)
+ATOMIC_OP(atomic_or)
+ATOMIC_OP(atomic_xor)
+ATOMIC_OP(atomic_add)
+ATOMIC_OP(atomic_and)
+ATOMIC_OP(atomic_sub)
+
+#undef ATOMIC_OP
+
+#define ATOMIC_FETCH_OP(name, op) \
+static inline int arch_##op##name(int i, atomic_t *v) \
+{ \
+ return __lse_ll_sc_body(op##name, i, v); \
+}
+
+#define ATOMIC_FETCH_OPS(op) \
+ ATOMIC_FETCH_OP(_relaxed, op) \
+ ATOMIC_FETCH_OP(_acquire, op) \
+ ATOMIC_FETCH_OP(_release, op) \
+ ATOMIC_FETCH_OP( , op)
+
+ATOMIC_FETCH_OPS(atomic_fetch_andnot)
+ATOMIC_FETCH_OPS(atomic_fetch_or)
+ATOMIC_FETCH_OPS(atomic_fetch_xor)
+ATOMIC_FETCH_OPS(atomic_fetch_add)
+ATOMIC_FETCH_OPS(atomic_fetch_and)
+ATOMIC_FETCH_OPS(atomic_fetch_sub)
+ATOMIC_FETCH_OPS(atomic_add_return)
+ATOMIC_FETCH_OPS(atomic_sub_return)
+
+#undef ATOMIC_FETCH_OP
+#undef ATOMIC_FETCH_OPS
+
+#define ATOMIC64_OP(op)
\
+static inline void arch_##op(long i, atomic64_t *v) \
+{ \
+ __lse_ll_sc_body(op, i, v); \
+}
+
+ATOMIC64_OP(atomic64_andnot)
+ATOMIC64_OP(atomic64_or)
+ATOMIC64_OP(atomic64_xor)
+ATOMIC64_OP(atomic64_add)
+ATOMIC64_OP(atomic64_and)
+ATOMIC64_OP(atomic64_sub)
+
+#undef ATOMIC64_OP
+
+#define ATOMIC64_FETCH_OP(name, op) \
+static inline long arch_##op##name(long i, atomic64_t *v) \
+{ \
+ return __lse_ll_sc_body(op##name, i, v); \
+}
+
+#define ATOMIC64_FETCH_OPS(op) \
+ ATOMIC64_FETCH_OP(_relaxed, op) \
+ ATOMIC64_FETCH_OP(_acquire, op) \
+ ATOMIC64_FETCH_OP(_release, op) \
+ ATOMIC64_FETCH_OP( , op)
+
+ATOMIC64_FETCH_OPS(atomic64_fetch_andnot)
+ATOMIC64_FETCH_OPS(atomic64_fetch_or)
+ATOMIC64_FETCH_OPS(atomic64_fetch_xor)
+ATOMIC64_FETCH_OPS(atomic64_fetch_add)
+ATOMIC64_FETCH_OPS(atomic64_fetch_and)
+ATOMIC64_FETCH_OPS(atomic64_fetch_sub)
+ATOMIC64_FETCH_OPS(atomic64_add_return)
+ATOMIC64_FETCH_OPS(atomic64_sub_return)
+
+#undef ATOMIC64_FETCH_OP
+#undef ATOMIC64_FETCH_OPS
+
+static inline long arch_atomic64_dec_if_positive(atomic64_t *v)
+{
+ return __lse_ll_sc_body(atomic64_dec_if_positive, v);
+}
+
+#define arch_atomic_read(v) __READ_ONCE((v)->counter)
+#define arch_atomic_set(v, i) __WRITE_ONCE(((v)->counter),
(i))
+
+#define arch_atomic_add_return_relaxed arch_atomic_add_return_relaxed
+#define arch_atomic_add_return_acquire arch_atomic_add_return_acquire
+#define arch_atomic_add_return_release arch_atomic_add_return_release
+#define arch_atomic_add_return arch_atomic_add_return
+
+#define arch_atomic_sub_return_relaxed arch_atomic_sub_return_relaxed
+#define arch_atomic_sub_return_acquire arch_atomic_sub_return_acquire
+#define arch_atomic_sub_return_release arch_atomic_sub_return_release
+#define arch_atomic_sub_return arch_atomic_sub_return
+
+#define arch_atomic_fetch_add_relaxed arch_atomic_fetch_add_relaxed
+#define arch_atomic_fetch_add_acquire arch_atomic_fetch_add_acquire
+#define arch_atomic_fetch_add_release arch_atomic_fetch_add_release
+#define arch_atomic_fetch_add arch_atomic_fetch_add
+
+#define arch_atomic_fetch_sub_relaxed arch_atomic_fetch_sub_relaxed
+#define arch_atomic_fetch_sub_acquire arch_atomic_fetch_sub_acquire
+#define arch_atomic_fetch_sub_release arch_atomic_fetch_sub_release
+#define arch_atomic_fetch_sub arch_atomic_fetch_sub
+
+#define arch_atomic_fetch_and_relaxed arch_atomic_fetch_and_relaxed
+#define arch_atomic_fetch_and_acquire arch_atomic_fetch_and_acquire
+#define arch_atomic_fetch_and_release arch_atomic_fetch_and_release
+#define arch_atomic_fetch_and arch_atomic_fetch_and
+
+#define arch_atomic_fetch_andnot_relaxed arch_atomic_fetch_andnot_relaxed
+#define arch_atomic_fetch_andnot_acquire arch_atomic_fetch_andnot_acquire
+#define arch_atomic_fetch_andnot_release arch_atomic_fetch_andnot_release
+#define arch_atomic_fetch_andnot arch_atomic_fetch_andnot
+
+#define arch_atomic_fetch_or_relaxed arch_atomic_fetch_or_relaxed
+#define arch_atomic_fetch_or_acquire arch_atomic_fetch_or_acquire
+#define arch_atomic_fetch_or_release arch_atomic_fetch_or_release
+#define arch_atomic_fetch_or arch_atomic_fetch_or
+
+#define arch_atomic_fetch_xor_relaxed arch_atomic_fetch_xor_relaxed
+#define arch_atomic_fetch_xor_acquire arch_atomic_fetch_xor_acquire
+#define arch_atomic_fetch_xor_release arch_atomic_fetch_xor_release
+#define arch_atomic_fetch_xor arch_atomic_fetch_xor
+
+#define arch_atomic_xchg_relaxed(v, new) \
+ arch_xchg_relaxed(&((v)->counter), (new))
+#define arch_atomic_xchg_acquire(v, new) \
+ arch_xchg_acquire(&((v)->counter), (new))
+#define arch_atomic_xchg_release(v, new) \
+ arch_xchg_release(&((v)->counter), (new))
+#define arch_atomic_xchg(v, new) \
+ arch_xchg(&((v)->counter), (new))
+
+#define arch_atomic_cmpxchg_relaxed(v, old, new) \
+ arch_cmpxchg_relaxed(&((v)->counter), (old), (new))
+#define arch_atomic_cmpxchg_acquire(v, old, new) \
+ arch_cmpxchg_acquire(&((v)->counter), (old), (new))
+#define arch_atomic_cmpxchg_release(v, old, new) \
+ arch_cmpxchg_release(&((v)->counter), (old), (new))
+#define arch_atomic_cmpxchg(v, old, new) \
+ arch_cmpxchg(&((v)->counter), (old), (new))
+
+#define arch_atomic_andnot arch_atomic_andnot
+
+/*
+ * 64-bit arch_atomic operations.
