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>

1 files changed, 5 insertions, 5 deletions

diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c
index aaf36090de1..b3207e16670 100644
--- a/drivers/acpi/apei/ghes.c
+++ b/drivers/acpi/apei/ghes.c
@@ -33,6 +33,7 @@
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/acpi.h>
+#include <linux/acpi_io.h>
 #include <linux/io.h>
 #include <linux/interrupt.h>
 #include <linux/timer.h>
@@ -48,7 +49,6 @@
 #include <linux/pci.h>
 #include <linux/aer.h>
 #include <acpi/apei.h>
-#include <acpi/atomicio.h>
 #include <acpi/hed.h>
 #include <asm/mce.h>
 #include <asm/tlbflush.h>
@@ -301,7 +301,7 @@ static struct ghes *ghes_new(struct acpi_hest_generic *generic)
 	if (!ghes)
 		return ERR_PTR(-ENOMEM);
 	ghes->generic = generic;
-	rc = acpi_pre_map_gar(&generic->error_status_address);
+	rc = acpi_os_map_generic_address(&generic->error_status_address);
 	if (rc)
 		goto err_free;
 	error_block_length = generic->error_block_length;
@@ -321,7 +321,7 @@ static struct ghes *ghes_new(struct acpi_hest_generic *generic)
 	return ghes;
 
 err_unmap:
-	acpi_post_unmap_gar(&generic->error_status_address);
+	acpi_os_unmap_generic_address(&generic->error_status_address);
 err_free:
 	kfree(ghes);
 	return ERR_PTR(rc);
@@ -330,7 +330,7 @@ err_free:
 static void ghes_fini(struct ghes *ghes)
 {
 	kfree(ghes->estatus);
-	acpi_post_unmap_gar(&ghes->generic->error_status_address);
+	acpi_os_unmap_generic_address(&ghes->generic->error_status_address);
 }
 
 enum {
@@ -401,7 +401,7 @@ static int ghes_read_estatus(struct ghes *ghes, int silent)
 	u32 len;
 	int rc;
 
-	rc = acpi_atomic_read(&buf_paddr, &g->error_status_address);
+	rc = apei_read(&buf_paddr, &g->error_status_address);
 	if (rc) {
 		if (!silent && printk_ratelimit())
 			pr_warning(FW_WARN GHES_PFX