From 5c5b06c3c09510a2e90f6453266823dc6f940c70 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Thu, 16 Aug 2012 07:49:31 +0000 Subject: ARM: kprobes: make more tests conditional The mls instruction is not available in ARMv6K or below, so we should make the test conditional on at least ARMv7. ldrexd/strexd are available in ARMv6K or ARMv7, which we can test by checking the CONFIG_CPU_32v6K symbol. /tmp/ccuMTZ8D.s: Assembler messages: /tmp/ccuMTZ8D.s:22188: Error: selected processor does not support ARM mode `mls r0,r1,r2,r3' /tmp/ccuMTZ8D.s:22222: Error: selected processor does not support ARM mode `mlshi r7,r8,r9,r10' /tmp/ccuMTZ8D.s:22252: Error: selected processor does not support ARM mode `mls lr,r1,r2,r13' Signed-off-by: Arnd Bergmann Acked-by: Jon Medhurst Acked-by: Nicolas Pitre Cc: Russell King Cc: Leif Lindholm --- arch/arm/kernel/kprobes-test-arm.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'arch/arm') diff --git a/arch/arm/kernel/kprobes-test-arm.c b/arch/arm/kernel/kprobes-test-arm.c index 38c1a3b103a..83931290506 100644 --- a/arch/arm/kernel/kprobes-test-arm.c +++ b/arch/arm/kernel/kprobes-test-arm.c @@ -366,7 +366,9 @@ void kprobe_arm_test_cases(void) TEST_UNSUPPORTED(".word 0xe04f0392 @ umaal r0, pc, r2, r3") TEST_UNSUPPORTED(".word 0xe0500090 @ undef") TEST_UNSUPPORTED(".word 0xe05fff9f @ undef") +#endif +#if __LINUX_ARM_ARCH__ >= 7 TEST_RRR( "mls r0, r",1, VAL1,", r",2, VAL2,", r",3, VAL3,"") TEST_RRR( "mlshi r7, r",8, VAL3,", r",9, VAL1,", r",10, VAL2,"") TEST_RR( "mls lr, r",1, VAL2,", r",2, VAL3,", r13") @@ -456,6 +458,8 @@ void kprobe_arm_test_cases(void) TEST_UNSUPPORTED(".word 0xe1700090") /* Unallocated space */ #if __LINUX_ARM_ARCH__ >= 6 TEST_UNSUPPORTED("ldrex r2, [sp]") +#endif +#if (__LINUX_ARM_ARCH__ >= 7) || defined(CONFIG_CPU_32v6K) TEST_UNSUPPORTED("strexd r0, r2, r3, [sp]") TEST_UNSUPPORTED("ldrexd r2, r3, [sp]") TEST_UNSUPPORTED("strexb r0, r2, [sp]") -- cgit v1.2.3-70-g09d2 From 05c769823cd0648fc56c8f0289c5f14d465389a8 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Thu, 16 Aug 2012 07:49:26 +0000 Subject: ARM: export set_irq_flags The recently added Emma Mobile GPIO driver calls set_irq_flags and irq_set_chip_and_handler for the interrupts it exports and it can be built as a module, which currently fails with ERROR: "set_irq_flags" [drivers/gpio/gpio-em.ko] undefined! We either need to replace the call to set_irq_flags with something else or export that function. This patch does the latter. Signed-off-by: Arnd Bergmann Acked-by: Thomas Gleixner Cc: Magnus Damm Cc: Linus Walleij Cc: Rafael J. Wysocki Cc: Russell King --- arch/arm/kernel/irq.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'arch/arm') diff --git a/arch/arm/kernel/irq.c b/arch/arm/kernel/irq.c index 16cedb42c0c..896165096d6 100644 --- a/arch/arm/kernel/irq.c +++ b/arch/arm/kernel/irq.c @@ -34,6 +34,7 @@ #include #include #include +#include #include #include @@ -109,6 +110,7 @@ void set_irq_flags(unsigned int irq, unsigned int iflags) /* Order is clear bits in "clr" then set bits in "set" */ irq_modify_status(irq, clr, set & ~clr); } +EXPORT_SYMBOL_GPL(set_irq_flags); void __init init_IRQ(void) { -- cgit v1.2.3-70-g09d2 From 31d2a638a91340d00502d397e558271f516b4f17 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Sun, 7 Oct 2012 20:35:18 +0000 Subject: ARM: Fix another build warning in arch/arm/mm/alignment.c One such warning was recently fixed in a761cebf "ARM: Fix build warning in arch/arm/mm/alignment.c" but only for the thumb2 case, this fixes the other half. arch/arm/mm/alignment.c: In function 'do_alignment': arch/arm/mm/alignment.c:327:15: error: 'offset.un' may be used uninitialized in this function arch/arm/mm/alignment.c:748:21: note: 'offset.un' was declared here Signed-off-by: Arnd Bergmann Cc: Russell King --- arch/arm/mm/alignment.