+ */
+#define ATOMIC64_INIT ATOMIC_INIT
+#define arch_atomic64_read arch_atomic_read
+#define arch_atomic64_set arch_atomic_set
+
+#define arch_atomic64_add_return_relaxed arch_atomic64_add_return_relaxed
+#define arch_atomic64_add_return_acquire arch_atomic64_add_return_acquire
+#define arch_atomic64_add_return_release arch_atomic64_add_return_release
+#define arch_atomic64_add_return arch_atomic64_add_return
+
+#define arch_atomic64_sub_return_relaxed arch_atomic64_sub_return_relaxed
+#define arch_atomic64_sub_return_acquire arch_atomic64_sub_return_acquire
+#define arch_atomic64_sub_return_release arch_atomic64_sub_return_release
+#define arch_atomic64_sub_return arch_atomic64_sub_return
+
+#define arch_atomic64_fetch_add_relaxed
arch_atomic64_fetch_add_relaxed
+#define arch_atomic64_fetch_add_acquire
arch_atomic64_fetch_add_acquire
+#define arch_atomic64_fetch_add_release
arch_atomic64_fetch_add_release
+#define arch_atomic64_fetch_add arch_atomic64_fetch_add
+
+#define arch_atomic64_fetch_sub_relaxed
arch_atomic64_fetch_sub_relaxed
+#define arch_atomic64_fetch_sub_acquire
arch_atomic64_fetch_sub_acquire
+#define arch_atomic64_fetch_sub_release
arch_atomic64_fetch_sub_release
+#define arch_atomic64_fetch_sub arch_atomic64_fetch_sub
+
+#define arch_atomic64_fetch_and_relaxed
arch_atomic64_fetch_and_relaxed
+#define arch_atomic64_fetch_and_acquire
arch_atomic64_fetch_and_acquire
+#define arch_atomic64_fetch_and_release
arch_atomic64_fetch_and_release
+#define arch_atomic64_fetch_and arch_atomic64_fetch_and
+
+#define arch_atomic64_fetch_andnot_relaxed
arch_atomic64_fetch_andnot_relaxed
+#define arch_atomic64_fetch_andnot_acquire
arch_atomic64_fetch_andnot_acquire
+#define arch_atomic64_fetch_andnot_release
arch_atomic64_fetch_andnot_release
+#define arch_atomic64_fetch_andnot arch_atomic64_fetch_andnot
+
+#define arch_atomic64_fetch_or_relaxed arch_atomic64_fetch_or_relaxed
+#define arch_atomic64_fetch_or_acquire arch_atomic64_fetch_or_acquire
+#define arch_atomic64_fetch_or_release arch_atomic64_fetch_or_release
+#define arch_atomic64_fetch_or arch_atomic64_fetch_or
+
+#define arch_atomic64_fetch_xor_relaxed
arch_atomic64_fetch_xor_relaxed
+#define arch_atomic64_fetch_xor_acquire
arch_atomic64_fetch_xor_acquire
+#define arch_atomic64_fetch_xor_release
arch_atomic64_fetch_xor_release
+#define arch_atomic64_fetch_xor arch_atomic64_fetch_xor
+
+#define arch_atomic64_xchg_relaxed arch_atomic_xchg_relaxed
+#define arch_atomic64_xchg_acquire arch_atomic_xchg_acquire
+#define arch_atomic64_xchg_release arch_atomic_xchg_release
+#define arch_atomic64_xchg arch_atomic_xchg
+
+#define arch_atomic64_cmpxchg_relaxed arch_atomic_cmpxchg_relaxed
+#define arch_atomic64_cmpxchg_acquire arch_atomic_cmpxchg_acquire
+#define arch_atomic64_cmpxchg_release arch_atomic_cmpxchg_release
+#define arch_atomic64_cmpxchg arch_atomic_cmpxchg
+
+#define arch_atomic64_andnot arch_atomic64_andnot
+
+#define arch_atomic64_dec_if_positive arch_atomic64_dec_if_positive
+
+#define ARCH_ATOMIC
+
+#endif /* __ASM_ATOMIC_H */
\ No newline at end of file
diff --git a/xen/include/asm-arm/arm64/atomic_ll_sc.h
b/xen/include/asm-arm/arm64/atomic_ll_sc.h
new file mode 100644
index 0000000000..e1009c0f94
--- /dev/null
+++ b/xen/include/asm-arm/arm64/atomic_ll_sc.h
@@ -0,0 +1,353 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Based on arch/arm/include/asm/atomic.h
+ *
+ * Copyright (C) 1996 Russell King.
+ * Copyright (C) 2002 Deep Blue Solutions Ltd.
+ * Copyright (C) 2012 ARM Ltd.
+ */
+
+#ifndef __ASM_ATOMIC_LL_SC_H
+#define __ASM_ATOMIC_LL_SC_H
+
+#include <linux/stringify.h>
+
+#ifdef CONFIG_ARM64_LSE_ATOMICS
+#define __LL_SC_FALLBACK(asm_ops) \
+" b 3f\n" \
+" .subsection 1\n" \
+"3:\n" \
+asm_ops "\n" \
+" b 4f\n" \
+" .previous\n" \
+"4:\n"
+#else
+#define __LL_SC_FALLBACK(asm_ops) asm_ops
+#endif
+
+#ifndef CONFIG_CC_HAS_K_CONSTRAINT
+#define K
+#endif
+
+/*
+ * AArch64 UP and SMP safe atomic ops. We use load exclusive and
+ * store exclusive to ensure that these are atomic. We may loop
+ * to ensure that the update happens.
+ */
+
+#define ATOMIC_OP(op, asm_op, constraint) \
+static inline void \
+__ll_sc_atomic_##op(int i, atomic_t *v)
\
+{ \
+ unsigned long tmp; \
+ int result; \
+ \
+ asm volatile("// atomic_" #op "\n" \
+ __LL_SC_FALLBACK( \
+" prfm pstl1strm, %2\n" \
+"1: ldxr %w0, %2\n" \
+" " #asm_op " %w0, %w0, %w3\n" \
+" stxr %w1, %w0, %2\n" \
+" cbnz %w1, 1b\n") \
+ : "=&r" (result), "=&r" (tmp), "+Q" (v->counter) \
+ : __stringify(constraint) "r" (i)); \
+}
+
+#define ATOMIC_OP_RETURN(name, mb, acq, rel, cl, op, asm_op, constraint)\
+static inline int \
+__ll_sc_atomic_##op##_return##name(int i, atomic_t *v) \
+{ \
+ unsigned long tmp; \
+ int result; \
+ \
+ asm volatile("// atomic_" #op "_return" #name "\n" \
+ __LL_SC_FALLBACK( \
+" prfm pstl1strm, %2\n" \
+"1: ld" #acq "xr %w0, %2\n" \
+" " #asm_op " %w0, %w0, %w3\n" \
+" st" #rel "xr %w1, %w0, %2\n" \
+" cbnz %w1, 1b\n" \
+" " #mb ) \
+ : "=&r" (result), "=&r" (tmp), "+Q" (v->counter) \
+ : __stringify(constraint) "r" (i) \
+ : cl); \
+ \
+ return result; \
+}
+
+#define ATOMIC_FETCH_OP(name, mb, acq, rel, cl, op, asm_op, constraint) \
+static inline int \
+__ll_sc_atomic_fetch_##op##name(int i, atomic_t *v) \
+{ \
+ unsigned long tmp; \
+ int val, result; \
+ \
+ asm volatile("// atomic_fetch_" #op #name "\n" \
+ __LL_SC_FALLBACK( \
+" prfm pstl1strm, %3\n" \
+"1: ld" #acq "xr %w0, %3\n" \
+" " #asm_op " %w1, %w0, %w4\n" \
+" st" #rel "xr %w2, %w1, %3\n" \
+" cbnz %w2, 1b\n" \
+" " #mb ) \
+ : "=&r" (result), "=&r" (val), "=&r" (tmp), "+Q" (v->counter) \
+ : __stringify(constraint) "r" (i) \
+ : cl); \
+ \
+ return result; \
+}
+
+#define ATOMIC_OPS(...)
