1 files changed, 469 insertions, 0 deletions

diff --git a/drivers/pci/access.c b/drivers/pci/access.c
new file mode 100644
index 00000000..2a581642
--- /dev/null
+++ b/drivers/pci/access.c
@@ -0,0 +1,469 @@
+#include <linux/delay.h>
+#include <linux/pci.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/ioport.h>
+#include <linux/wait.h>
+
+#include "pci.h"
+
+/*
+ * This interrupt-safe spinlock protects all accesses to PCI
+ * configuration space.
+ */
+
+DEFINE_RAW_SPINLOCK(pci_lock);
+
+/*
+ *  Wrappers for all PCI configuration access functions.  They just check
+ *  alignment, do locking and call the low-level functions pointed to
+ *  by pci_dev->ops.
+ */
+
+#define PCI_byte_BAD 0
+#define PCI_word_BAD (pos & 1)
+#define PCI_dword_BAD (pos & 3)
+
+#define PCI_OP_READ(size,type,len) \
+int pci_bus_read_config_##size \
+	(struct pci_bus *bus, unsigned int devfn, int pos, type *value)	\
+{									\
+	int res;							\
+	unsigned long flags;						\
+	u32 data = 0;							\
+	if (PCI_##size##_BAD) return PCIBIOS_BAD_REGISTER_NUMBER;	\
+	raw_spin_lock_irqsave(&pci_lock, flags);			\
+	res = bus->ops->read(bus, devfn, pos, len, &data);		\
+	*value = (type)data;						\
+	raw_spin_unlock_irqrestore(&pci_lock, flags);		\
+	return res;							\
+}
+
+#define PCI_OP_WRITE(size,type,len) \
+int pci_bus_write_config_##size \
+	(struct pci_bus *bus, unsigned int devfn, int pos, type value)	\
+{									\
+	int res;							\
+	unsigned long flags;						\
+	if (PCI_##size##_BAD) return PCIBIOS_BAD_REGISTER_NUMBER;	\
+	raw_spin_lock_irqsave(&pci_lock, flags);			\
+	res = bus->ops->write(bus, devfn, pos, len, value);		\
+	raw_spin_unlock_irqrestore(&pci_lock, flags);		\
+	return res;							\
+}
+
+PCI_OP_READ(byte, u8, 1)
+PCI_OP_READ(word, u16, 2)
+PCI_OP_READ(dword, u32, 4)
+PCI_OP_WRITE(byte, u8, 1)
+PCI_OP_WRITE(word, u16, 2)
+PCI_OP_WRITE(dword, u32, 4)
+
+EXPORT_SYMBOL(pci_bus_read_config_byte);
+EXPORT_SYMBOL(pci_bus_read_config_word);
+EXPORT_SYMBOL(pci_bus_read_config_dword);
+EXPORT_SYMBOL(pci_bus_write_config_byte);
+EXPORT_SYMBOL(pci_bus_write_config_word);
+EXPORT_SYMBOL(pci_bus_write_config_dword);
+
+/**
+ * pci_bus_set_ops - Set raw operations of pci bus
+ * @bus:	pci bus struct
+ * @ops:	new raw operations
+ *
+ * Return previous raw operations
+ */
+struct pci_ops *pci_bus_set_ops(struct pci_bus *bus, struct pci_ops *ops)
+{
+	struct pci_ops *old_ops;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&pci_lock, flags);
+	old_ops = bus->ops;
+	bus->ops = ops;
+	raw_spin_unlock_irqrestore(&pci_lock, flags);
+	return old_ops;
+}
+EXPORT_SYMBOL(pci_bus_set_ops);
+
+/**
+ * pci_read_vpd - Read one entry from Vital Product Data
+ * @dev:	pci device struct
+ * @pos:	offset in vpd space
+ * @count:	number of bytes to read
+ * @buf:	pointer to where to store result
+ *
+ */
+ssize_t pci_read_vpd(struct pci_dev *dev, loff_t pos, size_t count, void *buf)
+{
+	if (!dev->vpd || !dev->vpd->ops)
+		return -ENODEV;
+	return dev->vpd->ops->read(dev, pos, count, buf);
+}
+EXPORT_SYMBOL(pci_read_vpd);
+
+/**
+ * pci_write_vpd - Write entry to Vital Product Data
+ * @dev:	pci device struct
+ * @pos:	offset in vpd space
+ * @count:	number of bytes to write
+ * @buf:	buffer containing write data
+ *
+ */
+ssize_t pci_write_vpd(struct pci_dev *dev, loff_t pos, size_t count, const void *buf)
+{
+	if (!dev->vpd || !dev->vpd->ops)
+		return -ENODEV;
+	return dev->vpd->ops->write(dev, pos, count, buf);
+}
+EXPORT_SYMBOL(pci_write_vpd);
+
+/*
+ * The following routines are to prevent the user from accessing PCI config
+ * space when it's unsafe to do so.  Some devices require this during BIST and
+ * we're required to prevent it during D-state transitions.
