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SubjectRe: [PATCH] add PCI ROMs to sysfs
--- Matthew Wilcox <willy@debian.org> wrote:
> A few more bugfixes:
> - I was confused, it was hex 18, not decimal 16
> - Its/it's again ;-)
> - Only return the bits of the ROM that are in PCI format
> - Remove the actual resource, not some strange static one
> - Delete the static one that wasn't really used.

These are all good. The static resource was from an old version that I
missed deleting.

I'd still like for someone to check the code on ppc and sun.

> BTW, what do you think to moving all the ROM code from pci-sysfs.c to
> a new file rom.c? There's not much sense to the ROM accessing code
> being mixed in with the sysfs code like this. After all, we might
> choose to expose the ROM in some other way in the future.

I'm ok with it either way, it only about 200 lines of code.

We could save that for the next round. Next round every usage of
PCI_ROM_ADDRESS_ENABLE in the kernel probably needs to be adjusted to
use the new API. I've looked at a few of these and they are almost
always broken in some respect. About thirty places need to be looked
at. Twenty versions of this patch implies that ROM reading wasn't a
trivial problem.

=====
Jon Smirl
jonsmirl@yahoo.com


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http://promotions.yahoo.com/new_mail ===== arch/i386/pci/fixup.c 1.20 vs edited =====
--- 1.20/arch/i386/pci/fixup.c Wed Aug 4 07:57:17 2004
+++ edited/arch/i386/pci/fixup.c Sat Aug 28 13:15:51 2004
@@ -255,3 +255,41 @@
}
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE2, pci_fixup_nforce2);

+/*
+ * Fixup to mark boot BIOS video selected by BIOS before it changes
+ *
+ * From information provided by "Jon Smirl" <jonsmirl@yahoo.com>
+ *
+ * The standard boot ROM sequence for an x86 machine uses the BIOS
+ * to select an initial video card for boot display. This boot video
+ * card will have it's BIOS copied to C0000 in system RAM.
+ * IORESOURCE_ROM_SHADOW is used to associate the boot video
+ * card with this copy. On laptops this copy has to be used since
+ * the main ROM may be compressed or combined with another image.
+ * See pci_map_rom() for use of this flag. IORESOURCE_ROM_SHADOW
+ * is marked here since the boot video device will be the only enabled
+ * video device at this point.
+ *
+ */static void __devinit pci_fixup_video(struct pci_dev *pdev)
+{
+ struct pci_dev *bridge;
+ struct pci_bus *bus;
+ u16 l;
+
+ if ((pdev->class >> 8) != PCI_CLASS_DISPLAY_VGA)
+ return;
+
+ /* Is VGA routed to us? */
+ bus = pdev->bus;
+ while (bus) {
+ bridge = bus->self;
+ if (bridge) {
+ pci_read_config_word(bridge, PCI_BRIDGE_CONTROL, &l);
+ if (!(l & PCI_BRIDGE_CTL_VGA))
+ return;
+ }
+ bus = bus->parent;
+ }
+ pdev->resource[PCI_ROM_RESOURCE].flags |= IORESOURCE_ROM_SHADOW;
+}
+DECLARE_PCI_FIXUP_HEADER(PCI_ANY_ID, PCI_ANY_ID, pci_fixup_video);
===== drivers/pci/pci-sysfs.c 1.10 vs edited =====
--- 1.10/drivers/pci/pci-sysfs.c Fri Jun 4 09:23:04 2004
+++ edited/drivers/pci/pci-sysfs.c Sat Aug 28 13:16:03 2004
@@ -5,6 +5,8 @@
* (C) Copyright 2002-2004 IBM Corp.
* (C) Copyright 2003 Matthew Wilcox
* (C) Copyright 2003 Hewlett-Packard
+ * (C) Copyright 2004 Jon Smirl <jonsmirl@yahoo.com>
+ * (C) Copyright 2004 Silicon Graphics, Inc. Jesse Barnes <jbarnes@sgi.com>
*
* File attributes for PCI devices
*
@@ -20,6 +22,8 @@

#include "pci.h"

+static int sysfs_initialized; /* = 0 */
+
/* show configuration fields */
#define pci_config_attr(field, format_string) \
static ssize_t \
@@ -164,6 +168,245 @@
return count;
}

