Reviewed-by: Mark Gross <mgross.linux.intel.com>
On Wed, May 06, 2020 at 09:15:16AM +0200, Borislav Petkov wrote:
> From: Borislav Petkov <b...@suse.de>
>
> ... and get rid of the function pointers which would spit out the
> microcode revision based on the CPU stepping.
>
> Signed-off-by: Borislav Petkov <b...@suse.de>
> Cc: Peter Zijlstra (Intel) <pet...@infradead.org>
> ---
> arch/x86/kernel/apic/apic.c | 57 ++++++++-----------------------------
> 1 file changed, 12 insertions(+), 45 deletions(-)
>
> diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
> index e53dda210cd7..4b1d31be50b4 100644
> --- a/arch/x86/kernel/apic/apic.c
> +++ b/arch/x86/kernel/apic/apic.c
> @@ -544,46 +544,20 @@ static struct clock_event_device lapic_clockevent = {
> };
> static DEFINE_PER_CPU(struct clock_event_device, lapic_events);
>
> -static __init u32 hsx_deadline_rev(void)
> -{
> - switch (boot_cpu_data.x86_stepping) {
> - case 0x02: return 0x3a; /* EP */
> - case 0x04: return 0x0f; /* EX */
> - }
> -
> - return ~0U;
> -}
> -
> -static __init u32 bdx_deadline_rev(void)
> -{
> - switch (boot_cpu_data.x86_stepping) {
> - case 0x02: return 0x00000011;
> - case 0x03: return 0x0700000e;
> - case 0x04: return 0x0f00000c;
> - case 0x05: return 0x0e000003;
> - }
> -
> - return ~0U;
> -}
> -
> -static __init u32 skx_deadline_rev(void)
> -{
> - switch (boot_cpu_data.x86_stepping) {
> - case 0x03: return 0x01000136;
> - case 0x04: return 0x02000014;
> - }
> +static const struct x86_cpu_id deadline_match[] __initconst = {
> + X86_MATCH_INTEL_FAM6_MODEL_STEPPINGS(HASWELL_X, X86_STEPPINGS(0x2,
> 0x2), 0x3a), /* EP */
> + X86_MATCH_INTEL_FAM6_MODEL_STEPPINGS(HASWELL_X, X86_STEPPINGS(0x4,
> 0x4), 0x0f), /* EX */
>
> - if (boot_cpu_data.x86_stepping > 4)
> - return 0;
> + X86_MATCH_INTEL_FAM6_MODEL( BROADWELL_X, 0x0b000020),
>
> - return ~0U;
> -}
> + X86_MATCH_INTEL_FAM6_MODEL_STEPPINGS(BROADWELL_D, X86_STEPPINGS(0x2,
> 0x2), 0x00000011),
> + X86_MATCH_INTEL_FAM6_MODEL_STEPPINGS(BROADWELL_D, X86_STEPPINGS(0x3,
> 0x3), 0x0700000e),
> + X86_MATCH_INTEL_FAM6_MODEL_STEPPINGS(BROADWELL_D, X86_STEPPINGS(0x4,
> 0x4), 0x0f00000c),
> + X86_MATCH_INTEL_FAM6_MODEL_STEPPINGS(BROADWELL_D, X86_STEPPINGS(0x5,
> 0x5), 0x0e000003),
>
> -static const struct x86_cpu_id deadline_match[] __initconst = {
> - X86_MATCH_INTEL_FAM6_MODEL( HASWELL_X, &hsx_deadline_rev),
> - X86_MATCH_INTEL_FAM6_MODEL( BROADWELL_X, 0x0b000020),
> - X86_MATCH_INTEL_FAM6_MODEL( BROADWELL_D, &bdx_deadline_rev),
> - X86_MATCH_INTEL_FAM6_MODEL( SKYLAKE_X, &skx_deadline_rev),
> + X86_MATCH_INTEL_FAM6_MODEL_STEPPINGS(SKYLAKE_X, X86_STEPPINGS(0x3,
> 0x3), 0x01000136),
> + X86_MATCH_INTEL_FAM6_MODEL_STEPPINGS(SKYLAKE_X, X86_STEPPINGS(0x4,
> 0x4), 0x02000014),
> + X86_MATCH_INTEL_FAM6_MODEL_STEPPINGS(SKYLAKE_X, X86_STEPPINGS(0x5,
> 0xf), 0),
>
> X86_MATCH_INTEL_FAM6_MODEL( HASWELL, 0x22),
> X86_MATCH_INTEL_FAM6_MODEL( HASWELL_L, 0x20),
> @@ -615,14 +589,7 @@ static __init bool apic_validate_deadline_timer(void)
> if (!m)
> return true;
>
> - /*
> - * Function pointers will have the MSB set due to address layout,
> - * immediate revisions will not.
> - */
> - if ((long)m->driver_data < 0)
> - rev = ((u32 (*)(void))(m->driver_data))();
> - else
> - rev = (u32)m->driver_data;
> + rev = (u32)m->driver_data;
>
> if (boot_cpu_data.microcode >= rev)
> return true;
> --
> 2.21.0
>
