On Sun, Aug 16, 2009 at 08:41:32AM +0200, Ingo Molnar wrote: > -tip testing found this build bug caused by this patch: > > arch/x86/kernel/cpu/amd.c: In function ‘init_amd’: > arch/x86/kernel/cpu/amd.c:417: error: implicit declaration of function ‘wrmsr_amd_safe’ Oops, forgot paravirt. Here's a fixed version: -- From: Borislav Petkov <borislav.petkov@xxxxxxx> Date: Sat, 15 Aug 2009 17:06:39 +0000 Subject: [PATCH 1/2] x86, msr: Add a AMD wrmsr with exception handling Add native_write_msr_amd_safe() - we need this for a workaround. ( While at it, convert native_read_msr_amd_safe to using more robust named inline asm parameters as the rest of the functions. ) Signed-off-by: Borislav Petkov <borislav.petkov@xxxxxxx> Cc: kjwinchester@xxxxxxxxx Cc: mikpe@xxxxxxxx Cc: brgerst@xxxxxxxxx --- arch/x86/include/asm/msr.h | 32 ++++++++++++++++++++++++++++---- arch/x86/include/asm/paravirt.h | 11 +++++++++-- arch/x86/kernel/paravirt.c | 1 + 3 files changed, 38 insertions(+), 6 deletions(-) diff --git a/arch/x86/include/asm/msr.h b/arch/x86/include/asm/msr.h index 48ad9d2..3ea381b 100644 --- a/arch/x86/include/asm/msr.h +++ b/arch/x86/include/asm/msr.h @@ -76,14 +76,14 @@ static inline unsigned long long native_read_msr_amd_safe(unsigned int msr, { DECLARE_ARGS(val, low, high); - asm volatile("2: rdmsr ; xor %0,%0\n" + asm volatile("2: rdmsr ; xor %[err],%[err]\n" "1:\n\t" ".section .fixup,\"ax\"\n\t" - "3: mov %3,%0 ; jmp 1b\n\t" + "3: mov %[fault],%[err] ; jmp 1b\n\t" ".previous\n\t" _ASM_EXTABLE(2b, 3b) - : "=r" (*err), EAX_EDX_RET(val, low, high) - : "c" (msr), "D" (0x9c5a203a), "i" (-EFAULT)); + : [err] "=r" (*err), EAX_EDX_RET(val, low, high) + : "c" (msr), "D" (0x9c5a203a), [fault] "i" (-EFAULT)); return EAX_EDX_VAL(val, low, high); } @@ -111,6 +111,25 @@ notrace static inline int native_write_msr_safe(unsigned int msr, return err; } +static inline unsigned long long native_write_msr_amd_safe(unsigned int msr, + unsigned low, + unsigned high) +{ + int err; + asm volatile("2: wrmsr ; xor %[err],%[err]\n" + "1:\n\t" + ".section .fixup,\"ax\"\n\t" + "3: mov %[fault],%[err] ; jmp 1b\n\t" + ".previous\n\t" + _ASM_EXTABLE(2b, 3b) + : [err] "=a" (err) + : "c" (msr), "0" (low), "d" (high), [fault] "i" (-EFAULT), + "D" (0x9c5a203a) + : "memory"); + return err; + +} + extern unsigned long long native_read_tsc(void); static __always_inline unsigned long long __native_read_tsc(void) @@ -164,6 +183,11 @@ static inline int wrmsr_safe(unsigned msr, unsigned low, unsigned high) return native_write_msr_safe(msr, low, high); } +static inline int wrmsr_amd_safe(unsigned msr, unsigned low, unsigned high) +{ + return native_write_msr_amd_safe(msr, low, high); +} + /* rdmsr with exception handling */ #define rdmsr_safe(msr, p1, p2) \ ({ \ diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h index 4fb37c8..82143e5 100644 --- a/arch/x86/include/asm/paravirt.h +++ b/arch/x86/include/asm/paravirt.h @@ -169,6 +169,7 @@ struct pv_cpu_ops { u64 (*read_msr_amd)(unsigned int msr, int *err); u64 (*read_msr)(unsigned int msr, int *err); int (*write_msr)(unsigned int msr, unsigned low, unsigned high); + u64 (*write_msr_amd)(unsigned int msr, unsigned low, unsigned high); u64 (*read_tsc)(void); u64 (*read_pmc)(int counter); @@ -829,6 +830,11 @@ static inline int paravirt_write_msr(unsigned msr, unsigned low, unsigned high) return PVOP_CALL3(int, pv_cpu_ops.write_msr, msr, low, high); } +static inline int paravirt_write_msr_amd(unsigned msr, unsigned low, unsigned high) +{ + return PVOP_CALL3(u64, pv_cpu_ops.write_msr_amd, msr, low, high); +} + /* These should all do BUG_ON(_err), but our headers are too tangled. */ #define rdmsr(msr, val1, val2) \ do { \ @@ -849,8 +855,9 @@ do { \ val = paravirt_read_msr(msr, &_err); \ } while (0) -#define wrmsrl(msr, val) wrmsr(msr, (u32)((u64)(val)), ((u64)(val))>>32) -#define wrmsr_safe(msr, a, b) paravirt_write_msr(msr, a, b) +#define wrmsrl(msr, val) wrmsr(msr, (u32)((u64)(val)), ((u64)(val))>>32) +#define wrmsr_safe(msr, a, b) paravirt_write_msr(msr, a, b) +#define wrmsr_amd_safe(msr, a, b) paravirt_write_msr_amd(msr, a, b) /* rdmsr with exception handling */ #define rdmsr_safe(msr, a, b) \ diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c index 70ec9b9..9996e51 100644 --- a/arch/x86/kernel/paravirt.c +++ b/arch/x86/kernel/paravirt.c @@ -364,6 +364,7 @@ struct pv_cpu_ops pv_cpu_ops = { .read_msr = native_read_msr_safe, .read_msr_amd = native_read_msr_amd_safe, .write_msr = native_write_msr_safe, + .write_msr_amd = native_write_msr_amd_safe, .read_tsc = native_read_tsc, .read_pmc = native_read_pmc, .read_tscp = native_read_tscp, -- 1.6.3.3 -- Regards/Gruss, Boris. -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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