summaryrefslogtreecommitdiffstats
path: root/drivers/char
diff options
context:
space:
mode:
authorLv Zheng <lv.zheng@intel.com>2014-05-20 15:39:41 +0800
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2014-05-27 18:13:08 +0200
commita238317ce8185519ed083e81e84260907fbbcf7f (patch)
treef5b228ac40941946db2e7427b1085a90c78c85b5 /drivers/char
parent92985ef1db428cc6129a1d375a68c277aa05820b (diff)
downloadop-kernel-dev-a238317ce8185519ed083e81e84260907fbbcf7f.zip
op-kernel-dev-a238317ce8185519ed083e81e84260907fbbcf7f.tar.gz
ACPI: Clean up acpi_os_map/unmap_memory() to eliminate __iomem.
ACPICA doesn't include protections around address space checking, Linux build tests always complain increased sparse warnings around ACPICA internal acpi_os_map/unmap_memory() invocations. This patch tries to fix this issue permanently. There are 2 choices left for us to solve this issue: 1. Add __iomem address space awareness into ACPICA. 2. Remove sparse checker of __iomem from ACPICA source code. This patch chooses solution 2, because: 1. Most of the acpi_os_map/unmap_memory() invocations are used for ACPICA. table mappings, which in fact are not IO addresses. 2. The only IO addresses usage is for "system memory space" mapping code in: drivers/acpi/acpica/exregion.c drivers/acpi/acpica/evrgnini.c drivers/acpi/acpica/exregion.c The mapped address is accessed in the handler of "system memory space" - acpi_ex_system_memory_space_handler(). This function in fact can be changed to invoke acpi_os_read/write_memory() so that __iomem can always be type-casted in the OSL layer. According to the above investigation, we drew the following conclusion: It is not a good idea to introduce __iomem address space awareness into ACPICA mostly in order to protect non-IO addresses. We can simply remove __iomem for acpi_os_map/unmap_memory() to remove __iomem checker for ACPICA code. Then we need to enforce external usages to invoke other APIs that are aware of __iomem address space. The external usages are: drivers/acpi/apei/einj.c drivers/acpi/acpi_extlog.c drivers/char/tpm/tpm_acpi.c drivers/acpi/nvs.c This patch thus performs cleanups in this way: 1. Add acpi_os_map/unmap_iomem() to be invoked by non-ACPICA code. 2. Remove __iomem from acpi_os_map/unmap_memory(). Signed-off-by: Lv Zheng <lv.zheng@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/char')
-rw-r--r--drivers/char/tpm/tpm_acpi.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/char/tpm/tpm_acpi.c b/drivers/char/tpm/tpm_acpi.c
index b9a57fa..565a947 100644
--- a/drivers/char/tpm/tpm_acpi.c
+++ b/drivers/char/tpm/tpm_acpi.c
@@ -95,7 +95,7 @@ int read_log(struct tpm_bios_log *log)
log->bios_event_log_end = log->bios_event_log + len;
- virt = acpi_os_map_memory(start, len);
+ virt = acpi_os_map_iomem(start, len);
if (!virt) {
kfree(log->bios_event_log);
printk("%s: ERROR - Unable to map memory\n", __func__);
@@ -104,6 +104,6 @@ int read_log(struct tpm_bios_log *log)
memcpy_fromio(log->bios_event_log, virt, len);
- acpi_os_unmap_memory(virt, len);
+ acpi_os_unmap_iomem(virt, len);
return 0;
}
OpenPOWER on IntegriCloud