GHES currently maps two pages with atomic_ioremap. From now on, NMI is optional so there is no need to allocate an NMI page for platforms without NMI support.
To make it possible to not use a second page, swap the existing page order so that the IRQ context page is first, and the optional NMI context page is second. Then, use CONFIG_ACPI_APEI_NMI to decide at runtime how many pages are to be allocated. Finally, put in sanity checks to avoid accessing unallocated memory.
Signed-off-by: Tomasz Nowicki tomasz.nowicki@linaro.org --- arch/x86/kernel/acpi/apei.c | 6 ++++++ drivers/acpi/apei/ghes.c | 16 ++++++++-------- include/acpi/apei.h | 1 + 3 files changed, 15 insertions(+), 8 deletions(-)
diff --git a/arch/x86/kernel/acpi/apei.c b/arch/x86/kernel/acpi/apei.c index 221a3a6..842d158 100644 --- a/arch/x86/kernel/acpi/apei.c +++ b/arch/x86/kernel/acpi/apei.c @@ -79,3 +79,9 @@ void arch_apei_nmi_oops_begin(void) { oops_begin(); } + +void arch_apei_flush_tlb_one(unsigned long addr) +{ + __flush_tlb_one(addr); +} +EXPORT_SYMBOL_GPL(arch_apei_flush_tlb_one); diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c index 3c42629..55bf47f 100644 --- a/drivers/acpi/apei/ghes.c +++ b/drivers/acpi/apei/ghes.c @@ -113,12 +113,11 @@ static DEFINE_RAW_SPINLOCK(ghes_nmi_lock); */
/* - * Two virtual pages are used, one for NMI context, the other for - * IRQ/PROCESS context + * Two virtual pages are used, one for IRQ/PROCESS context, the other for + * NMI context (optionally). */ -#define GHES_IOREMAP_PAGES 2 -#define GHES_IOREMAP_NMI_PAGE(base) (base) -#define GHES_IOREMAP_IRQ_PAGE(base) ((base) + PAGE_SIZE) +#define GHES_IOREMAP_IRQ_PAGE(base) (base) +#define GHES_IOREMAP_NMI_PAGE(base) ((base) + PAGE_SIZE)
/* virtual memory area for atomic ioremap */ static struct vm_struct *ghes_ioremap_area; @@ -155,7 +154,8 @@ static struct ghes_notify_setup ghes_notify_tab[];
static int ghes_ioremap_init(void) { - ghes_ioremap_area = __get_vm_area(PAGE_SIZE * GHES_IOREMAP_PAGES, + ghes_ioremap_area = __get_vm_area( + PAGE_SIZE * (IS_ENABLED(CONFIG_ACPI_APEI_NMI) ? 2 : 1), VM_IOREMAP, VMALLOC_START, VMALLOC_END); if (!ghes_ioremap_area) { pr_err(GHES_PFX "Failed to allocate virtual memory area for atomic ioremap.\n"); @@ -199,7 +199,7 @@ static void ghes_iounmap_nmi(void __iomem *vaddr_ptr)
BUG_ON(vaddr != (unsigned long)GHES_IOREMAP_NMI_PAGE(base)); unmap_kernel_range_noflush(vaddr, PAGE_SIZE); - __flush_tlb_one(vaddr); + arch_apei_flush_tlb_one(vaddr); }
static void ghes_iounmap_irq(void __iomem *vaddr_ptr) @@ -209,7 +209,7 @@ static void ghes_iounmap_irq(void __iomem *vaddr_ptr)
BUG_ON(vaddr != (unsigned long)GHES_IOREMAP_IRQ_PAGE(base)); unmap_kernel_range_noflush(vaddr, PAGE_SIZE); - __flush_tlb_one(vaddr); + arch_apei_flush_tlb_one(vaddr); }
static int ghes_estatus_pool_init(void) diff --git a/include/acpi/apei.h b/include/acpi/apei.h index 348e1ea..ff2bb7e 100644 --- a/include/acpi/apei.h +++ b/include/acpi/apei.h @@ -51,6 +51,7 @@ int arch_apei_register_nmi(int (*nmi_handler)(unsigned int, struct pt_regs *), const char *name); void arch_apei_unregister_nmi(const char *name); void arch_apei_nmi_oops_begin(void); +void arch_apei_flush_tlb_one(unsigned long addr);
#endif #endif