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'arch/arm') diff --git a/arch/arm/mm/alignment.c b/arch/arm/mm/alignment.c index b9f60ebe3bc..023f443784e 100644 --- a/arch/arm/mm/alignment.c +++ b/arch/arm/mm/alignment.c @@ -856,8 +856,10 @@ do_alignment(unsigned long addr, unsigned int fsr, struct pt_regs *regs) if (thumb2_32b) { offset.un = 0; handler = do_alignment_t32_to_handler(&instr, regs, &offset); - } else + } else { + offset.un = 0; handler = do_alignment_ldmstm; + } break; default: -- cgit v1.2.3-70-g09d2 From f3accb122f2c758494a6db3b9e9a8cd62aafcf83 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Mon, 1 Oct 2012 14:47:31 +0000 Subject: ARM: export default read_current_timer read_current_timer is used by get_cycles since "ARM: 7538/1: delay: add registration mechanism for delay timer sources", and get_cycles can be used by device drivers in loadable modules, so it has to be exported. Without this patch, building imote2_defconfig fails with ERROR: "read_current_timer" [crypto/tcrypt.ko] undefined! Signed-off-by: Arnd Bergmann Cc: Stephen Boyd Cc: Jonathan Austin Cc: Will Deacon Cc: Russell King --- arch/arm/lib/delay.c | 1 + 1 file changed, 1 insertion(+) (limited to 'arch/arm') diff --git a/arch/arm/lib/delay.c b/arch/arm/lib/delay.c index 9d0a30032d7..0dc53854a5d 100644 --- a/arch/arm/lib/delay.c +++ b/arch/arm/lib/delay.c @@ -45,6 +45,7 @@ int read_current_timer(unsigned long *timer_val) *timer_val = delay_timer->read_current_timer(); return 0; } +EXPORT_SYMBOL_GPL(read_current_timer); static void __timer_delay(unsigned long cycles) { -- cgit v1.2.3-70-g09d2 From f880b67dcbdedb49453f88d2ccb1a0937b046d82 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Tue, 9 Oct 2012 10:33:52 +0000 Subject: ARM: Xen: fix initial build problems * The XEN_BALLOON code requires the balloon infrastructure that is not getting built on ARM. * The tmem hypercall is not available on ARM * ARMv6 does not support cmpxchg on 16-bit words that are used in the Xen grant table code, so we must ensure that Xen support is only built on ARMv7-only kernels not combined ARMv6/v7 kernels. * sys-hypervisor.c needs to include linux/err.h in order to use the IS_ERR/PTR_ERR/ERR_PTR family of functions. Signed-off-by: Arnd Bergmann Acked-by: Ian Campbell Cc: Stefano Stabellini Cc: Konrad Rzeszutek Wilk Cc: Jeremy Fitzhardinge Cc: xen-devel@lists.xensource.com --- arch/arm/Kconfig | 1 + drivers/xen/Kconfig | 2 ++ drivers/xen/sys-hypervisor.c | 1 + 3 files changed, 4 insertions(+) (limited to 'arch/arm') diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 6d2f7f5c003..e1d6ab2b3c9 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -1846,6 +1846,7 @@ config XEN_DOM0 config XEN bool "Xen guest support on ARM (EXPERIMENTAL)" depends on EXPERIMENTAL && ARM && OF + depends on CPU_V7 && !CPU_V6 help Say Y if you want to run Linux in a Virtual Machine on Xen on ARM. diff --git a/drivers/xen/Kconfig