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path: root/drivers/pci/rom.c
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Diffstat (limited to 'drivers/pci/rom.c')
-rw-r--r--drivers/pci/rom.c173
1 files changed, 71 insertions, 102 deletions
diff --git a/drivers/pci/rom.c b/drivers/pci/rom.c
index c5d0a08a8747..e18d3a4383ba 100644
--- a/drivers/pci/rom.c
+++ b/drivers/pci/rom.c
@@ -1,10 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0
/*
- * drivers/pci/rom.c
+ * PCI ROM access routines
*
* (C) Copyright 2004 Jon Smirl <jonsmirl@yahoo.com>
* (C) Copyright 2004 Silicon Graphics, Inc. Jesse Barnes <jbarnes@sgi.com>
- *
- * PCI ROM access routines
*/
#include <linux/kernel.h>
#include <linux/export.h>
@@ -24,20 +23,30 @@
*/
int pci_enable_rom(struct pci_dev *pdev)
{
- struct resource *res = pdev->resource + PCI_ROM_RESOURCE;
+ struct resource *res = &pdev->resource[PCI_ROM_RESOURCE];
struct pci_bus_region region;
u32 rom_addr;
if (!res->flags)
return -1;
- pcibios_resource_to_bus(pdev, &region, res);
+ /* Nothing to enable if we're using a shadow copy in RAM */
+ if (res->flags & IORESOURCE_ROM_SHADOW)
+ return 0;
+
+ /*
+ * Ideally pci_update_resource() would update the ROM BAR address,
+ * and we would only set the enable bit here. But apparently some
+ * devices have buggy ROM BARs that read as zero when disabled.
+ */
+ pcibios_resource_to_bus(pdev->bus, &region, res);
pci_read_config_dword(pdev, pdev->rom_base_reg, &rom_addr);
rom_addr &= ~PCI_ROM_ADDRESS_MASK;
rom_addr |= region.start | PCI_ROM_ADDRESS_ENABLE;
pci_write_config_dword(pdev, pdev->rom_base_reg, rom_addr);
return 0;
}
+EXPORT_SYMBOL_GPL(pci_enable_rom);
/**
* pci_disable_rom - disable ROM decoding for a PCI device
@@ -48,11 +57,17 @@ int pci_enable_rom(struct pci_dev *pdev)
*/
void pci_disable_rom(struct pci_dev *pdev)
{
+ struct resource *res = &pdev->resource[PCI_ROM_RESOURCE];
u32 rom_addr;
+
+ if (res->flags & IORESOURCE_ROM_SHADOW)
+ return;
+
pci_read_config_dword(pdev, pdev->rom_base_reg, &rom_addr);
rom_addr &= ~PCI_ROM_ADDRESS_ENABLE;
pci_write_config_dword(pdev, pdev->rom_base_reg, rom_addr);
}
+EXPORT_SYMBOL_GPL(pci_disable_rom);
/**
* pci_get_rom_size - obtain the actual size of the ROM image
@@ -65,35 +80,42 @@ void pci_disable_rom(struct pci_dev *pdev)
* The PCI window size could be much larger than the
* actual image size.
*/
-size_t pci_get_rom_size(struct pci_dev *pdev, void __iomem *rom, size_t size)
+static size_t pci_get_rom_size(struct pci_dev *pdev, void __iomem *rom,
+ size_t size)
{
void __iomem *image;
int last_image;
+ unsigned int length;
image = rom;
do {
void __iomem *pds;
/* Standard PCI ROMs start out with these bytes 55 AA */
- if (readb(image) != 0x55) {
- dev_err(&pdev->dev, "Invalid ROM contents\n");
+ if (readw(image) != 0xAA55) {
+ pci_info(pdev, "Invalid PCI ROM header signature: expecting 0xaa55, got %#06x\n",
+ readw(image));
break;
}
- if (readb(image + 1) != 0xAA)
- break;
- /* get the PCI data structure and check its signature */
+ /* get the PCI data structure and check its "PCIR" signature */
pds = image + readw(image + 24);
- if (readb(pds) != 'P')
- break;
- if (readb(pds + 1) != 'C')
- break;
- if (readb(pds + 2) != 'I')
- break;
- if (readb(pds + 3) != 'R')
+ if (readl(pds) != 0x52494350) {
+ pci_info(pdev, "Invalid PCI ROM data signature: expecting 0x52494350, got %#010x\n",
+ readl(pds));
break;
+ }
last_image = readb(pds + 21) & 0x80;
- /* this length is reliable */
- image += readw(pds + 16) * 512;
- } while (!last_image);
+ length = readw(pds + 16);
+ image += length * 512;
+ /* Avoid iterating through memory outside the resource window */
+ if (image >= rom + size)
+ break;
+ if (!last_image) {
+ if (readw(image) != 0xAA55) {
+ pci_info(pdev, "No more image in the PCI ROM\n");
+ break;
+ }
+ }
+ } while (length && !last_image);
/* never return a size larger than the PCI resource window */
/* there are known ROMs that get the size wrong */
@@ -117,46 +139,22 @@ void __iomem *pci_map_rom(struct pci_dev *pdev, size_t *size)
loff_t start;
void __iomem *rom;
- /*
- * IORESOURCE_ROM_SHADOW set on x86, x86_64 and IA64 supports legacy
- * memory map if the VGA enable bit of the Bridge Control register is
- * set for embedded VGA.
