From bcf0b0880710409420a4e3b15dbf4b9a63542c0b Mon Sep 17 00:00:00 2001 From: Kumar Gala Date: Wed, 30 Apr 2008 03:49:55 -0500 Subject: [PATCH] [POWERPC] Move to runtime allocated exception stacks For the additonal exception levels (critical, debug, machine check) on 40x/book-e we were using "static" allocations of the stack in the associated head.S. Move to a runtime allocation to make the code a bit easier to read as we mimic how we handle IRQ stacks. Its also a bit easier to setup the stack with a "dummy" thread_info in C code. Signed-off-by: Kumar Gala Acked-by: Paul Mackerras --- arch/powerpc/kernel/head_40x.S | 18 ++++----------- arch/powerpc/kernel/head_44x.S | 9 -------- arch/powerpc/kernel/head_booke.h | 29 ++++++++++-------------- arch/powerpc/kernel/head_fsl_booke.S | 9 -------- arch/powerpc/kernel/irq.c | 33 ++++++++++++++++++++++++++++ arch/powerpc/kernel/setup_32.c | 24 ++++++++++++++++++++ include/asm-powerpc/irq.h | 13 +++++++++++ 7 files changed, 85 insertions(+), 50 deletions(-) diff --git a/arch/powerpc/kernel/head_40x.S b/arch/powerpc/kernel/head_40x.S index 8552e67e3a..f2cf60d38f 100644 --- a/arch/powerpc/kernel/head_40x.S +++ b/arch/powerpc/kernel/head_40x.S @@ -148,14 +148,14 @@ _ENTRY(crit_r11) mfcr r10; /* save CR in r10 for now */\ mfspr r11,SPRN_SRR3; /* check whether user or kernel */\ andi. r11,r11,MSR_PR; \ - lis r11,critical_stack_top@h; \ - ori r11,r11,critical_stack_top@l; \ + lis r11,critirq_ctx@ha; \ + tophys(r11,r11); \ + lwz r11,critirq_ctx@l(r11); \ beq 1f; \ /* COMING FROM USER MODE */ \ mfspr r11,SPRN_SPRG3; /* if from user, start at top of */\ lwz r11,THREAD_INFO-THREAD(r11); /* this thread's kernel stack */\ - addi r11,r11,THREAD_SIZE; \ -1: subi r11,r11,INT_FRAME_SIZE; /* Allocate an exception frame */\ +1: addi r11,r11,THREAD_SIZE-INT_FRAME_SIZE; /* Alloc an excpt frm */\ tophys(r11,r11); \ stw r10,_CCR(r11); /* save various registers */\ stw r12,GPR12(r11); \ @@ -996,16 +996,6 @@ empty_zero_page: swapper_pg_dir: .space PGD_TABLE_SIZE - -/* Stack for handling critical exceptions from kernel mode */ - .section .bss - .align 12 -exception_stack_bottom: - .space 4096 -critical_stack_top: - .globl exception_stack_top -exception_stack_top: - /* Room for two PTE pointers, usually the kernel and current user pointers * to their respective root page table. */ diff --git a/arch/powerpc/kernel/head_44x.S b/arch/powerpc/kernel/head_44x.S index c2b9dc4fce..47ea8affad 100644 --- a/arch/powerpc/kernel/head_44x.S +++ b/arch/powerpc/kernel/head_44x.S @@ -737,15 +737,6 @@ empty_zero_page: swapper_pg_dir: .space PGD_TABLE_SIZE -/* Reserved 4k for the critical exception stack & 4k for the machine - * check stack per CPU for kernel mode exceptions */ - .section .bss - .align 12 -exception_stack_bottom: - .space BOOKE_EXCEPTION_STACK_SIZE - .globl exception_stack_top -exception_stack_top: - /* * Room for two PTE pointers, usually the kernel and current user pointers * to their respective root page table. diff --git a/arch/powerpc/kernel/head_booke.h b/arch/powerpc/kernel/head_booke.h index 721faef870..9eacf4ca44 100644 --- a/arch/powerpc/kernel/head_booke.h +++ b/arch/powerpc/kernel/head_booke.h @@ -43,9 +43,7 @@ SAVE_2GPRS(7, r11) /* To handle the additional exception priority levels on 40x and Book-E - * processors we allocate a 4k stack per additional priority level. The various - * head_xxx.S files allocate space (exception_stack_top) for each priority's - * stack times the number of CPUs + * processors we allocate a stack per additional priority level. * * On 40x critical is the only additional level * On 44x/e500 we have critical and machine check @@ -61,36 +59,31 @@ * going to critical or their own debug level we aren't currently * providing configurations that micro-optimize space usage. */ -#ifdef CONFIG_44x -#define NUM_EXCEPTION_LVLS 2 -#else -#define NUM_EXCEPTION_LVLS 3 -#endif -#define BOOKE_EXCEPTION_STACK_SIZE (4096 * NUM_EXCEPTION_LVLS) /* CRIT_SPRG only used in critical exception handling */ #define CRIT_SPRG SPRN_SPRG2 /* MCHECK_SPRG only used in machine check exception handling */ #define MCHECK_SPRG SPRN_SPRG6W -#define MCHECK_STACK_TOP (exception_stack_top - 4096) -#define CRIT_STACK_TOP (exception_stack_top) +#define MCHECK_STACK_BASE mcheckirq_ctx +#define CRIT_STACK_BASE critirq_ctx /* only on e200 for now */ -#define