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x86, pvops: Remove hooks for {rd,wr}msr_safe_regs
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There were paravirt_ops hooks for the full register set variant of
{rd,wr}msr_safe which are actually not used by anyone anymore. Remove
them to make the code cleaner and avoid silent breakages when the pvops
members were uninitialized. This has been boot-tested natively and under
Xen with PVOPS enabled and disabled on one machine.

Signed-off-by: Andre Przywara <andre.przywara@amd.com>
Link: http://lkml.kernel.org/r/1338562358-28182-2-git-send-email-bp@amd64.org
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
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Andre Przywara authored and H. Peter Anvin committed Jun 7, 2012
1 parent f8f5701 commit 1f975f7
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Showing 7 changed files with 35 additions and 91 deletions.
67 changes: 28 additions & 39 deletions arch/x86/include/asm/msr.h
Original file line number Diff line number Diff line change
Expand Up @@ -115,8 +115,8 @@ notrace static inline int native_write_msr_safe(unsigned int msr,

extern unsigned long long native_read_tsc(void);

extern int native_rdmsr_safe_regs(u32 regs[8]);
extern int native_wrmsr_safe_regs(u32 regs[8]);
extern int rdmsr_safe_regs(u32 regs[8]);
extern int wrmsr_safe_regs(u32 regs[8]);

static __always_inline unsigned long long __native_read_tsc(void)
{
Expand Down Expand Up @@ -187,43 +187,6 @@ static inline int rdmsrl_safe(unsigned msr, unsigned long long *p)
return err;
}

static inline int rdmsrl_amd_safe(unsigned msr, unsigned long long *p)
{
u32 gprs[8] = { 0 };
int err;

gprs[1] = msr;
gprs[7] = 0x9c5a203a;

err = native_rdmsr_safe_regs(gprs);

*p = gprs[0] | ((u64)gprs[2] << 32);

return err;
}

static inline int wrmsrl_amd_safe(unsigned msr, unsigned long long val)
{
u32 gprs[8] = { 0 };

gprs[0] = (u32)val;
gprs[1] = msr;
gprs[2] = val >> 32;
gprs[7] = 0x9c5a203a;

return native_wrmsr_safe_regs(gprs);
}

static inline int rdmsr_safe_regs(u32 regs[8])
{
return native_rdmsr_safe_regs(regs);
}

static inline int wrmsr_safe_regs(u32 regs[8])
{
return native_wrmsr_safe_regs(regs);
}

#define rdtscl(low) \
((low) = (u32)__native_read_tsc())

Expand All @@ -248,6 +211,32 @@ do { \

#endif /* !CONFIG_PARAVIRT */

static inline int rdmsrl_amd_safe(unsigned msr, unsigned long long *p)
{
u32 gprs[8] = { 0 };
int err;

gprs[1] = msr;
gprs[7] = 0x9c5a203a;

err = rdmsr_safe_regs(gprs);

*p = gprs[0] | ((u64)gprs[2] << 32);

return err;
}

static inline int wrmsrl_amd_safe(unsigned msr, unsigned long long val)
{
u32 gprs[8] = { 0 };

gprs[0] = (u32)val;
gprs[1] = msr;
gprs[2] = val >> 32;
gprs[7] = 0x9c5a203a;

return wrmsr_safe_regs(gprs);
}

#define checking_wrmsrl(msr, val) wrmsr_safe((msr), (u32)(val), \
(u32)((val) >> 32))
Expand Down
39 changes: 0 additions & 39 deletions arch/x86/include/asm/paravirt.h
Original file line number Diff line number Diff line change
Expand Up @@ -128,21 +128,11 @@ static inline u64 paravirt_read_msr(unsigned msr, int *err)
return PVOP_CALL2(u64, pv_cpu_ops.read_msr, msr, err);
}

static inline int paravirt_rdmsr_regs(u32 *regs)
{
return PVOP_CALL1(int, pv_cpu_ops.rdmsr_regs, regs);
}

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_wrmsr_regs(u32 *regs)
{
return PVOP_CALL1(int, pv_cpu_ops.wrmsr_regs, regs);
}

/* These should all do BUG_ON(_err), but our headers are too tangled. */
#define rdmsr(msr, val1, val2) \
do { \
Expand Down Expand Up @@ -176,42 +166,13 @@ do { \
_err; \
})

#define rdmsr_safe_regs(regs) paravirt_rdmsr_regs(regs)
#define wrmsr_safe_regs(regs) paravirt_wrmsr_regs(regs)

static inline int rdmsrl_safe(unsigned msr, unsigned long long *p)
{
int err;

