Skip to content

Commit

Permalink
x86: msr-on-cpu: remove unnecessary level of abstraction
Browse files Browse the repository at this point in the history
Remove an unnecessary level of abstraction in the msr-on-cpu library.
Although this duplicates some code, the duplicated code is less than
the additional code, and this way should be faster.

Additionally, change the order of the functions to make the regular
structure of this file more obvious.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
  • Loading branch information
H. Peter Anvin committed Aug 26, 2008
1 parent 94d4ac2 commit bdd3146
Showing 1 changed file with 36 additions and 42 deletions.
78 changes: 36 additions & 42 deletions arch/x86/lib/msr-on-cpu.c
Original file line number Diff line number Diff line change
Expand Up @@ -16,37 +16,46 @@ static void __rdmsr_on_cpu(void *info)
rdmsr(rv->msr_no, rv->l, rv->h);
}

static void __rdmsr_safe_on_cpu(void *info)
static void __wrmsr_on_cpu(void *info)
{
struct msr_info *rv = info;

rv->err = rdmsr_safe(rv->msr_no, &rv->l, &rv->h);
wrmsr(rv->msr_no, rv->l, rv->h);
}

static int _rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h, int safe)
int rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h)
{
int err = 0;
int err;
struct msr_info rv;

rv.msr_no = msr_no;
if (safe) {
err = smp_call_function_single(cpu, __rdmsr_safe_on_cpu,
&rv, 1);
err = err ? err : rv.err;
} else {
err = smp_call_function_single(cpu, __rdmsr_on_cpu, &rv, 1);
}
err = smp_call_function_single(cpu, __rdmsr_on_cpu, &rv, 1);
*l = rv.l;
*h = rv.h;

return err;
}

static void __wrmsr_on_cpu(void *info)
int wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
{
int err;
struct msr_info rv;

rv.msr_no = msr_no;
rv.l = l;
rv.h = h;
err = smp_call_function_single(cpu, __wrmsr_on_cpu, &rv, 1);

return err;
}

/* These "safe" variants are slower and should be used when the target MSR
may not actually exist. */
static void __rdmsr_safe_on_cpu(void *info)
{
struct msr_info *rv = info;

wrmsr(rv->msr_no, rv->l, rv->h);
rv->err = rdmsr_safe(rv->msr_no, &rv->l, &rv->h);
}

static void __wrmsr_safe_on_cpu(void *info)
Expand All @@ -56,45 +65,30 @@ static void __wrmsr_safe_on_cpu(void *info)
rv->err = wrmsr_safe(rv->msr_no, rv->l, rv->h);
}

static int _wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h, int safe)
int rdmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h)
{
int err = 0;
int err;
struct msr_info rv;

rv.msr_no = msr_no;
rv.l = l;
rv.h = h;
if (safe) {
err = smp_call_function_single(cpu, __wrmsr_safe_on_cpu,
&rv, 1);
err = err ? err : rv.err;
} else {
err = smp_call_function_single(cpu, __wrmsr_on_cpu, &rv, 1);
}

return err;
}
err = smp_call_function_single(cpu, __rdmsr_safe_on_cpu, &rv, 1);
*l = rv.l;
*h = rv.h;

int wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
{
return _wrmsr_on_cpu(cpu, msr_no, l, h, 0);
return err ? err : rv.err;
}

int rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h)
{
return _rdmsr_on_cpu(cpu, msr_no, l, h, 0);
}

/* These "safe" variants are slower and should be used when the target MSR
may not actually exist. */
int wrmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
{
return _wrmsr_on_cpu(cpu, msr_no, l, h, 1);
}
int err;
struct msr_info rv;

int rdmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h)
{
return _rdmsr_on_cpu(cpu, msr_no, l, h, 1);
rv.msr_no = msr_no;
rv.l = l;
rv.h = h;
err = smp_call_function_single(cpu, __wrmsr_safe_on_cpu, &rv, 1);

return err ? err : rv.err;
}

EXPORT_SYMBOL(rdmsr_on_cpu);
Expand Down

0 comments on commit bdd3146

Please sign in to comment.