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 <[EMAIL PROTECTED]>
---
Fixed 40x handling based on Josh's feedback and help.
- k
arch/powerpc/kernel/head_40x.S | 19 +++++--------------
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, 86 insertions(+), 50 deletions(-)
diff --git a/arch/powerpc/kernel/head_40x.S b/arch/powerpc/kernel/head_40x.S
index 8552e67..8ef77e3 100644
--- a/arch/powerpc/kernel/head_40x.S
+++ b/arch/powerpc/kernel/head_40x.S
@@ -148,14 +148,15 @@ _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,[EMAIL PROTECTED]; \
- ori r11,r11,[EMAIL PROTECTED]; \
+ lis r11,[EMAIL PROTECTED]; \
+ tophys(r11,r11); \
+ lwz r11,[EMAIL PROTECTED](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; \
+ subi r11,r11,INT_FRAME_SIZE; /* Allocate an exception frame */\
tophys(r11,r11); \
stw r10,_CCR(r11); /* save various registers */\
stw r12,GPR12(r11); \
@@ -996,16 +997,6 @@ 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 c2b9dc4..47ea8af 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 721faef..9eacf4c 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,[EMAIL PROTECTED]; \
- addi r8,r8,[EMAIL PROTECTED]
+ slwi r8,r8,2; \
+ addis r8,r8,[EMAIL PROTECTED]; \
+ lwz r8,[EMAIL PROTECTED](r8); \
+ addi r8,r8,THREAD_SIZE;
#else
#define BOOKE_LOAD_EXC_LEVEL_STACK(level) \
- lis r8,[EMAIL PROTECTED]; \
- ori r8,r8,[EMAIL PROTECTED]
+ lis r8,[EMAIL PROTECTED]; \
+ lwz r8,[EMAIL PROTECTED](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 e581524..503f860 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 2f73f70..b519975 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 5112a4a..bef0be3 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 5089deb..1ef8e30 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.
--
1.5.4.5
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