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authorXie Xiaobo <xiaobo.xie@nxp.com>2017-12-12 08:12:33 (GMT)
committerXie Xiaobo <xiaobo.xie@nxp.com>2017-12-12 08:12:33 (GMT)
commitc0246a9ec4d461ef4dd7647f94005380bb9e7f0b (patch)
tree7588601aa6ce98f5e9fd083a1b351d9023c0b295 /arch/mips/include/asm/irq.h
parent50fd1a6d79d48a7c35890aecce5a5d6b872a461d (diff)
parent56f4a560c6d6318b5a8e18a1b3e44909a5158d1e (diff)
downloadlinux-c0246a9ec4d461ef4dd7647f94005380bb9e7f0b.tar.xz
Merge Linaro linux 4.9.62 into linux-4.9
Signed-off-by: Xiaobo Xie <xiaobo.xie@nxp.com>
Diffstat (limited to 'arch/mips/include/asm/irq.h')
-rw-r--r--arch/mips/include/asm/irq.h15
1 files changed, 15 insertions, 0 deletions
diff --git a/arch/mips/include/asm/irq.h b/arch/mips/include/asm/irq.h
index 956db6e..c5d3517 100644
--- a/arch/mips/include/asm/irq.h
+++ b/arch/mips/include/asm/irq.h
@@ -18,9 +18,24 @@
#include <irq.h>
#define IRQ_STACK_SIZE THREAD_SIZE
+#define IRQ_STACK_START (IRQ_STACK_SIZE - 16)
extern void *irq_stack[NR_CPUS];
+/*
+ * The highest address on the IRQ stack contains a dummy frame put down in
+ * genex.S (handle_int & except_vec_vi_handler) which is structured as follows:
+ *
+ * top ------------
+ * | task sp | <- irq_stack[cpu] + IRQ_STACK_START
+ * ------------
+ * | | <- First frame of IRQ context
+ * ------------
+ *
+ * task sp holds a copy of the task stack pointer where the struct pt_regs
+ * from exception entry can be found.
+ */
+
static inline bool on_irq_stack(int cpu, unsigned long sp)
{
unsigned long low = (unsigned long)irq_stack[cpu];