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 <[email protected]> --- drivers/acpi/apei/ghes.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c index 624878b..20377ac 100644 --- a/drivers/acpi/apei/ghes.c +++ b/drivers/acpi/apei/ghes.c @@ -109,12 +109,11 @@ static DEFINE_MUTEX(ghes_list_mutex); */ /* - * 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; @@ -141,7 +140,8 @@ 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"); @@ -310,6 +310,8 @@ static void ghes_copy_tofrom_phys(void *buffer, u64 paddr, u32 len, u64 offset; u32 trunk; + BUG_ON(in_nmi && !IS_ENABLED(CONFIG_ACPI_APEI_NMI)); + while (len > 0) { offset = paddr - (paddr & PAGE_MASK); if (in_nmi) { -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
