From 700130b41f4ee54520ac2ef2f7f1d072789711a4 Mon Sep 17 00:00:00 2001 From: Myron Stowe Date: Mon, 7 Nov 2011 16:23:41 -0700 Subject: ACPI APEI: Convert atomicio routines APEI needs memory access in interrupt context. The obvious choice is acpi_read(), but originally it couldn't be used in interrupt context because it makes temporary mappings with ioremap(). Therefore, we added drivers/acpi/atomicio.c, which provides: acpi_pre_map_gar() -- ioremap in process context acpi_atomic_read() -- memory access in interrupt context acpi_post_unmap_gar() -- iounmap Later we added acpi_os_map_generic_address() (2971852) and enhanced acpi_read() so it works in interrupt context as long as the address has been previously mapped (620242a). Now this sequence: acpi_os_map_generic_address() -- ioremap in process context acpi_read()/apei_read() -- now OK in interrupt context acpi_os_unmap_generic_address() is equivalent to what atomicio.c provides. This patch introduces apei_read() and apei_write(), which currently are functional equivalents of acpi_read() and acpi_write(). This is mainly proactive, to prevent APEI breakages if acpi_read() and acpi_write() are ever augmented to support the 'bit_offset' field of GAS, as APEI's __apei_exec_write_register() precludes splitting up functionality related to 'bit_offset' and APEI's 'mask' (see its APEI_EXEC_PRESERVE_REGISTER block). With apei_read() and apei_write() in place, usages of atomicio routines are converted to apei_read()/apei_write() and existing calls within osl.c and the CA, based on the re-factoring that was done in an earlier patch series - http://marc.info/?l=linux-acpi&m=128769263327206&w=2: acpi_pre_map_gar() --> acpi_os_map_generic_address() acpi_post_unmap_gar() --> acpi_os_unmap_generic_address() acpi_atomic_read() --> apei_read() acpi_atomic_write() --> apei_write() Note that acpi_read() and acpi_write() currently use 'bit_width' for accessing GARs which seems incorrect. 'bit_width' is the size of the register, while 'access_width' is the size of the access the processor must generate on the bus. The 'access_width' may be larger, for example, if the hardware only supports 32-bit or 64-bit reads. I wanted to minimize any possible impacts with this patch series so I did *not* change this behavior. Signed-off-by: Myron Stowe Signed-off-by: Len Brown --- drivers/acpi/apei/apei-base.c | 102 +++++++++++++++++++++++++++++++++++++++--- 1 file changed, 96 insertions(+), 6 deletions(-) (limited to 'drivers/acpi/apei/apei-base.c') diff --git a/drivers/acpi/apei/apei-base.c b/drivers/acpi/apei/apei-base.c index 4abb6c74a938..e45350cb6ac8 100644 --- a/drivers/acpi/apei/apei-base.c +++ b/drivers/acpi/apei/apei-base.c @@ -34,13 +34,13 @@ #include #include #include +#include #include #include #include #include #include #include -#include #include "apei-internal.h" @@ -70,7 +70,7 @@ int __apei_exec_read_register(struct acpi_whea_header *entry, u64 *val) { int rc; - rc = acpi_atomic_read(val, &entry->register_region); + rc = apei_read(val, &entry->register_region); if (rc) return rc; *val >>= entry->register_region.bit_offset; @@ -116,13 +116,13 @@ int __apei_exec_write_register(struct acpi_whea_header *entry, u64 val) val <<= entry->register_region.bit_offset; if (entry->flags & APEI_EXEC_PRESERVE_REGISTER) { u64 valr = 0; - rc = acpi_atomic_read(&valr, &entry->register_region); + rc = apei_read(&valr, &entry->register_region); if (rc) return rc; valr &= ~(entry->mask << entry->register_region.bit_offset); val |= valr; } - rc = acpi_atomic_write(val, &entry->register_region); + rc = apei_write(val, &entry->register_region); return rc; } @@ -243,7 +243,7 @@ static int pre_map_gar_callback(struct apei_exec_context *ctx, u8 ins = entry->instruction; if (ctx->ins_table[ins].flags & APEI_EXEC_INS_ACCESS_REGISTER) - return acpi_pre_map_gar(&entry->register_region); + return acpi_os_map_generic_address(&entry->register_region); return 0; } @@ -276,7 +276,7 @@ static int post_unmap_gar_callback(struct apei_exec_context *ctx, u8 ins = entry->instruction; if (ctx->ins_table[ins].flags & APEI_EXEC_INS_ACCESS_REGISTER) - acpi_post_unmap_gar(&entry->register_region); + acpi_os_unmap_generic_address(&entry->register_region); return 0; } @@ -591,6 +591,96 @@ static int apei_check_gar(struct acpi_generic_address *reg, u64 *paddr) return 0; } +/* read GAR in interrupt (including NMI) or process context */ +int apei_read(u64 *val, struct acpi_generic_address *reg) +{ + int rc; + u64 address; + u32 tmp, width = reg->bit_width; + acpi_status status; + + rc = apei_check_gar(reg, &address); + if (rc) + return rc; + + if (width == 64) + width = 32; /* Break into two 32-bit transfers */ + + *val = 0; + switch(reg->space_id) { + case ACPI_ADR_SPACE_SYSTEM_MEMORY: + status = acpi_os_read_memory((acpi_physical_address) + address, &tmp, width); + if (ACPI_FAILURE(status)) + return -EIO; + *val = tmp; + + if (reg->bit_width == 64) { + /* Read the top 32 bits */ + status = acpi_os_read_memory((acpi_physical_address) + (address + 4), &tmp, 32); + if (ACPI_FAILURE(status)) + return -EIO; + *val |= ((u64)tmp << 32); + } + break; + case ACPI_ADR_SPACE_SYSTEM_IO: + status = acpi_os_read_port(address, (u32 *)val, reg->bit_width); + if (ACPI_FAILURE(status)) + return -EIO; + break; + default: + return -EINVAL; + } + + return 0; +} +EXPORT_SYMBOL_GPL(apei_read); + +/* write GAR in interrupt (including NMI) or process context */ +int apei_write(u64 val, struct acpi_generic_address *reg) +{ + int rc; + u64 address; + u32 width = reg->bit_width; + acpi_status status; + + rc = apei_check_gar(reg, &address); + if (rc) + return rc; + + if (width == 64) + width = 32; /* Break into two 32-bit transfers */ + + switch (reg->space_id) { + case ACPI_ADR_SPACE_SYSTEM_MEMORY: + status = acpi_os_write_memory((acpi_physical_address) + address, ACPI_LODWORD(val), + width); + if (ACPI_FAILURE(status)) + return -EIO; + + if (reg->bit_width == 64) { + status = acpi_os_write_memory((acpi_physical_address) + (address + 4), + ACPI_HIDWORD(val), 32); + if (ACPI_FAILURE(status)) + return -EIO; + } + break; + case ACPI_ADR_SPACE_SYSTEM_IO: + status = acpi_os_write_port(address, val, reg->bit_width); + if (ACPI_FAILURE(status)) + return -EIO; + break; + default: + return -EINVAL; + } + + return 0; +} +EXPORT_SYMBOL_GPL(apei_write); + static int collect_res_callback(struct apei_exec_context *ctx, struct acpi_whea_header *entry, void *data) -- cgit v1.2.3