b/drivers/xen/Kconfig index d4dffcd5287..126d8ce591c 100644 --- a/drivers/xen/Kconfig +++ b/drivers/xen/Kconfig @@ -3,6 +3,7 @@ menu "Xen driver support" config XEN_BALLOON bool "Xen memory balloon driver" + depends on !ARM default y help The balloon driver allows the Xen domain to request more memory from @@ -145,6 +146,7 @@ config SWIOTLB_XEN config XEN_TMEM bool + depends on !ARM default y if (CLEANCACHE || FRONTSWAP) help Shim to interface in-kernel Transcendent Memory hooks diff --git a/drivers/xen/sys-hypervisor.c b/drivers/xen/sys-hypervisor.c index 5e5ad7e2885..66a0a1475ac 100644 --- a/drivers/xen/sys-hypervisor.c +++ b/drivers/xen/sys-hypervisor.c @@ -11,6 +11,7 @@ #include #include #include +#include #include #include -- cgit v1.2.3-70-g09d2 From 91802a8ef410810db58907d2ea4c4adc00ef4688 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Fri, 10 Aug 2012 11:12:20 +0000 Subject: ARM: pass -marm to gcc by default for both C and assembler The Linaro cross toolchain and probably others nowadays default to building in THUMB2 mode. When building a kernel for a CPU that does not support THUMB2, the compiler complains about incorrect flags. We can work around this by setting -marm for all non-T2 builds. -marm was passed unconditionally for C files previously, but nothing was passed to the gcc frontend when processing .S files, resulting in a warning. The assembler never defaults to ARM unless -Wa,-mthumb is supplied explicitly, so the files were still assembled correctly. This patch makes sure that -marm is passed for .S files too, and also avoids the redundant gcc -marm -mthumb in Thumb kernels. Without this patch, building assabet_defconfig results in: usr/initramfs_data.S:1:0: warning: target CPU does not support THUMB instructions [enabled by default] arch/arm/nwfpe/entry.S:1:0: warning: target CPU does not support THUMB instructions [enabled by default] firmware/cis/PCMLM28.cis.gen.S:1:0: warning: target CPU does not support THUMB instructions [enabled by default] (and many more) Signed-off-by: Arnd Bergmann Acked-by: Nicolas Pitre Acked-by: Dave Martin Cc: Russell King --- arch/arm/Makefile | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) (limited to 'arch/arm') diff --git a/arch/arm/Makefile b/arch/arm/Makefile index f023e3acdfb..5f914fca911 100644 --- a/arch/arm/Makefile +++ b/arch/arm/Makefile @@ -21,8 +21,6 @@ endif OBJCOPYFLAGS :=-O binary -R .comment -S GZFLAGS :=-9 #KBUILD_CFLAGS +=-pipe -# Explicitly specifiy 32-bit ARM ISA since toolchain default can be -mthumb: -KBUILD_CFLAGS +=$(call cc-option,-marm,) # Never generate .eh_frame KBUILD_CFLAGS += $(call cc-option,-fno-dwarf2-cfi-asm) @@ -105,17 +103,20 @@ endif ifeq ($(CONFIG_THUMB2_KERNEL),y) AFLAGS_AUTOIT :=$(call as-option,-Wa$(comma)-mimplicit-it=always,-Wa$(comma)-mauto-it) AFLAGS_NOWARN :=$(call as-option,-Wa$(comma)-mno-warn-deprecated,-Wa$(comma)-W) -CFLAGS_THUMB2 :=-mthumb $(AFLAGS_AUTOIT) $(AFLAGS_NOWARN) -AFLAGS_THUMB2 :=$(CFLAGS_THUMB2) -Wa$(comma)-mthumb +CFLAGS_ISA :=-mthumb $(AFLAGS_AUTOIT) $(AFLAGS_NOWARN) +AFLAGS_ISA :=$(CFLAGS_ISA) -Wa$(comma)-mthumb # Work around buggy relocation from gas if requested: ifeq ($(CONFIG_THUMB2_AVOID_R_ARM_THM_JUMP11),y) CFLAGS_MODULE +=-fno-optimize-sibling-calls endif +else +CFLAGS_ISA :=$(call cc-option,-marm,) +AFLAGS_ISA :=$(CFLAGS_ISA) endif # Need -Uarm for gcc < 3.x -KBUILD_CFLAGS +=$(CFLAGS_ABI) $(CFLAGS_THUMB2) $(arch-y) $(tune-y) $(call cc-option,-mshort-load-bytes,$(call cc-option,-malignment-traps,)) -msoft-float -Uarm -KBUILD_AFLAGS +=$(CFLAGS_ABI) $(AFLAGS_THUMB2) $(arch-y) $(tune-y) -include asm/unified.h -msoft-float +KBUILD_CFLAGS +=$(CFLAGS_ABI) $(CFLAGS_ISA) $(arch-y) $(tune-y) $(call cc-option,-mshort-load-bytes,$(call cc-option,-malignment-traps,)) -msoft-float -Uarm +KBUILD_AFLAGS +=$(CFLAGS_ABI) $(AFLAGS_ISA) $(arch-y) $(tune-y) -include asm/unified.h -msoft-float CHECKFLAGS += -D__arm__ -- cgit v1.2.3-70-g09d2 From edc88ceb0c7d285b9f58bc29a638cd8163b59989 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Mon, 30 Apr 2012 12:16:16 +0000 Subject: ARM: be really quiet when building with 'make -s' Sometimes we want the kernel build process to only print messages on errors, e.g. in automated build testing. This uses the "kecho" macro that the build system provides to hide a few informational messages. Nothing changes for a regular "make" or "make V=1". Without this patch, building any ARM kernel results in: Kernel: arch/arm/boot/Image is ready Kernel: arch/arm/boot/zImage is ready Signed-off-by: Arnd Bergmann Acked-by: Nicolas Pitre Cc: Russell King Cc: Catalin Marinas Cc: Michal Marek --- arch/arm/boot/Makefile | 10 +++++----- arch/arm/tools/Makefile | 2 +- 2 files changed, 6 insertions(+), 6 deletions(-) (limited to 'arch/arm') diff --git a/arch/arm/boot/Makefile b/arch/arm/boot/Makefile index 3fdab016aa5..f2aa09eb658 100644 --- a/arch/arm/boot/Makefile +++ b/arch/arm/boot/Makefile @@ -33,7 +33,7 @@ ifeq ($(CONFIG_XIP_KERNEL),y) $(obj)/xipImage: vmlinux FORCE $(call if_changed,objcopy) - @echo ' Kernel: $@ is ready (physical address: $(CONFIG_XIP_PHYS_ADDR))' + $(kecho) ' Kernel: $@ is ready (physical address: $(CONFIG_XIP_PHYS_ADDR))' $(obj)/Image $(obj)/zImage: FORCE @echo 'Kernel configured for XIP (CONFIG_XIP_KERNEL=y)' @@ -48,14 +48,14 @@ $(obj)/xipImage: FORCE $(obj)/Image: vmlinux FORCE $(call if_changed,objcopy) - @echo ' Kernel: $@ is ready' + $(kecho) ' Kernel: $@ is ready' $(obj)/compressed/vmlinux: $(obj)/Image FORCE $(Q)$(MAKE) $(build)=$(obj)/compressed $@ $(obj)/zImage: $(obj)/compressed/vmlinux FORCE $(call if_changed,objcopy) - @echo ' Kernel: $@ is ready' + $(kecho) ' Kernel: $@ is ready' endif @@ -90,7 +90,7 @@ fi $(obj)/uImage: $(obj)/zImage FORCE @$(check_for_multiple_loadaddr) $(call if_changed,uimage) - @echo ' Image $@ is ready' + $(kecho) ' Image $@ is ready' $(obj)/bootp/bootp: $(obj)/zImage initrd FORCE $(Q)$(MAKE) $(build)=$(obj)/bootp $@ @@ -98,7 +98,7 @@ $(obj)/bootp/bootp: $(obj)/zImage initrd FORCE $(obj)/bootpImage: $(obj)/bootp/bootp FORCE $(call if_changed,objcopy) - @echo ' Kernel: $@ is ready' + $(kecho) ' Kernel: $@ is ready' PHONY += initrd FORCE initrd: diff --git a/arch/arm/tools/Makefile b/arch/arm/tools/Makefile index 635cb1865e4..cd60a81163e 100644 --- a/arch/arm/tools/Makefile +++ b/arch/arm/tools/Makefile @@ -5,6 +5,6 @@ # include/generated/mach-types.h: $(src)/gen-mach-types $(src)/mach-types - @echo ' Generating $@' + $(kecho) ' Generating $@' @mkdir -p $(dir $@) $(Q)$(AWK) -f $^ > $@ || { rm -f $@; /bin/false; } -- cgit v1.2.3-70-g09d2 From f6d5d8a5ed60c726354605877e8f8214fb11cc02 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Mon, 30 Apr 2012 13:18:37 +0000 Subject: ARM: binfmt_flat: unused variable 'persistent' The flat_get_addr_from_rp() macro does not use the 'persistent' argument on ARM, causing a harmless compiler warning. A cast to void removes that warning. Without this patch, building at91x40_defconfig results in: fs/binfmt_flat.c: In function 'load_flat_file': fs/binfmt_flat.c:746:17: warning: unused variable 'persistent' [-Wunused-variable] Signed-off-by: Arnd Bergmann Acked-by: Greg Ungerer Cc: Russell King Cc: Bryan Wu --- arch/arm/include/asm/flat.