On 2015/08/02 19:02, Thomas Gleixner wrote:
> On Wed, 29 Jul 2015, Takao Indoh wrote:
>> +/*
>> + * Table of Physical Addresses bits
>> + */
>> +enum topa_sz {
>> + TOPA_4K = 0,
>> + TOPA_8K,
>> + TOPA_16K,
>> + TOPA_32K,
>> + TOPA_64K,
>> + TOPA_128K,
>> + TOPA_256K,
>> + TOPA_512K,
>> + TOPA_1MB,
>> + TOPA_2MB,
>> + TOPA_4MB,
>> + TOPA_8MB,
>> + TOPA_16MB,
>> + TOPA_32MB,
>> + TOPA_64MB,
>> + TOPA_128MB,
>> + TOPA_SZ_END,
>> +};
>
> While moving this around, can we pretty please clean that up? That
> enum just pointless. None of the values is ever used and they hardly
> have any value as they are just computable.
Ok, I'll update my patches based on Alex's comments, but before that
I'll clean up intel_pt.h and perf_event_intel_pt.c.
Thanks,
Takao Indoh
>
>> +static inline unsigned int sizes(enum topa_sz tsz)
>> +{
>> + return 1 << (tsz + 12);
>
> 12?? PAGE_SHIFT perhaps?
>
>> +#define TOPA_SHIFT 12
>
> Sigh.
>
>> diff --git a/arch/x86/kernel/cpu/intel_pt_cap.c
>> b/arch/x86/kernel/cpu/intel_pt_cap.c
>> new file mode 100644
>> index 0000000..a2cfbfc
>> --- /dev/null
>> +++ b/arch/x86/kernel/cpu/intel_pt_cap.c
>> @@ -0,0 +1,69 @@
>> +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
>> +
>> +#include <linux/mm.h>
>> +#include <asm/intel_pt.h>
>> +
>> +enum cpuid_regs {
>> + CR_EAX = 0,
>> + CR_ECX,
>> + CR_EDX,
>> + CR_EBX
>> +};
>> +
>> +static u32 cpuid_cache[4 * PT_CPUID_LEAVES];
>
> 4 ? Magic constant pulled from thin air?
>
>> +static int pt_cap_initialized;
>> +
>> +#define PT_CAP(_n, _l, _r, _m)
>> \
>> + [PT_CAP_ ## _n] = { .name = __stringify(_n), .leaf = _l, \
>> + .reg = _r, .mask = _m }
>> +
>> +static struct pt_cap_desc {
>> + const char *name;
>> + u32 leaf;
>> + u8 reg;
>> + u32 mask;
>> +} pt_caps[] = {
>> + PT_CAP(max_subleaf, 0, CR_EAX, 0xffffffff),
>> + PT_CAP(cr3_filtering, 0, CR_EBX, BIT(0)),
>> + PT_CAP(topa_output, 0, CR_ECX, BIT(0)),
>> + PT_CAP(topa_multiple_entries, 0, CR_ECX, BIT(1)),
>> + PT_CAP(payloads_lip, 0, CR_ECX, BIT(31)),
>> +};
>> +
>> +u32 pt_cap_get(enum pt_capabilities cap)
>> +{
>> + struct pt_cap_desc *cd = &pt_caps[cap];
>> + u32 c = cpuid_cache[cd->leaf * 4 + cd->reg];
>
> Ditto
>
>> + unsigned int shift = __ffs(cd->mask);
>> +
>> + return (c & cd->mask) >> shift;
>> +}
>> +
>> +const char *pt_cap_name(enum pt_capabilities cap)
>> +{
>> + return pt_caps[cap].name;
>> +}
>> +
>> +int pt_cap_num(void)
>> +{
>> + return ARRAY_SIZE(pt_caps);
>> +}
>> +
>> +void __init pt_cap_init(void)
>> +{
>> + int i;
>> +
>> + if (pt_cap_initialized)
>> + return;
>> +
>> + for (i = 0; i < PT_CPUID_LEAVES; i++) {
>> + cpuid_count(20, i,
>> + &cpuid_cache[CR_EAX + i*4],
>
> Once more.
>
> Thanks,
>
> tglx
>
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