PCI/VPD: Move VPD access code to vpd.c

Move the VPD-related code from access.c to vpd.c.  The goal is to
encapsulate all the VPD code and structures in vpd.c.

No functional change intended.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

1 files changed, 369 insertions, 0 deletions

diff --git a/drivers/pci/vpd.c b/drivers/pci/vpd.c
index 70fba57d6103..4596452d58bf 100644
--- a/drivers/pci/vpd.c
+++ b/drivers/pci/vpd.c
@@ -7,7 +7,376 @@
  */
 
 #include <linux/pci.h>
+#include <linux/delay.h>
 #include <linux/export.h>
+#include <linux/sched/signal.h>
+#include "pci.h"
+
+/* VPD access through PCI 2.2+ VPD capability */
+
+/**
+ * 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);
+
+/**
+ * pci_set_vpd_size - Set size of Vital Product Data space
+ * @dev:	pci device struct
+ * @len:	size of vpd space
+ */
+int pci_set_vpd_size(struct pci_dev *dev, size_t len)
+{
+	if (!dev->vpd || !dev->vpd->ops)
+		return -ENODEV;
+	return dev->vpd->ops->set_size(dev, len);
+}
+EXPORT_SYMBOL(pci_set_vpd_size);
+
+#define PCI_VPD_MAX_SIZE (PCI_VPD_ADDR_MASK + 1)
+
+/**
+ * pci_vpd_size - determine actual size of Vital Product Data
+ * @dev:	pci device struct
+ * @old_size:	current assumed size, also maximum allowed size
+ */
+static size_t pci_vpd_size(struct pci_dev *dev, size_t old_size)
+{
+	size_t off = 0;
+	unsigned char header[1+2];	/* 1 byte tag, 2 bytes length */
+
+	while (off < old_size &&
+	       pci_read_vpd(dev, off, 1, header) == 1) {
+		unsigned char tag;
+
+		if (header[0] & PCI_VPD_LRDT) {
+			/* Large Resource Data Type Tag */
+			tag = pci_vpd_lrdt_tag(header);
+			/* Only read length from known tag items */
+			if ((tag == PCI_VPD_LTIN_ID_STRING) ||
+			    (tag == PCI_VPD_LTIN_RO_DATA) ||
+			    (tag == PCI_VPD_LTIN_RW_DATA)) {
+				if (pci_read_vpd(dev, off+1, 2,
+						 &header[1]) != 2) {
+					pci_warn(dev, "invalid large VPD tag %02x size at offset %zu",
+						 tag, off + 1);
+					return 0;
+				}
+				off += PCI_VPD_LRDT_TAG_SIZE +
+					pci_vpd_lrdt_size(header);
+			}
+		} else {
+			/* Short Resource Data Type Tag */
+			off += PCI_VPD_SRDT_TAG_SIZE +
+				pci_vpd_srdt_size(header);
+			tag = pci_vpd_srdt_tag(header);
+		}
+
+		if (tag == PCI_VPD_STIN_END)	/* End tag descriptor */
+			return off;
+
+		if ((tag != PCI_VPD_LTIN_ID_STRING) &&
+		    (tag != PCI_VPD_LTIN_RO_DATA) &&
+		    (tag != PCI_VPD_LTIN_RW_DATA)) {
+			pci_warn(dev, "invalid %s VPD tag %02x at offset %zu",
+				 (header[0] & PCI_VPD_LRDT) ? "large" : "short",
+				 tag, off);
+			return 0;
+		}
+	}
+	return 0;
+}
+
+/*
+ * 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_wait(struct pci_dev *dev)
+{
+	struct pci_vpd *vpd = dev->vpd;
+	unsigned long timeout = jiffies + msecs_to_jiffies(125);
+	unsigned long max_sleep = 16;
+	u16 status;
+	int ret;
+
+	if (!vpd->busy)
+		return 0;
+
+	while (time_before(jiffies, timeout)) {
+		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 = 0;
+			return 0;
+		}
+
+		if (fatal_signal_pending(current))
+			return -EINTR;
+
+		usleep_range(10, max_sleep);
+		if (max_sleep < 1024)
+			max_sleep *= 2;
+	}
+
+	pci_warn(dev, "VPD access failed.  This is likely a firmware bug on this device.  Contact the card vendor for a firmware update\n");
