[PATCH 2/3] ACPI, APEI: Add RAM mapping support to ACPI

Myron Stowe
2012-01-21T02:14:10Z

From: Myron Stowe <mstowe@redhat.com>

This patch adds support for RAM to ACPI's mapping capabilities in order
to support APEI error injection (EINJ) actions.

This patch re-factors similar functionality introduced in commit
76da3fb3575, bringing it into osl.c in preparation for removing
./drivers/acpi/atomicio.[ch].

Signed-off-by: Myron Stowe <myron.stowe@redhat.com>
---

drivers/acpi/osl.c | 36 ++++++++++++++++++++++++++++++++++--
1 files changed, 34 insertions(+), 2 deletions(-)

diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c
index f363a55..8ee64ea 100644
--- a/drivers/acpi/osl.c
+++ b/drivers/acpi/osl.c
@@ -31,6 +31,7 @@
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/mm.h>
+#include <linux/highmem.h>
#include <linux/pci.h>
#include <linux/interrupt.h>
#include <linux/kmod.h>
@@ -321,6 +322,37 @@ acpi_map_lookup_virt(void __iomem *virt, acpi_size size)
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(acpi_physical_address 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 acpi_os_ioremap(pg_off, pg_sz);
+}
+
+static void acpi_unmap(acpi_physical_address 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);
+}
+
void __iomem *__init_refok
acpi_os_map_memory(acpi_physical_address phys, acpi_size size)
{
@@ -353,7 +385,7 @@ acpi_os_map_memory(acpi_physical_address phys, acpi_size size)

pg_off = round_down(phys, PAGE_SIZE);
pg_sz = round_up(phys + size, PAGE_SIZE) - pg_off;
- virt = acpi_os_ioremap(pg_off, pg_sz);
+ virt = acpi_map(pg_off, pg_sz);
if (!virt) {
mutex_unlock(&acpi_ioremap_lock);
kfree(map);
@@ -384,7 +416,7 @@ static void acpi_os_map_cleanup(struct acpi_ioremap *map)
{
if (!map->refcount) {
synchronize_rcu();
- iounmap(map->virt);
+ acpi_unmap(map->phys, map->virt);
kfree(map);
}
}