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/arm') diff --git a/arch/arm/include/asm/flat.h b/arch/arm/include/asm/flat.h index 59426a4595c..e847d23351e 100644 --- a/arch/arm/include/asm/flat.h +++ b/arch/arm/include/asm/flat.h @@ -8,7 +8,7 @@ #define flat_argvp_envp_on_stack() 1 #define flat_old_ram_flag(flags) (flags) #define flat_reloc_valid(reloc, size) ((reloc) <= (size)) -#define flat_get_addr_from_rp(rp, relval, flags, persistent) get_unaligned(rp) +#define flat_get_addr_from_rp(rp, relval, flags, persistent) ((void)persistent,get_unaligned(rp)) #define flat_put_addr_at_rp(rp, val, relval) put_unaligned(val,rp) #define flat_get_relocate_addr(rel) (rel) #define flat_set_persistent(relval, p) 0 -- cgit v1.2.3-70-g09d2 From 8e7fc18b5eacc37b6e6fcf486ec4eafbfef91738 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Mon, 30 Apr 2012 13:18:46 +0000 Subject: ARM: warnings in arch/arm/include/asm/uaccess.h On NOMMU ARM, the __addr_ok() and __range_ok() macros do not evaluate their arguments, which may lead to harmless build warnings in some code where the variables are not used otherwise. Adding a cast to void gets rid of the warning and does not make any semantic changes. Without this patch, building at91x40_defconfig results in: fs/read_write.c: In function 'rw_copy_check_uvector': fs/read_write.c:684:9: warning: unused variable 'buf' [-Wunused-variable] Signed-off-by: Arnd Bergmann Acked-by: Greg Ungerer Cc: Russell King --- arch/arm/include/asm/uaccess.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch/arm') diff --git a/arch/arm/include/asm/uaccess.h b/arch/arm/include/asm/uaccess.h index 77bd79f2ffd..7e1f76027f6 100644 --- a/arch/arm/include/asm/uaccess.h +++ b/arch/arm/include/asm/uaccess.h @@ -200,8 +200,8 @@ extern int __put_user_8(void *, unsigned long long); #define USER_DS KERNEL_DS #define segment_eq(a,b) (1) -#define __addr_ok(addr) (1) -#define __range_ok(addr,size) (0) +#define __addr_ok(addr) ((void)(addr),1) +#define __range_ok(addr,size) ((void)(addr),0) #define get_fs() (KERNEL_DS) static inline void set_fs(mm_segment_t fs) -- cgit v1.2.3-70-g09d2 From 2456f44dd7a9aaffc2cd21a13f78198b3d94da08 Mon Sep 17 00:00:00 2001 From: Aaro Koskinen Date: Tue, 16 Oct 2012 19:35:14 +0100 Subject: ARM: 7555/1: kexec: fix segment memory addresses check Commit c564df4db85aac8d1d65a56176a0a25f46138064 (ARM: 7540/1: kexec: Check segment memory addresses) added a safety check with accidentally reversed condition, and broke kexec functionality on ARM. Fix this. Acked-by: Will Deacon Signed-off-by: Aaro Koskinen Signed-off-by: Russell King --- arch/arm/kernel/machine_kexec.