\
+ ATOMIC_OP(__VA_ARGS__) \
+ ATOMIC_OP_RETURN( , dmb ish, , l, "memory", __VA_ARGS__)\
+ ATOMIC_OP_RETURN(_relaxed, , , , , __VA_ARGS__)\
+ ATOMIC_OP_RETURN(_acquire, , a, , "memory", __VA_ARGS__)\
+ ATOMIC_OP_RETURN(_release, , , l, "memory", __VA_ARGS__)\
+ ATOMIC_FETCH_OP ( , dmb ish, , l, "memory", __VA_ARGS__)\
+ ATOMIC_FETCH_OP (_relaxed, , , , , __VA_ARGS__)\
+ ATOMIC_FETCH_OP (_acquire, , a, , "memory", __VA_ARGS__)\
+ ATOMIC_FETCH_OP (_release, , , l, "memory", __VA_ARGS__)
+
+ATOMIC_OPS(add, add, I)
+ATOMIC_OPS(sub, sub, J)
+
+#undef ATOMIC_OPS
+#define ATOMIC_OPS(...)
\
+ ATOMIC_OP(__VA_ARGS__) \
+ ATOMIC_FETCH_OP ( , dmb ish, , l, "memory", __VA_ARGS__)\
+ ATOMIC_FETCH_OP (_relaxed, , , , , __VA_ARGS__)\
+ ATOMIC_FETCH_OP (_acquire, , a, , "memory", __VA_ARGS__)\
+ ATOMIC_FETCH_OP (_release, , , l, "memory", __VA_ARGS__)
+
+ATOMIC_OPS(and, and, K)
+ATOMIC_OPS(or, orr, K)
+ATOMIC_OPS(xor, eor, K)
+/*
+ * GAS converts the mysterious and undocumented BIC (immediate) alias to
+ * an AND (immediate) instruction with the immediate inverted. We don't
+ * have a constraint for this, so fall back to register.
+ */
+ATOMIC_OPS(andnot, bic, )
+
+#undef ATOMIC_OPS
+#undef ATOMIC_FETCH_OP
+#undef ATOMIC_OP_RETURN
+#undef ATOMIC_OP
+
+#define ATOMIC64_OP(op, asm_op, constraint) \
+static inline void \
+__ll_sc_atomic64_##op(s64 i, atomic64_t *v) \
+{ \
+ s64 result; \
+ unsigned long tmp; \
+ \
+ asm volatile("// atomic64_" #op "\n" \
+ __LL_SC_FALLBACK( \
+" prfm pstl1strm, %2\n" \
+"1: ldxr %0, %2\n" \
+" " #asm_op " %0, %0, %3\n" \
+" stxr %w1, %0, %2\n" \
+" cbnz %w1, 1b") \
+ : "=&r" (result), "=&r" (tmp), "+Q" (v->counter) \
+ : __stringify(constraint) "r" (i)); \
+}
+
+#define ATOMIC64_OP_RETURN(name, mb, acq, rel, cl, op, asm_op, constraint)\
+static inline long \
+__ll_sc_atomic64_##op##_return##name(s64 i, atomic64_t *v) \
+{ \
+ s64 result; \
+ unsigned long tmp; \
+ \
+ asm volatile("// atomic64_" #op "_return" #name "\n" \
+ __LL_SC_FALLBACK( \
+" prfm pstl1strm, %2\n" \
+"1: ld" #acq "xr %0, %2\n" \
+" " #asm_op " %0, %0, %3\n" \
+" st" #rel "xr %w1, %0, %2\n" \
+" cbnz %w1, 1b\n" \
+" " #mb ) \
+ : "=&r" (result), "=&r" (tmp), "+Q" (v->counter) \
+ : __stringify(constraint) "r" (i) \
+ : cl); \
+ \
+ return result; \
+}
+
+#define ATOMIC64_FETCH_OP(name, mb, acq, rel, cl, op, asm_op, constraint)\
+static inline long \
+__ll_sc_atomic64_fetch_##op##name(s64 i, atomic64_t *v) \
+{ \
+ s64 result, val; \
+ unsigned long tmp; \
+ \
+ asm volatile("// atomic64_fetch_" #op #name "\n" \
+ __LL_SC_FALLBACK( \
+" prfm pstl1strm, %3\n" \
+"1: ld" #acq "xr %0, %3\n" \
+" " #asm_op " %1, %0, %4\n" \
+" st" #rel "xr %w2, %1, %3\n" \
+" cbnz %w2, 1b\n" \
+" " #mb ) \
+ : "=&r" (result), "=&r" (val), "=&r" (tmp), "+Q" (v->counter) \
+ : __stringify(constraint) "r" (i) \
+ : cl); \
+ \
+ return result; \
+}
+
+#define ATOMIC64_OPS(...) \
+ ATOMIC64_OP(__VA_ARGS__) \
+ ATOMIC64_OP_RETURN(, dmb ish, , l, "memory", __VA_ARGS__) \
+ ATOMIC64_OP_RETURN(_relaxed,, , , , __VA_ARGS__) \
+ ATOMIC64_OP_RETURN(_acquire,, a, , "memory", __VA_ARGS__) \
+ ATOMIC64_OP_RETURN(_release,, , l, "memory", __VA_ARGS__) \
+ ATOMIC64_FETCH_OP (, dmb ish, , l, "memory", __VA_ARGS__) \
+ ATOMIC64_FETCH_OP (_relaxed,, , , , __VA_ARGS__) \
+ ATOMIC64_FETCH_OP (_acquire,, a, , "memory", __VA_ARGS__) \
+ ATOMIC64_FETCH_OP (_release,, , l, "memory", __VA_ARGS__)
+
+ATOMIC64_OPS(add, add, I)
+ATOMIC64_OPS(sub, sub, J)
+
+#undef ATOMIC64_OPS
+#define ATOMIC64_OPS(...) \
+ ATOMIC64_OP(__VA_ARGS__) \
+ ATOMIC64_FETCH_OP (, dmb ish, , l, "memory", __VA_ARGS__) \
+ ATOMIC64_FETCH_OP (_relaxed,, , , , __VA_ARGS__) \
+ ATOMIC64_FETCH_OP (_acquire,, a, , "memory", __VA_ARGS__) \
+ ATOMIC64_FETCH_OP (_release,, , l, "memory", __VA_ARGS__)
+
+ATOMIC64_OPS(and, and, L)
+ATOMIC64_OPS(or, orr, L)
+ATOMIC64_OPS(xor, eor, L)
+/*
+ * GAS converts the mysterious and undocumented BIC (immediate) alias to
+ * an AND (immediate) instruction with the immediate inverted. We don't
+ * have a constraint for this, so fall back to register.
+ */
+ATOMIC64_OPS(andnot, bic, )
+
+#undef ATOMIC64_OPS
+#undef ATOMIC64_FETCH_OP
+#undef ATOMIC64_OP_RETURN
+#undef ATOMIC64_OP
+
+static inline s64
+__ll_sc_atomic64_dec_if_positive(atomic64_t *v)
+{
+ s64 result;
+ unsigned long tmp;
+
+ asm volatile("// atomic64_dec_if_positive\n"
+ __LL_SC_FALLBACK(
+" prfm pstl1strm, %2\n"
+"1: ldxr %0, %2\n"
+" subs %0, %0, #1\n"
+" b.lt 2f\n"
+" stlxr %w1, %0, %2\n"
+" cbnz %w1, 1b\n"
+" dmb ish\n"
+"2:")
+ : "=&r" (result), "=&r" (tmp), "+Q" (v->counter)
+ :
+ : "cc", "memory");
+
+ return result;
+}
+
+#define __CMPXCHG_CASE(w, sfx, name, sz, mb, acq, rel, cl, constraint) \
+static inline u##sz \
+__ll_sc__cmpxchg_case_##name##sz(volatile void *ptr, \
+ unsigned long old, \
+ u##sz new) \
+{ \
+ unsigned long tmp; \
+ u##sz oldval; \
+ \
+ /* \
+ * Sub-word sizes require explicit casting so that the compare \
+ * part of the cmpxchg doesn't end up interpreting non-zero \
+ * upper bits of the register containing "old". \
+ */ \
+ if (sz < 32) \
+ old = (u##sz)old; \
+ \
+ asm volatile( \
+ __LL_SC_FALLBACK( \
+ " prfm pstl1strm, %[v]\n" \
+ "1: ld" #acq "xr" #sfx "\t%" #w "[oldval], %[v]\n" \
+ " eor %" #w "[tmp], %" #w "[oldval], %" #w "[old]\n" \
+ " cbnz %" #w "[tmp], 2f\n" \
+ " st" #rel "xr" #sfx "\t%w[tmp], %" #w "[new], %[v]\n" \
+ " cbnz %w[tmp], 1b\n" \
+ " " #mb "\n" \
+ "2:") \
+ : [tmp] "=&r" (tmp), [oldval] "=&r" (oldval), \
+ [v] "+Q" (*(u##sz *)ptr) \
+ : [old] __stringify(constraint) "r" (old), [new] "r" (new) \
+ : cl); \
+ \
+ return oldval; \
+}
+
+/*
+ * Earlier versions of GCC (no later than 8.1.0) appear to incorrectly
+ * handle the 'K' constraint for the value 4294967295 - thus we use no
+ * constraint for 32 bit operations.
