From: David Daney <david.da...@cavium.com>
Some versions of the assembler will not assemble CFC1 for OCTEON, so
override the ISA for these.
Add r4k_fpu.o to handle low level FPU initialization.
Modify octeon_switch.S to save the FPU registers. And include
r4k_switch.S to pick up more FPU support.
Get rid of "#define cpu_has_fpu 0"
Signed-off-by: David Daney <david.da...@cavium.com>
Signed-off-by: Andreas Herrmann <andreas.herrm...@caviumnetworks.com>
---
.../asm/mach-cavium-octeon/cpu-feature-overrides.h | 1 -
arch/mips/kernel/Makefile | 2 +-
arch/mips/kernel/branch.c | 6 +-
arch/mips/kernel/octeon_switch.S | 84 ++++++++++++++------
arch/mips/kernel/r4k_switch.S | 3 +
arch/mips/math-emu/cp1emu.c | 6 +-
6 files changed, 75 insertions(+), 27 deletions(-)
diff --git a/arch/mips/include/asm/mach-cavium-octeon/cpu-feature-overrides.h
b/arch/mips/include/asm/mach-cavium-octeon/cpu-feature-overrides.h
index 94ed063..cf80228 100644
--- a/arch/mips/include/asm/mach-cavium-octeon/cpu-feature-overrides.h
+++ b/arch/mips/include/asm/mach-cavium-octeon/cpu-feature-overrides.h
@@ -22,7 +22,6 @@
#define cpu_has_3k_cache 0
#define cpu_has_4k_cache 0
#define cpu_has_tx39_cache 0
-#define cpu_has_fpu 0
#define cpu_has_counter 1
#define cpu_has_watch 1
#define cpu_has_divec 1
diff --git a/arch/mips/kernel/Makefile b/arch/mips/kernel/Makefile
index 8f8b531..e00a1eb 100644
--- a/arch/mips/kernel/Makefile
+++ b/arch/mips/kernel/Makefile
@@ -41,7 +41,7 @@ obj-$(CONFIG_CPU_R4K_FPU) += r4k_fpu.o r4k_switch.o
obj-$(CONFIG_CPU_R3000) += r2300_fpu.o r2300_switch.o
obj-$(CONFIG_CPU_R6000) += r6000_fpu.o r4k_switch.o
obj-$(CONFIG_CPU_TX39XX) += r2300_fpu.o r2300_switch.o
-obj-$(CONFIG_CPU_CAVIUM_OCTEON) += octeon_switch.o
+obj-$(CONFIG_CPU_CAVIUM_OCTEON) += r4k_fpu.o octeon_switch.o
obj-$(CONFIG_SMP) += smp.o
obj-$(CONFIG_SMP_UP) += smp-up.o
diff --git a/arch/mips/kernel/branch.c b/arch/mips/kernel/branch.c
index 101ab9a..7b2df22 100644
--- a/arch/mips/kernel/branch.c
+++ b/arch/mips/kernel/branch.c
@@ -562,7 +562,11 @@ int __compute_return_epc_for_insn(struct pt_regs *regs,
case cop1_op:
preempt_disable();
if (is_fpu_owner())
- asm volatile("cfc1\t%0,$31" : "=r" (fcr31));
+ asm volatile(
+ ".set push\n"
+ "\t.set mips1\n"
+ "\tcfc1\t%0,$31\n"
+ "\t.set pop" : "=r" (fcr31));
else
fcr31 = current->thread.fpu.fcr31;
preempt_enable();
diff --git a/arch/mips/kernel/octeon_switch.S b/arch/mips/kernel/octeon_switch.S
index 029e002..f654768 100644
--- a/arch/mips/kernel/octeon_switch.S
+++ b/arch/mips/kernel/octeon_switch.S
@@ -10,24 +10,12 @@
* Copyright (C) 2000 MIPS Technologies, Inc.
* written by Carsten Langgaard, carst...@mips.com
*/
-#include <asm/asm.h>
-#include <asm/cachectl.h>
-#include <asm/fpregdef.h>
-#include <asm/mipsregs.h>
-#include <asm/asm-offsets.h>
-#include <asm/pgtable-bits.h>
-#include <asm/regdef.h>
-#include <asm/stackframe.h>
-#include <asm/thread_info.h>
-
-#include <asm/asmmacro.h>
-
-/*
- * Offset to the current process status flags, the first 32 bytes of the
- * stack are not used.
