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authorMatthew Garrett <matthew.garrett@nebula.com>2013-03-26 17:25:54 -0400
committerBjorn Helgaas <bhelgaas@google.com>2013-03-26 17:19:41 -0600
commitfffe01f7a768d07cc50ace71abe28fbf2f786a43 (patch)
tree6e20b8c21f80d5d27f473e59fdb1696e165fbe1e /drivers/pci
parent8bb9660418e05bb1845ac1a2428444d78e322cc7 (diff)
PCI: Add PCI ROM helper for platform-provided ROM images
It turns out that some UEFI systems provide apparently an apparently valid PCI ROM BAR that turns out to contain garbage, so the attempt in 547b52463 to prefer the ROM from the BAR actually breaks a different set of machines. As Linus pointed out, the graphics drivers are probably in the best position to make this judgement, so this basically reverts 547b52463 and f9a37be0f and adds a new helper function. Followup patches will add support to nouveau and radeon for probing this ROM source if they can't find a ROM from some other source. [bhelgaas: added reporter and bugzilla pointers, s/f4eb5ff05/547b52463] Reference: https://bugzilla.redhat.com/show_bug.cgi?id=927451 Reference: http://lkml.kernel.org/r/kg69ef$vdb$1@ger.gmane.org Reported-by: Mantas Mikulėnas <grawity@gmail.com> Reported-by: Chris Murphy <bugzilla@colorremedies.com> Signed-off-by: Matthew Garrett <matthew.garrett@nebula.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Diffstat (limited to 'drivers/pci')
-rw-r--r--drivers/pci/rom.c67
1 files changed, 31 insertions, 36 deletions
diff --git a/drivers/pci/rom.c b/drivers/pci/rom.c
index b41ac7756a4..c5d0a08a874 100644
--- a/drivers/pci/rom.c
+++ b/drivers/pci/rom.c
@@ -100,27 +100,6 @@ size_t pci_get_rom_size(struct pci_dev *pdev, void __iomem *rom, size_t size)
return min((size_t)(image - rom), size);
}
-static loff_t pci_find_rom(struct pci_dev *pdev, size_t *size)
-{
- struct resource *res = &pdev->resource[PCI_ROM_RESOURCE];
- loff_t start;
-
- /* assign the ROM an address if it doesn't have one */
- if (res->parent == NULL && pci_assign_resource(pdev, PCI_ROM_RESOURCE))
- return 0;
- start = pci_resource_start(pdev, PCI_ROM_RESOURCE);
- *size = pci_resource_len(pdev, PCI_ROM_RESOURCE);
-
- if (*size == 0)
- return 0;
-
- /* Enable ROM space decodes */
- if (pci_enable_rom(pdev))
- return 0;
-
- return start;
-}
-
/**
* pci_map_rom - map a PCI ROM to kernel space
* @pdev: pointer to pci device struct
@@ -135,7 +114,7 @@ static loff_t pci_find_rom(struct pci_dev *pdev, size_t *size)
void __iomem *pci_map_rom(struct pci_dev *pdev, size_t *size)
{
struct resource *res = &pdev->resource[PCI_ROM_RESOURCE];
- loff_t start = 0;
+ loff_t start;
void __iomem *rom;
/*
@@ -154,21 +133,21 @@ void __iomem *pci_map_rom(struct pci_dev *pdev, size_t *size)
return (void __iomem *)(unsigned long)
pci_resource_start(pdev, PCI_ROM_RESOURCE);
} else {
- start = pci_find_rom(pdev, size);
- }
- }
+ /* assign the ROM an address if it doesn't have one */
+ if (res->parent == NULL &&
+ pci_assign_resource(pdev,PCI_ROM_RESOURCE))
+ return NULL;
+ start = pci_resource_start(pdev, PCI_ROM_RESOURCE);
+ *size = pci_resource_len(pdev, PCI_ROM_RESOURCE);
+ if (*size == 0)
+ return NULL;
- /*
- * Some devices may provide ROMs via a source other than the BAR
- */
- if (!start && pdev->rom && pdev->romlen) {
- *size = pdev->romlen;
- return phys_to_virt(pdev->rom);
+ /* Enable ROM space decodes */
+ if (pci_enable_rom(pdev))
+ return NULL;
+ }
}
- if (!start)
- return NULL;
-
rom = ioremap(start, *size);
if (!rom) {
/* restore enable if ioremap fails */
@@ -202,8 +181,7 @@ void pci_unmap_rom(struct pci_dev *pdev, void __iomem *rom)
if (res->flags & (IORESOURCE_ROM_COPY | IORESOURCE_ROM_BIOS_COPY))
return;
- if (!pdev->rom || !pdev->romlen)
- iounmap(rom);
+ iounmap(rom);
/* Disable again before continuing, leave enabled if pci=rom */
if (!(res->flags & (IORESOURCE_ROM_ENABLE | IORESOURCE_ROM_SHADOW)))
@@ -227,7 +205,24 @@ void pci_cleanup_rom(struct pci_dev *pdev)
}
}
+/**
+ * pci_platform_rom - provides a pointer to any ROM image provided by the
+ * platform
+ * @pdev: pointer to pci device struct
+ * @size: pointer to receive size of pci window over ROM
+ */
+void __iomem *pci_platform_rom(struct pci_dev *pdev, size_t *size)
+{
+ if (pdev->rom && pdev->romlen) {
+ *size = pdev->romlen;
+ return phys_to_virt((phys_addr_t)pdev->rom);
+ }
+
+ return NULL;
+}
+
EXPORT_SYMBOL(pci_map_rom);
EXPORT_SYMBOL(pci_unmap_rom);
EXPORT_SYMBOL_GPL(pci_enable_rom);
EXPORT_SYMBOL_GPL(pci_disable_rom);
+EXPORT_SYMBOL(pci_platform_rom);