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authorMax Filippov <jcmvbkbc@gmail.com>2012-11-15 03:25:48 +0100
committerChris Zankel <chris@zankel.net>2012-12-19 06:10:22 +0100
commit733536b865441d9bad02c4711a4372d48ce21e54 (patch)
treee54c74b6f27dab1175701128e1c0ac2a18cccdc3 /arch/xtensa
parentxtensa: display s32c1i feature flag in cpuinfo (diff)
downloadlinux-733536b865441d9bad02c4711a4372d48ce21e54.tar.xz
linux-733536b865441d9bad02c4711a4372d48ce21e54.zip
xtensa: save and restore scompare1 SR on kernel entry
Although scompare1 may be saved/restored by xchal_ncp_{load,store} macros, explicit save/restore of registers manipulated by the kernel itself is considered more correct. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Chris Zankel <chris@zankel.net>
Diffstat (limited to 'arch/xtensa')
-rw-r--r--arch/xtensa/include/asm/ptrace.h2
-rw-r--r--arch/xtensa/kernel/asm-offsets.c1
-rw-r--r--arch/xtensa/kernel/entry.S13
3 files changed, 15 insertions, 1 deletions
diff --git a/arch/xtensa/include/asm/ptrace.h b/arch/xtensa/include/asm/ptrace.h
index da21c17f23aa..9fe249c8f90e 100644
--- a/arch/xtensa/include/asm/ptrace.h
+++ b/arch/xtensa/include/asm/ptrace.h
@@ -37,7 +37,7 @@ struct pt_regs {
unsigned long windowstart; /* 52 */
unsigned long syscall; /* 56 */
unsigned long icountlevel; /* 60 */
- int reserved[1]; /* 64 */
+ unsigned long scompare1; /* 64 */
/* Additional configurable registers that are used by the compiler. */
xtregs_opt_t xtregs_opt;
diff --git a/arch/xtensa/kernel/asm-offsets.c b/arch/xtensa/kernel/asm-offsets.c
index 7dc3f9157185..845475afc683 100644
--- a/arch/xtensa/kernel/asm-offsets.c
+++ b/arch/xtensa/kernel/asm-offsets.c
@@ -41,6 +41,7 @@ int main(void)
DEFINE(PT_SAR, offsetof (struct pt_regs, sar));
DEFINE(PT_ICOUNTLEVEL, offsetof (struct pt_regs, icountlevel));
DEFINE(PT_SYSCALL, offsetof (struct pt_regs, syscall));
+ DEFINE(PT_SCOMPARE1, offsetof(struct pt_regs, scompare1));
DEFINE(PT_AREG, offsetof (struct pt_regs, areg[0]));
DEFINE(PT_AREG0, offsetof (struct pt_regs, areg[0]));
DEFINE(PT_AREG1, offsetof (struct pt_regs, areg[1]));
diff --git a/arch/xtensa/kernel/entry.S b/arch/xtensa/kernel/entry.S
index 41ad9cfe9a2a..4c2f2706ad5b 100644
--- a/arch/xtensa/kernel/entry.S
+++ b/arch/xtensa/kernel/entry.S
@@ -372,6 +372,13 @@ common_exception:
s32i a2, a1, PT_LBEG
s32i a3, a1, PT_LEND
+ /* Save SCOMPARE1 */
+
+#if XCHAL_HAVE_S32C1I
+ rsr a2, scompare1
+ s32i a2, a1, PT_SCOMPARE1
+#endif
+
/* Save optional registers. */
save_xtregs_opt a1 a2 a4 a5 a6 a7 PT_XTREGS_OPT
@@ -433,6 +440,12 @@ common_exception_return:
load_xtregs_opt a1 a2 a4 a5 a6 a7 PT_XTREGS_OPT
+ /* Restore SCOMPARE1 */
+
+#if XCHAL_HAVE_S32C1I
+ l32i a2, a1, PT_SCOMPARE1
+ wsr a2, scompare1
+#endif
wsr a3, ps /* disable interrupts */
_bbci.l a3, PS_UM_BIT, kernel_exception_exit