Revert "ARM: 7804/2: Add check for Cortex-A15 errata 798181 ECO"

This reverts commit 34905a33184af10e0704b3a575cd35872c411761.

Conflicts:
	arch/arm/kernel/smp_tlb.c

5 files changed, 31 insertions, 48 deletions

diff --git a/arch/arm/include/asm/cputype.h b/arch/arm/include/asm/cputype.h
index acdde76b39bb..9672e978d50d 100644
--- a/arch/arm/include/asm/cputype.h
+++ b/arch/arm/include/asm/cputype.h
@@ -10,7 +10,6 @@
 #define CPUID_TLBTYPE	3
 #define CPUID_MPUIR	4
 #define CPUID_MPIDR	5
-#define CPUID_REVIDR	6
 
 #ifdef CONFIG_CPU_V7M
 #define CPUID_EXT_PFR0	0x40
diff --git a/arch/arm/include/asm/tlbflush.h b/arch/arm/include/asm/tlbflush.h
index 87a9d9a5b6fb..34b848c5af63 100644
--- a/arch/arm/include/asm/tlbflush.h
+++ b/arch/arm/include/asm/tlbflush.h
@@ -560,16 +560,36 @@ static inline void __flush_bp_all(void)
 		asm("mcr p15, 0, %0, c7, c1, 6" : : "r" (zero));
 }
 
-extern void erratum_a15_798181_init(void);
-extern bool (*erratum_a15_798181_handler)(void);
+#include <asm/cputype.h>
+#ifdef CONFIG_ARM_ERRATA_798181
+static inline int erratum_a15_798181(void)
+{
+	unsigned int midr = read_cpuid_id();
+
+	/* Cortex-A15 r0p0..r3p2 affected */
+	if ((midr & 0xff0ffff0) != 0x410fc0f0 || midr > 0x413fc0f2)
+		return 0;
+	return 1;
+}
+
+static inline void dummy_flush_tlb_a15_erratum(void)
+{
+	/*
+	 * Dummy TLBIMVAIS. Using the unmapped address 0 and ASID 0.
+	 */
+	asm("mcr p15, 0, %0, c8, c3, 1" : : "r" (0));
+	dsb();
+}
+#else
+static inline int erratum_a15_798181(void)
+{
+	return 0;
+}
 
-static inline bool erratum_a15_798181(void)
+static inline void dummy_flush_tlb_a15_erratum(void)
 {
-	if (unlikely(IS_ENABLED(CONFIG_ARM_ERRATA_798181) &&
-		erratum_a15_798181_handler))
-		return erratum_a15_798181_handler();
-	return false;
 }
+#endif
 
 /*
  *	flush_pmd_entry
diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
index a4852dea088b..0e1e2b3afa45 100644
--- a/arch/arm/kernel/setup.c
+++ b/arch/arm/kernel/setup.c
@@ -599,8 +599,6 @@ static void __init setup_processor(void)
 	elf_hwcap &= ~(HWCAP_THUMB | HWCAP_IDIVT);
 #endif
 
-	erratum_a15_798181_init();
-
 	feat_v6_fixup();
 
 	cacheid_init();
diff --git a/arch/arm/kernel/smp_tlb.c b/arch/arm/kernel/smp_tlb.c
index 3bb055d6c13c..83ccca303df8 100644
--- a/arch/arm/kernel/smp_tlb.c
+++ b/arch/arm/kernel/smp_tlb.c
@@ -70,43 +70,6 @@ static inline void ipi_flush_bp_all(void *ignored)
 	local_flush_bp_all();
 }
 
-bool (*erratum_a15_798181_handler)(void);
-
-static bool erratum_a15_798181_partial(void)
-{
-	asm("mcr p15, 0, %0, c8, c3, 1" : : "r" (0));
-	dsb(ish);
-	return false;
-}
-
-static bool erratum_a15_798181_broadcast(void)
-{
-	asm("mcr p15, 0, %0, c8, c3, 1" : : "r" (0));
-	dsb(ish);
-	return true;
-}
-
-bool (*erratum_a15_798181_handler)(void);
-
-void erratum_a15_798181_init(void)
-{
-	unsigned int midr = read_cpuid_id();
-	unsigned int revidr = read_cpuid(CPUID_REVIDR);
-
-	if (!IS_ENABLED(CONFIG_ARM_ERRATA_798181))
-		return;
-
-	/* Cortex-A15 r0p0..r3p2 w/o ECO fix affected */
-	if ((midr & 0xff0ffff0) != 0x410fc0f0 || midr > 0x413fc0f2 ||
-	    (revidr & 0x210) == 0x210) {
-		return;
-	}
-	if (revidr & 0x10)
-		erratum_a15_798181_handler = erratum_a15_798181_partial;
-	else
-		erratum_a15_798181_handler = erratum_a15_798181_broadcast;
-}
-
 static void ipi_flush_tlb_a15_erratum(void *arg)
 {
 	dmb();
@@ -117,6 +80,7 @@ static void broadcast_tlb_a15_erratum(void)
 	if (!erratum_a15_798181())
 		return;
 
+	dummy_flush_tlb_a15_erratum();
 	smp_call_function(ipi_flush_tlb_a15_erratum, NULL, 1);
 }
 
@@ -128,6 +92,7 @@ static void broadcast_tlb_mm_a15_erratum(struct mm_struct *mm)
 	if (!erratum_a15_798181())
 		return;
 
+	dummy_flush_tlb_a15_erratum();
 	this_cpu = get_cpu();
 	a15_erratum_get_cpumask(this_cpu, mm, &mask);
 	smp_call_function_many(&mask, ipi_flush_tlb_a15_erratum, NULL, 1);
diff --git a/arch/arm/mm/context.c b/arch/arm/mm/context.c
index acb571ec2be8..fce737afe4aa 100644
--- a/arch/arm/mm/context.c
+++ b/arch/arm/mm/context.c
@@ -242,7 +242,8 @@ void check_and_switch_context(struct mm_struct *mm, struct task_struct *tsk)
 	if (cpumask_test_and_clear_cpu(cpu, &tlb_flush_pending)) {
 		local_flush_bp_all();
 		local_flush_tlb_all();
-		erratum_a15_798181();
+		if (erratum_a15_798181())
+			dummy_flush_tlb_a15_erratum();
 	}
 
 	atomic64_set(&per_cpu(active_asids, cpu), asid);