1 files changed, 29 insertions, 8 deletions

diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
index 8a16ee5..c031063 100644
--- a/arch/arm/kernel/setup.c
+++ b/arch/arm/kernel/setup.c
@@ -133,6 +133,7 @@ struct stack {
 	u32 irq[3];
 	u32 abt[3];
 	u32 und[3];
+	u32 fiq[3];
 } ____cacheline_aligned;
 
 #ifndef CONFIG_CPU_V7M
@@ -393,19 +394,34 @@ static void __init cpuid_init_hwcaps(void)
 		elf_hwcap |= HWCAP_LPAE;
 }
 
-static void __init feat_v6_fixup(void)
+static void __init elf_hwcap_fixup(void)
 {
-	int id = read_cpuid_id();
-
-	if ((id & 0xff0f0000) != 0x41070000)
-		return;
+	unsigned id = read_cpuid_id();
+	unsigned sync_prim;
 
 	/*
 	 * HWCAP_TLS is available only on 1136 r1p0 and later,
 	 * see also kuser_get_tls_init.
 	 */
-	if ((((id >> 4) & 0xfff) == 0xb36) && (((id >> 20) & 3) == 0))
+	if (read_cpuid_part() == ARM_CPU_PART_ARM1136 &&
+	    ((id >> 20) & 3) == 0) {
 		elf_hwcap &= ~HWCAP_TLS;
+		return;
+	}
+
+	/* Verify if CPUID scheme is implemented */
+	if ((id & 0x000f0000) != 0x000f0000)
+		return;
+
+	/*
+	 * If the CPU supports LDREX/STREX and LDREXB/STREXB,
+	 * avoid advertising SWP; it may not be atomic with
+	 * multiprocessing cores.
+	 */
+	sync_prim = ((read_cpuid_ext(CPUID_EXT_ISAR3) >> 8) & 0xf0) |
+		    ((read_cpuid_ext(CPUID_EXT_ISAR4) >> 20) & 0x0f);
+	if (sync_prim >= 0x13)
+		elf_hwcap &= ~HWCAP_SWP;
 }
 
 /*
@@ -455,7 +471,10 @@ void notrace cpu_init(void)
 	"msr	cpsr_c, %5\n\t"
 	"add	r14, %0, %6\n\t"
 	"mov	sp, r14\n\t"
-	"msr	cpsr_c, %7"
+	"msr	cpsr_c, %7\n\t"
+	"add	r14, %0, %8\n\t"
+	"mov	sp, r14\n\t"
+	"msr	cpsr_c, %9"
 	    :
 	    : "r" (stk),
 	      PLC (PSR_F_BIT | PSR_I_BIT | IRQ_MODE),
@@ -464,6 +483,8 @@ void notrace cpu_init(void)
 	      "I" (offsetof(struct stack, abt[0])),
 	      PLC (PSR_F_BIT | PSR_I_BIT | UND_MODE),
 	      "I" (offsetof(struct stack, und[0])),
+	      PLC (PSR_F_BIT | PSR_I_BIT | FIQ_MODE),
+	      "I" (offsetof(struct stack, fiq[0])),
 	      PLC (PSR_F_BIT | PSR_I_BIT | SVC_MODE)
 	    : "r14");
 #endif
@@ -609,7 +630,7 @@ static void __init setup_processor(void)
 #endif
 	erratum_a15_798181_init();
 
-	feat_v6_fixup();
+	elf_hwcap_fixup();
 
 	cacheid_init();
 	cpu_init();