+ *
+ * We have a bit per device to indicate it's blocked and a global wait queue
+ * for callers to sleep on until devices are unblocked.
+ */
+static DECLARE_WAIT_QUEUE_HEAD(pci_cfg_wait);
+
+static noinline void pci_wait_cfg(struct pci_dev *dev)
+{
+	DECLARE_WAITQUEUE(wait, current);
+
+	__add_wait_queue(&pci_cfg_wait, &wait);
+	do {
+		set_current_state(TASK_UNINTERRUPTIBLE);
+		raw_spin_unlock_irq(&pci_lock);
+		schedule();
+		raw_spin_lock_irq(&pci_lock);
+	} while (dev->block_cfg_access);
+	__remove_wait_queue(&pci_cfg_wait, &wait);
+}
+
+/* Returns 0 on success, negative values indicate error. */
+#define PCI_USER_READ_CONFIG(size,type)					\
+int pci_user_read_config_##size						\
+	(struct pci_dev *dev, int pos, type *val)			\
+{									\
+	int ret = 0;							\
+	u32 data = -1;							\
+	if (PCI_##size##_BAD)						\
+		return -EINVAL;						\
+	raw_spin_lock_irq(&pci_lock);				\
+	if (unlikely(dev->block_cfg_access))				\
+		pci_wait_cfg(dev);					\
+	ret = dev->bus->ops->read(dev->bus, dev->devfn,			\
+					pos, sizeof(type), &data);	\
+	raw_spin_unlock_irq(&pci_lock);				\
+	*val = (type)data;						\
+	if (ret > 0)							\
+		ret = -EINVAL;						\
+	return ret;							\
+}
+
+/* Returns 0 on success, negative values indicate error. */
+#define PCI_USER_WRITE_CONFIG(size,type)				\
+int pci_user_write_config_##size					\
+	(struct pci_dev *dev, int pos, type val)			\
+{									\
+	int ret = -EIO;							\
+	if (PCI_##size##_BAD)						\
+		return -EINVAL;						\
+	raw_spin_lock_irq(&pci_lock);				\
+	if (unlikely(dev->block_cfg_access))				\
+		pci_wait_cfg(dev);					\
+	ret = dev->bus->ops->write(dev->bus, dev->devfn,		\
+					pos, sizeof(type), val);	\
+	raw_spin_unlock_irq(&pci_lock);				\
+	if (ret > 0)							\
+		ret = -EINVAL;						\
+	return ret;							\
+}
+
+PCI_USER_READ_CONFIG(byte, u8)
+PCI_USER_READ_CONFIG(word, u16)
+PCI_USER_READ_CONFIG(dword, u32)
+PCI_USER_WRITE_CONFIG(byte, u8)
+PCI_USER_WRITE_CONFIG(word, u16)
+PCI_USER_WRITE_CONFIG(dword, u32)
+
+/* VPD access through PCI 2.2+ VPD capability */
+
+#define PCI_VPD_PCI22_SIZE (PCI_VPD_ADDR_MASK + 1)
+
+struct pci_vpd_pci22 {
+	struct pci_vpd base;
+	struct mutex lock;
+	u16	flag;
+	bool	busy;
+	u8	cap;
+};
+
+/*
+ * Wait for last operation to complete.
+ * This code has to spin since there is no other notification from the PCI
+ * hardware. Since the VPD is often implemented by serial attachment to an
+ * EEPROM, it may take many milliseconds to complete.
