From 8903826d0cd99aed9267e792d38284cf3092042b Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Fri, 30 Sep 2011 11:43:29 +0100 Subject: ARM: idmap: populate identity map pgd at init time using .init.text When disabling and re-enabling the MMU, it is necessary to take out an identity mapping for the code that manipulates the SCTLR in order to avoid it disappearing from under our feet. This is useful when soft rebooting and returning from CPU suspend. This patch allocates a set of page tables during boot and populates them with an identity mapping for the .idmap.text section. This means that users of the identity map do not need to manage their own pgd and can instead annotate their functions with __idmap or, in the case of assembly code, place them in the correct section. Acked-by: Dave Martin Reviewed-by: Catalin Marinas Tested-by: Lorenzo Pieralisi Signed-off-by: Will Deacon --- arch/arm/kernel/smp.c | 1 + 1 file changed, 1 insertion(+) (limited to 'arch/arm/kernel/smp.c') diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c index ef5640b9e218..8afadda37459 100644 --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -31,6 +31,7 @@ #include #include #include +#include #include #include #include -- cgit v1.2.3 From 4e8ee7de227e3ab9a72040b448ad728c5428a042 Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Wed, 23 Nov 2011 12:26:25 +0000 Subject: ARM: SMP: use idmap_pgd for mapping MMU enable during secondary booting The ARM SMP booting code allocates a temporary set of page tables containing an identity mapping of the kernel image and provides this to secondary CPUs for initial booting. In reality, we only need to include the __turn_mmu_on function in the identity mapping since the rest of the kernel is executing from virtual addresses after this point. This patch adds __turn_mmu_on to the .idmap.text section, allowing the SMP booting code to use the idmap_pgd directly and not have to populate its own set of page table. As a result of this patch, we can make the identity_mapping_add function static (since it is only used within mm/idmap.c) and also remove the identity_mapping_del function. The identity map population is moved to an early initcall so that it is setup in time for secondary CPU bringup. Reviewed-by: Catalin Marinas Signed-off-by: Will Deacon --- arch/arm/include/asm/idmap.h | 3 --- arch/arm/kernel/head.S | 4 +++- arch/arm/kernel/smp.c | 31 +------------------------------ arch/arm/mm/idmap.c | 34 ++-------------------------------- 4 files changed, 6 insertions(+), 66 deletions(-) (limited to 'arch/arm/kernel/smp.c') diff --git a/arch/arm/include/asm/idmap.h b/arch/arm/include/asm/idmap.h index 62e3d19c9ad7..bf863edb517d 100644 --- a/arch/arm/include/asm/idmap.h +++ b/arch/arm/include/asm/idmap.h @@ -9,9 +9,6 @@ extern pgd_t *idmap_pgd; -void identity_mapping_add(pgd_t *, unsigned long, unsigned long); -void identity_mapping_del(pgd_t *, unsigned long, unsigned long); - void setup_mm_for_reboot(void); #endif /* __ASM_IDMAP_H */ diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S index 43e3aa3b0573..64e9943ea4f0 100644 --- a/arch/arm/kernel/head.S +++ b/arch/arm/kernel/head.S @@ -398,7 +398,8 @@ ENDPROC(__enable_mmu) * other registers depend on the function called upon completion */ .align 5 -__turn_mmu_on: + .pushsection .idmap.text, "ax" +ENTRY(__turn_mmu_on) mov r0, r0 mcr p15, 0, r0, c1, c0, 0 @ write control reg mrc p15, 0, r3, c0, c0, 0 @ read id reg @@ -407,6 +408,7 @@ __turn_mmu_on: mov pc, r3 __turn_mmu_on_end: ENDPROC(__turn_mmu_on) + .popsection #ifdef CONFIG_SMP_ON_UP diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c index 8afadda37459..76ff28d87bf3 100644 --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -62,7 +62,6 @@ int __cpuinit __cpu_up(unsigned int cpu) { struct cpuinfo_arm *ci = &per_cpu(cpu_data, cpu); struct task_struct *idle = ci->idle; - pgd_t *pgd; int ret; /* @@ -84,30 +83,12 @@ int __cpuinit __cpu_up(unsigned int cpu) init_idle(idle, cpu); } - /* - * Allocate initial page tables to allow the new CPU to - * enable the MMU safely. This essentially means a set - * of our "standard" page tables, with the addition of - * a 1:1 mapping for the physical address of the kernel. - */ - pgd = pgd_alloc(&init_mm); - if (!pgd) - return -ENOMEM; - - if (PHYS_OFFSET != PAGE_OFFSET) { -#ifndef CONFIG_HOTPLUG_CPU - identity_mapping_add(pgd, __pa(__init_begin), __pa(__init_end)); -#endif - identity_mapping_add(pgd, __pa(_stext), __pa(_etext)); - identity_mapping_add(pgd, __pa(_sdata), __pa(_edata)); - } - /* * We need to tell the secondary core where to find * its stack and the page tables. */ secondary_data.stack = task_stack_page(idle) + THREAD_START_SP; - secondary_data.pgdir = virt_to_phys(pgd); + secondary_data.pgdir = virt_to_phys(idmap_pgd); secondary_data.swapper_pg_dir = virt_to_phys(swapper_pg_dir); __cpuc_flush_dcache_area(&secondary_data, sizeof(secondary_data)); outer_clean_range(__pa(&secondary_data), __pa(&secondary_data + 1)); @@ -143,16 +124,6 @@ int __cpuinit __cpu_up(unsigned int cpu) secondary_data.stack = NULL; secondary_data.pgdir = 0; - if (PHYS_OFFSET != PAGE_OFFSET) { -#ifndef CONFIG_HOTPLUG_CPU - identity_mapping_del(pgd, __pa(__init_begin), __pa(__init_end)); -#endif - identity_mapping_del(pgd, __pa(_stext), __pa(_etext)); - identity_mapping_del(pgd, __pa(_sdata), __pa(_edata)); - } - - pgd_free(&init_mm, pgd); - return ret; } diff --git a/arch/arm/mm/idmap.c b/arch/arm/mm/idmap.c index b01760e6da18..660f1bc68f99 100644 --- a/arch/arm/mm/idmap.c +++ b/arch/arm/mm/idmap.c @@ -32,7 +32,7 @@ static void idmap_add_pud(pgd_t *pgd, unsigned long addr, unsigned long end, } while (pud++, addr = next, addr != end); } -void identity_mapping_add(pgd_t *pgd, unsigned long addr, unsigned long end) +static void identity_mapping_add(pgd_t *pgd, unsigned long addr, unsigned long end) { unsigned long prot, next; @@ -47,36 +47,6 @@ void identity_mapping_add(pgd_t *pgd, unsigned long addr, unsigned long end) } while (pgd++, addr = next, addr != end); } -#ifdef CONFIG_SMP -static void idmap_del_pmd(pud_t *pud, unsigned long addr, unsigned long end) -{ - pmd_t *pmd = pmd_offset(pud, addr); - pmd_clear(pmd); -} - -static void idmap_del_pud(pgd_t *pgd, unsigned long addr, unsigned long end) -{ - pud_t *pud = pud_offset(pgd, addr); - unsigned long next; - - do { - next = pud_addr_end(addr, end); - idmap_del_pmd(pud, addr, next); - } while (pud++, addr = next, addr != end); -} - -void identity_mapping_del(pgd_t *pgd, unsigned long addr, unsigned long end) -{ - unsigned long next; - - pgd += pgd_index(addr); - do { - next = pgd_addr_end(addr, end); - idmap_del_pud(pgd, addr, next); - } while (pgd++, addr = next, addr != end); -} -#endif - extern char __idmap_text_start[], __idmap_text_end[]; static int __init init_static_idmap(void) @@ -97,7 +67,7 @@ static int __init init_static_idmap(void) return 0; } -arch_initcall(init_static_idmap); +early_initcall(init_static_idmap); /* * In order to soft-boot, we need to switch to a 1:1 mapping for the -- cgit v1.2.3 From 02b73e2e9c288cbbb6ec96bef628cf08e29824c4 Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Mon, 6 Jun 2011 15:49:23 +0100 Subject: ARM: stop: execute platform callback from cpu_stop code Sending IPI_CPU_STOP to a CPU causes it to execute a busy cpu_relax loop forever. This makes it impossible to kexec successfully on an SMP system since the secondary CPUs do not reset. This patch