- */
-#define ST_OFF (_THREAD_SIZE - 32 - PT_SIZE + PT_STATUS)
+#define USE_ALTERNATE_RESUME_IMPL 1
+ .set push
+ .set arch=mips64r2
+#include "r4k_switch.S"
+ .set pop
/*
* task_struct *resume(task_struct *prev, task_struct *next,
* struct thread_info *next_ti, int usedfpu)
@@ -40,6 +28,61 @@
cpu_save_nonscratch a0
LONG_S ra, THREAD_REG31(a0)
+ /*
+ * check if we need to save FPU registers
+ */
+ PTR_L t3, TASK_THREAD_INFO(a0)
+ LONG_L t0, TI_FLAGS(t3)
+ li t1, _TIF_USEDFPU
+ and t2, t0, t1
+ beqz t2, 1f
+ nor t1, zero, t1
+
+ and t0, t0, t1
+ LONG_S t0, TI_FLAGS(t3)
+
+ /*
+ * clear saved user stack CU1 bit
+ */
+ LONG_L t0, ST_OFF(t3)
+ li t1, ~ST0_CU1
+ and t0, t0, t1
+ LONG_S t0, ST_OFF(t3)
+
+ .set push
+ .set arch=mips64r2
+ fpu_save_double a0 t0 t1 # c0_status passed in t0
+ # clobbers t1
+ .set pop
+1:
+
+ /* check if we need to save COP2 registers */
+ PTR_L t2, TASK_THREAD_INFO(a0)
+ LONG_L t0, ST_OFF(t2)
+ bbit0 t0, 30, 1f
+
+ /* Disable COP2 in the stored process state */
+ li t1, ST0_CU2
+ xor t0, t1
+ LONG_S t0, ST_OFF(t2)
+
+ /* Enable COP2 so we can save it */
+ mfc0 t0, CP0_STATUS
+ or t0, t1
+ mtc0 t0, CP0_STATUS
+
+ /* Save COP2 */
+ daddu a0, THREAD_CP2
+ jal octeon_cop2_save
+ dsubu a0, THREAD_CP2
+
+ /* Disable COP2 now that we are done */
+ mfc0 t0, CP0_STATUS
+ li t1, ST0_CU2
+ xor t0, t1
+ mtc0 t0, CP0_STATUS
+
+1:
#if CONFIG_CAVIUM_OCTEON_CVMSEG_SIZE > 0
/* Check if we need to store CVMSEG state */
mfc0 t0, $11,7 /* CvmMemCtl */
@@ -85,12 +128,7 @@
move $28, a2
cpu_restore_nonscratch a1
-#if (_THREAD_SIZE - 32) < 0x8000
- PTR_ADDIU t0, $28, _THREAD_SIZE - 32
-#else
- PTR_LI t0, _THREAD_SIZE - 32
- PTR_ADDU t0, $28
-#endif
+ PTR_ADDU t0, $28, _THREAD_SIZE - 32
set_saved_sp t0, t1, t2
mfc0 t1, CP0_STATUS /* Do we really need this? */
diff --git a/arch/mips/kernel/r4k_switch.S b/arch/mips/kernel/r4k_switch.S
index 547c522..81ca3f7 100644
--- a/arch/mips/kernel/r4k_switch.S
+++ b/arch/mips/kernel/r4k_switch.S
@@ -28,6 +28,7 @@
*/
#define ST_OFF (_THREAD_SIZE - 32 - PT_SIZE + PT_STATUS)
+#ifndef USE_ALTERNATE_RESUME_IMPL
/*
* task_struct *resume(task_struct *prev, task_struct *next,
* struct thread_info *next_ti, s32 fp_save)
@@ -99,6 +100,8 @@
jr ra
END(resume)
+#endif /* USE_ALTERNATE_RESUME_IMPL */
+
/*
* Save a thread's fp context.
*/
diff --git a/arch/mips/math-emu/cp1emu.c b/arch/mips/math-emu/cp1emu.c
index 08e6a74..5afda3c 100644
--- a/arch/mips/math-emu/cp1emu.c
+++ b/arch/mips/math-emu/cp1emu.c
@@ -584,7 +584,11 @@ static int isBranchInstr(struct pt_regs *regs, struct
mm_decoded_insn dec_insn,
if (insn.i_format.rs == bc_op) {
preempt_disable();
if (is_fpu_owner())
- asm volatile("cfc1\t%0,$31" : "=r" (fcr31));
+ asm volatile(
+ ".set push\n"
+ "\t.set mips1\n"
+ "\tcfc1\t%0,$31\n"
+ "\t.set pop" : "=r" (fcr31));
else
fcr31 = current->thread.fpu.fcr31;
preempt_enable();
--
1.7.9.5
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