+ *
+ * Returns 0 on success, negative values indicate error.
+ */
+static int pci_vpd_pci22_wait(struct pci_dev *dev)
+{
+	struct pci_vpd_pci22 *vpd =
+		container_of(dev->vpd, struct pci_vpd_pci22, base);
+	unsigned long timeout = jiffies + HZ/20 + 2;
+	u16 status;
+	int ret;
+
+	if (!vpd->busy)
+		return 0;
+
+	for (;;) {
+		ret = pci_user_read_config_word(dev, vpd->cap + PCI_VPD_ADDR,
+						&status);
+		if (ret < 0)
+			return ret;
+
+		if ((status & PCI_VPD_ADDR_F) == vpd->flag) {
+			vpd->busy = false;
+			return 0;
+		}
+
+		if (time_after(jiffies, timeout)) {
+			dev_printk(KERN_DEBUG, &dev->dev,
+				   "vpd r/w failed.  This is likely a firmware "
+				   "bug on this device.  Contact the card "
+				   "vendor for a firmware update.");
+			return -ETIMEDOUT;
+		}
+		if (fatal_signal_pending(current))
+			return -EINTR;
+		if (!cond_resched())
+			udelay(10);
+	}
+}
+
+static ssize_t pci_vpd_pci22_read(struct pci_dev *dev, loff_t pos, size_t count,
+				  void *arg)
+{
+	struct pci_vpd_pci22 *vpd =
+		container_of(dev->vpd, struct pci_vpd_pci22, base);
+	int ret;
+	loff_t end = pos + count;
+	u8 *buf = arg;
+
+	if (pos < 0 || pos > vpd->base.len || end > vpd->base.len)
+		return -EINVAL;
+
+	if (mutex_lock_killable(&vpd->lock))
+		return -EINTR;
+
+	ret = pci_vpd_pci22_wait(dev);
+	if (ret < 0)
+		goto out;
+
+	while (pos < end) {
+		u32 val;
+		unsigned int i, skip;
+
+		ret = pci_user_write_config_word(dev, vpd->cap + PCI_VPD_ADDR,
+						 pos & ~3);
+		if (ret < 0)
+			break;
+		vpd->busy = true;
+		vpd->flag = PCI_VPD_ADDR_F;
+		ret = pci_vpd_pci22_wait(dev);
+		if (ret < 0)
+			break;
+
+		ret = pci_user_read_config_dword(dev, vpd->cap + PCI_VPD_DATA, &val);
+		if (ret < 0)
+			break;
+
+		skip = pos & 3;
+		for (i = 0;  i < sizeof(u32); i++) {
+			if (i >= skip) {
+				*buf++ = val;
+				if (++pos == end)
+					break;
+			}
+			val >>= 8;
+		}
+	}
+out:
+	mutex_unlock(&vpd->lock);
+	return ret ? ret : count;
+}
+
+static ssize_t pci_vpd_pci22_write(struct pci_dev *dev, loff_t pos, size_t count,
+				   const void *arg)
+{
+	struct pci_vpd_pci22 *vpd =
+		container_of(dev->vpd, struct pci_vpd_pci22, base);
+	const u8 *buf = arg;
+	loff_t end = pos + count;
+	int ret = 0;
+
+	if (pos < 0 || (pos & 3) || (count & 3) || end > vpd->base.len)
+		return -EINVAL;
+
+	if (mutex_lock_killable(&vpd->lock))
+		return -EINTR;
+
+	ret = pci_vpd_pci22_wait(dev);
+	if (ret < 0)
+		goto out;
+
+	while (pos < end) {
+		u32 val;
+
+		val = *buf++;
+		val |= *buf++ << 8;
+		val |= *buf++ << 16;
+		val |= *buf++ << 24;
+
+		ret = pci_user_write_config_dword(dev, vpd->cap + PCI_VPD_DATA, val);
+		if (ret < 0)
+			break;
+		ret = pci_user_write_config_word(dev, vpd->cap + PCI_VPD_ADDR,
+						 pos | PCI_VPD_ADDR_F);
+		if (ret < 0)
+			break;
+
+		vpd->busy = true;
+		vpd->flag = 0;
+		ret = pci_vpd_pci22_wait(dev);
+		if (ret < 0)
+			break;
+
+		pos += sizeof(u32);
+	}
+out:
+	mutex_unlock(&vpd->lock);
