Import iosubmit_cmds512() from arch/x86/include/asm/io.h into tools/ so
it can be used by VFIO selftests to interact with Intel DSA devices.
Also pull in movdir64b() from arch/x86/include/asm/special_insns.h into
tools/, which is the underlying instruction used by iosubmit_cmds512().
Changes made when importing: None
Signed-off-by: David Matlack <dmatl...@google.com>
---
tools/arch/x86/include/asm/io.h | 26 +++++++++++++++++++++
tools/arch/x86/include/asm/special_insns.h | 27 ++++++++++++++++++++++
2 files changed, 53 insertions(+)
create mode 100644 tools/arch/x86/include/asm/special_insns.h
diff --git a/tools/arch/x86/include/asm/io.h b/tools/arch/x86/include/asm/io.h
index 4c787a2363de..ecad61a3ea52 100644
--- a/tools/arch/x86/include/asm/io.h
+++ b/tools/arch/x86/include/asm/io.h
@@ -4,6 +4,7 @@
#include <linux/compiler.h>
#include <linux/types.h>
+#include "special_insns.h"
#define build_mmio_read(name, size, type, reg, barrier) \
static inline type name(const volatile void __iomem *addr) \
@@ -72,4 +73,29 @@ build_mmio_write(__writeq, "q", u64, "r", )
#include <asm-generic/io.h>
+/**
+ * iosubmit_cmds512 - copy data to single MMIO location, in 512-bit units
+ * @dst: destination, in MMIO space (must be 512-bit aligned)
+ * @src: source
+ * @count: number of 512 bits quantities to submit
+ *
+ * Submit data from kernel space to MMIO space, in units of 512 bits at a
+ * time. Order of access is not guaranteed, nor is a memory barrier
+ * performed afterwards.
+ *
+ * Warning: Do not use this helper unless your driver has checked that the CPU
+ * instruction is supported on the platform.
+ */
+static inline void iosubmit_cmds512(void __iomem *dst, const void *src,
+ size_t count)
+{
+ const u8 *from = src;
+ const u8 *end = from + count * 64;
+
+ while (from < end) {
+ movdir64b(dst, from);
+ from += 64;
+ }
+}
+
#endif /* _TOOLS_ASM_X86_IO_H */
diff --git a/tools/arch/x86/include/asm/special_insns.h
b/tools/arch/x86/include/asm/special_insns.h
new file mode 100644
index 000000000000..04af42a99c38
--- /dev/null
+++ b/tools/arch/x86/include/asm/special_insns.h
@@ -0,0 +1,27 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _TOOLS_ASM_X86_SPECIAL_INSNS_H
+#define _TOOLS_ASM_X86_SPECIAL_INSNS_H
+
+/* The dst parameter must be 64-bytes aligned */
+static inline void movdir64b(void *dst, const void *src)
+{
+ const struct { char _[64]; } *__src = src;
+ struct { char _[64]; } *__dst = dst;
+
+ /*
+ * MOVDIR64B %(rdx), rax.
+ *
+ * Both __src and __dst must be memory constraints in order to tell the
+ * compiler that no other memory accesses should be reordered around
+ * this one.
+ *
+ * Also, both must be supplied as lvalues because this tells
+ * the compiler what the object is (its size) the instruction accesses.
+ * I.e., not the pointers but what they point to, thus the deref'ing
'*'.
+ */
+ asm volatile(".byte 0x66, 0x0f, 0x38, 0xf8, 0x02"
+ : "+m" (*__dst)
+ : "m" (*__src), "a" (__dst), "d" (__src));
+}
+
+#endif /* _TOOLS_ASM_X86_SPECIAL_INSNS_H */
--
2.49.0.1151.ga128411c76-goog