DEBUG_STACK_TOP (exception_stack_top - 8192) +#define DEBUG_STACK_BASE dbgirq_ctx #define DEBUG_SPRG SPRN_SPRG6W #ifdef CONFIG_SMP #define BOOKE_LOAD_EXC_LEVEL_STACK(level) \ mfspr r8,SPRN_PIR; \ - mulli r8,r8,BOOKE_EXCEPTION_STACK_SIZE; \ - neg r8,r8; \ - addis r8,r8,level##_STACK_TOP@ha; \ - addi r8,r8,level##_STACK_TOP@l + slwi r8,r8,2; \ + addis r8,r8,level##_STACK_BASE@ha; \ + lwz r8,level##_STACK_BASE@l(r8); \ + addi r8,r8,THREAD_SIZE; #else #define BOOKE_LOAD_EXC_LEVEL_STACK(level) \ - lis r8,level##_STACK_TOP@h; \ - ori r8,r8,level##_STACK_TOP@l + lis r8,level##_STACK_BASE@ha; \ + lwz r8,level##_STACK_BASE@l(r8); \ + addi r8,r8,THREAD_SIZE; #endif /* diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S index e581524d85..503f86030b 100644 --- a/arch/powerpc/kernel/head_fsl_booke.S +++ b/arch/powerpc/kernel/head_fsl_booke.S @@ -1080,15 +1080,6 @@ empty_zero_page: swapper_pg_dir: .space PGD_TABLE_SIZE -/* Reserved 4k for the critical exception stack & 4k for the machine - * check stack per CPU for kernel mode exceptions */ - .section .bss - .align 12 -exception_stack_bottom: - .space BOOKE_EXCEPTION_STACK_SIZE * NR_CPUS - .globl exception_stack_top -exception_stack_top: - /* * Room for two PTE pointers, usually the kernel and current user pointers * to their respective root page table. diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c index 2f73f705d5..b5199752ac 100644 --- a/arch/powerpc/kernel/irq.c +++ b/arch/powerpc/kernel/irq.c @@ -356,9 +356,42 @@ void __init init_IRQ(void) { if (ppc_md.init_IRQ) ppc_md.init_IRQ(); + + exc_lvl_ctx_init(); + irq_ctx_init(); } +#if defined(CONFIG_BOOKE) || defined(CONFIG_40x) +struct thread_info *critirq_ctx[NR_CPUS] __read_mostly; +struct thread_info *dbgirq_ctx[NR_CPUS] __read_mostly; +struct thread_info *mcheckirq_ctx[NR_CPUS] __read_mostly; + +void exc_lvl_ctx_init(void) +{ + struct thread_info *tp; + int i; + + for_each_possible_cpu(i) { + memset((void *)critirq_ctx[i], 0, THREAD_SIZE); + tp = critirq_ctx[i]; + tp->cpu = i; + tp->preempt_count = 0; + +#ifdef CONFIG_BOOKE + memset((void *)dbgirq_ctx[i], 0, THREAD_SIZE); + tp = dbgirq_ctx[i]; + tp->cpu = i; + tp->preempt_count = 0; + + memset((void *)mcheckirq_ctx[i], 0, THREAD_SIZE); + tp = mcheckirq_ctx[i]; + tp->cpu = i; + tp->preempt_count = HARDIRQ_OFFSET; +#endif + } +} +#endif #ifdef CONFIG_IRQSTACKS struct thread_info *softirq_ctx[NR_CPUS] __read_mostly; diff --git a/arch/powerpc/kernel/setup_32.c b/arch/powerpc/kernel/setup_32.c index 5112a4aa80..bef0be3fd9 100644 --- a/arch/powerpc/kernel/setup_32.c +++ b/arch/powerpc/kernel/setup_32.c @@ -248,6 +248,28 @@ static void __init irqstack_early_init(void) #define irqstack_early_init() #endif +#if defined(CONFIG_BOOKE) || defined(CONFIG_40x) +static void __init exc_lvl_early_init(void) +{ + unsigned int i; + + /* interrupt stacks must be in lowmem, we get that for free on ppc32 + * as the lmb is limited to lowmem by LMB_REAL_LIMIT */ + for_each_possible_cpu(i) { + critirq_ctx[i] = (struct thread_info *) + __va(lmb_alloc(THREAD_SIZE, THREAD_SIZE)); +#ifdef CONFIG_BOOKE + dbgirq_ctx[i] = (struct thread_info *) + __va(lmb_alloc(THREAD_SIZE, THREAD_SIZE)); + mcheckirq_ctx[i] = (struct thread_info *) + __va(lmb_alloc(THREAD_SIZE, THREAD_SIZE)); +#endif + } +} +#else +#define exc_lvl_early_init() +#endif + /* Warning, IO base is not yet inited */ void __init setup_arch(char **cmdline_p) { @@ -305,6 +327,8 @@ void __init setup_arch(char **cmdline_p) init_mm.end_data = (unsigned long) _edata; init_mm.brk = klimit; + exc_lvl_early_init(); + irqstack_early_init(); /* set up the bootmem stuff with available memory */ diff --git a/include/asm-powerpc/irq.h b/include/asm-powerpc/irq.h index 5089deb8fe..1ef8e304e0 100644 --- a/include/asm-powerpc/irq.h +++ b/include/asm-powerpc/irq.h @@ -619,6 +619,19 @@ struct pt_regs; #define __ARCH_HAS_DO_SOFTIRQ +#if defined(CONFIG_BOOKE) || defined(CONFIG_40x) +/* + * Per-cpu stacks for handling critical, debug and machine check + * level interrupts. + */ +extern struct thread_info *critirq_ctx[NR_CPUS]; +extern struct thread_info *dbgirq_ctx[NR_CPUS]; +extern struct thread_info *mcheckirq_ctx[NR_CPUS]; +extern void exc_lvl_ctx_init(void); +#else +#define exc_lvl_ctx_init() +#endif + #ifdef CONFIG_IRQSTACKS /* * Per-cpu stacks for handling hard and soft interrupts. -- 2.39.5