+	return ret ? ret : count;
+}
+
+static void pci_vpd_pci22_release(struct pci_dev *dev)
+{
+	kfree(container_of(dev->vpd, struct pci_vpd_pci22, base));
+}
+
+static const struct pci_vpd_ops pci_vpd_pci22_ops = {
+	.read = pci_vpd_pci22_read,
+	.write = pci_vpd_pci22_write,
+	.release = pci_vpd_pci22_release,
+};
+
+int pci_vpd_pci22_init(struct pci_dev *dev)
+{
+	struct pci_vpd_pci22 *vpd;
+	u8 cap;
+
+	cap = pci_find_capability(dev, PCI_CAP_ID_VPD);
+	if (!cap)
+		return -ENODEV;
+	vpd = kzalloc(sizeof(*vpd), GFP_ATOMIC);
+	if (!vpd)
+		return -ENOMEM;
+
+	vpd->base.len = PCI_VPD_PCI22_SIZE;
+	vpd->base.ops = &pci_vpd_pci22_ops;
+	mutex_init(&vpd->lock);
+	vpd->cap = cap;
+	vpd->busy = false;
+	dev->vpd = &vpd->base;
+	return 0;
+}
+
+/**
+ * pci_vpd_truncate - Set available Vital Product Data size
+ * @dev:	pci device struct
+ * @size:	available memory in bytes
+ *
+ * Adjust size of available VPD area.
+ */
+int pci_vpd_truncate(struct pci_dev *dev, size_t size)
+{
+	if (!dev->vpd)
+		return -EINVAL;
+
+	/* limited by the access method */
+	if (size > dev->vpd->len)
+		return -EINVAL;
+
+	dev->vpd->len = size;
+	if (dev->vpd->attr)
+		dev->vpd->attr->size = size;
+
+	return 0;
+}
+EXPORT_SYMBOL(pci_vpd_truncate);
+
+/**
+ * pci_cfg_access_lock - Lock PCI config reads/writes
+ * @dev:	pci device struct
+ *
+ * When access is locked, any userspace reads or writes to config
+ * space and concurrent lock requests will sleep until access is
+ * allowed via pci_cfg_access_unlocked again.
+ */
+void pci_cfg_access_lock(struct pci_dev *dev)
+{
+	might_sleep();
+
+	raw_spin_lock_irq(&pci_lock);
+	if (dev->block_cfg_access)
+		pci_wait_cfg(dev);
+	dev->block_cfg_access = 1;
+	raw_spin_unlock_irq(&pci_lock);
+}
+EXPORT_SYMBOL_GPL(pci_cfg_access_lock);
+
+/**
+ * pci_cfg_access_trylock - try to lock PCI config reads/writes
+ * @dev:	pci device struct
+ *
+ * Same as pci_cfg_access_lock, but will return 0 if access is
+ * already locked, 1 otherwise. This function can be used from
+ * atomic contexts.
+ */
+bool pci_cfg_access_trylock(struct pci_dev *dev)
+{
+	unsigned long flags;
+	bool locked = true;
+
+	raw_spin_lock_irqsave(&pci_lock, flags);
+	if (dev->block_cfg_access)
+		locked = false;
+	else
+		dev->block_cfg_access = 1;
+	raw_spin_unlock_irqrestore(&pci_lock, flags);
+
+	return locked;
+}
+EXPORT_SYMBOL_GPL(pci_cfg_access_trylock);
+
+/**
+ * pci_cfg_access_unlock - Unlock PCI config reads/writes
+ * @dev:	pci device struct
+ *
+ * This function allows PCI config accesses to resume.
+ */
+void pci_cfg_access_unlock(struct pci_dev *dev)
+{
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&pci_lock, flags);
+
+	/* This indicates a problem in the caller, but we don't need
+	 * to kill them, unlike a double-block above. */
+	WARN_ON(!dev->block_cfg_access);
+
+	dev->block_cfg_access = 0;
+	wake_up_all(&pci_cfg_wait);
+	raw_spin_unlock_irqrestore(&pci_lock, flags);
+}
+EXPORT_SYMBOL_GPL(pci_cfg_access_unlock);