Messages in this thread Patch in this message | | | Date | Sun, 31 Mar 2019 23:40:28 +0200 | From | Thomas Gleixner <> | Subject | [patch 08/14] x86/cpu_entry_area: Provide exception stack accessor |
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Store a pointer to the per cpu entry area exception stack mappings to allow fast retrieval.
Required for converting various places from using the shadow IST array to directly doing address calculations on the actual mapping address.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> --- arch/x86/include/asm/cpu_entry_area.h | 4 ++++ arch/x86/mm/cpu_entry_area.c | 4 ++++ 2 files changed, 8 insertions(+)
--- a/arch/x86/include/asm/cpu_entry_area.h +++ b/arch/x86/include/asm/cpu_entry_area.h @@ -82,6 +82,7 @@ struct cpu_entry_area { #define CPU_ENTRY_AREA_TOT_SIZE (CPU_ENTRY_AREA_SIZE * NR_CPUS) DECLARE_PER_CPU(struct cpu_entry_area *, cpu_entry_area); +DECLARE_PER_CPU(struct cea_exception_stacks *, cea_exception_stacks); extern void setup_cpu_entry_areas(void); extern void cea_set_pte(void *cea_vaddr, phys_addr_t pa, pgprot_t flags); @@ -101,4 +102,7 @@ static inline struct entry_stack *cpu_en return &get_cpu_entry_area(cpu)->entry_stack_page.stack; } +#define __this_cpu_ist_top_va(name) \ + (unsigned long)__this_cpu_read(cea_exception_stacks)->name## _stack_guard + #endif --- a/arch/x86/mm/cpu_entry_area.c +++ b/arch/x86/mm/cpu_entry_area.c @@ -14,6 +14,7 @@ static DEFINE_PER_CPU_PAGE_ALIGNED(struc #ifdef CONFIG_X86_64 static DEFINE_PER_CPU_PAGE_ALIGNED(struct exception_stacks, exception_stacks); +DEFINE_PER_CPU(struct cea_exception_stacks*, cea_exception_stacks); #endif struct cpu_entry_area *get_cpu_entry_area(int cpu) @@ -91,6 +92,9 @@ static void __init percpu_setup_exceptio unsigned int npages; BUILD_BUG_ON(sizeof(exception_stacks) % PAGE_SIZE != 0); + + per_cpu(cea_exception_stacks, cpu) = &cea->estacks; + /* * The exceptions stack mappings in the per cpu area are protected * by guard pages so each stack must be mapped seperately.
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