From b849a60e0903b1c5430c3859864554662e127a8d Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= Date: Mon, 16 Jan 2012 10:34:31 +0100 Subject: [PATCH 1/5] ARM: make cr_alignment read-only #ifndef CONFIG_CPU_CP15 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This makes cr_alignment a constant 0 to break code that tries to modify the value as it's likely that it's built on wrong assumption when CONFIG_CPU_CP15 isn't defined. For code that is only reading the value 0 is more or less a fine value to report. Signed-off-by: Uwe Kleine-König Message-Id: 1358413196-5609-2-git-send-email-u.kleine-koenig@pengutronix.de (v8) --- arch/arm/include/asm/cp15.h | 16 +++++++++++++++- arch/arm/kernel/head-common.S | 9 +++++++-- arch/arm/mm/alignment.c | 2 ++ arch/arm/mm/mmu.c | 17 +++++++++++++++++ 4 files changed, 41 insertions(+), 3 deletions(-) diff --git a/arch/arm/include/asm/cp15.h b/arch/arm/include/asm/cp15.h index 5ef4d8015a604..1f3262e99d81e 100644 --- a/arch/arm/include/asm/cp15.h +++ b/arch/arm/include/asm/cp15.h @@ -42,6 +42,8 @@ #define vectors_high() (0) #endif +#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 */ @@ -82,6 +84,18 @@ static inline void set_copro_access(unsigned int val) isb(); } -#endif +#else /* ifdef CONFIG_CPU_CP15 */ + +/* + * cr_alignment and cr_no_alignment are tightly coupled to cp15 (at least in the + * minds of the developers). Yielding 0 for machines without a cp15 (and making + * it read-only) is fine for most cases and saves quite some #ifdeffery. + */ +#define cr_no_alignment UL(0) +#define cr_alignment UL(0) + +#endif /* ifdef CONFIG_CPU_CP15 / else */ + +#endif /* ifndef __ASSEMBLY__ */ #endif diff --git a/arch/arm/kernel/head-common.S b/arch/arm/kernel/head-common.S index 854bd22380d33..5b391a689b47b 100644 --- a/arch/arm/kernel/head-common.S +++ b/arch/arm/kernel/head-common.S @@ -98,8 +98,9 @@ __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 + bicne r4, r0, #CR_A @ Clear 'A' bit + stmneia r7, {r0, r4} @ Save control register values b start_kernel ENDPROC(__mmap_switched) @@ -113,7 +114,11 @@ __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 @ r7 +#endif .long init_thread_union + THREAD_START_SP @ sp .size __mmap_switched_data, . - __mmap_switched_data diff --git a/arch/arm/mm/alignment.c b/arch/arm/mm/alignment.c index b820edaf31843..feeb3eaccb1c4 100644 --- a/arch/arm/mm/alignment.c +++ b/arch/arm/mm/alignment.c @@ -964,12 +964,14 @@ 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 ce328c7f5c945..7c347bcc94211 100644 --- a/arch/arm/mm/mmu.c +++ b/arch/arm/mm/mmu.c @@ -97,6 +97,7 @@ static struct cachepolicy cache_policies[] __initdata = { } }; +#ifdef CONFIG_CPU_CP15 /* * These are useful for identifying cache coherency * problems by allowing the cache or the cache and @@ -195,6 +196,22 @@ void adjust_cr(unsigned long mask, unsigned long set) } #endif +#else /* ifdef CONFIG_CPU_CP15 */ + +static int __init early_cachepolicy(char *p) +{ + pr_warning("cachepolicy kernel parameter not supported without cp15\n"); +} +early_param("cachepolicy", early_cachepolicy); + +static int __init noalign_setup(char *__unused) +{ + pr_warning("noalign kernel parameter not supported without cp15\n"); +} +__setup("noalign", noalign_setup); + +#endif /* ifdef CONFIG_CPU_CP15 / else */ + #define PROT_PTE_DEVICE L_PTE_PRESENT|L_PTE_YOUNG|L_PTE_DIRTY|L_PTE_XN #define PROT_SECT_DEVICE PMD_TYPE_SECT|PMD_SECT_AP_WRITE From bc7dea00a9a0ea385bbc4aed67dfdcf7d8879953 