pci-sysfs.c

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/*
 * drivers/pci/pci-sysfs.c
 *
 * (C) Copyright 2002-2004 Greg Kroah-Hartman <[e-mail]>
 * (C) Copyright 2002-2004 IBM Corp.
 * (C) Copyright 2003 Matthew Wilcox
 * (C) Copyright 2003 Hewlett-Packard
 * (C) Copyright 2004 Jon Smirl <[e-mail]>
 * (C) Copyright 2004 Silicon Graphics, Inc. Jesse Barnes <[e-mail]>
 *
 * File attributes for PCI devices
 *
 * Modeled after usb's driverfs.c 
 *
 */


#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/stat.h>
#include <linux/topology.h>
#include <linux/mm.h>
#include <linux/capability.h>
#include "pci.h"

static int sysfs_initialized;	/* = 0 */

/* show configuration fields */
#define pci_config_attr(field, format_string)				\
static ssize_t								\
field##_show(struct device *dev, struct device_attribute *attr, char *buf)				\
{									\
	struct pci_dev *pdev;						\
									\
	pdev = to_pci_dev (dev);					\
	return sprintf (buf, format_string, pdev->field);		\
}

pci_config_attr(vendor, "0x%04x\n");
pci_config_attr(device, "0x%04x\n");
pci_config_attr(subsystem_vendor, "0x%04x\n");
pci_config_attr(subsystem_device, "0x%04x\n");
pci_config_attr(class, "0x%06x\n");
pci_config_attr(irq, "%u\n");

static ssize_t broken_parity_status_show(struct device *dev,
					 struct device_attribute *attr,
					 char *buf)
{
	struct pci_dev *pdev = to_pci_dev(dev);
	return sprintf (buf, "%u\n", pdev->broken_parity_status);
}

static ssize_t broken_parity_status_store(struct device *dev,
					  struct device_attribute *attr,
					  const char *buf, size_t count)
{
	struct pci_dev *pdev = to_pci_dev(dev);
	ssize_t consumed = -EINVAL;

	if ((count > 0) && (*buf == '0' || *buf == '1')) {
		pdev->broken_parity_status = *buf == '1' ? 1 : 0;
		consumed = count;
	}
	return consumed;
}

static ssize_t local_cpus_show(struct device *dev,
			struct device_attribute *attr, char *buf)
{		
	cpumask_t mask;
	int len;

	mask = pcibus_to_cpumask(to_pci_dev(dev)->bus);
	len = cpumask_scnprintf(buf, PAGE_SIZE-2, mask);
	strcat(buf,"\n"); 
	return 1+len;
}

/* show resources */
static ssize_t
resource_show(struct device * dev, struct device_attribute *attr, char * buf)
{
	struct pci_dev * pci_dev = to_pci_dev(dev);
	char * str = buf;
	int i;
	int max = 7;
	resource_size_t start, end;

	if (pci_dev->subordinate)
		max = DEVICE_COUNT_RESOURCE;

	for (i = 0; i < max; i++) {
		struct resource *res =  &pci_dev->resource[i];
		pci_resource_to_user(pci_dev, i, res, &start, &end);
		str += sprintf(str,"0x%016llx 0x%016llx 0x%016llx\n",
			       (unsigned long long)start,
			       (unsigned long long)end,
			       (unsigned long long)res->flags);
	}
	return (str - buf);
}

static ssize_t modalias_show(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct pci_dev *pci_dev = to_pci_dev(dev);

	return sprintf(buf, "pci:v%08Xd%08Xsv%08Xsd%08Xbc%02Xsc%02Xi%02x\n",
		       pci_dev->vendor, pci_dev->device,
		       pci_dev->subsystem_vendor, pci_dev->subsystem_device,
		       (u8)(pci_dev->class >> 16), (u8)(pci_dev->class >> 8),
		       (u8)(pci_dev->class));
}

static ssize_t is_enabled_store(struct device *dev,
				struct device_attribute *attr, const char *buf,
				size_t count)
{
	ssize_t result = -EINVAL;
	struct pci_dev *pdev = to_pci_dev(dev);

	/* this can crash the machine when done on the "wrong" device */
	if (!capable(CAP_SYS_ADMIN))
		return count;

	if (*buf == '0') {
		if (atomic_read(&pdev->enable_cnt) != 0)
			pci_disable_device(pdev);
		else
			result = -EIO;
	} else if (*buf == '1')
		result = pci_enable_device(pdev);

	return result < 0 ? result : count;
}

static ssize_t is_enabled_show(struct device *dev,
			       struct device_attribute *attr, char *buf)
{
	struct pci_dev *pdev;

	pdev = to_pci_dev (dev);
	return sprintf (buf, "%u\n", atomic_read(&pdev->enable_cnt));
}

#ifdef CONFIG_NUMA
static ssize_t
numa_node_show(struct device *dev, struct device_attribute *attr, char *buf)
{
	return sprintf (buf, "%d\n", dev->numa_node);
}
#endif

static ssize_t
msi_bus_show(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct pci_dev *pdev = to_pci_dev(dev);

	if (!pdev->subordinate)
		return 0;

	return sprintf (buf, "%u\n",
			!(pdev->subordinate->bus_flags & PCI_BUS_FLAGS_NO_MSI));
}

static ssize_t
msi_bus_store(struct device *dev, struct device_attribute *attr,
	      const char *buf, size_t count)
{
	struct pci_dev *pdev = to_pci_dev(dev);

