[PATCH 2/3] x86: add wrapper functions for mtrr functions handling also pat

[Juergen Gross]

There are several MTRR functions which also do PAT handling. In order
to support PAT handling without MTRR in the future, add some wrappers
for those functions.

Cc: <stable@xxxxxxxxxxxxxxx> # 5.17
Fixes: bdd8b6c98239 ("drm/i915: replace X86_FEATURE_PAT with pat_enabled()")
Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
---
 arch/x86/include/asm/mtrr.h      |  2 --
 arch/x86/include/asm/processor.h |  7 +++++
 arch/x86/kernel/cpu/common.c     | 44 +++++++++++++++++++++++++++++++-
 arch/x86/kernel/cpu/mtrr/mtrr.c  | 25 +++---------------
 arch/x86/kernel/setup.c          |  5 +---
 arch/x86/kernel/smpboot.c        |  8 +++---
 arch/x86/power/cpu.c             |  2 +-
 7 files changed, 59 insertions(+), 34 deletions(-)

diff --git a/arch/x86/include/asm/mtrr.h b/arch/x86/include/asm/mtrr.h
index 12a16caed395..900083ac9f60 100644
--- a/arch/x86/include/asm/mtrr.h
+++ b/arch/x86/include/asm/mtrr.h
@@ -43,7 +43,6 @@ extern int mtrr_del(int reg, unsigned long base, unsigned long size);
 extern int mtrr_del_page(int reg, unsigned long base, unsigned long size);
 extern void mtrr_centaur_report_mcr(int mcr, u32 lo, u32 hi);
 extern void mtrr_ap_init(void);
-extern void set_mtrr_aps_delayed_init(void);
 extern void mtrr_aps_init(void);
 extern void mtrr_bp_restore(void);
 extern int mtrr_trim_uncached_memory(unsigned long end_pfn);
@@ -86,7 +85,6 @@ static inline void mtrr_centaur_report_mcr(int mcr, u32 lo, u32 hi)
 {
 }
 #define mtrr_ap_init() do {} while (0)
-#define set_mtrr_aps_delayed_init() do {} while (0)
 #define mtrr_aps_init() do {} while (0)
 #define mtrr_bp_restore() do {} while (0)
 #define mtrr_disable() do {} while (0)
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index 5c934b922450..e2140204fb7e 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -865,7 +865,14 @@ bool arch_is_platform_page(u64 paddr);
 #define arch_is_platform_page arch_is_platform_page
 #endif
 
+extern bool cache_aps_delayed_init;
+
 void cache_disable(void);
 void cache_enable(void);
+void cache_bp_init(void);
+void cache_ap_init(void);
+void cache_set_aps_delayed_init(void);
+void cache_aps_init(void);
+void cache_bp_restore(void);
 
 #endif /* _ASM_X86_PROCESSOR_H */
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index e43322f8a4ef..0a1bd14f7966 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -1929,7 +1929,7 @@ void identify_secondary_cpu(struct cpuinfo_x86 *c)
 #ifdef CONFIG_X86_32
 	enable_sep_cpu();
 #endif
-	mtrr_ap_init();
+	cache_ap_init();
 	validate_apic_and_package_id(c);
 	x86_spec_ctrl_setup_ap();
 	update_srbds_msr();
@@ -2403,3 +2403,45 @@ void cache_enable(void) __releases(cache_disable_lock)
 
 	raw_spin_unlock(&cache_disable_lock);
 }
+
+void __init cache_bp_init(void)
+{
+	if (IS_ENABLED(CONFIG_MTRR))
+		mtrr_bp_init();
+	else
+		pat_disable("PAT support disabled because CONFIG_MTRR is disabled in the kernel.");
+}
+
+void cache_ap_init(void)
+{
+	if (cache_aps_delayed_init)
+		return;
+
+	mtrr_ap_init();
+}
+
+bool cache_aps_delayed_init;
+
+void cache_set_aps_delayed_init(void)
+{
+	cache_aps_delayed_init = true;
+}
+
+void cache_aps_init(void)
+{
+	/*
+	 * Check if someone has requested the delay of AP cache initialization,
+	 * by doing cache_set_aps_delayed_init(), prior to this point. If not,
+	 * then we are done.
+	 */
+	if (!cache_aps_delayed_init)
+		return;
+
+	mtrr_aps_init();
+	cache_aps_delayed_init = false;
+}
+
+void cache_bp_restore(void)
+{
+	mtrr_bp_restore();
+}
diff --git a/arch/x86/kernel/cpu/mtrr/mtrr.c b/arch/x86/kernel/cpu/mtrr/mtrr.c
index 2746cac9d8a9..c1593cfae641 100644
--- a/arch/x86/kernel/cpu/mtrr/mtrr.c
+++ b/arch/x86/kernel/cpu/mtrr/mtrr.c
@@ -69,7 +69,6 @@ unsigned int mtrr_usage_table[MTRR_MAX_VAR_RANGES];
 static DEFINE_MUTEX(mtrr_mutex);
 
 u64 size_or_mask, size_and_mask;
-static bool mtrr_aps_delayed_init;
 
 static const struct mtrr_ops *mtrr_ops[X86_VENDOR_NUM] __ro_after_init;
 