+/**
+ * pci_enable_rom - enable ROM decoding for a PCI device
+ * @dev: PCI device to enable
+ *
+ * Enable ROM decoding on @dev. This involves simply turning on the last
+ * bit of the PCI ROM BAR. Note that some cards may share address decoders
+ * between the ROM and other resources, so enabling it may disable access
+ * to MMIO registers or other card memory.
+ */
+static void
+pci_enable_rom(struct pci_dev *pdev)
+{
+ u32 rom_addr;
+
+ 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);
+}
+
+/**
+ * pci_disable_rom - disable ROM decoding for a PCI device
+ * @dev: PCI device to disable
+ *
+ * Disable ROM decoding on a PCI device by turning off the last bit in the
+ * ROM BAR.
+ */
+static void
+pci_disable_rom(struct pci_dev *pdev)
+{
+ u32 rom_addr;
+ 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);
+}
+
+/**
+ * pci_map_rom - map a PCI ROM to kernel space
+ * @dev: 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.
+ */
+unsigned char *
+pci_map_rom(struct pci_dev *pdev, size_t *size)
+{
+ struct resource *res = &pdev->resource[PCI_ROM_RESOURCE];
+ loff_t start;
+ unsigned char *rom, *image;
+ int last_image;
+
+ if (res->flags & IORESOURCE_ROM_SHADOW) { /* IORESOURCE_ROM_SHADOW only set on x86 */
+ start = (loff_t)0xC0000; /* primary video rom always starts here */
+ *size = 0x20000; /* cover C000:0 through E000:0 */
+ } else {
+ if (res->flags & IORESOURCE_ROM_COPY) {
+ *size = pci_resource_len(pdev, PCI_ROM_RESOURCE);
+ return (unsigned char *)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);
+
+ 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 */
+ pci_enable_rom(pdev);
+ }
+ }
+
+ 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);
+ 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. */
+ /* True size is important if the ROM is going to be copied. */
+ image = rom;
+ do {
+ char *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);
+
+ *size = image - rom;
+
+ return rom;
+}
+
+/**
+ * pci_map_rom_copy - map a PCI ROM to kernel space, create a copy
+ * @dev: 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.
+ */
+unsigned char *
+pci_map_rom_copy(struct pci_dev *pdev, size_t *size)
+{
+ struct resource *res = &pdev->resource[PCI_ROM_RESOURCE];
+ unsigned char *rom;
+
+ rom = pci_map_rom(pdev, size);
+ if (!rom)
+ return NULL;
+
+ if (res->flags & (IORESOURCE_ROM_COPY | IORESOURCE_ROM_SHADOW))
+ return rom;
+
+ res->start = (unsigned long)kmalloc(*size, GFP_KERNEL);
+ if (!res->start)
+ return rom;
+
+ res->end = res->start + *size;
+ memcpy((void*)res->start, rom, *size);
+ pci_unmap_rom(pdev, rom);
+ res->flags |= IORESOURCE_ROM_COPY;
+
+ return (unsigned char *)res->start;
+}
+
+/**
+ * pci_unmap_rom - unmap the ROM from kernel space
+ * @dev: pointer to pci device struct
+ * @rom: virtual address of the previous mapping
+ *
+ * Remove a mapping of a previously mapped ROM
+ */
+void
+pci_unmap_rom(struct pci_dev *pdev, unsigned char *rom)
+{
+ struct resource *res = &pdev->resource[PCI_ROM_RESOURCE];
+
+ if (res->flags & IORESOURCE_ROM_COPY)
+ return;
+
+ iounmap(rom);
+
+ /* Disable again before continuing, leave enabled if pci=rom */
+ if (!(res->flags & (IORESOURCE_ROM_ENABLE | IORESOURCE_ROM_SHADOW)))
+ pci_disable_rom(pdev);
+}
+
+/**
+ * pci_remove_rom - disable the ROM and remove its sysfs attribute
+ * @dev: pointer to pci device struct
+ *
+ */
+void
+pci_remove_rom(struct pci_dev *pdev)
+{
+ struct resource *res = &pdev->resource[PCI_ROM_RESOURCE];
+
+ if (pci_resource_len(pdev, PCI_ROM_RESOURCE))
+ sysfs_remove_bin_file(&pdev->dev.kobj, pdev->rom_attr);
+ if (!(res->flags & (IORESOURCE_ROM_ENABLE | IORESOURCE_ROM_SHADOW | IORESOURCE_ROM_COPY)))
+ pci_disable_rom(pdev);
+}
+
+/**
+ * pci_cleanup_rom - internal routine for freeing the ROM copy created
+ * by pci_map_rom_copy called from remove.c
+ * @dev: pointer to pci device struct
+ *
+ */
+void
+pci_cleanup_rom(struct pci_dev *pdev)
+{
+ struct resource *res = &pdev->resource[PCI_ROM_RESOURCE];
+ if (res->flags & IORESOURCE_ROM_COPY) {
+ kfree((void*)res->start);
+ res->flags &= ~IORESOURCE_ROM_COPY;
+ res->start = 0;
+ res->end = 0;
+ }
+}
+
+/**
+ * pci_read_rom - read a PCI ROM
+ * @kobj: kernel object handle
+ * @buf: where to put the data we read from the ROM
+ * @off: file offset
+ * @count: number of bytes to read
+ *
+ * Put @count bytes starting at @off into @buf from the ROM in the PCI
+ * device corresponding to @kobj.
+ */
+static ssize_t
+pci_read_rom(struct kobject *kobj, char *buf, loff_t off, size_t count)
+{
+ struct pci_dev *pdev = to_pci_dev(container_of(kobj, struct device, kobj));
+ unsigned char *rom;
+ size_t size;
+
+ rom = pci_map_rom(pdev, &size); /* size starts out as PCI window size */
+ if (!rom)
+ return 0;
+
+ if (off >= size)
+ count = 0;
+ else {
+ if (off + count > size)
+ count = size - off;
+
+ memcpy_fromio(buf, rom + off, count);
+ }
+ pci_unmap_rom(pdev, rom);
+
+ return count;
+}
+
static struct bin_attribute pci_config_attr = {
.attr = {
.name = "config",
@@ -186,13 +429,72 @@
.write = pci_write_config,
};

