[PATCH 1/5] ARM: protect usage of cr_alignment by #ifdef CONFIG_CPU_CP15
From: Ryan Mallon <hidden>
Date: 2012-02-17 00:28:29
On 17/02/12 07:18, Uwe Kleine-K?nig wrote:
Signed-off-by: Uwe Kleine-K?nig <redacted> --- arch/arm/include/asm/system.h | 2 ++ arch/arm/kernel/entry-armv.S | 4 ++++ arch/arm/kernel/head-common.S | 10 ++++++++-- arch/arm/kernel/setup.c | 8 ++++++-- arch/arm/mm/alignment.c | 6 ++++++ arch/arm/mm/mmu.c | 8 +++++++- 6 files changed, 33 insertions(+), 5 deletions(-)
Hi Uwe, Couple of points below, Thanks, ~Ryan
quoted hunk ↗ jump to hunk
diff --git a/arch/arm/include/asm/system.h b/arch/arm/include/asm/system.h index e4c96cc..de46477 100644 --- a/arch/arm/include/asm/system.h +++ b/arch/arm/include/asm/system.h@@ -185,6 +185,7 @@ extern unsigned int user_debug; #define set_mb(var, value) do { var = value; smp_mb(); } while (0) #define nop() __asm__ __volatile__("mov\tr0,r0\t@ nop\n\t"); +#ifdef CONFIG_CPU_CP15 extern unsigned long cr_no_alignment; /* defined in entry-armv.S */ extern unsigned long cr_alignment; /* defined in entry-armv.S */@@ -224,6 +225,7 @@ static inline void set_copro_access(unsigned int val) : : "r" (val) : "cc"); isb(); } +#endif /* * switch_mm() may do a full cache flush over the context switch,diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S index be16a48..a6f2ef5 100644 --- a/arch/arm/kernel/entry-armv.S +++ b/arch/arm/kernel/entry-armv.S@@ -314,8 +314,10 @@ __pabt_svc: ENDPROC(__pabt_svc) .align 5 +#ifdef CONFIG_CPU_CP15 .LCcralign: .word cr_alignment +#endif #ifdef MULTI_DABORT .LCprocfns: .word processor@@ -1146,12 +1148,14 @@ __vectors_end: .data +#ifdef CONFIG_CPU_CP15 .globl cr_alignment .globl cr_no_alignment cr_alignment: .space 4 cr_no_alignment: .space 4 +#endif #ifdef CONFIG_MULTI_IRQ_HANDLER .globl handle_arch_irqdiff --git a/arch/arm/kernel/head-common.S b/arch/arm/kernel/head-common.S index 854bd22..5ca01bb 100644 --- a/arch/arm/kernel/head-common.S +++ b/arch/arm/kernel/head-common.S@@ -98,8 +98,10 @@ __mmap_switched: str r9, [r4] @ Save processor ID str r1, [r5] @ Save machine type str r2, [r6] @ Save atags pointer - bic r4, r0, #CR_A @ Clear 'A' bit - stmia r7, {r0, r4} @ Save control register values + cmp r7, #0 + itt ne + bicne r4, r0, #CR_A @ Clear 'A' bit + stmneia r7, {r0, r4} @ Save control register values
Can the cr_alignment variable ever have a value of zero if CONFIG_CPU_15
is enabled? If so you fail to do the stmnia which is possibly not
correct? Why do the registers not need to be stored if cr_alignment is
zero? I think this at least deserves a comment explaining.
Also, couldn't it just be done like this:
#ifndef CONFIG_CPU_CP15
bic r4, r0, #CR_A
stimia r7, {r0, r4}
#endif
Since r7 will always be zero in the !CP15 case?
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b start_kernel ENDPROC(__mmap_switched)@@ -113,7 +115,11 @@ __mmap_switched_data: .long processor_id @ r4 .long __machine_arch_type @ r5 .long __atags_pointer @ r6 +#ifdef CONFIG_CPU_CP15 .long cr_alignment @ r7 +#else + .long 0 +#endif .long init_thread_union + THREAD_START_SP @ sp .size __mmap_switched_data, . - __mmap_switched_datadiff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c index a255c39..50d3df8 100644 --- a/arch/arm/kernel/setup.c +++ b/arch/arm/kernel/setup.c@@ -472,9 +472,13 @@ static void __init setup_processor(void) cpu_cache = *list->cache; #endif - printk("CPU: %s [%08x] revision %d (ARMv%s), cr=%08lx\n", + printk("CPU: %s [%08x] revision %d (ARMv%s)", cpu_name, read_cpuid_id(), read_cpuid_id() & 15, - proc_arch[cpu_architecture()], cr_alignment); + proc_arch[cpu_architecture()]); + +#ifdef CONFIG_CPU_CP15 + printk(KERN_CONT ", cr=%08lx\n", cr_alignment);
#else printk(KERN_CONT "\n"); ?
+#endif
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snprintf(init_utsname()->machine, __NEW_UTS_LEN + 1, "%s%c", list->arch_name, ENDIANNESS);diff --git a/arch/arm/mm/alignment.c b/arch/arm/mm/alignment.c index caf14dc..119d178 100644 --- a/arch/arm/mm/alignment.c +++ b/arch/arm/mm/alignment.c@@ -89,7 +89,11 @@ core_param(alignment, ai_usermode, int, 0600); /* Return true if and only if the ARMv6 unaligned access model is in use. */ static bool cpu_is_v6_unaligned(void) { +#ifdef CONFIG_CPU_CP15 return cpu_architecture() >= CPU_ARCH_ARMv6 && (cr_alignment & CR_U); +#else + return 0;
+#endif
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} static int safe_usermode(int new_usermode, bool warn)@@ -961,12 +965,14 @@ static int __init alignment_init(void) return -ENOMEM; #endif +#ifdef CONFIG_CPU_CP15 if (cpu_is_v6_unaligned()) { cr_alignment &= ~CR_A; cr_no_alignment &= ~CR_A; set_cr(cr_alignment); ai_usermode = safe_usermode(ai_usermode, false); } +#endif hook_fault_code(FAULT_CODE_ALIGNMENT, do_alignment, SIGBUS, BUS_ADRALN, "alignment exception");diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c index 94c5a0c..f6dbe1a 100644 --- a/arch/arm/mm/mmu.c +++ b/arch/arm/mm/mmu.c@@ -109,8 +109,10 @@ static int __init early_cachepolicy(char *p) if (memcmp(p, cache_policies[i].policy, len) == 0) { cachepolicy = i; +#ifdef CONFIG_CPU_CP15 cr_alignment &= ~cache_policies[i].cr_mask; cr_no_alignment &= ~cache_policies[i].cr_mask; +#endif break; } }@@ -128,7 +130,9 @@ static int __init early_cachepolicy(char *p) cachepolicy = CPOLICY_WRITEBACK; } flush_cache_all(); +#ifdef CONFIG_CPU_CP15 set_cr(cr_alignment); +#endif return 0; } early_param("cachepolicy", early_cachepolicy);@@ -163,6 +167,7 @@ static int __init early_ecc(char *p) early_param("ecc", early_ecc); #endif +#ifdef CONFIG_CPU_CP15 static int __init noalign_setup(char *__unused) { cr_alignment &= ~CR_A;@@ -171,8 +176,9 @@ static int __init noalign_setup(char *__unused) return 1; } __setup("noalign", noalign_setup); +#endif -#ifndef CONFIG_SMP +#if !defined(CONFIG_SMP) && defined(CONFIG_CPU_CP15) void adjust_cr(unsigned long mask, unsigned long set) { unsigned long flags;