linux-kernel - [tip:x86/timers] x86/apic: Add TSC

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Date:   Sun, 4 Jun 2017 13:01:57 -0700
From:   tip-bot for Peter Zijlstra <tipbot@...or.com>
To:     linux-tip-commits@...r.kernel.org
Cc:     linux-kernel@...r.kernel.org, tglx@...utronix.de, hpa@...or.com,
        mingo@...nel.org, peterz@...radead.org
Subject: [tip:x86/timers] x86/apic: Add TSC_DEADLINE quirk due to errata

Commit-ID:  bd9240a18edfbfa72e957fc2ba831cf1f13ea073
Gitweb:     http://git.kernel.org/tip/bd9240a18edfbfa72e957fc2ba831cf1f13ea073
Author:     Peter Zijlstra <peterz@...radead.org>
AuthorDate: Wed, 31 May 2017 17:52:03 +0200
Committer:  Thomas Gleixner <tglx@...utronix.de>
CommitDate: Sun, 4 Jun 2017 21:55:53 +0200

x86/apic: Add TSC_DEADLINE quirk due to errata

Due to errata it is possible for the TSC_DEADLINE timer to misbehave
after using TSC_ADJUST. A microcode update is available to fix this
situation.

Avoid using the TSC_DEADLINE timer if it is affected by this issue and
report the required microcode version.

[ tglx: Renamed function to apic_check_deadline_errata() ]

Signed-off-by: Peter Zijlstra (Intel) <peterz@...radead.org>
Cc: kevin.b.stanton@...el.com
Link: http://lkml.kernel.org/r/20170531155306.050849877@infradead.org
Signed-off-by: Thomas Gleixner <tglx@...utronix.de>

---
 arch/x86/kernel/apic/apic.c | 79 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 79 insertions(+)

diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index 87d721a1..3b215ff 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -54,6 +54,8 @@
 #include <asm/mce.h>
 #include <asm/tsc.h>
 #include <asm/hypervisor.h>
+#include <asm/cpu_device_id.h>
+#include <asm/intel-family.h>
 
 unsigned int num_processors;
 
@@ -545,6 +547,81 @@ static struct clock_event_device lapic_clockevent = {
 };
 static DEFINE_PER_CPU(struct clock_event_device, lapic_events);
 
+#define DEADLINE_MODEL_MATCH_FUNC(model, func)	\
+	{ X86_VENDOR_INTEL, 6, model, X86_FEATURE_ANY, (unsigned long)&func }
+
+#define DEADLINE_MODEL_MATCH_REV(model, rev)	\
+	{ X86_VENDOR_INTEL, 6, model, X86_FEATURE_ANY, (unsigned long)rev }
+
+static u32 hsx_deadline_rev(void)
+{
+	switch (boot_cpu_data.x86_mask) {
+	case 0x02: return 0x3a; /* EP */
+	case 0x04: return 0x0f; /* EX */
+	}
+
+	return ~0U;
+}
+
+static u32 bdx_deadline_rev(void)
+{
+	switch (boot_cpu_data.x86_mask) {
+	case 0x02: return 0x00000011;
+	case 0x03: return 0x0700000e;
+	case 0x04: return 0x0f00000c;
+	case 0x05: return 0x0e000003;
+	}
+
+	return ~0U;
+}
+
+static const struct x86_cpu_id deadline_match[] = {
+	DEADLINE_MODEL_MATCH_FUNC( INTEL_FAM6_HASWELL_X,	hsx_deadline_rev),
+	DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_BROADWELL_X,	0x0b000020),
+	DEADLINE_MODEL_MATCH_FUNC( INTEL_FAM6_BROADWELL_XEON_D,	bdx_deadline_rev),
+	DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_SKYLAKE_X,	0x02000014),
+
+	DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_HASWELL_CORE,	0x22),
+	DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_HASWELL_ULT,	0x20),
+	DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_HASWELL_GT3E,	0x17),
+
+	DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_BROADWELL_CORE,	0x25),
+	DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_BROADWELL_GT3E,	0x17),
+
+	DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_SKYLAKE_MOBILE,	0xb2),
+	DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_SKYLAKE_DESKTOP,	0xb2),
+
+	DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_KABYLAKE_MOBILE,	0x52),
+	DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_KABYLAKE_DESKTOP,	0x52),
+
+	{},
+};
+
+static void apic_check_deadline_errata(void)
+{
+	const struct x86_cpu_id *m = x86_match_cpu(deadline_match);
+	u32 rev;
+
+	if (!m)
+		return;
+
+	/*
+	 * 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;
+
+	if (boot_cpu_data.microcode >= rev)
+		return;
+
+	setup_clear_cpu_cap(X86_FEATURE_TSC_DEADLINE_TIMER);
+	pr_err(FW_BUG "TSC_DEADLINE disabled due to Errata; "
+	       "please update microcode to version: 0x%x (or later)\n", rev);
+}
+
 /*
  * Setup the local APIC timer for this CPU. Copy the initialized values
  * of the boot CPU and register the clock event in the framework.
@@ -1780,6 +1857,8 @@ void __init init_apic_mappings(void)
 {
 	unsigned int new_apicid;
 
+	apic_check_deadline_errata();
+
 	if (x2apic_mode) {
 		boot_cpu_physical_apicid = read_apic_id();
 		return;