diff options
| -rw-r--r-- | arch/sh/Kconfig.debug | 10 | ||||
| -rw-r--r-- | arch/sh/kernel/cpu/irq/ipr.c | 2 | ||||
| -rw-r--r-- | arch/sh/kernel/entry.S | 4 | ||||
| -rw-r--r-- | arch/sh/kernel/head.S | 5 | ||||
| -rw-r--r-- | arch/sh/kernel/irq.c | 153 | ||||
| -rw-r--r-- | arch/sh/kernel/traps.c | 18 | ||||
| -rw-r--r-- | arch/sh/kernel/vmlinux.lds.S | 1 | ||||
| -rw-r--r-- | include/asm-sh/irq.h | 9 | ||||
| -rw-r--r-- | include/asm-sh/thread_info.h | 12 |
9 files changed, 190 insertions, 24 deletions
diff --git a/arch/sh/Kconfig.debug b/arch/sh/Kconfig.debug index f0188e626be0..48479e014dac 100644 --- a/arch/sh/Kconfig.debug +++ b/arch/sh/Kconfig.debug @@ -46,6 +46,16 @@ config DEBUG_STACK_USAGE This option will slow down process creation somewhat. +config 4KSTACKS + bool "Use 4Kb for kernel stacks instead of 8Kb" + depends on DEBUG_KERNEL + help + If you say Y here the kernel will use a 4Kb stacksize for the + kernel stack attached to each process/thread. This facilitates + running more threads on a system and also reduces the pressure + on the VM subsystem for higher order allocations. This option + will also use IRQ stacks to compensate for the reduced stackspace. + config KGDB bool "Include KGDB kernel debugger" select FRAME_POINTER diff --git a/arch/sh/kernel/cpu/irq/ipr.c b/arch/sh/kernel/cpu/irq/ipr.c index 4c4fd4118d1a..f785822cd5de 100644 --- a/arch/sh/kernel/cpu/irq/ipr.c +++ b/arch/sh/kernel/cpu/irq/ipr.c @@ -190,6 +190,8 @@ void __init init_IRQ(void) /* Perform the machine specific initialisation */ if (sh_mv.mv_init_irq != NULL) sh_mv.mv_init_irq(); + + irq_ctx_init(smp_processor_id()); } #if !defined(CONFIG_CPU_HAS_PINT_IRQ) diff --git a/arch/sh/kernel/entry.S b/arch/sh/kernel/entry.S index fd5fe2349f20..fe8221855b28 100644 --- a/arch/sh/kernel/entry.S +++ b/arch/sh/kernel/entry.S @@ -716,8 +716,8 @@ ENTRY(handle_exception) bt/s 1f ! It's a kernel to kernel transition. mov r15, k0 ! save original stack to k0 /* User space to kernel */ - mov #0x20, k1 - shll8 k1 ! k1 := 8192 (== THREAD_SIZE) + mov #(THREAD_SIZE >> 8), k1 + shll8 k1 ! k1 := THREAD_SIZE add current, k1 mov k1, r15 ! change to kernel stack ! diff --git a/arch/sh/kernel/head.S b/arch/sh/kernel/head.S index 3e7d00b7985a..f5f53d14f245 100644 --- a/arch/sh/kernel/head.S +++ b/arch/sh/kernel/head.S @@ -12,7 +12,6 @@ */ #include <linux/linkage.h> #include <asm/thread_info.h> -#include <asm/page.h> #ifdef CONFIG_CPU_SH4A #define SYNCO() synco @@ -69,8 +68,8 @@ ENTRY(_stext) ! mov.l 2f, r0 mov r0, r15 ! Set initial r15 (stack pointer) - mov #0x20, r1 ! - shll8 r1 ! r1 = 8192 + mov #(THREAD_SIZE >> 8), r1 + shll8 r1 ! r1 = THREAD_SIZE sub r1, r0 ! ldc r0, r7_bank ! ... and initial thread_info diff --git a/arch/sh/kernel/irq.c b/arch/sh/kernel/irq.c index 7066611aeb72..c7ebd6aec951 100644 --- a/arch/sh/kernel/irq.c +++ b/arch/sh/kernel/irq.c @@ -1,5 +1,4 @@ -/* $Id: irq.c,v 1.20 2004/01/13 05:52:11 kkojima Exp $ - * +/* * linux/arch/sh/kernel/irq.c * * Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar @@ -7,13 +6,15 @@ * * SuperH version: Copyright (C) 1999 Niibe Yutaka */ - #include <linux/irq.h> #include <linux/interrupt.h> +#include <linux/module.h> #include <linux/kernel_stat.h> #include <linux/seq_file.h> #include <asm/irq.h> #include <asm/processor.h> +#include <asm/uaccess.h> +#include <asm/thread_info.h> #include <asm/cpu/mmu_context.h> /* @@ -60,11 +61,27 @@ unlock: } #endif +#ifdef CONFIG_4KSTACKS +/* + * per-CPU IRQ handling contexts (thread information and stack) + */ +union irq_ctx { + struct thread_info tinfo; + u32 stack[THREAD_SIZE/sizeof(u32)]; +}; + +static union irq_ctx *hardirq_ctx[NR_CPUS]; +static union irq_ctx *softirq_ctx[NR_CPUS]; +#endif + asmlinkage int do_IRQ(unsigned long r4, unsigned long r5, unsigned long r6, unsigned long r7, struct pt_regs regs) { int irq = r4; +#ifdef CONFIG_4KSTACKS + union irq_ctx *curctx, *irqctx; +#endif irq_enter(); @@ -102,7 +119,135 @@ asmlinkage int do_IRQ(unsigned long r4, unsigned long r5, #endif irq = irq_demux(irq); - __do_IRQ(irq, ®s); + +#ifdef CONFIG_4KSTACKS + curctx = (union irq_ctx *)current_thread_info(); + irqctx = hardirq_ctx[smp_processor_id()]; + + /* + * this is where we switch to the IRQ stack. However, if we are + * already using the IRQ stack (because we interrupted a hardirq + * handler) we can't do that and just have to keep using the + * current stack (which is the irq stack already after all) + */ + if (curctx != irqctx) { + u32 *isp; + + isp = (u32 *)((char *)irqctx + sizeof(*irqctx)); + irqctx->tinfo.task = curctx->tinfo.task; + irqctx->tinfo.previous_sp = current_stack_pointer; + + __asm__ __volatile__ ( + "mov %0, r4 \n" + "mov %1, r5 \n" + "mov r15, r9 \n" + "jsr @%2 \n" + /* swith to the irq stack */ + " mov %3, r15 \n" + /* restore the stack (ring zero) */ + "mov r9, r15 \n" + : /* no outputs */ + : "r" (irq), "r" (®s), "r" (__do_IRQ), "r" (isp) + /* XXX: A somewhat excessive clobber list? -PFM */ + : "memory", "r0", "r1", "r2", "r3", "r4", + "r5", "r6", "r7", "r8", "t", "pr" + ); + } else +#endif + __do_IRQ(irq, ®s); + irq_exit(); + return 1; } + +#ifdef CONFIG_4KSTACKS +/* + * These should really be __section__(".bss.page_aligned") as well, but + * gcc's 3.0 and earlier don't handle that correctly. + */ +static char softirq_stack[NR_CPUS * THREAD_SIZE] + __attribute__((__aligned__(THREAD_SIZE))); + +static char hardirq_stack[NR_CPUS * THREAD_SIZE] + __attribute__((__aligned__(THREAD_SIZE))); + +/* + * allocate per-cpu stacks for hardirq and for softirq processing + */ +void irq_ctx_init(int cpu) +{ + union irq_ctx *irqctx; + + if (hardirq_ctx[cpu]) + return; + + irqctx = (union irq_ctx *)&hardirq_stack[cpu * THREAD_SIZE]; + irqctx->tinfo.task = NULL; + irqctx->tinfo.exec_domain = NULL; + irqctx->tinfo.cpu = cpu; + irqctx->tinfo.preempt_count = HARDIRQ_OFFSET; + irqctx->tinfo.addr_limit = MAKE_MM_SEG(0); + + hardirq_ctx[cpu] = irqctx; + + irqctx = (union irq_ctx *)&softirq_stack[cpu * THREAD_SIZE]; + irqctx->tinfo.task = NULL; + irqctx->tinfo.exec_domain = NULL; + irqctx->tinfo.cpu = cpu; + irqctx->tinfo.preempt_count = SOFTIRQ_OFFSET; + irqctx->tinfo.addr_limit = MAKE_MM_SEG(0); + + softirq_ctx[cpu] = irqctx; + + printk("CPU %u irqstacks, hard=%p soft=%p\n", + cpu, hardirq_ctx[cpu], softirq_ctx[cpu]); +} + +void irq_ctx_exit(int cpu) +{ + hardirq_ctx[cpu] = NULL; +} + +extern asmlinkage void __do_softirq(void); + +asmlinkage void do_softirq(void) +{ + unsigned long flags; + struct thread_info *curctx; + union irq_ctx *irqctx; + u32 *isp; + + if (in_interrupt()) + return; + + local_irq_save(flags); + + if (local_softirq_pending()) { + curctx = current_thread_info(); + irqctx = softirq_ctx[smp_processor_id()]; + irqctx->tinfo.task = curctx->task; + irqctx->tinfo.previous_sp = current_stack_pointer; + + /* build the stack frame on the softirq stack */ + isp = (u32 *)((char *)irqctx + sizeof(*irqctx)); + + __asm__ __volatile__ ( + "mov r15, r9 \n" + "jsr @%0 \n" + /* switch to the softirq stack */ + " mov %1, r15 \n" + /* restore the thread stack */ + "mov r9, r15 \n" + : /* no outputs */ + : "r" (__do_softirq), "r" (isp) + /* XXX: A somewhat excessive clobber list? -PFM */ + : "memory", "r0", "r1", "r2", "r3", "r4", + "r5", "r6", "r7", "r8", "r9", "r15", "t", "pr" + ); + } + + local_irq_restore(flags); +} +EXPORT_SYMBOL(do_softirq); +#endif diff --git a/arch/sh/kernel/traps.c b/arch/sh/kernel/traps.c index 95c810b3c97e..c2c597e09482 100644 --- a/arch/sh/kernel/traps.c +++ b/arch/sh/kernel/traps.c @@ -741,20 +741,12 @@ void show_stack(struct task_struct *tsk, unsigned long *sp) unsigned long module_end = VMALLOC_END; int i = 1; - if (tsk && !sp) { + if (!tsk) + tsk = current; + if (tsk == current) + sp = (unsigned long *)current_stack_pointer; + else sp = (unsigned long *)tsk->thread.sp; - } - - if (!sp) { - __asm__ __volatile__ ( - "mov r15, %0\n\t" - "stc r7_bank, %1\n\t" - : "=r" (module_start), - "=r" (module_end) - ); - - sp = (unsigned long *)module_start; - } stack = sp; diff --git a/arch/sh/kernel/vmlinux.lds.S b/arch/sh/kernel/vmlinux.lds.S index 0220d8a838a7..5eb930918186 100644 --- a/arch/sh/kernel/vmlinux.lds.S +++ b/arch/sh/kernel/vmlinux.lds.S @@ -3,7 +3,6 @@ * Written by Niibe Yutaka */ #include <asm/thread_info.h> -#include <asm/page.h> #include <asm-generic/vmlinux.lds.h> #ifdef CONFIG_CPU_LITTLE_ENDIAN diff --git a/include/asm-sh/irq.h b/include/asm-sh/irq.h index dd05e102fc0e..0e5f365aff70 100644 --- a/include/asm-sh/irq.h +++ b/include/asm-sh/irq.h @@ -719,6 +719,15 @@ static inline int generic_irq_demux(int irq) #define irq_canonicalize(irq) (irq) #define irq_demux(irq) __irq_demux(sh_mv.mv_irq_demux(irq)) +#ifdef CONFIG_4KSTACKS +extern void irq_ctx_init(int cpu); +extern void irq_ctx_exit(int cpu); +# define __ARCH_HAS_DO_SOFTIRQ +#else +# define irq_ctx_init(cpu) do { } while (0) +# define irq_ctx_exit(cpu) do { } while (0) +#endif + #if defined(CONFIG_CPU_SUBTYPE_SH73180) #include <asm/irq-sh73180.h> #endif diff --git a/include/asm-sh/thread_info.h b/include/asm-sh/thread_info.h index 605259f88113..3ebc3f9039eb 100644 --- a/include/asm-sh/thread_info.h +++ b/include/asm-sh/thread_info.h @@ -9,8 +9,8 @@ * Copyright (C) 2002 David Howells (dhowells@redhat.com) * - Incorporating suggestions made by Linus Torvalds and Dave Miller */ - #ifdef __KERNEL__ +#include <asm/page.h> #ifndef __ASSEMBLY__ #include <asm/processor.h> @@ -23,13 +23,20 @@ struct thread_info { int preempt_count; /* 0 => preemptable, <0 => BUG */ mm_segment_t addr_limit; /* thread address space */ struct restart_block restart_block; + unsigned long previous_sp; /* sp of previous stack in case + of nested IRQ stacks */ __u8 supervisor_stack[0]; }; #endif #define PREEMPT_ACTIVE 0x10000000 + +#ifdef CONFIG_4KSTACKS +#define THREAD_SIZE (PAGE_SIZE) +#else #define THREAD_SIZE (PAGE_SIZE * 2) +#endif #define STACK_WARN (THREAD_SIZE / 8) /* @@ -52,6 +59,9 @@ struct thread_info { #define init_thread_info (init_thread_union.thread_info) #define init_stack (init_thread_union.stack) +/* how to get the current stack pointer from C */ +register unsigned long current_stack_pointer asm("r15") __attribute_used__; + /* how to get the thread information struct from C */ static inline struct thread_info *current_thread_info(void) { |