-void pci_create_sysfs_dev_files (struct pci_dev *pdev)
+int pci_create_sysfs_dev_files (struct pci_dev *pdev)
{
+ if (!sysfs_initialized)
+ return -EACCES;
+
if (pdev->cfg_size < 4096)
sysfs_create_bin_file(&pdev->dev.kobj, &pci_config_attr);
else
sysfs_create_bin_file(&pdev->dev.kobj, &pcie_config_attr);

+ /* If the device has a ROM, try to expose it in sysfs. */
+ if (pci_resource_len(pdev, PCI_ROM_RESOURCE)) {
+ struct bin_attribute *rom_attr;
+
+ rom_attr = kmalloc(sizeof(*rom_attr), GFP_ATOMIC);
+ if (rom_attr) {
+ pdev->rom_attr = rom_attr;
+ rom_attr->size = pci_resource_len(pdev, PCI_ROM_RESOURCE);
+ rom_attr->attr.name = "rom";
+ rom_attr->attr.mode = S_IRUSR;
+ rom_attr->attr.owner = THIS_MODULE;
+ rom_attr->read = pci_read_rom;
+ sysfs_create_bin_file(&pdev->dev.kobj, rom_attr);
+ }
+ }
/* add platform-specific attributes */
pcibios_add_platform_entries(pdev);
+
+ return 0;
+}
+
+/**
+ * pci_remove_sysfs_dev_files - cleanup PCI specific sysfs files
+ * @pdev: device whose entries we should free
+ *
+ * Cleanup when @pdev is removed from sysfs.
+ */
+void pci_remove_sysfs_dev_files(struct pci_dev *pdev)
+{
+ if (pdev->cfg_size < 4096)
+ sysfs_remove_bin_file(&pdev->dev.kobj, &pci_config_attr);
+ else
+ sysfs_remove_bin_file(&pdev->dev.kobj, &pcie_config_attr);
+
+ if (pci_resource_len(pdev, PCI_ROM_RESOURCE)) {
+ if (pdev->rom_attr) {
+ sysfs_remove_bin_file(&pdev->dev.kobj, pdev->rom_attr);
+ kfree(pdev->rom_attr);
+ }
+ }
}
+
+static int __init pci_sysfs_init(void)
+{
+ struct pci_dev *pdev = NULL;
+
+ sysfs_initialized = 1;
+ while ((pdev = pci_find_device(PCI_ANY_ID, PCI_ANY_ID, pdev)) != NULL)
+ pci_create_sysfs_dev_files(pdev);
+
+ return 0;
+}
+
+__initcall(pci_sysfs_init);
+
+EXPORT_SYMBOL(pci_map_rom);
+EXPORT_SYMBOL(pci_map_rom_copy);
+EXPORT_SYMBOL(pci_unmap_rom);
+EXPORT_SYMBOL(pci_remove_rom);
===== drivers/pci/pci.h 1.12 vs edited =====
--- 1.12/drivers/pci/pci.h Fri Jun 4 09:23:04 2004
+++ edited/drivers/pci/pci.h Sat Aug 28 13:15:52 2004
@@ -2,7 +2,9 @@

