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authorMatt Fleming <matt.fleming@intel.com>2012-11-14 09:42:35 +0000
committerH. Peter Anvin <hpa@linux.intel.com>2013-01-30 11:51:59 -0800
commit83e68189745ad931c2afd45d8ee3303929233e7f (patch)
tree35673a4eebff4c71bda4b1023ccc7cbea36f84b2 /drivers
parentf44310b98ddb7f0d06550d73ed67df5865e3eda5 (diff)
downloadlinux-83e68189745ad931c2afd45d8ee3303929233e7f.tar.bz2
efi: Make 'efi_enabled' a function to query EFI facilities
Originally 'efi_enabled' indicated whether a kernel was booted from EFI firmware. Over time its semantics have changed, and it now indicates whether or not we are booted on an EFI machine with bit-native firmware, e.g. 64-bit kernel with 64-bit firmware. The immediate motivation for this patch is the bug report at, https://bugs.launchpad.net/ubuntu-cdimage/+bug/1040557 which details how running a platform driver on an EFI machine that is designed to run under BIOS can cause the machine to become bricked. Also, the following report, https://bugzilla.kernel.org/show_bug.cgi?id=47121 details how running said driver can also cause Machine Check Exceptions. Drivers need a new means of detecting whether they're running on an EFI machine, as sadly the expression, if (!efi_enabled) hasn't been a sufficient condition for quite some time. Users actually want to query 'efi_enabled' for different reasons - what they really want access to is the list of available EFI facilities. For instance, the x86 reboot code needs to know whether it can invoke the ResetSystem() function provided by the EFI runtime services, while the ACPI OSL code wants to know whether the EFI config tables were mapped successfully. There are also checks in some of the platform driver code to simply see if they're running on an EFI machine (which would make it a bad idea to do BIOS-y things). This patch is a prereq for the samsung-laptop fix patch. Cc: David Airlie <airlied@linux.ie> Cc: Corentin Chary <corentincj@iksaif.net> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Olof Johansson <olof@lixom.net> Cc: Peter Jones <pjones@redhat.com> Cc: Colin Ian King <colin.king@canonical.com> Cc: Steve Langasek <steve.langasek@canonical.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Konrad Rzeszutek Wilk <konrad@kernel.org> Cc: Rafael J. Wysocki <rjw@sisk.pl> Cc: <stable@vger.kernel.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/acpi/osl.c2
-rw-r--r--drivers/firmware/dmi_scan.c2
-rw-r--r--drivers/firmware/efivars.c4
-rw-r--r--drivers/firmware/iscsi_ibft_find.c2
-rw-r--r--drivers/gpu/drm/radeon/radeon_device.c3
-rw-r--r--drivers/platform/x86/ibm_rtl.c2
-rw-r--r--drivers/scsi/isci/init.c2
7 files changed, 9 insertions, 8 deletions
diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c
index 3ff267861541..bd22f8667eed 100644
--- a/drivers/acpi/osl.c
+++ b/drivers/acpi/osl.c
@@ -250,7 +250,7 @@ acpi_physical_address __init acpi_os_get_root_pointer(void)
return acpi_rsdp;
#endif
- if (efi_enabled) {
+ if (efi_enabled(EFI_CONFIG_TABLES)) {
if (efi.acpi20 != EFI_INVALID_TABLE_ADDR)
return efi.acpi20;
else if (efi.acpi != EFI_INVALID_TABLE_ADDR)
diff --git a/drivers/firmware/dmi_scan.c b/drivers/firmware/dmi_scan.c
index fd3ae6290d71..982f1f5f5742 100644
--- a/drivers/firmware/dmi_scan.c
+++ b/drivers/firmware/dmi_scan.c
@@ -471,7 +471,7 @@ void __init dmi_scan_machine(void)
char __iomem *p, *q;
int rc;
- if (efi_enabled) {
+ if (efi_enabled(EFI_CONFIG_TABLES)) {
if (efi.smbios == EFI_INVALID_TABLE_ADDR)
goto error;
diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c
index 7b1c37497c9a..1065119dff92 100644
--- a/drivers/firmware/efivars.c
+++ b/drivers/firmware/efivars.c
@@ -1782,7 +1782,7 @@ efivars_init(void)
printk(KERN_INFO "EFI Variables Facility v%s %s\n", EFIVARS_VERSION,
EFIVARS_DATE);
- if (!efi_enabled)
+ if (!efi_enabled(EFI_RUNTIME_SERVICES))
return 0;
/* For now we'll register the efi directory at /sys/firmware/efi */
@@ -1822,7 +1822,7 @@ err_put:
static void __exit
efivars_exit(void)
{
- if (efi_enabled) {
+ if (efi_enabled(EFI_RUNTIME_SERVICES)) {
unregister_efivars(&__efivars);
kobject_put(efi_kobj);
}
diff --git a/drivers/firmware/iscsi_ibft_find.c b/drivers/firmware/iscsi_ibft_find.c
index 4da4eb9ae926..2224f1dc074b 100644
--- a/drivers/firmware/iscsi_ibft_find.c
+++ b/drivers/firmware/iscsi_ibft_find.c
@@ -99,7 +99,7 @@ unsigned long __init find_ibft_region(unsigned long *sizep)
/* iBFT 1.03 section 1.4.3.1 mandates that UEFI machines will
* only use ACPI for this */
- if (!efi_enabled)
+ if (!efi_enabled(EFI_BOOT))
find_ibft_in_mem();
if (ibft_addr) {
diff --git a/drivers/gpu/drm/radeon/radeon_device.c b/drivers/gpu/drm/radeon/radeon_device.c
index edfc54e41842..0d6562bb0c93 100644
--- a/drivers/gpu/drm/radeon/radeon_device.c
+++ b/drivers/gpu/drm/radeon/radeon_device.c
@@ -429,7 +429,8 @@ bool radeon_card_posted(struct radeon_device *rdev)
{
uint32_t reg;
- if (efi_enabled && rdev->pdev->subsystem_vendor == PCI_VENDOR_ID_APPLE)
+ if (efi_enabled(EFI_BOOT) &&
+ rdev->pdev->subsystem_vendor == PCI_VENDOR_ID_APPLE)
return false;
/* first check CRTCs */
diff --git a/drivers/platform/x86/ibm_rtl.c b/drivers/platform/x86/ibm_rtl.c
index 7481146a5b47..97c2be195efc 100644
--- a/drivers/platform/x86/ibm_rtl.c
+++ b/drivers/platform/x86/ibm_rtl.c
@@ -244,7 +244,7 @@ static int __init ibm_rtl_init(void) {
if (force)
pr_warn("module loaded by force\n");
/* first ensure that we are running on IBM HW */
- else if (efi_enabled || !dmi_check_system(ibm_rtl_dmi_table))
+ else if (efi_enabled(EFI_BOOT) || !dmi_check_system(ibm_rtl_dmi_table))
return -ENODEV;
/* Get the address for the Extended BIOS Data Area */
diff --git a/drivers/scsi/isci/init.c b/drivers/scsi/isci/init.c
index d73fdcfeb45a..2839baa82a5a 100644
--- a/drivers/scsi/isci/init.c
+++ b/drivers/scsi/isci/init.c
@@ -633,7 +633,7 @@ static int isci_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
return -ENOMEM;
pci_set_drvdata(pdev, pci_info);
- if (efi_enabled)
+ if (efi_enabled(EFI_RUNTIME_SERVICES))
orom = isci_get_efi_var(pdev);
if (!orom)