[tip: x86/cpu] x86/apic: Convert the TSC deadline timer matching to steppings macro

From: tip-bot2 for Borislav Petkov
Date: Thu May 07 2020 - 11:51:58 EST


The following commit has been merged into the x86/cpu branch of tip:

Commit-ID: 66abf2388331b800f290e854cca3ae71de7977fe
Gitweb: https://git.kernel.org/tip/66abf2388331b800f290e854cca3ae71de7977fe
Author: Borislav Petkov <bp@xxxxxxx>
AuthorDate: Tue, 05 May 2020 19:27:16 +02:00
Committer: Borislav Petkov <bp@xxxxxxx>
CommitterDate: Thu, 07 May 2020 13:50:32 +02:00

x86/apic: Convert the TSC deadline timer matching to steppings macro

... and get rid of the function pointers which would spit out the
microcode revision based on the CPU stepping.

Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Reviewed-by: Mark Gross <mgross.linux.intel.com>
Cc: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Link: https://lkml.kernel.org/r/20200506071516.25445-4-bp@xxxxxxxxx
---
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 e53dda2..4b1d31b 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;