+ */
+__CMPXCHG_CASE(w, b, , 8, , , , , K)
+__CMPXCHG_CASE(w, h, , 16, , , , , K)
+__CMPXCHG_CASE(w, , , 32, , , , , K)
+__CMPXCHG_CASE( , , , 64, , , , , L)
+__CMPXCHG_CASE(w, b, acq_, 8, , a, , "memory", K)
+__CMPXCHG_CASE(w, h, acq_, 16, , a, , "memory", K)
+__CMPXCHG_CASE(w, , acq_, 32, , a, , "memory", K)
+__CMPXCHG_CASE( , , acq_, 64, , a, , "memory", L)
+__CMPXCHG_CASE(w, b, rel_, 8, , , l, "memory", K)
+__CMPXCHG_CASE(w, h, rel_, 16, , , l, "memory", K)
+__CMPXCHG_CASE(w, , rel_, 32, , , l, "memory", K)
+__CMPXCHG_CASE( , , rel_, 64, , , l, "memory", L)
+__CMPXCHG_CASE(w, b, mb_, 8, dmb ish, , l, "memory", K)
+__CMPXCHG_CASE(w, h, mb_, 16, dmb ish, , l, "memory", K)
+__CMPXCHG_CASE(w, , mb_, 32, dmb ish, , l, "memory", K)
+__CMPXCHG_CASE( , , mb_, 64, dmb ish, , l, "memory", L)
+
+#undef __CMPXCHG_CASE
+
+#define __CMPXCHG_DBL(name, mb, rel, cl) \
+static inline long \
+__ll_sc__cmpxchg_double##name(unsigned long old1, \
+ unsigned long old2, \
+ unsigned long new1, \
+ unsigned long new2, \
+ volatile void *ptr) \
+{ \
+ unsigned long tmp, ret; \
+ \
+ asm volatile("// __cmpxchg_double" #name "\n" \
+ __LL_SC_FALLBACK( \
+ " prfm pstl1strm, %2\n" \
+ "1: ldxp %0, %1, %2\n" \
+ " eor %0, %0, %3\n" \
+ " eor %1, %1, %4\n" \
+ " orr %1, %0, %1\n" \
+ " cbnz %1, 2f\n" \
+ " st" #rel "xp %w0, %5, %6, %2\n" \
+ " cbnz %w0, 1b\n" \
+ " " #mb "\n" \
+ "2:") \
+ : "=&r" (tmp), "=&r" (ret), "+Q" (*(unsigned long *)ptr) \
+ : "r" (old1), "r" (old2), "r" (new1), "r" (new2) \
+ : cl); \
+ \
+ return ret; \
+}
+
+__CMPXCHG_DBL( , , , )
+__CMPXCHG_DBL(_mb, dmb ish, l, "memory")
+
+#undef __CMPXCHG_DBL
+#undef K
+
+#endif /* __ASM_ATOMIC_LL_SC_H */
\ No newline at end of file
diff --git a/xen/include/asm-arm/arm64/atomic_lse.h
b/xen/include/asm-arm/arm64/atomic_lse.h
new file mode 100644
index 0000000000..b3b0d43a7d
--- /dev/null
+++ b/xen/include/asm-arm/arm64/atomic_lse.h
@@ -0,0 +1,419 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Based on arch/arm/include/asm/atomic.h
+ *
+ * Copyright (C) 1996 Russell King.
+ * Copyright (C) 2002 Deep Blue Solutions Ltd.
+ * Copyright (C) 2012 ARM Ltd.
+ */
+
+#ifndef __ASM_ATOMIC_LSE_H
+#define __ASM_ATOMIC_LSE_H
+
+#define ATOMIC_OP(op, asm_op) \
+static inline void __lse_atomic_##op(int i, atomic_t *v)
\
+{ \
+ asm volatile( \
+ __LSE_PREAMBLE \
+" " #asm_op " %w[i], %[v]\n" \
+ : [i] "+r" (i), [v] "+Q" (v->counter) \
+ : "r" (v)); \
+}
+
+ATOMIC_OP(andnot, stclr)
+ATOMIC_OP(or, stset)
+ATOMIC_OP(xor, steor)
+ATOMIC_OP(add, stadd)
+
+#undef ATOMIC_OP
+
+#define ATOMIC_FETCH_OP(name, mb, op, asm_op, cl...) \
+static inline int __lse_atomic_fetch_##op##name(int i, atomic_t *v) \
+{ \
+ asm volatile( \
+ __LSE_PREAMBLE \
+" " #asm_op #mb " %w[i], %w[i], %[v]" \
+ : [i] "+r" (i), [v] "+Q" (v->counter) \
+ : "r" (v) \
+ : cl); \
+ \
+ return i; \
+}
+
+#define ATOMIC_FETCH_OPS(op, asm_op) \
+ ATOMIC_FETCH_OP(_relaxed, , op, asm_op) \
+ ATOMIC_FETCH_OP(_acquire, a, op, asm_op, "memory") \
+ ATOMIC_FETCH_OP(_release, l, op, asm_op, "memory") \
+ ATOMIC_FETCH_OP( , al, op, asm_op, "memory")
+
+ATOMIC_FETCH_OPS(andnot, ldclr)
+ATOMIC_FETCH_OPS(or, ldset)
+ATOMIC_FETCH_OPS(xor, ldeor)
+ATOMIC_FETCH_OPS(add, ldadd)
+
+#undef ATOMIC_FETCH_OP
+#undef ATOMIC_FETCH_OPS
+
+#define ATOMIC_OP_ADD_RETURN(name, mb, cl...) \
+static inline int __lse_atomic_add_return##name(int i, atomic_t *v) \
+{ \
+ u32 tmp; \
+ \
+ asm volatile( \
+ __LSE_PREAMBLE \
+ " ldadd" #mb " %w[i], %w[tmp], %[v]\n" \
+ " add %w[i], %w[i], %w[tmp]" \
+ : [i] "+r" (i), [v] "+Q" (v->counter), [tmp] "=&r" (tmp) \
+ : "r" (v) \
+ : cl); \
+ \
+ return i; \
+}
+
+ATOMIC_OP_ADD_RETURN(_relaxed, )
+ATOMIC_OP_ADD_RETURN(_acquire, a, "memory")
+ATOMIC_OP_ADD_RETURN(_release, l, "memory")
+ATOMIC_OP_ADD_RETURN( , al, "memory")
+
+#undef ATOMIC_OP_ADD_RETURN
+
+static inline void __lse_atomic_and(int i, atomic_t *v)
+{
+ asm volatile(
+ __LSE_PREAMBLE
+ " mvn %w[i], %w[i]\n"
+ " stclr %w[i], %[v]"
+ : [i] "+&r" (i), [v] "+Q" (v->counter)
+ : "r" (v));
+}
+
+#define ATOMIC_FETCH_OP_AND(name, mb, cl...) \
+static inline int __lse_atomic_fetch_and##name(int i, atomic_t *v) \
+{ \
+ asm volatile( \
+ __LSE_PREAMBLE \
+ " mvn %w[i], %w[i]\n" \
+ " ldclr" #mb " %w[i], %w[i], %[v]" \
