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Date: Fri, 13 Jun 2008 22:29:13 +0100
From: Ben Hutchings <bhutchings@...arflare.com>
To: Jesse Barnes <jbarnes@...tuousgeek.org>
Cc: Matthew Wilcox <matthew@....cx>, linux-kernel@...r.kernel.org,
linux-pci@...r.kernel.org
Subject: [PATCH 1/2] PCI: ROM access changes to support PCI 2.1 VPD
Move body of ROM image sizing loop into a separate function so it can be
reused for finding VPD.
Move first part of pci_map_rom() into a separate function for use when
reading VPD.
Signed-off-by: Ben Hutchings <bhutchings@...arflare.com>
---
drivers/pci/rom.c | 107 ++++++++++++++++++++++++++++++++--------------------
1 files changed, 66 insertions(+), 41 deletions(-)
diff --git a/drivers/pci/rom.c b/drivers/pci/rom.c
index bd5c0e0..94d2afd 100644
--- a/drivers/pci/rom.c
+++ b/drivers/pci/rom.c
@@ -54,59 +54,65 @@ static void pci_disable_rom(struct pci_dev *pdev)
}
/**
- * pci_get_rom_size - obtain the actual size of the ROM image
- * @rom: kernel virtual pointer to image of ROM
+ * pci_get_rom_image_size - obtain the actual size of a ROM image
+ * @rom: kernel virtual pointer to ROM
* @size: size of PCI window
- * return: size of actual ROM image
+ * @image: kernel virtual pointer to image
+ * @last: pointer to return flag for whether this is the last image
+ * return: size of image, or 0 if image is invalid
*
* Determine the actual length of the ROM image.
+ */
+static size_t pci_get_rom_image_size(void __iomem *rom, size_t size,
+ void __iomem *image, bool *last)
+{
+ void __iomem *pds;
+ size_t image_size;
+
+ /* Standard PCI ROMs start out with these bytes 55 AA */
+ if (readb(image) != 0x55 || readb(image + 1) != 0xAA)
+ goto invalid;
+
+ /* get the PCI data structure and check its signature */
+ pds = image + readw(image + 24);
+ if (readb(pds) != 'P' || readb(pds + 1) != 'C' ||
+ readb(pds + 2) != 'I' || readb(pds + 3) != 'R')
+ goto invalid;
+
+ image_size = readw(pds + 16) * 512;
+ *last = !!(readb(pds + 21) & 0x80);
+
+ /* Check that the size does not extend outside the PCI window */
+ return min_t(size_t, image_size, rom + size - image);
+
+invalid:
+ *last = true;
+ return 0;
+}
+
+/**
+ * pci_get_rom_size - obtain the total size of the ROM images
+ * @rom: kernel virtual pointer to ROM
+ * @size: size of PCI window
+ * return: size of actual ROM images
+ *
+ * Determine the actual length of the ROM images.
* The PCI window size could be much larger than the
* actual image size.
*/
size_t pci_get_rom_size(void __iomem *rom, size_t size)
{
void __iomem *image;
- int last_image;
+ bool last;
image = rom;
- do {
- void __iomem *pds;
- /* Standard PCI ROMs start out with these bytes 55 AA */
- if (readb(image) != 0x55)
- break;
- if (readb(image + 1) != 0xAA)
- break;
- /* get the PCI data structure and check its 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')
- break;
- last_image = readb(pds + 21) & 0x80;
- /* this length is reliable */
- image += readw(pds + 16) * 512;
- } while (!last_image);
-
- /* never return a size larger than the PCI resource window */
- /* there are known ROMs that get the size wrong */
- return min((size_t)(image - rom), size);
+ do
+ image += pci_get_rom_image_size(rom, size, image, &last);
+ while (!last);
+ return image - rom;
}
-/**
- * pci_map_rom - map a PCI ROM to kernel space
- * @pdev: pointer to pci device struct
- * @size: pointer to receive size of pci window over ROM
- * @return: kernel virtual pointer to image of ROM
- *
- * Map a PCI ROM into kernel space. If ROM is boot video ROM,
- * the shadow BIOS copy will be returned instead of the
- * actual ROM.
- */
-void __iomem *pci_map_rom(struct pci_dev *pdev, size_t *size)
+static void __iomem *__pci_map_rom(struct pci_dev *pdev, size_t *size)
{
struct resource *res = &pdev->resource[PCI_ROM_RESOURCE];
loff_t start;
@@ -150,9 +156,28 @@ void __iomem *pci_map_rom(struct pci_dev *pdev, size_t *size)
IORESOURCE_ROM_SHADOW |
IORESOURCE_ROM_COPY)))
pci_disable_rom(pdev);
- return NULL;
}
+ return rom;
+}
+
+/**
+ * pci_map_rom - map a PCI ROM to kernel space
+ * @pdev: pointer to pci device struct
+ * @size: pointer to receive size of pci window over ROM
+ * @return: kernel virtual pointer to image of ROM
+ *
+ * Map a PCI ROM into kernel space. If ROM is boot video ROM,
+ * the shadow BIOS copy will be returned instead of the
+ * actual ROM.
+ */
+void __iomem *pci_map_rom(struct pci_dev *pdev, size_t *size)
+{
+ void __iomem *rom = __pci_map_rom(pdev, size);
+
+ if (!rom)
+ return NULL;
+
/*
* Try to find the true size of the ROM since sometimes the PCI window
* size is much larger than the actual size of the ROM.
--
Ben Hutchings, Senior Software Engineer, Solarflare Communications
Not speaking for my employer; that's the marketing department's job.
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