*p = paravirt_read_msr(msr, &err);
return err;
}
static inline int rdmsrl_amd_safe(unsigned msr, unsigned long long *p)
{
u32 gprs[8] = { 0 };
int err;

gprs[1] = msr;
gprs[7] = 0x9c5a203a;

err = paravirt_rdmsr_regs(gprs);

*p = gprs[0] | ((u64)gprs[2] << 32);

return err;
}

static inline int wrmsrl_amd_safe(unsigned msr, unsigned long long val)
{
u32 gprs[8] = { 0 };

gprs[0] = (u32)val;
gprs[1] = msr;
gprs[2] = val >> 32;
gprs[7] = 0x9c5a203a;

return paravirt_wrmsr_regs(gprs);
}

static inline u64 paravirt_read_tsc(void)
{
Expand Down
2 changes: 0 additions & 2 deletions arch/x86/include/asm/paravirt_types.h
Original file line number Diff line number Diff line change
Expand Up @@ -153,9 +153,7 @@ struct pv_cpu_ops {
/* MSR, PMC and TSR operations.
err = 0/-EFAULT. wrmsr returns 0/-EFAULT. */
u64 (*read_msr)(unsigned int msr, int *err);
int (*rdmsr_regs)(u32 *regs);
int (*write_msr)(unsigned int msr, unsigned low, unsigned high);
int (*wrmsr_regs)(u32 *regs);

u64 (*read_tsc)(void);
u64 (*read_pmc)(int counter);
Expand Down
2 changes: 0 additions & 2 deletions arch/x86/kernel/paravirt.c
Original file line number Diff line number Diff line change
Expand Up @@ -352,9 +352,7 @@ struct pv_cpu_ops pv_cpu_ops = {
#endif
.wbinvd = native_wbinvd,
.read_msr = native_read_msr_safe,
.rdmsr_regs = native_rdmsr_safe_regs,
.write_msr = native_write_msr_safe,
.wrmsr_regs = native_wrmsr_safe_regs,
.read_tsc = native_read_tsc,
.read_pmc = native_read_pmc,
.read_tscp = native_read_tscp,
Expand Down
4 changes: 2 additions & 2 deletions arch/x86/lib/msr-reg-export.c
Original file line number Diff line number Diff line change
@@ -1,5 +1,5 @@
#include <linux/module.h>
#include <asm/msr.h>

EXPORT_SYMBOL(native_rdmsr_safe_regs);
EXPORT_SYMBOL(native_wrmsr_safe_regs);
EXPORT_SYMBOL(rdmsr_safe_regs);
EXPORT_SYMBOL(wrmsr_safe_regs);
10 changes: 5 additions & 5 deletions arch/x86/lib/msr-reg.S
Original file line number Diff line number Diff line change
Expand Up @@ -6,13 +6,13 @@

#ifdef CONFIG_X86_64
/*
* int native_{rdmsr,wrmsr}_safe_regs(u32 gprs[8]);
* int {rdmsr,wrmsr}_safe_regs(u32 gprs[8]);
*
* reg layout: u32 gprs[eax, ecx, edx, ebx, esp, ebp, esi, edi]
*
*/
.macro op_safe_regs op
ENTRY(native_\op\()_safe_regs)
ENTRY(\op\()_safe_regs)
CFI_STARTPROC
pushq_cfi %rbx
pushq_cfi %rbp
Expand Down Expand Up @@ -45,13 +45,13 @@ ENTRY(native_\op\()_safe_regs)

_ASM_EXTABLE(1b, 3b)
CFI_ENDPROC
ENDPROC(native_\op\()_safe_regs)
ENDPROC(\op\()_safe_regs)
.endm

#else /* X86_32 */

.macro op_safe_regs op
ENTRY(native_\op\()_safe_regs)
ENTRY(\op\()_safe_regs)
CFI_STARTPROC
pushl_cfi %ebx
pushl_cfi %ebp
Expand Down Expand Up @@ -92,7 +92,7 @@ ENTRY(native_\op\()_safe_regs)

_ASM_EXTABLE(1b, 3b)
CFI_ENDPROC
ENDPROC(native_\op\()_safe_regs)
ENDPROC(\op\()_safe_regs)
.endm

#endif
Expand Down
2 changes: 0 additions & 2 deletions arch/x86/xen/enlighten.c
Original file line number Diff line number Diff line change
Expand Up @@ -1116,9 +1116,7 @@ static const struct pv_cpu_ops xen_cpu_ops __initconst = {
.wbinvd = native_wbinvd,

.read_msr = native_read_msr_safe,
.rdmsr_regs = native_rdmsr_safe_regs,
.write_msr = xen_write_msr_safe,
.wrmsr_regs = native_wrmsr_safe_regs,

.read_tsc = native_read_tsc,
.read_pmc = native_read_pmc,
Expand Down

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