+ : [i] "+&r" (i), [v] "+Q" (v->counter) \
+ : "r" (v) \
+ : cl); \
+ \
+ return i; \
+}
+
+ATOMIC_FETCH_OP_AND(_relaxed, )
+ATOMIC_FETCH_OP_AND(_acquire, a, "memory")
+ATOMIC_FETCH_OP_AND(_release, l, "memory")
+ATOMIC_FETCH_OP_AND( , al, "memory")
+
+#undef ATOMIC_FETCH_OP_AND
+
+static inline void __lse_atomic_sub(int i, atomic_t *v)
+{
+ asm volatile(
+ __LSE_PREAMBLE
+ " neg %w[i], %w[i]\n"
+ " stadd %w[i], %[v]"
+ : [i] "+&r" (i), [v] "+Q" (v->counter)
+ : "r" (v));
+}
+
+#define ATOMIC_OP_SUB_RETURN(name, mb, cl...) \
+static inline int __lse_atomic_sub_return##name(int i, atomic_t *v) \
+{ \
+ u32 tmp; \
+ \
+ asm volatile( \
+ __LSE_PREAMBLE \
+ " neg %w[i], %w[i]\n" \
+ " ldadd" #mb " %w[i], %w[tmp], %[v]\n" \
+ " add %w[i], %w[i], %w[tmp]" \
+ : [i] "+&r" (i), [v] "+Q" (v->counter), [tmp] "=&r" (tmp) \
+ : "r" (v) \
+ : cl); \
+ \
+ return i; \
+}
+
+ATOMIC_OP_SUB_RETURN(_relaxed, )
+ATOMIC_OP_SUB_RETURN(_acquire, a, "memory")
+ATOMIC_OP_SUB_RETURN(_release, l, "memory")
+ATOMIC_OP_SUB_RETURN( , al, "memory")
+
+#undef ATOMIC_OP_SUB_RETURN
+
+#define ATOMIC_FETCH_OP_SUB(name, mb, cl...) \
+static inline int __lse_atomic_fetch_sub##name(int i, atomic_t *v) \
+{ \
+ asm volatile( \
+ __LSE_PREAMBLE \
+ " neg %w[i], %w[i]\n" \
+ " ldadd" #mb " %w[i], %w[i], %[v]" \
+ : [i] "+&r" (i), [v] "+Q" (v->counter) \
+ : "r" (v) \
+ : cl); \
+ \
+ return i; \
+}
+
+ATOMIC_FETCH_OP_SUB(_relaxed, )
+ATOMIC_FETCH_OP_SUB(_acquire, a, "memory")
+ATOMIC_FETCH_OP_SUB(_release, l, "memory")
+ATOMIC_FETCH_OP_SUB( , al, "memory")
+
+#undef ATOMIC_FETCH_OP_SUB
+
+#define ATOMIC64_OP(op, asm_op)
\
+static inline void __lse_atomic64_##op(s64 i, atomic64_t *v) \
+{ \
+ asm volatile( \
+ __LSE_PREAMBLE \
+" " #asm_op " %[i], %[v]\n" \
+ : [i] "+r" (i), [v] "+Q" (v->counter) \
+ : "r" (v)); \
+}
+
+ATOMIC64_OP(andnot, stclr)
+ATOMIC64_OP(or, stset)
+ATOMIC64_OP(xor, steor)
+ATOMIC64_OP(add, stadd)
+
+#undef ATOMIC64_OP
+
+#define ATOMIC64_FETCH_OP(name, mb, op, asm_op, cl...) \
+static inline long __lse_atomic64_fetch_##op##name(s64 i, atomic64_t *v)\
+{ \
+ asm volatile( \
+ __LSE_PREAMBLE \
+" " #asm_op #mb " %[i], %[i], %[v]" \
+ : [i] "+r" (i), [v] "+Q" (v->counter) \
+ : "r" (v) \
+ : cl); \
+ \
+ return i; \
+}
+
+#define ATOMIC64_FETCH_OPS(op, asm_op) \
+ ATOMIC64_FETCH_OP(_relaxed, , op, asm_op) \
+ ATOMIC64_FETCH_OP(_acquire, a, op, asm_op, "memory") \
+ ATOMIC64_FETCH_OP(_release, l, op, asm_op, "memory") \
+ ATOMIC64_FETCH_OP( , al, op, asm_op, "memory")
+
+ATOMIC64_FETCH_OPS(andnot, ldclr)
+ATOMIC64_FETCH_OPS(or, ldset)
+ATOMIC64_FETCH_OPS(xor, ldeor)
+ATOMIC64_FETCH_OPS(add, ldadd)
+
+#undef ATOMIC64_FETCH_OP
+#undef ATOMIC64_FETCH_OPS
+
+#define ATOMIC64_OP_ADD_RETURN(name, mb, cl...)
\
+static inline long __lse_atomic64_add_return##name(s64 i, atomic64_t *v)\
+{ \
+ unsigned long tmp; \
+ \
+ asm volatile( \
+ __LSE_PREAMBLE \
+ " ldadd" #mb " %[i], %x[tmp], %[v]\n" \
+ " add %[i], %[i], %x[tmp]" \
+ : [i] "+r" (i), [v] "+Q" (v->counter), [tmp] "=&r" (tmp) \
+ : "r" (v) \
+ : cl); \
+ \
+ return i; \
+}
+
+ATOMIC64_OP_ADD_RETURN(_relaxed, )
+ATOMIC64_OP_ADD_RETURN(_acquire, a, "memory")
+ATOMIC64_OP_ADD_RETURN(_release, l, "memory")
+ATOMIC64_OP_ADD_RETURN( , al, "memory")
+
+#undef ATOMIC64_OP_ADD_RETURN
+
+static inline void __lse_atomic64_and(s64 i, atomic64_t *v)
+{
+ asm volatile(
+ __LSE_PREAMBLE
+ " mvn %[i], %[i]\n"
+ " stclr %[i], %[v]"
+ : [i] "+&r" (i), [v] "+Q" (v->counter)
+ : "r" (v));
+}
+
+#define ATOMIC64_FETCH_OP_AND(name, mb, cl...) \
+static inline long __lse_atomic64_fetch_and##name(s64 i, atomic64_t *v)
\
+{ \
+ asm volatile( \
+ __LSE_PREAMBLE \
+ " mvn %[i], %[i]\n" \
+ " ldclr" #mb " %[i], %[i], %[v]" \
+ : [i] "+&r" (i), [v] "+Q" (v->counter) \
+ : "r" (v) \
+ : cl); \
+ \
+ return i; \
+}
+
+ATOMIC64_FETCH_OP_AND(_relaxed, )
+ATOMIC64_FETCH_OP_AND(_acquire, a, "memory")
+ATOMIC64_FETCH_OP_AND(_release, l, "memory")
+ATOMIC64_FETCH_OP_AND( , al, "memory")
+
+#undef ATOMIC64_FETCH_OP_AND
+
+static inline void __lse_atomic64_sub(s64 i, atomic64_t *v)
+{
+ asm volatile(
+ __LSE_PREAMBLE
+ " neg %[i], %[i]\n"
+ " stadd %[i], %[v]"
+ : [i] "+&r" (i), [v] "+Q" (v->counter)
+ : "r" (v));
+}
+
+#define ATOMIC64_OP_SUB_RETURN(name, mb, cl...)
