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authorDavid Daney <david.daney@cavium.com>2014-05-28 23:52:04 +0200
committerRalf Baechle <ralf@linux-mips.org>2014-05-30 21:01:09 +0200
commita36d8225bceba4b7be47ade34d175945f85cffbc (patch)
treee410a514298003ab96d3a10cf091c518a8a423c8 /arch/mips/kernel/octeon_switch.S
parentdadaa1c2c0eddc09d11d7494b040c3f331ecd98f (diff)
MIPS: OCTEON: Enable use of FPU
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.daney@cavium.com> Signed-off-by: Andreas Herrmann <andreas.herrmann@caviumnetworks.com> Cc: linux-mips@linux-mips.org Cc: James Hogan <james.hogan@imgtec.com> Cc: kvm@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/7006/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'arch/mips/kernel/octeon_switch.S')
-rw-r--r--arch/mips/kernel/octeon_switch.S84
1 files changed, 61 insertions, 23 deletions
diff --git a/arch/mips/kernel/octeon_switch.S b/arch/mips/kernel/octeon_switch.S
index 029e002a4ea0..f6547680c81c 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, carstenl@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? */