adds a callback to platform_cpu_kill, defined when CONFIG_HOTPLUG_CPU=y, from the ipi_cpu_stop handling code. This function currently just returns 1 on all platforms that define it but allows them to do something more sophisticated in the future. Signed-off-by: Will Deacon --- arch/arm/Kconfig | 2 +- arch/arm/kernel/smp.c | 4 ++++ 2 files changed, 5 insertions(+), 1 deletion(-) (limited to 'arch/arm/kernel/smp.c') diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 4b01d71bdbd1..abba5b8c9d74 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -2001,7 +2001,7 @@ config XIP_PHYS_ADDR config KEXEC bool "Kexec system call (EXPERIMENTAL)" - depends on EXPERIMENTAL + depends on EXPERIMENTAL && (!SMP || HOTPLUG_CPU) help kexec is a system call that implements the ability to shutdown your current kernel, and to start another kernel. It is like a reboot diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c index 76ff28d87bf3..57db122a4f62 100644 --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -522,6 +522,10 @@ static void ipi_cpu_stop(unsigned int cpu) local_fiq_disable(); local_irq_disable(); +#ifdef CONFIG_HOTPLUG_CPU + platform_cpu_kill(cpu); +#endif + while (1) cpu_relax(); } -- cgit v1.2.3 From 7deabca0acfe02b8e18f59a4c95676012f49a304 Mon Sep 17 00:00:00 2001 From: Russell King Date: Thu, 19 Jan 2012 15:20:58 +0000 Subject: ARM: fix rcu stalls on SMP platforms We can stall RCU processing on SMP platforms if a CPU sits in its idle loop for a long time. This happens because we don't call irq_enter() and irq_exit() around generic_smp_call_function_interrupt() and friends. Add the necessary calls, and remove the one from within ipi_timer(), so that they're all in a common place. Signed-off-by: Russell King --- arch/arm/kernel/smp.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) (limited to 'arch/arm/kernel/smp.c') diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c index 57db122a4f62..26cdc494ee9b 100644 --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -443,9 +443,7 @@ static DEFINE_PER_CPU(struct clock_event_device, percpu_clockevent); static void ipi_timer(void) { struct clock_event_device *evt = &__get_cpu_var(percpu_clockevent); - irq_enter(); evt->event_handler(evt); - irq_exit(); } #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST @@ -548,7 +546,9 @@ void handle_IPI(int ipinr, struct pt_regs *regs) switch (ipinr) { case IPI_TIMER: + irq_enter(); ipi_timer(); + irq_exit(); break; case IPI_RESCHEDULE: @@ -556,15 +556,21 @@ void handle_IPI(int ipinr, struct pt_regs *regs) break; case IPI_CALL_FUNC: + irq_enter(); generic_smp_call_function_interrupt(); + irq_exit(); break; case IPI_CALL_FUNC_SINGLE: + irq_enter(); generic_smp_call_function_single_interrupt(); + irq_exit(); break; case IPI_CPU_STOP: + irq_enter(); ipi_cpu_stop(cpu); + irq_exit(); break; default: -- cgit v1.2.3 From eb50439b92b6298bf209a982f295ba9c0f7cb30b Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Fri, 20 Jan 2012 12:01:12 +0100 Subject: ARM: 7293/1: logical_cpu_map: decouple CPU mapping from SMP It turns out that the logical CPU mapping is useful even when !CONFIG_SMP for manipulation of devices like interrupt and power controllers when running a UP kernel on a CPU other than 0. This can happen when kexecing a UP image from an SMP kernel. In the future, multi-cluster systems running AMP configurations will require something similar for mapping cluster IDs, so it makes sense to decouple this logic in preparation for this support. Acked-by: Yang Bai Acked-by: Marc Zyngier Reported-by: Joerg Roedel Signed-off-by: Will Deacon Signed-off-by: Russell King --- arch/arm/common/gic.c | 7 ++----- arch/arm/include/asm/smp.h | 6 ------ arch/arm/include/asm/smp_plat.h | 6 ++++++ arch/arm/kernel/setup.c | 14 ++++++++++++++ arch/arm/kernel/smp.c | 14 -------------- arch/arm/mach-exynos/hotplug.c | 1 + arch/arm/mach-exynos/platsmp.c | 1 + arch/arm/mach-highbank/highbank.c | 3 +-- arch/arm/mach-imx/src.c | 5 +---- arch/arm/mach-msm/hotplug.c | 1 + arch/arm/mach-msm/platsmp.c | 1 + arch/arm/mach-realview/hotplug.c | 1 + arch/arm/mach-shmobile/smp-r8a7779.c | 1 + arch/arm/mach-shmobile/smp-sh73a0.c | 1 + arch/arm/mach-ux500/hotplug.c | 1 + arch/arm/mach-ux500/platsmp.c | 1 + arch/arm/mach-vexpress/hotplug.c | 1 + arch/arm/plat-versatile/platsmp.c | 1 + 18 files changed, 35 insertions(+), 31 deletions(-) (limited to 'arch/arm/kernel/smp.c') diff --git a/arch/arm/common/gic.c b/arch/arm/common/gic.c index b2dc2dd7f1df..c47d6199b784 100644 --- a/arch/arm/common/gic.c +++ b/arch/arm/common/gic.c @@ -41,6 +41,7 @@ #include #include +#include #include #include @@ -352,11 +353,7 @@ static void __init gic_dist_init(struct gic_chip_data *gic) unsigned int gic_irqs = gic->gic_irqs; struct irq_domain *domain = &gic->domain; void __iomem *base = gic_data_dist_base(gic); - u32 cpu = 0; - -#ifdef CONFIG_SMP - cpu = cpu_logical_map(smp_processor_id()); -#endif + u32 cpu = cpu_logical_map(smp_processor_id()); cpumask = 1 << cpu; cpumask |= cpumask << 8; diff --git a/arch/arm/include/asm/smp.h b/arch/arm/include/asm/smp.h index 1e5717afc4ac..ae29293270a3 100644 --- a/arch/arm/include/asm/smp.h +++ b/arch/arm/include/asm/smp.h @@ -70,12 +70,6 @@ extern void platform_secondary_init(unsigned int cpu); */ extern void platform_smp_prepare_cpus(unsigned int); -/* - * Logical CPU mapping. - */ -extern int __cpu_logical_map[NR_CPUS]; -#define cpu_logical_map(cpu) __cpu_logical_map[cpu] - /* * Initial data for bringing up a secondary CPU. */ diff --git a/arch/arm/include/asm/smp_plat.h b/arch/arm/include/asm/smp_plat.h index f24c1b9e211d..558d6c80aca9 100644 --- a/arch/arm/include/asm/smp_plat.h +++ b/arch/arm/include/asm/smp_plat.h @@ -43,4 +43,10 @@ static inline int cache_ops_need_broadcast(void) } #endif +/* + * Logical CPU mapping. + */ +extern int __cpu_logical_map[]; +#define cpu_logical_map(cpu) __cpu_logical_map[cpu] + #endif diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c index ab70c9124538..a255c39612ca 100644 --- a/arch/arm/kernel/setup.c +++ b/arch/arm/kernel/setup.c @@ -426,6 +426,20 @@ void cpu_init(void) : "r14"); } +int __cpu_logical_map[NR_CPUS]; + +void __init smp_setup_processor_id(void) +{ + int i; + u32 cpu = is_smp() ? read_cpuid_mpidr() & 0xff : 0; + + cpu_logical_map(0) = cpu; + for (i = 1; i < NR_CPUS; ++i) + cpu_logical_map(i) = i == cpu ? 0 : i; + + printk(KERN_INFO "Booting Linux on physical CPU %d\n", cpu); +} + static void __init setup_processor(void) { struct proc_info_list *list; diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c index 26cdc494ee9b..cdeb727527d3 100644 --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -233,20 +233,6 @@ void __ref cpu_die(void) } #endif /* CONFIG_HOTPLUG_CPU */ -int __cpu_logical_map[NR_CPUS]; - -void __init smp_setup_processor_id(void) -{ - int i; - u32 cpu = is_smp() ? read_cpuid_mpidr() & 0xff : 0; - - cpu_logical_map(0) = cpu; - for (i = 1; i < NR_CPUS; ++i) - cpu_logical_map(i) = i == cpu ? 