\
+static inline long __lse_atomic64_sub_return##name(s64 i, atomic64_t *v)
\
+{ \
+ unsigned long tmp; \
+ \
+ asm volatile( \
+ __LSE_PREAMBLE \
+ " neg %[i], %[i]\n" \
+ " ldadd" #mb " %[i], %x[tmp], %[v]\n" \
+ " add %[i], %[i], %x[tmp]" \
+ : [i] "+&r" (i), [v] "+Q" (v->counter), [tmp] "=&r" (tmp) \
+ : "r" (v) \
+ : cl); \
+ \
+ return i; \
+}
+
+ATOMIC64_OP_SUB_RETURN(_relaxed, )
+ATOMIC64_OP_SUB_RETURN(_acquire, a, "memory")
+ATOMIC64_OP_SUB_RETURN(_release, l, "memory")
+ATOMIC64_OP_SUB_RETURN( , al, "memory")
+
+#undef ATOMIC64_OP_SUB_RETURN
+
+#define ATOMIC64_FETCH_OP_SUB(name, mb, cl...) \
+static inline long __lse_atomic64_fetch_sub##name(s64 i, atomic64_t *v)
\
+{ \
+ asm volatile( \
+ __LSE_PREAMBLE \
+ " neg %[i], %[i]\n" \
+ " ldadd" #mb " %[i], %[i], %[v]" \
+ : [i] "+&r" (i), [v] "+Q" (v->counter) \
+ : "r" (v) \
+ : cl); \
+ \
+ return i; \
+}
+
+ATOMIC64_FETCH_OP_SUB(_relaxed, )
+ATOMIC64_FETCH_OP_SUB(_acquire, a, "memory")
+ATOMIC64_FETCH_OP_SUB(_release, l, "memory")
+ATOMIC64_FETCH_OP_SUB( , al, "memory")
+
+#undef ATOMIC64_FETCH_OP_SUB
+
+static inline s64 __lse_atomic64_dec_if_positive(atomic64_t *v)
+{
+ unsigned long tmp;
+
+ asm volatile(
+ __LSE_PREAMBLE
+ "1: ldr %x[tmp], %[v]\n"
+ " subs %[ret], %x[tmp], #1\n"
+ " b.lt 2f\n"
+ " casal %x[tmp], %[ret], %[v]\n"
+ " sub %x[tmp], %x[tmp], #1\n"
+ " sub %x[tmp], %x[tmp], %[ret]\n"
+ " cbnz %x[tmp], 1b\n"
+ "2:"
+ : [ret] "+&r" (v), [v] "+Q" (v->counter), [tmp] "=&r" (tmp)
+ :
+ : "cc", "memory");
+
+ return (long)v;
+}
+
+#define __CMPXCHG_CASE(w, sfx, name, sz, mb, cl...) \
+static __always_inline u##sz \
+__lse__cmpxchg_case_##name##sz(volatile void *ptr, \
+ u##sz old, \
+ u##sz new) \
+{ \
+ register unsigned long x0 asm ("x0") = (unsigned long)ptr; \
+ register u##sz x1 asm ("x1") = old; \
+ register u##sz x2 asm ("x2") = new; \
+ unsigned long tmp; \
+ \
+ asm volatile( \
+ __LSE_PREAMBLE \
+ " mov %" #w "[tmp], %" #w "[old]\n" \
+ " cas" #mb #sfx "\t%" #w "[tmp], %" #w "[new], %[v]\n" \
+ " mov %" #w "[ret], %" #w "[tmp]" \
+ : [ret] "+r" (x0), [v] "+Q" (*(unsigned long *)ptr), \
+ [tmp] "=&r" (tmp) \
+ : [old] "r" (x1), [new] "r" (x2) \
+ : cl); \
+ \
+ return x0; \
+}
+
+__CMPXCHG_CASE(w, b, , 8, )
+__CMPXCHG_CASE(w, h, , 16, )
+__CMPXCHG_CASE(w, , , 32, )
+__CMPXCHG_CASE(x, , , 64, )
+__CMPXCHG_CASE(w, b, acq_, 8, a, "memory")
+__CMPXCHG_CASE(w, h, acq_, 16, a, "memory")
+__CMPXCHG_CASE(w, , acq_, 32, a, "memory")
+__CMPXCHG_CASE(x, , acq_, 64, a, "memory")
+__CMPXCHG_CASE(w, b, rel_, 8, l, "memory")
+__CMPXCHG_CASE(w, h, rel_, 16, l, "memory")
+__CMPXCHG_CASE(w, , rel_, 32, l, "memory")
+__CMPXCHG_CASE(x, , rel_, 64, l, "memory")
+__CMPXCHG_CASE(w, b, mb_, 8, al, "memory")
+__CMPXCHG_CASE(w, h, mb_, 16, al, "memory")
+__CMPXCHG_CASE(w, , mb_, 32, al, "memory")
+__CMPXCHG_CASE(x, , mb_, 64, al, "memory")
+
+#undef __CMPXCHG_CASE
+
+#define __CMPXCHG_DBL(name, mb, cl...) \
+static __always_inline long \
+__lse__cmpxchg_double##name(unsigned long old1,
\
+ unsigned long old2, \
+ unsigned long new1, \
+ unsigned long new2, \
+ volatile void *ptr) \
+{ \
+ unsigned long oldval1 = old1; \
+ unsigned long oldval2 = old2; \
+ register unsigned long x0 asm ("x0") = old1; \
+ register unsigned long x1 asm ("x1") = old2; \
+ register unsigned long x2 asm ("x2") = new1; \
+ register unsigned long x3 asm ("x3") = new2; \
+ register unsigned long x4 asm ("x4") = (unsigned long)ptr; \
+ \
+ asm volatile( \
+ __LSE_PREAMBLE \
+ " casp" #mb "\t%[old1], %[old2], %[new1], %[new2], %[v]\n"\
+ " eor %[old1], %[old1], %[oldval1]\n" \
+ " eor %[old2], %[old2], %[oldval2]\n" \
+ " orr %[old1], %[old1], %[old2]" \
+ : [old1] "+&r" (x0), [old2] "+&r" (x1), \
+ [v] "+Q" (*(unsigned long *)ptr) \
+ : [new1] "r" (x2), [new2] "r" (x3), [ptr] "r" (x4), \
+ [oldval1] "r" (oldval1), [oldval2] "r" (oldval2) \
+ : cl); \
+ \
+ return x0; \
+}
+
+__CMPXCHG_DBL( , )
+__CMPXCHG_DBL(_mb, al, "memory")
+
+#undef __CMPXCHG_DBL
+
+#endif /* __ASM_ATOMIC_LSE_H */
\ No newline at end of file
diff --git a/xen/include/asm-arm/arm64/cmpxchg.h
b/xen/include/asm-arm/arm64/cmpxchg.h
new file mode 100644
index 0000000000..c51388216e
--- /dev/null
+++ b/xen/include/asm-arm/arm64/cmpxchg.h
@@ -0,0 +1,285 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Based on arch/arm/include/asm/cmpxchg.h
+ *
+ * Copyright (C) 2012 ARM Ltd.
+ */
+#ifndef __ASM_CMPXCHG_H
+#define __ASM_CMPXCHG_H
+
+#include <linux/build_bug.h>
+#include <linux/compiler.h>
+
+#include <asm/barrier.h>
+#include <asm/lse.h>
+
+/*
+ * We need separate acquire parameters for ll/sc and lse, since the full
+ * barrier case is generated as release+dmb for the former and
+ * acquire+release for the latter.