- */
- if (res->flags & IORESOURCE_ROM_SHADOW) {
- /* primary video rom always starts here */
- start = (loff_t)0xC0000;
- *size = 0x20000; /* cover C000:0 through E000:0 */
- } else {
- if (res->flags &
- (IORESOURCE_ROM_COPY | IORESOURCE_ROM_BIOS_COPY)) {
- *size = pci_resource_len(pdev, PCI_ROM_RESOURCE);
- return (void __iomem *)(unsigned long)
- pci_resource_start(pdev, PCI_ROM_RESOURCE);
- } else {
- /* 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;
-
- /* Enable ROM space decodes */
- if (pci_enable_rom(pdev))
- return NULL;
- }
- }
+ /* assign the ROM an address if it doesn't have one */
+ if (res->parent == NULL && pci_assign_resource(pdev, PCI_ROM_RESOURCE))
+ return NULL;
- rom = ioremap(start, *size);
- if (!rom) {
- /* restore enable if ioremap fails */
- if (!(res->flags & (IORESOURCE_ROM_ENABLE |
- IORESOURCE_ROM_SHADOW |
- IORESOURCE_ROM_COPY)))
- pci_disable_rom(pdev);
+ start = pci_resource_start(pdev, PCI_ROM_RESOURCE);
+ *size = pci_resource_len(pdev, PCI_ROM_RESOURCE);
+ if (*size == 0)
return NULL;
- }
+
+ /* Enable ROM space decodes */
+ if (pci_enable_rom(pdev))
+ return NULL;
+
+ rom = ioremap(start, *size);
+ if (!rom)
+ goto err_ioremap;
/*
* Try to find the true size of the ROM since sometimes the PCI window
@@ -164,8 +162,20 @@ void __iomem *pci_map_rom(struct pci_dev *pdev, size_t *size)
* True size is important if the ROM is going to be copied.
*/
*size = pci_get_rom_size(pdev, rom, *size);
+ if (!*size)
+ goto invalid_rom;
+
return rom;
+
+invalid_rom:
+ iounmap(rom);
+err_ioremap:
+ /* restore enable if ioremap fails */
+ if (!(res->flags & IORESOURCE_ROM_ENABLE))
+ pci_disable_rom(pdev);
+ return NULL;
}
+EXPORT_SYMBOL(pci_map_rom);
/**
* pci_unmap_rom - unmap the ROM from kernel space
@@ -178,51 +188,10 @@ void pci_unmap_rom(struct pci_dev *pdev, void __iomem *rom)
{
struct resource *res = &pdev->resource[PCI_ROM_RESOURCE];
- if (res->flags & (IORESOURCE_ROM_COPY | IORESOURCE_ROM_BIOS_COPY))
- return;
-
iounmap(rom);
- /* Disable again before continuing, leave enabled if pci=rom */
- if (!(res->flags & (IORESOURCE_ROM_ENABLE | IORESOURCE_ROM_SHADOW)))
+ /* Disable again before continuing */
+ if (!(res->flags & IORESOURCE_ROM_ENABLE))
pci_disable_rom(pdev);
}
-
-/**
- * pci_cleanup_rom - free the ROM copy created by pci_map_rom_copy
- * @pdev: pointer to pci device struct
- *
- * Free the copied ROM if we allocated one.
- */
-void pci_cleanup_rom(struct pci_dev *pdev)
-{
- struct resource *res = &pdev->resource[PCI_ROM_RESOURCE];
- if (res->flags & IORESOURCE_ROM_COPY) {
- kfree((void*)(unsigned long)res->start);
- res->flags &= ~IORESOURCE_ROM_COPY;
- res->start = 0;
- res->end = 0;
- }
-}
-
-/**
- * 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);
generated by cgit (git 2.34.1) at 2025-12-25 03:36:22 +0000