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) (limited to 'arch/arm') diff --git a/arch/arm/kernel/machine_kexec.c b/arch/arm/kernel/machine_kexec.c index e29c3337ca8..8ef8c933780 100644 --- a/arch/arm/kernel/machine_kexec.c +++ b/arch/arm/kernel/machine_kexec.c @@ -45,10 +45,9 @@ int machine_kexec_prepare(struct kimage *image) for (i = 0; i < image->nr_segments; i++) { current_segment = &image->segment[i]; - err = memblock_is_region_memory(current_segment->mem, - current_segment->memsz); - if (err) - return - EINVAL; + if (!memblock_is_region_memory(current_segment->mem, + current_segment->memsz)) + return -EINVAL; err = get_user(header, (__be32*)current_segment->buf); if (err) -- cgit v1.2.3-70-g09d2 From 3581fe0ef37ce12ac7a4f74831168352ae848edc Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Wed, 17 Oct 2012 12:01:34 +0100 Subject: ARM: 7556/1: perf: fix updated event period in response to PERF_EVENT_IOC_PERIOD The PERF_EVENT_IOC_PERIOD ioctl command can be used to change the sample period of a running perf_event. Consequently, when calculating the next event period, the new period will only be considered after the previous one has overflowed. This patch changes the calculation of the remaining event ticks so that they are offset if the period has changed. Cc: Peter Zijlstra Reported-by: Andreas Sandberg Signed-off-by: Will Deacon Signed-off-by: Russell King --- arch/arm/kernel/perf_event.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'arch/arm') diff --git a/arch/arm/kernel/perf_event.c b/arch/arm/kernel/perf_event.c index 93971b1a4f0..53c0304b734 100644 --- a/arch/arm/kernel/perf_event.c +++ b/arch/arm/kernel/perf_event.c @@ -96,6 +96,10 @@ armpmu_event_set_period(struct perf_event *event, s64 period = hwc->sample_period; int ret = 0; + /* The period may have been changed by PERF_EVENT_IOC_PERIOD */ + if (unlikely(period != hwc->last_period)) + left = period - (hwc->last_period - left); + if (unlikely(left <= -period)) { left = period; local64_set(&hwc->period_left, left); -- cgit v1.2.3-70-g09d2 From 5f40b909728ad784eb43aa309d3c4e9bdf050781 Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Fri, 19 Oct 2012 17:53:01 +0100 Subject: ARM: 7559/1: smp: switch away from the idmap before updating init_mm.mm_count When booting a secondary CPU, the primary CPU hands two sets of page tables via the secondary_data struct: (1) swapper_pg_dir: a normal, cacheable, shared (if SMP) mapping of the kernel image (i.e. the tables used by init_mm). (2) idmap_pgd: an uncached mapping of the .idmap.text ELF section. The idmap is generally used when enabling and disabling the MMU, which includes early CPU boot. In this case, the secondary CPU switches to swapper as soon as it enters C code: struct mm_struct *mm = &init_mm; unsigned int cpu = smp_processor_id(); /* * All kernel threads share the same mm context; grab a * reference and switch to it. */ atomic_inc(&mm->mm_count); current->active_mm = mm; cpumask_set_cpu(cpu, mm_cpumask(mm)); cpu_switch_mm(mm->pgd, mm); This causes a problem on ARMv7, where the identity mapping is treated as strongly-ordered leading to architecturally UNPREDICTABLE behaviour of exclusive accesses, such as those used by atomic_inc. This patch re-orders the secondary_start_kernel function so that we switch to swapper before performing any exclusive accesses. Cc: Cc: David McKay Reported-by: Gilles Chanteperdrix Signed-off-by: Will Deacon Signed-off-by: Russell King --- arch/arm/kernel/smp.