+ */
+#define __XCHG_CASE(w, sfx, name, sz, mb, nop_lse, acq, acq_lse, rel, cl)
\
+static inline u##sz __xchg_case_##name##sz(u##sz x, volatile void *ptr)
\
+{
\
+ u##sz ret;
\
+ unsigned long tmp;
\
+
\
+ asm volatile(ARM64_LSE_ATOMIC_INSN(
\
+ /* LL/SC */
\
+ " prfm pstl1strm, %2\n"
\
+ "1: ld" #acq "xr" #sfx "\t%" #w "0, %2\n"
\
+ " st" #rel "xr" #sfx "\t%w1, %" #w "3, %2\n"
\
+ " cbnz %w1, 1b\n"
\
+ " " #mb,
\
+ /* LSE atomics */
\
+ " swp" #acq_lse #rel #sfx "\t%" #w "3, %" #w "0, %2\n"
\
+ __nops(3)
\
+ " " #nop_lse)
\
+ : "=&r" (ret), "=&r" (tmp), "+Q" (*(u##sz *)ptr)
\
+ : "r" (x)
\
+ : cl);
\
+
\
+ return ret;
\
+}
+
+__XCHG_CASE(w, b, , 8, , , , , , )
+__XCHG_CASE(w, h, , 16, , , , , , )
+__XCHG_CASE(w, , , 32, , , , , , )
+__XCHG_CASE( , , , 64, , , , , , )
+__XCHG_CASE(w, b, acq_, 8, , , a, a, , "memory")
+__XCHG_CASE(w, h, acq_, 16, , , a, a, , "memory")
+__XCHG_CASE(w, , acq_, 32, , , a, a, , "memory")
+__XCHG_CASE( , , acq_, 64, , , a, a, , "memory")
+__XCHG_CASE(w, b, rel_, 8, , , , , l, "memory")
+__XCHG_CASE(w, h, rel_, 16, , , , , l, "memory")
+__XCHG_CASE(w, , rel_, 32, , , , , l, "memory")
+__XCHG_CASE( , , rel_, 64, , , , , l, "memory")
+__XCHG_CASE(w, b, mb_, 8, dmb ish, nop, , a, l, "memory")
+__XCHG_CASE(w, h, mb_, 16, dmb ish, nop, , a, l, "memory")
+__XCHG_CASE(w, , mb_, 32, dmb ish, nop, , a, l, "memory")
+__XCHG_CASE( , , mb_, 64, dmb ish, nop, , a, l, "memory")
+
+#undef __XCHG_CASE
+
+#define __XCHG_GEN(sfx)
\
+static __always_inline unsigned long __xchg##sfx(unsigned long x, \
+ volatile void *ptr, \
+ int size) \
+{ \
+ switch (size) { \
+ case 1: \
+ return __xchg_case##sfx##_8(x, ptr); \
+ case 2: \
+ return __xchg_case##sfx##_16(x, ptr); \
+ case 4: \
+ return __xchg_case##sfx##_32(x, ptr); \
+ case 8: \
+ return __xchg_case##sfx##_64(x, ptr); \
+ default: \
+ BUILD_BUG(); \
+ } \
+ \
+ unreachable(); \
+}
+
+__XCHG_GEN()
+__XCHG_GEN(_acq)
+__XCHG_GEN(_rel)
+__XCHG_GEN(_mb)
+
+#undef __XCHG_GEN
+
+#define __xchg_wrapper(sfx, ptr, x) \
+({ \
+ __typeof__(*(ptr)) __ret; \
+ __ret = (__typeof__(*(ptr))) \
+ __xchg##sfx((unsigned long)(x), (ptr), sizeof(*(ptr))); \
+ __ret; \
+})
+
+/* xchg */
+#define arch_xchg_relaxed(...) __xchg_wrapper( , __VA_ARGS__)
+#define arch_xchg_acquire(...) __xchg_wrapper(_acq, __VA_ARGS__)
+#define arch_xchg_release(...) __xchg_wrapper(_rel, __VA_ARGS__)
+#define arch_xchg(...) __xchg_wrapper( _mb, __VA_ARGS__)
+
+#define __CMPXCHG_CASE(name, sz) \
+static inline u##sz __cmpxchg_case_##name##sz(volatile void *ptr, \
+ u##sz old, \
+ u##sz new) \
+{ \
+ return __lse_ll_sc_body(_cmpxchg_case_##name##sz, \
+ ptr, old, new); \
+}
+
+__CMPXCHG_CASE( , 8)
+__CMPXCHG_CASE( , 16)
+__CMPXCHG_CASE( , 32)
+__CMPXCHG_CASE( , 64)
+__CMPXCHG_CASE(acq_, 8)
+__CMPXCHG_CASE(acq_, 16)
+__CMPXCHG_CASE(acq_, 32)
+__CMPXCHG_CASE(acq_, 64)
+__CMPXCHG_CASE(rel_, 8)
+__CMPXCHG_CASE(rel_, 16)
+__CMPXCHG_CASE(rel_, 32)
+__CMPXCHG_CASE(rel_, 64)
+__CMPXCHG_CASE(mb_, 8)
+__CMPXCHG_CASE(mb_, 16)
+__CMPXCHG_CASE(mb_, 32)
+__CMPXCHG_CASE(mb_, 64)
+
+#undef __CMPXCHG_CASE
+
+#define __CMPXCHG_DBL(name) \
+static inline long __cmpxchg_double##name(unsigned long old1, \
+ unsigned long old2, \
+ unsigned long new1, \
+ unsigned long new2, \
+ volatile void *ptr) \
+{ \
+ return __lse_ll_sc_body(_cmpxchg_double##name, \
+ old1, old2, new1, new2, ptr); \
+}
+
+__CMPXCHG_DBL( )
+__CMPXCHG_DBL(_mb)
+
+#undef __CMPXCHG_DBL
+
+#define __CMPXCHG_GEN(sfx) \
+static __always_inline unsigned long __cmpxchg##sfx(volatile void *ptr,
\
+ unsigned long old, \
+ unsigned long new, \
+ int size) \
+{ \
+ switch (size) { \
+ case 1: \
+ return __cmpxchg_case##sfx##_8(ptr, old, new); \
+ case 2: \
+ return __cmpxchg_case##sfx##_16(ptr, old, new); \
+ case 4: \
+ return __cmpxchg_case##sfx##_32(ptr, old, new); \
+ case 8: \
+ return __cmpxchg_case##sfx##_64(ptr, old, new); \
+ default: \
+ BUILD_BUG(); \
+ } \
+ \
+ unreachable(); \
+}
+
+__CMPXCHG_GEN()
+__CMPXCHG_GEN(_acq)
+__CMPXCHG_GEN(_rel)
+__CMPXCHG_GEN(_mb)
+
+#undef __CMPXCHG_GEN
+
+#define __cmpxchg_wrapper(sfx, ptr, o, n) \
+({ \
+ __typeof__(*(ptr)) __ret; \
+ __ret = (__typeof__(*(ptr))) \
+ __cmpxchg##sfx((ptr), (unsigned long)(o), \
+ (unsigned long)(n), sizeof(*(ptr))); \
+ __ret; \
+})
+
+/* cmpxchg */
+#define arch_cmpxchg_relaxed(...) __cmpxchg_wrapper( , __VA_ARGS__)
+#define arch_cmpxchg_acquire(...) __cmpxchg_wrapper(_acq, __VA_ARGS__)
+#define arch_cmpxchg_release(...) __cmpxchg_wrapper(_rel, __VA_ARGS__)
+#define arch_cmpxchg(...) __cmpxchg_wrapper( _mb, __VA_ARGS__)
+#define arch_cmpxchg_local arch_cmpxchg_relaxed
+
+/* cmpxchg64 */
+#define arch_cmpxchg64_relaxed arch_cmpxchg_relaxed
+#define arch_cmpxchg64_acquire arch_cmpxchg_acquire
+#define arch_cmpxchg64_release arch_cmpxchg_release
+#define arch_cmpxchg64 arch_cmpxchg
+#define arch_cmpxchg64_local arch_cmpxchg_local
+
+/* cmpxchg_double */
+#define system_has_cmpxchg_double() 1
+
+#define __cmpxchg_double_check(ptr1, ptr2)
\
+({
\
+ if (sizeof(*(ptr1)) != 8)
\
+ BUILD_BUG();
\
+ VM_BUG_ON((unsigned long *)(ptr2) - (unsigned long *)(ptr1) != 1);
\
+})
+
+#define arch_cmpxchg_double(ptr1, ptr2, o1, o2, n1, n2)
\
+({
\
+ int __ret;
\
+ __cmpxchg_double_check(ptr1, ptr2);
\
+ __ret = !__cmpxchg_double_mb((unsigned long)(o1), (unsigned long)(o2),
\
+ (unsigned long)(n1), (unsigned long)(n2),
\
+ ptr1);
\
+ __ret;
\
+})
+
+#define arch_cmpxchg_double_local(ptr1, ptr2, o1, o2, n1, n2)
\
+({
\
+ int __ret;
\
+ __cmpxchg_double_check(ptr1, ptr2);
\
+ __ret = !__cmpxchg_double((unsigned long)(o1), (unsigned long)(o2),
\
+ (unsigned long)(n1), (unsigned long)(n2),
\
+ ptr1);
\
+ __ret;
\
+})
+
+#define __CMPWAIT_CASE(w, sfx, sz) \
+static inline void __cmpwait_case_##sz(volatile void *ptr, \
+ unsigned long val) \
+{ \
+ unsigned long tmp; \