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= Date: Fri, 9 Dec 2011 20:52:10 +0100 Subject: [PATCH 2/5] ARM: let CPUs not being able to run in ARM mode enter in THUMB mode MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Some ARM cores are not capable to run in ARM mode (e.g. Cortex-M3). So obviously these cannot enter the kernel in ARM mode. Make an exception for them and let them enter in THUMB mode. Signed-off-by: Uwe Kleine-König Message-Id: 1358162123-30113-1-git-send-email-u.kleine-koenig@pengutronix.de Acked-by: Nicolas Pitre --- arch/arm/Kconfig | 3 ++- arch/arm/kernel/head-nommu.S | 8 +++++++- arch/arm/mm/Kconfig | 9 ++++++++- 3 files changed, 17 insertions(+), 3 deletions(-) diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 67874b82a4edf..e04c7793f47e2 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -1656,8 +1656,9 @@ config HZ default 100 config THUMB2_KERNEL - bool "Compile the kernel in Thumb-2 mode" + bool "Compile the kernel in Thumb-2 mode" if !CPU_THUMBONLY depends on CPU_V7 && !CPU_V6 && !CPU_V6K + default y if CPU_THUMBONLY select AEABI select ARM_ASM_UNIFIED select ARM_UNWIND diff --git a/arch/arm/kernel/head-nommu.S b/arch/arm/kernel/head-nommu.S index 2c228a07e58c7..6a2e09c952c71 100644 --- a/arch/arm/kernel/head-nommu.S +++ b/arch/arm/kernel/head-nommu.S @@ -32,15 +32,21 @@ * numbers for r1. * */ - .arm __HEAD + +#ifdef CONFIG_CPU_THUMBONLY + .thumb +ENTRY(stext) +#else + .arm ENTRY(stext) THUMB( adr r9, BSYM(1f) ) @ Kernel is always entered in ARM. THUMB( bx r9 ) @ If this is a Thumb-2 kernel, THUMB( .thumb ) @ switch to Thumb now. THUMB(1: ) +#endif setmode PSR_F_BIT | PSR_I_BIT | SVC_MODE, r9 @ ensure svc mode @ and irqs disabled diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig index 3fd629d5a5132..8defd638c79e6 100644 --- a/arch/arm/mm/Kconfig +++ b/arch/arm/mm/Kconfig @@ -397,6 +397,13 @@ config CPU_V7 select CPU_PABRT_V7 select CPU_TLB_V7 if MMU +config CPU_THUMBONLY + bool + # There are no CPUs available with MMU that don't implement an ARM ISA: + depends on !MMU + help + Select this if your CPU doesn't support the 32 bit ARM instructions. + # Figure out what processor architecture version we should be using. # This defines the compiler instruction set which depends on the machine type. config CPU_32v3 @@ -608,7 +615,7 @@ config ARCH_DMA_ADDR_T_64BIT bool config ARM_THUMB - bool "Support Thumb user binaries" + bool "Support Thumb user binaries" if !CPU_THUMBONLY depends on CPU_ARM720T || CPU_ARM740T || CPU_ARM920T || CPU_ARM922T || CPU_ARM925T || CPU_ARM926T || CPU_ARM940T || CPU_ARM946E || CPU_ARM1020 || CPU_ARM1020E || CPU_ARM1022 || CPU_ARM1026 || CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK || CPU_V6 || CPU_V6K || CPU_V7 || CPU_FEROCEON default y help From 473296e072ae77e96586dcb39a1dd5d10db22611 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= Date: Wed, 30 Jan 2013 12:07:14 +0100 Subject: [PATCH 3/5] ARM: sync comments about available data abort models with the code MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit While at it bring both in the same increasing order. Signed-off-by: Uwe Kleine-König Message-Id: 1359544151-26744-1-git-send-email-u.kleine-koenig@pengutronix.de --- arch/arm/include/asm/glue-df.h | 20 ++++++++++---------- 1 file changed, 10 insertions(+), 10 deletions(-) diff --git a/arch/arm/include/asm/glue-df.h b/arch/arm/include/asm/glue-df.h index 8cacbcda76da9..b6e9f2c108b5d 100644 --- a/arch/arm/include/asm/glue-df.h +++ b/arch/arm/include/asm/glue-df.h @@ -18,12 +18,12 @@ * ================ * * We have the following to choose from: - * arm6 - ARM6 style * arm7 - ARM7 style * v4_early - ARMv4 without Thumb early abort handler * v4t_late - ARMv4 with Thumb late abort handler * v4t_early - ARMv4 with Thumb early abort handler - * v5tej_early - ARMv5 with Thumb and Java early abort handler + * v5t_early - ARMv5 with Thumb early abort handler + * v5tj_early - ARMv5 with Thumb and Java early abort handler * xscale - ARMv5 with Thumb with Xscale extensions * v6_early - ARMv6 generic early abort handler * v7_early - ARMv7 generic early abort handler @@ -39,19 +39,19 @@ # endif #endif -#ifdef CONFIG_CPU_ABRT_LV4T +#ifdef CONFIG_CPU_ABRT_EV4 # ifdef CPU_DABORT_HANDLER # define MULTI_DABORT 1 # else -# define CPU_DABORT_HANDLER v4t_late_abort +# define CPU_DABORT_HANDLER v4_early_abort # endif #endif -#ifdef CONFIG_CPU_ABRT_EV4 +#ifdef CONFIG_CPU_ABRT_LV4T # ifdef CPU_DABORT_HANDLER # define MULTI_DABORT 1 # else -# define CPU_DABORT_HANDLER v4_early_abort +# define CPU_DABORT_HANDLER v4t_late_abort # endif #endif @@ -63,19 +63,19 @@ # endif #endif -#ifdef CONFIG_CPU_ABRT_EV5TJ +#ifdef CONFIG_CPU_ABRT_EV5T # ifdef CPU_DABORT_HANDLER # define MULTI_DABORT 1 # else -# define CPU_DABORT_HANDLER v5tj_early_abort +# define CPU_DABORT_HANDLER v5t_early_abort # endif #endif -#ifdef CONFIG_CPU_ABRT_EV5T +#ifdef CONFIG_CPU_ABRT_EV5TJ # ifdef CPU_DABORT_HANDLER # define MULTI_DABORT 1 # else -# define CPU_DABORT_HANDLER v5t_early_abort +# define CPU_DABORT_HANDLER v5tj_early_abort # endif #endif From ac52e83f4c76992925e13d0f4e901ffd4c207261 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= Date: Wed, 30 Jan 2013 17:38:21 +0100 Subject: [PATCH 4/5] ARM: use read_cpuid_id() instead of read_cpuid(CPUID_ID) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Both calls are identical currently. This patch prepares to deprecate read_cpuid on machines without cp15. Also move an unconditional usage of read_cpuid_cachetype to a more local scope as read_cpuid_cachetype uses read_cpuid, too. Signed-off-by: Uwe Kleine-König Message-Id: 1359646587-1788-1-git-send-email-u.kleine-koenig@pengutronix.de --- arch/arm/kernel/setup.c | 2 +- arch/arm/kernel/smp_scu.c | 2 +- arch/arm/mach-omap2/id.c | 4 ++-- arch/arm/mach-omap2/omap-smp.c | 2 +- 4 files changed, 5 insertions(+), 5 deletions(-) diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c index 3f6cbb2e3edae..1cc9e1796415c 100644 --- a/arch/arm/kernel/setup.c +++ b/arch/arm/kernel/setup.c @@ -291,10 +291,10 @@ static int cpu_has_aliasing_icache(unsigned int arch) static void __init cacheid_init(void) { - unsigned int cachetype = read_cpuid_cachetype(); unsigned int arch = cpu_architecture(); if (arch >= CPU_ARCH_ARMv6) { + unsigned int cachetype = read_cpuid_cachetype(); if ((cachetype & (7 << 29)) == 4 << 29) { /* ARMv7 register format */ arch = CPU_ARCH_ARMv7; diff --git a/arch/arm/kernel/smp_scu.c b/arch/arm/kernel/smp_scu.c index b9f015e843d8d..743a3bfe6a675 100644 --- a/arch/arm/kernel/smp_scu.c +++ b/arch/arm/kernel/smp_scu.c @@ -41,7 +41,7 @@ void scu_enable(void __iomem *scu_base) #ifdef CONFIG_ARM_ERRATA_764369 /* Cortex-A9 only */ - if ((read_cpuid(CPUID_ID) & 0xff0ffff0) == 0x410fc090) { + if ((read_cpuid_id() & 0xff0ffff0) == 0x410fc090) { scu_ctrl = __raw_readl(scu_base + 0x30); if (!