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From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
To: benh@kernel.crashing.org, paulus@samba.org, mpe@ellerman.id.au
Cc: linuxppc-dev@lists.ozlabs.org,
	"Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Subject: [PATCH for-4.8 10/10] powerpc/mm: Catch the usage of cpu/mmu_has_feature before jump label init
Date: Wed, 13 Jul 2016 15:08:10 +0530	[thread overview]
Message-ID: <1468402690-5373-11-git-send-email-aneesh.kumar@linux.vnet.ibm.com> (raw)
In-Reply-To: <1468402690-5373-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com>

This enable us to catch the wrong usage of cpu_has_feature and
mmu_has_feature in the code. We need to use the feature bit based
check in show_regs because that is used in the reporting code.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
---
 arch/powerpc/Kconfig.debug             | 11 +++++++++++
 arch/powerpc/include/asm/cpufeatures.h |  6 ++++++
 arch/powerpc/include/asm/mmu.h         | 13 +++++++++++++
 arch/powerpc/kernel/process.c          |  2 +-
 4 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/Kconfig.debug b/arch/powerpc/Kconfig.debug
index 3bc551b66999..89117cb7bd28 100644
--- a/arch/powerpc/Kconfig.debug
+++ b/arch/powerpc/Kconfig.debug
@@ -60,6 +60,17 @@ config CODE_PATCHING_SELFTEST
 	depends on DEBUG_KERNEL
 	default n
 
+config FEATURE_FIXUP_DEBUG
+	bool "Do extra check on feature fixup calls"
+	depends on DEBUG_KERNEL
+	default n
+	help
+	  This catch the wrong usage of cpu_has_feature and mmu_has_feature
+	  in the code.
+
+	  If you don't know what this means, say N
+
+
 config FTR_FIXUP_SELFTEST
 	bool "Run self-tests of the feature-fixup code"
 	depends on DEBUG_KERNEL
diff --git a/arch/powerpc/include/asm/cpufeatures.h b/arch/powerpc/include/asm/cpufeatures.h
index 4a4a0b898463..93e7e3e87af4 100644
--- a/arch/powerpc/include/asm/cpufeatures.h
+++ b/arch/powerpc/include/asm/cpufeatures.h
@@ -22,6 +22,12 @@ static __always_inline bool cpu_has_feature(unsigned long feature)
 {
 	int i;
 
+#ifdef CONFIG_FEATURE_FIXUP_DEBUG
+	if (!static_key_initialized) {
+		WARN_ON(1);
+		return __cpu_has_feature(feature);
+	}
+#endif
 	if (CPU_FTRS_ALWAYS & feature)
 		return true;
 
diff --git a/arch/powerpc/include/asm/mmu.h b/arch/powerpc/include/asm/mmu.h
index 3726161f6a8d..5c1f3a4cb99f 100644
--- a/arch/powerpc/include/asm/mmu.h
+++ b/arch/powerpc/include/asm/mmu.h
@@ -152,6 +152,12 @@ static __always_inline bool mmu_has_feature(unsigned long feature)
 {
 	int i;
 
+#ifdef CONFIG_FEATURE_FIXUP_DEBUG
+	if (!static_key_initialized) {
+		WARN_ON(1);
+		return __mmu_has_feature(feature);
+	}
+#endif
 	if (!(MMU_FTRS_POSSIBLE & feature))
 		return false;
 
@@ -163,6 +169,13 @@ static inline void mmu_clear_feature(unsigned long feature)
 {
 	int i;
 
+#ifdef CONFIG_FEATURE_FIXUP_DEBUG
+	if (!static_key_initialized) {
+		WARN_ON(1);
+		cur_cpu_spec->mmu_features &= ~feature;
+		return;
+	}
+#endif
 	i = __builtin_ctzl(feature);
 	cur_cpu_spec->mmu_features &= ~feature;
 	static_branch_disable(&mmu_feat_keys[i]);
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 2a61cf1bcf37..a7dbd54a94da 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1315,7 +1315,7 @@ void show_regs(struct pt_regs * regs)
 	print_msr_bits(regs->msr);
 	printk("  CR: %08lx  XER: %08lx\n", regs->ccr, regs->xer);
 	trap = TRAP(regs);
-	if ((regs->trap != 0xc00) && cpu_has_feature(CPU_FTR_CFAR))
+	if ((regs->trap != 0xc00) && __cpu_has_feature(CPU_FTR_CFAR))
 		printk("CFAR: "REG" ", regs->orig_gpr3);
 	if (trap == 0x200 || trap == 0x300 || trap == 0x600)
 #if defined(CONFIG_4xx) || defined(CONFIG_BOOKE)
-- 
2.7.4

      parent reply	other threads:[~2016-07-13  9:39 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-07-13  9:38 [PATCH for-4.8_set3 00/10] Use jump label for cpu/mmu_has_feature Aneesh Kumar K.V
2016-07-13  9:38 ` [PATCH for-4.8 01/10] powerpc/mm: Add __cpu/__mmu_has_feature Aneesh Kumar K.V
2016-07-13  9:38 ` [PATCH for-4.8 02/10] powerpc/mm: Convert early cpu/mmu feature check to use the new helpers Aneesh Kumar K.V
2016-07-13 12:09   ` Benjamin Herrenschmidt
2016-07-13 13:58     ` Aneesh Kumar K.V
2016-07-13 14:06     ` Aneesh Kumar K.V
2016-07-13 14:45       ` Benjamin Herrenschmidt
2016-07-13  9:38 ` [PATCH for-4.8 03/10] powerpc/mm/radix: Add radix_set_pte to use in early init Aneesh Kumar K.V
2016-07-13  9:38 ` [PATCH for-4.8 04/10] jump_label: make it possible for the archs to invoke jump_label_init() much earlier Aneesh Kumar K.V
2016-07-13  9:38 ` [PATCH for-4.8 05/10] powerpc: Call jump_label_init early Aneesh Kumar K.V
2016-07-13  9:38 ` [PATCH for-4.8 06/10] powerpc: kill mfvtb() Aneesh Kumar K.V
2016-07-13  9:38 ` [PATCH for-4.8 07/10] powerpc: move the cpu_has_feature to a separate file Aneesh Kumar K.V
2016-07-13  9:38 ` [PATCH for-4.8 08/10] powerpc: use the jump label for cpu_has_feature Aneesh Kumar K.V
2016-07-13  9:38 ` [PATCH for-4.8 09/10] powerpc: use jump label for mmu_has_feature Aneesh Kumar K.V
2016-07-13  9:38 ` Aneesh Kumar K.V [this message]

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