+ \
+ asm volatile( \
+ " sevl\n" \
+ " wfe\n" \
+ " ldxr" #sfx "\t%" #w "[tmp], %[v]\n" \
+ " eor %" #w "[tmp], %" #w "[tmp], %" #w "[val]\n" \
+ " cbnz %" #w "[tmp], 1f\n" \
+ " wfe\n" \
+ "1:" \
+ : [tmp] "=&r" (tmp), [v] "+Q" (*(unsigned long *)ptr) \
+ : [val] "r" (val)); \
+}
+
+__CMPWAIT_CASE(w, b, 8);
+__CMPWAIT_CASE(w, h, 16);
+__CMPWAIT_CASE(w, , 32);
+__CMPWAIT_CASE( , , 64);
+
+#undef __CMPWAIT_CASE
+
+#define __CMPWAIT_GEN(sfx) \
+static __always_inline void __cmpwait##sfx(volatile void *ptr, \
+ unsigned long val, \
+ int size) \
+{ \
+ switch (size) { \
+ case 1: \
+ return __cmpwait_case##sfx##_8(ptr, (u8)val); \
+ case 2: \
+ return __cmpwait_case##sfx##_16(ptr, (u16)val); \
+ case 4: \
+ return __cmpwait_case##sfx##_32(ptr, val); \
+ case 8: \
+ return __cmpwait_case##sfx##_64(ptr, val); \
+ default: \
+ BUILD_BUG(); \
+ } \
+ \
+ unreachable(); \
+}
+
+__CMPWAIT_GEN()
+
+#undef __CMPWAIT_GEN
+
+#define __cmpwait_relaxed(ptr, val) \
+ __cmpwait((ptr), (unsigned long)(val), sizeof(*(ptr)))
+
+#endif /* __ASM_CMPXCHG_H */
\ No newline at end of file
diff --git a/xen/include/asm-arm/arm64/lse.h b/xen/include/asm-arm/arm64/lse.h
new file mode 100644
index 0000000000..704be3e4e4
--- /dev/null
+++ b/xen/include/asm-arm/arm64/lse.h
@@ -0,0 +1,48 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ASM_LSE_H
+#define __ASM_LSE_H
+
+#include <asm/atomic_ll_sc.h>
+
+#ifdef CONFIG_ARM64_LSE_ATOMICS
+
+#define __LSE_PREAMBLE ".arch_extension lse\n"
+
+#include <linux/compiler_types.h>
+#include <linux/export.h>
+#include <linux/jump_label.h>
+#include <linux/stringify.h>
+#include <asm/alternative.h>
+#include <asm/atomic_lse.h>
+#include <asm/cpucaps.h>
+
+extern struct static_key_false cpu_hwcap_keys[ARM64_NCAPS];
+extern struct static_key_false arm64_const_caps_ready;
+
+static inline bool system_uses_lse_atomics(void)
+{
+ return (static_branch_likely(&arm64_const_caps_ready)) &&
+ static_branch_likely(&cpu_hwcap_keys[ARM64_HAS_LSE_ATOMICS]);
+}
+
+#define __lse_ll_sc_body(op, ...) \
+({ \
+ system_uses_lse_atomics() ? \
+ __lse_##op(__VA_ARGS__) : \
+ __ll_sc_##op(__VA_ARGS__); \
+})
+
+/* In-line patching at runtime */
+#define ARM64_LSE_ATOMIC_INSN(llsc, lse) \
+ ALTERNATIVE(llsc, __LSE_PREAMBLE lse, ARM64_HAS_LSE_ATOMICS)
+
+#else /* CONFIG_ARM64_LSE_ATOMICS */
+
+static inline bool system_uses_lse_atomics(void) { return false; }
+
+#define __lse_ll_sc_body(op, ...) __ll_sc_##op(__VA_ARGS__)
+
+#define ARM64_LSE_ATOMIC_INSN(llsc, lse) llsc
+
+#endif /* CONFIG_ARM64_LSE_ATOMICS */
+#endif /* __ASM_LSE_H */
\ No newline at end of file
diff --git a/xen/include/xen/rwonce.h b/xen/include/xen/rwonce.h
new file mode 100644
index 0000000000..6b47392d1c
--- /dev/null
+++ b/xen/include/xen/rwonce.h
@@ -0,0 +1,90 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Prevent the compiler from merging or refetching reads or writes. The
+ * compiler is also forbidden from reordering successive instances of
+ * READ_ONCE and WRITE_ONCE, but only when the compiler is aware of some
+ * particular ordering. One way to make the compiler aware of ordering is to
+ * put the two invocations of READ_ONCE or WRITE_ONCE in different C
+ * statements.
+ *
+ * These two macros will also work on aggregate data types like structs or
+ * unions.
+ *
+ * Their two major use cases are: (1) Mediating communication between
+ * process-level code and irq/NMI handlers, all running on the same CPU,
+ * and (2) Ensuring that the compiler does not fold, spindle, or otherwise
+ * mutilate accesses that either do not require ordering or that interact
+ * with an explicit memory barrier or atomic instruction that provides the
+ * required ordering.
+ */
+#ifndef __ASM_GENERIC_RWONCE_H
+#define __ASM_GENERIC_RWONCE_H
+
+#ifndef __ASSEMBLY__
+
+#include <linux/compiler_types.h>
+#include <linux/kasan-checks.h>
+#include <linux/kcsan-checks.h>
+
+/*
+ * Yes, this permits 64-bit accesses on 32-bit architectures. These will
+ * actually be atomic in some cases (namely Armv7 + LPAE), but for others we
+ * rely on the access being split into 2x32-bit accesses for a 32-bit quantity
+ * (e.g. a virtual address) and a strong prevailing wind.
+ */
+#define compiletime_assert_rwonce_type(t)
\
+ compiletime_assert(__native_word(t) || sizeof(t) == sizeof(long long),
\
+ "Unsupported access size for {READ,WRITE}_ONCE().")
+
+/*
+ * Use __READ_ONCE() instead of READ_ONCE() if you do not require any
+ * atomicity. Note that this may result in tears!
+ */
+#ifndef __READ_ONCE
+#define __READ_ONCE(x) (*(const volatile __unqual_scalar_typeof(x) *)&(x))
+#endif
+
+#define READ_ONCE(x) \
+({ \
+ compiletime_assert_rwonce_type(x); \
+ __READ_ONCE(x); \
+})
+
+#define __WRITE_ONCE(x, val) \
+do { \
+ *(volatile typeof(x) *)&(x) = (val); \
+} while (0)
+
+#define WRITE_ONCE(x, val) \
+do { \
+ compiletime_assert_rwonce_type(x); \
+ __WRITE_ONCE(x, val); \
+} while (0)
+
+static __no_sanitize_or_inline
+unsigned long __read_once_word_nocheck(const void *addr)
+{
+ return __READ_ONCE(*(unsigned long *)addr);
+}
+
+/*
+ * Use READ_ONCE_NOCHECK() instead of READ_ONCE() if you need to load a
+ * word from memory atomically but without telling KASAN/KCSAN. This is
+ * usually used by unwinding code when walking the stack of a running process.
+ */
+#define READ_ONCE_NOCHECK(x) \
+({ \
+ compiletime_assert(sizeof(x) == sizeof(unsigned long), \
+ "Unsupported access size for READ_ONCE_NOCHECK()."); \
+ (typeof(x))__read_once_word_nocheck(&(x)); \
+})
+
+static __no_kasan_or_inline
+unsigned long read_word_at_a_time(const void *addr)
+{
+ kasan_check_read(addr, 1);
+ return *(unsigned long *)addr;
+}
+
+#endif /* __ASSEMBLY__ */
+#endif /* __ASM_GENERIC_RWONCE_H */
\ No newline at end of file
--
2.24.3 (Apple Git-128)