0 : i; - - printk(KERN_INFO "Booting Linux on physical CPU %d\n", cpu); -} - /* * Called by both boot and secondaries to move global data into * per-processor storage. diff --git a/arch/arm/mach-exynos/hotplug.c b/arch/arm/mach-exynos/hotplug.c index da70e7e39937..dd1ad55524c9 100644 --- a/arch/arm/mach-exynos/hotplug.c +++ b/arch/arm/mach-exynos/hotplug.c @@ -16,6 +16,7 @@ #include #include +#include #include diff --git a/arch/arm/mach-exynos/platsmp.c b/arch/arm/mach-exynos/platsmp.c index 683aec786b78..0f2035a1eb6e 100644 --- a/arch/arm/mach-exynos/platsmp.c +++ b/arch/arm/mach-exynos/platsmp.c @@ -23,6 +23,7 @@ #include #include +#include #include #include diff --git a/arch/arm/mach-highbank/highbank.c b/arch/arm/mach-highbank/highbank.c index 7afbe1e55beb..8394d512a402 100644 --- a/arch/arm/mach-highbank/highbank.c +++ b/arch/arm/mach-highbank/highbank.c @@ -25,6 +25,7 @@ #include #include +#include #include #include #include @@ -72,9 +73,7 @@ static void __init highbank_map_io(void) void highbank_set_cpu_jump(int cpu, void *jump_addr) { -#ifdef CONFIG_SMP cpu = cpu_logical_map(cpu); -#endif writel(virt_to_phys(jump_addr), HB_JUMP_TABLE_VIRT(cpu)); __cpuc_flush_dcache_area(HB_JUMP_TABLE_VIRT(cpu), 16); outer_clean_range(HB_JUMP_TABLE_PHYS(cpu), diff --git a/arch/arm/mach-imx/src.c b/arch/arm/mach-imx/src.c index 29bd1243781e..e15f1555c59b 100644 --- a/arch/arm/mach-imx/src.c +++ b/arch/arm/mach-imx/src.c @@ -15,6 +15,7 @@ #include #include #include +#include #define SRC_SCR 0x000 #define SRC_GPR1 0x020 @@ -24,10 +25,6 @@ static void __iomem *src_base; -#ifndef CONFIG_SMP -#define cpu_logical_map(cpu) 0 -#endif - void imx_enable_cpu(int cpu, bool enable) { u32 mask, val; diff --git a/arch/arm/mach-msm/hotplug.c b/arch/arm/mach-msm/hotplug.c index 41c252de0215..a446fc14221f 100644 --- a/arch/arm/mach-msm/hotplug.c +++ b/arch/arm/mach-msm/hotplug.c @@ -11,6 +11,7 @@ #include #include +#include extern volatile int pen_release; diff --git a/arch/arm/mach-msm/platsmp.c b/arch/arm/mach-msm/platsmp.c index 0b3e357c4c8c..db0117ec55f4 100644 --- a/arch/arm/mach-msm/platsmp.c +++ b/arch/arm/mach-msm/platsmp.c @@ -20,6 +20,7 @@ #include #include #include +#include #include diff --git a/arch/arm/mach-realview/hotplug.c b/arch/arm/mach-realview/hotplug.c index ac1aed2a8da4..eb55f05bef3a 100644 --- a/arch/arm/mach-realview/hotplug.c +++ b/arch/arm/mach-realview/hotplug.c @@ -13,6 +13,7 @@ #include #include +#include extern volatile int pen_release; diff --git a/arch/arm/mach-shmobile/smp-r8a7779.c b/arch/arm/mach-shmobile/smp-r8a7779.c index cc97ef892d1b..4fe2e9eaf501 100644 --- a/arch/arm/mach-shmobile/smp-r8a7779.c +++ b/arch/arm/mach-shmobile/smp-r8a7779.c @@ -25,6 +25,7 @@ #include #include #include +#include #include #include #include diff --git a/arch/arm/mach-shmobile/smp-sh73a0.c b/arch/arm/mach-shmobile/smp-sh73a0.c index be1ade76ccc8..0d159d64a345 100644 --- a/arch/arm/mach-shmobile/smp-sh73a0.c +++ b/arch/arm/mach-shmobile/smp-sh73a0.c @@ -23,6 +23,7 @@ #include #include #include +#include #include #include #include diff --git a/arch/arm/mach-ux500/hotplug.c b/arch/arm/mach-ux500/hotplug.c index 572015e57cd9..c76f0f456f04 100644 --- a/arch/arm/mach-ux500/hotplug.c +++ b/arch/arm/mach-ux500/hotplug.c @@ -13,6 +13,7 @@ #include #include +#include extern volatile int pen_release; diff --git a/arch/arm/mach-ux500/platsmp.c b/arch/arm/mach-ux500/platsmp.c index a19e398dade3..d2058ef8345f 100644 --- a/arch/arm/mach-ux500/platsmp.c +++ b/arch/arm/mach-ux500/platsmp.c @@ -19,6 +19,7 @@ #include #include +#include #include #include #include diff --git a/arch/arm/mach-vexpress/hotplug.c b/arch/arm/mach-vexpress/hotplug.c index 813ee08f96e6..3034a4dab4a1 100644 --- a/arch/arm/mach-vexpress/hotplug.c +++ b/arch/arm/mach-vexpress/hotplug.c @@ -13,6 +13,7 @@ #include #include +#include #include extern volatile int pen_release; diff --git a/arch/arm/plat-versatile/platsmp.c b/arch/arm/plat-versatile/platsmp.c index 92f18d372b69..49c7db48c7f1 100644 --- a/arch/arm/plat-versatile/platsmp.c +++ b/arch/arm/plat-versatile/platsmp.c @@ -16,6 +16,7 @@ #include #include +#include #include /* -- cgit v1.2.3