@@ -176,7 +175,8 @@ static int mtrr_rendezvous_handler(void *info)
 	if (data->smp_reg != ~0U) {
 		mtrr_if->set(data->smp_reg, data->smp_base,
 			     data->smp_size, data->smp_type);
-	} else if (mtrr_aps_delayed_init || !cpu_online(smp_processor_id())) {
+	} else if ((use_intel() && cache_aps_delayed_init) ||
+		   !cpu_online(smp_processor_id())) {
 		mtrr_if->set_all();
 	}
 	return 0;
@@ -789,7 +789,7 @@ void mtrr_ap_init(void)
 	if (!mtrr_enabled())
 		return;
 
-	if (!use_intel() || mtrr_aps_delayed_init)
+	if (!use_intel())
 		return;
 
 	/*
@@ -823,16 +823,6 @@ void mtrr_save_state(void)
 	smp_call_function_single(first_cpu, mtrr_save_fixed_ranges, NULL, 1);
 }
 
-void set_mtrr_aps_delayed_init(void)
-{
-	if (!mtrr_enabled())
-		return;
-	if (!use_intel())
-		return;
-
-	mtrr_aps_delayed_init = true;
-}
-
 /*
  * Delayed MTRR initialization for all AP's
  */
@@ -841,16 +831,7 @@ void mtrr_aps_init(void)
 	if (!use_intel() || !mtrr_enabled())
 		return;
 
-	/*
-	 * Check if someone has requested the delay of AP MTRR initialization,
-	 * by doing set_mtrr_aps_delayed_init(), prior to this point. If not,
-	 * then we are done.
-	 */
-	if (!mtrr_aps_delayed_init)
-		return;
-
 	set_mtrr(~0U, 0, 0, 0);
-	mtrr_aps_delayed_init = false;
 }
 
 void mtrr_bp_restore(void)
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index bd6c6fd373ae..27d61f73c68a 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -1001,10 +1001,7 @@ void __init setup_arch(char **cmdline_p)
 	max_pfn = e820__end_of_ram_pfn();
 
 	/* update e820 for memory not covered by WB MTRRs */
-	if (IS_ENABLED(CONFIG_MTRR))
-		mtrr_bp_init();
-	else
-		pat_disable("PAT support disabled because CONFIG_MTRR is disabled in the kernel.");
+	cache_bp_init();
 
 	if (mtrr_trim_uncached_memory(max_pfn))
 		max_pfn = e820__end_of_ram_pfn();
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 5e7f9532a10d..535d73a47062 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -1432,7 +1432,7 @@ void __init native_smp_prepare_cpus(unsigned int max_cpus)
 
 	uv_system_init();
 
-	set_mtrr_aps_delayed_init();
+	cache_set_aps_delayed_init();
 
 	smp_quirk_init_udelay();
 
@@ -1443,12 +1443,12 @@ void __init native_smp_prepare_cpus(unsigned int max_cpus)
 
 void arch_thaw_secondary_cpus_begin(void)
 {
-	set_mtrr_aps_delayed_init();
+	cache_set_aps_delayed_init();
 }
 
 void arch_thaw_secondary_cpus_end(void)
 {
-	mtrr_aps_init();
+	cache_aps_init();
 }
 
 /*
@@ -1491,7 +1491,7 @@ void __init native_smp_cpus_done(unsigned int max_cpus)
 
 	nmi_selftest();
 	impress_friends();
-	mtrr_aps_init();
+	cache_aps_init();
 }
 
 static int __initdata setup_possible_cpus = -1;
diff --git a/arch/x86/power/cpu.c b/arch/x86/power/cpu.c
index bb176c72891c..21e014715322 100644
--- a/arch/x86/power/cpu.c
+++ b/arch/x86/power/cpu.c
@@ -261,7 +261,7 @@ static void notrace __restore_processor_state(struct saved_context *ctxt)
 	do_fpu_end();
 	tsc_verify_tsc_adjust(true);
 	x86_platform.restore_sched_clock_state();
-	mtrr_bp_restore();
+	cache_bp_restore();
 	perf_restore_debug_store();
 
 	c = &cpu_data(smp_processor_id());
-- 
2.35.3