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authorMyron Stowe <mstowe@redhat.com>2011-11-07 16:23:41 -0700
committerLen Brown <len.brown@intel.com>2012-01-17 04:36:40 -0500
commit700130b41f4ee54520ac2ef2f7f1d072789711a4 (patch)
tree8fe06ea2fdce1afab67db16ca9ecf8b25e150ff5 /drivers/acpi/apei/apei-base.c
parent6f68c91c55ea3576d366797fa8d45e31c4aa79f8 (diff)
downloadlinux-700130b41f4ee54520ac2ef2f7f1d072789711a4.tar.bz2
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 <myron.stowe@redhat.com> Signed-off-by: Len Brown <len.brown@intel.com>
Diffstat (limited to 'drivers/acpi/apei/apei-base.c')
-rw-r--r--drivers/acpi/apei/apei-base.c102
1 files changed, 96 insertions, 6 deletions
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 <linux/module.h>
#include <linux/init.h>
#include <linux/acpi.h>
+#include <linux/acpi_io.h>
#include <linux/slab.h>
#include <linux/io.h>
#include <linux/kref.h>
#include <linux/rculist.h>
#include <linux/interrupt.h>
#include <linux/debugfs.h>
-#include <acpi/atomicio.h>
#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)