(scu_ctrl & 1)) __raw_writel(scu_ctrl | 0x1, scu_base + 0x30); diff --git a/arch/arm/mach-omap2/id.c b/arch/arm/mach-omap2/id.c index 45cc7ed4dd587..1377c363fdedd 100644 --- a/arch/arm/mach-omap2/id.c +++ b/arch/arm/mach-omap2/id.c @@ -300,7 +300,7 @@ void __init omap3xxx_check_revision(void) * If the processor type is Cortex-A8 and the revision is 0x0 * it means its Cortex r0p0 which is 3430 ES1.0. */ - cpuid = read_cpuid(CPUID_ID); + cpuid = read_cpuid_id(); if ((((cpuid >> 4) & 0xfff) == 0xc08) && ((cpuid & 0xf) == 0x0)) { omap_revision = OMAP3430_REV_ES1_0; cpu_rev = "1.0"; @@ -450,7 +450,7 @@ void __init omap4xxx_check_revision(void) * Use ARM register to detect the correct ES version */ if (!rev && (hawkeye != 0xb94e) && (hawkeye != 0xb975)) { - idcode = read_cpuid(CPUID_ID); + idcode = read_cpuid_id(); rev = (idcode & 0xf) - 1; } diff --git a/arch/arm/mach-omap2/omap-smp.c b/arch/arm/mach-omap2/omap-smp.c index cd42d921940dc..707098ecf8d3b 100644 --- a/arch/arm/mach-omap2/omap-smp.c +++ b/arch/arm/mach-omap2/omap-smp.c @@ -209,7 +209,7 @@ static void __init omap4_smp_init_cpus(void) unsigned int i = 0, ncores = 1, cpu_id; /* Use ARM cpuid check here, as SoC detection will not work so early */ - cpu_id = read_cpuid(CPUID_ID) & CPU_MASK; + cpu_id = read_cpuid_id() & CPU_MASK; if (cpu_id == CPU_CORTEX_A9) { /* * Currently we can't call ioremap here because From 6ebd4d038dbb626a43d87db3007e71f92f49d7b3 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= Date: Thu, 31 Jan 2013 11:08:03 +0100 Subject: [PATCH 5/5] ARM: stub out read_cpuid and read_cpuid_ext for CPU_CP15=n MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Traditionally for !CPU_CP15 read_cpuid and read_cpuid_ext returned the processor id independent of the parameter passed in. This is wrong of course but theoretically this doesn't harm because it's only called on machines having a cp15. Instead return 0 unconditionally which might make unused code paths be better optimizable and so smaller and warn about unexpected usage. Signed-off-by: Uwe Kleine-König Message-Id: 1359646587-1788-2-git-send-email-u.kleine-koenig@pengutronix.de --- arch/arm/include/asm/cputype.h | 31 +++++++++++++++++++++++++++---- 1 file changed, 27 insertions(+), 4 deletions(-) diff --git a/arch/arm/include/asm/cputype.h b/arch/arm/include/asm/cputype.h index a59dcb5ab5fce..574269ed2232d 100644 --- a/arch/arm/include/asm/cputype.h +++ b/arch/arm/include/asm/cputype.h @@ -50,6 +50,7 @@ extern unsigned int processor_id; : "cc"); \ __val; \ }) + #define read_cpuid_ext(ext_reg) \ ({ \ unsigned int __val; \ @@ -59,11 +60,24 @@ extern unsigned int processor_id; : "cc"); \ __val; \ }) -#else -#define read_cpuid(reg) (processor_id) -#define read_cpuid_ext(reg) 0 -#endif + +#else /* ifdef CONFIG_CPU_CP15 */ +/* + * read_cpuid and read_cpuid_ext should only ever be called on machines that + * have cp15 so warn on other usages. + */ +#define read_cpuid(reg) \ + ({ \ + WARN_ON_ONCE(1); \ + 0; \ + }) + +#define read_cpuid_ext(reg) read_cpuid(reg) + +#endif /* ifdef CONFIG_CPU_CP15 / else */ + +#ifdef CONFIG_CPU_CP15 /* * The CPU ID never changes at run time, so we might as well tell the * compiler that it's constant. Use this function to read the CPU ID @@ -74,6 +88,15 @@ static inline unsigned int __attribute_const__ read_cpuid_id(void) return read_cpuid(CPUID_ID); } +#else /* ifdef CONFIG_CPU_CP15 */ + +static inline unsigned int __attribute_const__ read_cpuid_id(void) +{ + return processor_id; +} + +#endif /* ifdef CONFIG_CPU_CP15 / else */ + static inline unsigned int __attribute_const__ read_cpuid_cachetype(void) { return read_cpuid(CPUID_CACHETYPE);