	/* bad things may happen if the no_msi flag is changed
	 * while some drivers are loaded */
	if (!capable(CAP_SYS_ADMIN))
		return count;

	if (!pdev->subordinate)
		return count;

	if (*buf == '0') {
		pdev->subordinate->bus_flags |= PCI_BUS_FLAGS_NO_MSI;
		dev_warn(&pdev->dev, "forced subordinate bus to not support MSI,"
			 " bad things could happen.\n");
	}

	if (*buf == '1') {
		pdev->subordinate->bus_flags &= ~PCI_BUS_FLAGS_NO_MSI;
		dev_warn(&pdev->dev, "forced subordinate bus to support MSI,"
			 " bad things could happen.\n");
	}

	return count;
}

struct device_attribute pci_dev_attrs[] = {
	__ATTR_RO(resource),
	__ATTR_RO(vendor),
	__ATTR_RO(device),
	__ATTR_RO(subsystem_vendor),
	__ATTR_RO(subsystem_device),
	__ATTR_RO(class),
	__ATTR_RO(irq),
	__ATTR_RO(local_cpus),
	__ATTR_RO(modalias),
#ifdef CONFIG_NUMA
	__ATTR_RO(numa_node),
#endif
	__ATTR(enable, 0600, is_enabled_show, is_enabled_store),
	__ATTR(broken_parity_status,(S_IRUGO|S_IWUSR),
		broken_parity_status_show,broken_parity_status_store),
	__ATTR(msi_bus, 0644, msi_bus_show, msi_bus_store),
	__ATTR_NULL,
};

static ssize_t
pci_read_config(struct kobject *kobj, struct bin_attribute *bin_attr,
		char *buf, loff_t off, size_t count)
{
	struct pci_dev *dev = to_pci_dev(container_of(kobj,struct device,kobj));
	unsigned int size = 64;
	loff_t init_off = off;
	u8 *data = (u8*) buf;

	/* Several chips lock up trying to read undefined config space */
	if (capable(CAP_SYS_ADMIN)) {
		size = dev->cfg_size;
	} else if (dev->hdr_type == PCI_HEADER_TYPE_CARDBUS) {
		size = 128;
	}

	if (off > size)
		return 0;
	if (off + count > size) {
		size -= off;
		count = size;
	} else {
		size = count;
	}

	if ((off & 1) && size) {
		u8 val;
		pci_user_read_config_byte(dev, off, &val);
		data[off - init_off] = val;
		off++;
		size--;
	}

	if ((off & 3) && size > 2) {
		u16 val;
		pci_user_read_config_word(dev, off, &val);
		data[off - init_off] = val & 0xff;
		data[off - init_off + 1] = (val >> 8) & 0xff;
		off += 2;
		size -= 2;
	}

	while (size > 3) {
		u32 val;
		pci_user_read_config_dword(dev, off, &val);
		data[off - init_off] = val & 0xff;
		data[off - init_off + 1] = (val >> 8) & 0xff;
		data[off - init_off + 2] = (val >> 16) & 0xff;
		data[off - init_off + 3] = (val >> 24) & 0xff;
		off += 4;
		size -= 4;
	}

	if (size >= 2) {
		u16 val;
		pci_user_read_config_word(dev, off, &val);
		data[off - init_off] = val & 0xff;
		data[off - init_off + 1] = (val >> 8) & 0xff;
		off += 2;
		size -= 2;
	}

	if (size > 0) {
		u8 val;
		pci_user_read_config_byte(dev, off, &val);
		data[off - init_off] = val;
		off++;
		--size;
	}

	return count;
}

static ssize_t
pci_write_config(struct kobject *kobj, struct bin_attribute *bin_attr,
		 char *buf, loff_t off, size_t count)
{
	struct pci_dev *dev = to_pci_dev(container_of(kobj,struct device,kobj));
	unsigned int size = count;
	loff_t init_off = off;
	u8 *data = (u8*) buf;

	if (off > dev->cfg_size)
		return 0;
	if (off + count > dev->cfg_size) {
		size = dev->cfg_size - off;
		count = size;
	}
	
	if ((off & 1) && size) {
		pci_user_write_config_byte(dev, off, data[off - init_off]);
		off++;
		size--;
	}
	
	if ((off & 3) && size > 2) {
		u16 val = data[off - init_off];
		val |= (u16) data[off - init_off + 1] << 8;
                pci_user_write_config_word(dev, off, val);
                off += 2;
                size -= 2;
        }

	while (size > 3) {
		u32 val = data[off - init_off];
		val |= (u32) data[off - init_off + 1] << 8;
		val |= (u32) data[off - init_off + 2] << 16;
		val |= (u32) data[off - init_off + 3] << 24;
		pci_user_write_config_dword(dev, off, val);
		off += 4;
		size -= 4;
	}
	
	if (size >= 2) {
		u16 val = data[off - init_off];
		val |= (u16) data[off - init_off + 1] << 8;
		pci_user_write_config_word(dev, off, val);
		off += 2;
		size -= 2;
	}

	if (size) {
		pci_user_write_config_byte(dev, off, data[off - init_off]);
		off++;
		--size;
	}

	return count;
}

#ifdef HAVE_PCI_LEGACY
/**
 * pci_read_legacy_io - read byte(s) from legacy I/O port space
 * @kobj: kobject corresponding to file to read from
 * @buf: buffer to store results
 * @off: offset into legacy I/O port space
 * @count: number of bytes to read
 *
 * Reads 1, 2, or 4 bytes from legacy I/O port space using an arch specific
 * callback routine (pci_legacy_read).
 */
ssize_t
pci_read_legacy_io(struct kobject *kobj, struct bin_attribute *bin_attr,
		   char *buf, loff_t off, size_t count)