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) (limited to 'arch/arm') diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c index 8e20754dd31..fbc8b2623d8 100644 --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -294,18 +294,24 @@ static void percpu_timer_setup(void); asmlinkage void __cpuinit secondary_start_kernel(void) { struct mm_struct *mm = &init_mm; - unsigned int cpu = smp_processor_id(); + unsigned int cpu; + + /* + * The identity mapping is uncached (strongly ordered), so + * switch away from it before attempting any exclusive accesses. + */ + cpu_switch_mm(mm->pgd, mm); + enter_lazy_tlb(mm, current); + local_flush_tlb_all(); /* * All kernel threads share the same mm context; grab a * reference and switch to it. */ + cpu = smp_processor_id(); atomic_inc(&mm->mm_count); current->active_mm = mm; cpumask_set_cpu(cpu, mm_cpumask(mm)); - cpu_switch_mm(mm->pgd, mm); - enter_lazy_tlb(mm, current); - local_flush_tlb_all(); printk("CPU%u: Booted secondary processor\n", cpu); -- cgit v1.2.3-70-g09d2 From ad17a26e2273d18d27fcbb4a8d8a341ebb2d721f Mon Sep 17 00:00:00 2001 From: Linus Walleij Date: Mon, 22 Oct 2012 10:17:24 +0100 Subject: ARM: 7560/1: SMP_TWD: use DIV_ROUND_CLOSEST() for periodic mode The periodic mode is currently calculated by a simple division but we should pay more attention to our integer arithmetics. Also delete a comment that does not make any sense. Signed-off-by: Linus Walleij Signed-off-by: Russell King --- arch/arm/kernel/smp_twd.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch/arm') diff --git a/arch/arm/kernel/smp_twd.c b/arch/arm/kernel/smp_twd.c index e1f906989bb..b22d700fea2 100644 --- a/arch/arm/kernel/smp_twd.c +++ b/arch/arm/kernel/smp_twd.c @@ -42,10 +42,10 @@ static void twd_set_mode(enum clock_event_mode mode, switch (mode) { case CLOCK_EVT_MODE_PERIODIC: - /* timer load already set up */ ctrl = TWD_TIMER_CONTROL_ENABLE | TWD_TIMER_CONTROL_IT_ENABLE | TWD_TIMER_CONTROL_PERIODIC; - __raw_writel(twd_timer_rate / HZ, twd_base + TWD_TIMER_LOAD); + __raw_writel(DIV_ROUND_CLOSEST(twd_timer_rate, HZ), + twd_base + TWD_TIMER_LOAD); break; case CLOCK_EVT_MODE_ONESHOT: /* period set, and timer enabled in 'next_event' hook */ -- cgit v1.2.3-70-g09d2 From 00b7dede8bc3881b29f2efbcae1355fc769252ab Mon Sep 17 00:00:00 2001 From: Russell King Date: Mon, 22 Oct 2012 22:54:30 +0100 Subject: ARM: drop experimental status for hotplug and Thumb2 Both these features have been around for a long time now, and haven't had any recent issues brought up. So lets drop their experimental status. In any case, hotplugis selected by other non-experimental options which then cause a Kconfig warning. Signed-off-by: Russell King --- arch/arm/Kconfig | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'arch/arm') diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 73067efd484..35a26d42ef3 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -1603,8 +1603,8 @@ config NR_CPUS default "4" config HOTPLUG_CPU - bool "Support for hot-pluggable CPUs (EXPERIMENTAL)" - depends on SMP && HOTPLUG && EXPERIMENTAL + bool "Support for hot-pluggable CPUs" + depends on SMP && HOTPLUG help Say Y here to experiment with turning CPUs off and on. CPUs can be controlled through /sys/devices/system/cpu. @@ -1645,8 +1645,8 @@ config HZ default 100 config THUMB2_KERNEL - bool "Compile the kernel in Thumb-2 mode (EXPERIMENTAL)" - depends on CPU_V7 && !CPU_V6 && !CPU_V6K && EXPERIMENTAL + bool "Compile the kernel in Thumb-2 mode" + depends on CPU_V7 && !CPU_V6 && !CPU_V6K select AEABI select ARM_ASM_UNIFIED select ARM_UNWIND -- cgit v1.2.3-70-g09d2