extern int pci_hotplug (struct device *dev, char **envp, int num_envp,
char *buffer, int buffer_size);
-extern void pci_create_sysfs_dev_files(struct pci_dev *pdev);
+extern int pci_create_sysfs_dev_files(struct pci_dev *pdev);
+extern void pci_remove_sysfs_dev_files(struct pci_dev *pdev);
+extern void pci_cleanup_rom(struct pci_dev *dev);
extern int pci_bus_alloc_resource(struct pci_bus *bus, struct resource *res,
unsigned long size, unsigned long align,
unsigned long min, unsigned int type_mask,
===== drivers/pci/probe.c 1.67 vs edited =====
--- 1.67/drivers/pci/probe.c Thu Aug 26 13:10:09 2004
+++ edited/drivers/pci/probe.c Sat Aug 28 13:15:52 2004
@@ -170,7 +170,7 @@
if (sz && sz != 0xffffffff) {
sz = pci_size(l, sz, PCI_ROM_ADDRESS_MASK);
if (sz) {
- res->flags = (l & PCI_ROM_ADDRESS_ENABLE) |
+ res->flags = (l & IORESOURCE_ROM_ENABLE) |
IORESOURCE_MEM | IORESOURCE_PREFETCH |
IORESOURCE_READONLY | IORESOURCE_CACHEABLE;
res->start = l & PCI_ROM_ADDRESS_MASK;
===== drivers/pci/remove.c 1.4 vs edited =====
--- 1.4/drivers/pci/remove.c Thu Aug 26 13:10:09 2004
+++ edited/drivers/pci/remove.c Sat Aug 28 13:15:52 2004
@@ -16,6 +16,7 @@

msi_remove_pci_irq_vectors(dev);

+ pci_cleanup_rom(dev);
for (i = 0; i < PCI_NUM_RESOURCES; i++) {
struct resource *res = dev->resource + i;
if (res->parent)
@@ -26,6 +27,7 @@
static void pci_destroy_dev(struct pci_dev *dev)
{
pci_proc_detach_device(dev);
+ pci_remove_sysfs_dev_files(dev);
device_unregister(&dev->dev);

/* Remove the device from the device lists, and prevent any further
===== drivers/pci/setup-res.c 1.25 vs edited =====
--- 1.25/drivers/pci/setup-res.c Thu Mar 18 18:40:56 2004
+++ edited/drivers/pci/setup-res.c Sat Aug 28 13:15:53 2004
@@ -56,7 +56,7 @@
if (resno < 6) {
reg = PCI_BASE_ADDRESS_0 + 4 * resno;
} else if (resno == PCI_ROM_RESOURCE) {
- new |= res->flags & PCI_ROM_ADDRESS_ENABLE;
+ new |= res->flags & IORESOURCE_ROM_ENABLE;
reg = dev->rom_base_reg;
} else {
/* Hmm, non-standard resource. */
===== include/linux/ioport.h 1.14 vs edited =====
--- 1.14/include/linux/ioport.h Thu Dec 18 00:48:57 2003
+++ edited/include/linux/ioport.h Sat Aug 28 13:15:53 2004
@@ -82,6 +82,11 @@
#define IORESOURCE_MEM_SHADOWABLE (1<<5) /* dup: IORESOURCE_SHADOWABLE */
#define IORESOURCE_MEM_EXPANSIONROM (1<<6)

+/* PCI ROM control bits (IORESOURCE_BITS) */
+#define IORESOURCE_ROM_ENABLE (1<<0) /* ROM is enabled, same as PCI_ROM_ADDRESS_ENABLE */
+#define IORESOURCE_ROM_SHADOW (1<<1) /* ROM is copy at C000:0 */
+#define IORESOURCE_ROM_COPY (1<<2) /* ROM is alloc'd copy, resource field overlaid */
+
/* PC/ISA/whatever - the normal PC address spaces: IO and memory */
extern struct resource ioport_resource;
extern struct resource iomem_resource;
===== include/linux/pci.h 1.136 vs edited =====
--- 1.136/include/linux/pci.h Thu Aug 26 13:10:27 2004
+++ edited/include/linux/pci.h Sat Aug 28 13:15:54 2004
@@ -537,6 +537,7 @@
unsigned int is_busmaster:1; /* device is busmaster */

u32 saved_config_space[16]; /* config space saved at suspend time */
+ struct bin_attribute *rom_attr; /* attribute descriptor for sysfs ROM entry */
#ifdef CONFIG_PCI_NAMES
#define PCI_NAME_SIZE 96
#define PCI_NAME_HALF __stringify(43) /* less than half to handle slop */
@@ -777,6 +778,12 @@
int pci_dac_set_dma_mask(struct pci_dev *dev, u64 mask);
int pci_set_consistent_dma_mask(struct pci_dev *dev, u64 mask);
int pci_assign_resource(struct pci_dev *dev, int i);
+
+/* ROM control related routines */
+unsigned char *pci_map_rom(struct pci_dev *pdev, size_t *size);
+unsigned char *pci_map_rom_copy(struct pci_dev *pdev, size_t *size);
+void pci_unmap_rom(struct pci_dev *pdev, unsigned char *rom);
+void pci_remove_rom(struct pci_dev *pdev);

/* Power management related routines */
int pci_save_state(struct pci_dev *dev, u32 *buffer);
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