From 76da3fb3575e39fb23b2c072997ccd1187a2ce9d Mon Sep 17 00:00:00 2001 From: Huang Ying Date: Thu, 8 Dec 2011 11:25:46 +0800 Subject: [PATCH] ACPI, Add RAM mapping support to ACPI atomic IO support On one of our testing machine, the following EINJ command lines: # echo 0x10000000 > param1 # echo 0xfffffffffffff000 > param2 # echo 0x8 > error_type # echo 1 > error_inject Will get: echo: write error: Input/output error The EIO comes from: rc = apei_exec_pre_map_gars(&trigger_ctx); The root cause is as follow. Normally, ACPI atomic IO support is used to access IO memory. But in EINJ of that machine, it is used to access RAM to trigger the injected error. And the ioremap() called by apei_exec_pre_map_gars() can not map the RAM. This patch add RAM mapping support to ACPI atomic IO support to satisfy EINJ requirement. Signed-off-by: Huang Ying Tested-by: Tony Luck Signed-off-by: Len Brown --- drivers/acpi/atomicio.c | 41 +++++++++++++++++++++++++++++++++++++---- 1 file changed, 37 insertions(+), 4 deletions(-) diff --git a/drivers/acpi/atomicio.c b/drivers/acpi/atomicio.c index 1016f186c17c..d4a5b3d3657b 100644 --- a/drivers/acpi/atomicio.c +++ b/drivers/acpi/atomicio.c @@ -32,6 +32,8 @@ #include #include #include +#include +#include #include #define ACPI_PFX "ACPI: " @@ -97,6 +99,37 @@ static void __iomem *__acpi_try_ioremap(phys_addr_t paddr, return NULL; } +#ifndef CONFIG_IA64 +#define should_use_kmap(pfn) page_is_ram(pfn) +#else +/* ioremap will take care of cache attributes */ +#define should_use_kmap(pfn) 0 +#endif + +static void __iomem *acpi_map(phys_addr_t pg_off, unsigned long pg_sz) +{ + unsigned long pfn; + + pfn = pg_off >> PAGE_SHIFT; + if (should_use_kmap(pfn)) { + if (pg_sz > PAGE_SIZE) + return NULL; + return (void __iomem __force *)kmap(pfn_to_page(pfn)); + } else + return ioremap(pg_off, pg_sz); +} + +static void acpi_unmap(phys_addr_t pg_off, void __iomem *vaddr) +{ + unsigned long pfn; + + pfn = pg_off >> PAGE_SHIFT; + if (page_is_ram(pfn)) + kunmap(pfn_to_page(pfn)); + else + iounmap(vaddr); +} + /* * Used to pre-map the specified IO memory area. First try to find * whether the area is already pre-mapped, if it is, increase the @@ -119,7 +152,7 @@ static void __iomem *acpi_pre_map(phys_addr_t paddr, pg_off = paddr & PAGE_MASK; pg_sz = ((paddr + size + PAGE_SIZE - 1) & PAGE_MASK) - pg_off; - vaddr = ioremap(pg_off, pg_sz); + vaddr = acpi_map(pg_off, pg_sz); if (!vaddr) return NULL; map = kmalloc(sizeof(*map), GFP_KERNEL); @@ -135,7 +168,7 @@ static void __iomem *acpi_pre_map(phys_addr_t paddr, vaddr = __acpi_try_ioremap(paddr, size); if (vaddr) { spin_unlock_irqrestore(&acpi_iomaps_lock, flags); - iounmap(map->vaddr); + acpi_unmap(pg_off, map->vaddr); kfree(map); return vaddr; } @@ -144,7 +177,7 @@ static void __iomem *acpi_pre_map(phys_addr_t paddr, return map->vaddr + (paddr - map->paddr); err_unmap: - iounmap(vaddr); + acpi_unmap(pg_off, vaddr); return NULL; } @@ -177,7 +210,7 @@ static void acpi_post_unmap(phys_addr_t paddr, unsigned long size) return; synchronize_rcu(); - iounmap(map->vaddr); + acpi_unmap(map->paddr, map->vaddr); kfree(map); } -- 2.20.1