+	return -ETIMEDOUT;
+}
+
+static ssize_t pci_vpd_read(struct pci_dev *dev, loff_t pos, size_t count,
+			    void *arg)
+{
+	struct pci_vpd *vpd = dev->vpd;
+	int ret;
+	loff_t end = pos + count;
+	u8 *buf = arg;
+
+	if (pos < 0)
+		return -EINVAL;
+
+	if (!vpd->valid) {
+		vpd->valid = 1;
+		vpd->len = pci_vpd_size(dev, vpd->len);
+	}
+
+	if (vpd->len == 0)
+		return -EIO;
+
+	if (pos > vpd->len)
+		return 0;
+
+	if (end > vpd->len) {
+		end = vpd->len;
+		count = end - pos;
+	}
+
+	if (mutex_lock_killable(&vpd->lock))
+		return -EINTR;
+
+	ret = pci_vpd_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 = 1;
+		vpd->flag = PCI_VPD_ADDR_F;
+		ret = pci_vpd_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_write(struct pci_dev *dev, loff_t pos, size_t count,
+			     const void *arg)
+{
+	struct pci_vpd *vpd = dev->vpd;
+	const u8 *buf = arg;
+	loff_t end = pos + count;
+	int ret = 0;
+
+	if (pos < 0 || (pos & 3) || (count & 3))
+		return -EINVAL;
+
+	if (!vpd->valid) {
+		vpd->valid = 1;
+		vpd->len = pci_vpd_size(dev, vpd->len);
+	}
+
+	if (vpd->len == 0)
+		return -EIO;
+
+	if (end > vpd->len)
+		return -EINVAL;
+
+	if (mutex_lock_killable(&vpd->lock))
+		return -EINTR;
+
+	ret = pci_vpd_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 = 1;
+		vpd->flag = 0;
+		ret = pci_vpd_wait(dev);
+		if (ret < 0)
+			break;
+
+		pos += sizeof(u32);
+	}
+out:
+	mutex_unlock(&vpd->lock);
+	return ret ? ret : count;
+}
+
+static int pci_vpd_set_size(struct pci_dev *dev, size_t len)
+{
+	struct pci_vpd *vpd = dev->vpd;
+
+	if (len == 0 || len > PCI_VPD_MAX_SIZE)
+		return -EIO;
+
+	vpd->valid = 1;
+	vpd->len = len;
+
+	return 0;
+}
+
+static const struct pci_vpd_ops pci_vpd_ops = {
+	.read = pci_vpd_read,
+	.write = pci_vpd_write,
+	.set_size = pci_vpd_set_size,
+};
+
+static ssize_t pci_vpd_f0_read(struct pci_dev *dev, loff_t pos, size_t count,
+			       void *arg)
+{
+	struct pci_dev *tdev = pci_get_slot(dev->bus,
+					    PCI_DEVFN(PCI_SLOT(dev->devfn), 0));
+	ssize_t ret;
+
+	if (!tdev)
+		return -ENODEV;
+
+	ret = pci_read_vpd(tdev, pos, count, arg);
+	pci_dev_put(tdev);
+	return ret;
+}
+
+static ssize_t pci_vpd_f0_write(struct pci_dev *dev, loff_t pos, size_t count,
+				const void *arg)
+{
+	struct pci_dev *tdev = pci_get_slot(dev->bus,
+					    PCI_DEVFN(PCI_SLOT(dev->devfn), 0));
+	ssize_t ret;
+
+	if (!tdev)
+		return -ENODEV;
+
+	ret = pci_write_vpd(tdev, pos, count, arg);
+	pci_dev_put(tdev);
+	return ret;
+}
+
+static int pci_vpd_f0_set_size(struct pci_dev *dev, size_t len)
+{
+	struct pci_dev *tdev = pci_get_slot(dev->bus,
+					    PCI_DEVFN(PCI_SLOT(dev->devfn), 0));
+	int ret;
+
+	if (!tdev)
+		return -ENODEV;
+
+	ret = pci_set_vpd_size(tdev, len);
+	pci_dev_put(tdev);
+	return ret;
+}
+
+static const struct pci_vpd_ops pci_vpd_f0_ops = {
+	.read = pci_vpd_f0_read,
+	.write = pci_vpd_f0_write,
+	.set_size = pci_vpd_f0_set_size,
+};
+
+int pci_vpd_init(struct pci_dev *dev)
+{
+	struct pci_vpd *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->len = PCI_VPD_MAX_SIZE;
+	if (dev->dev_flags & PCI_DEV_FLAGS_VPD_REF_F0)
+		vpd->ops = &pci_vpd_f0_ops;
+	else
+		vpd->ops = &pci_vpd_ops;
+	mutex_init(&vpd->lock);
+	vpd->cap = cap;
+	vpd->busy = 0;
+	vpd->valid = 0;
+	dev->vpd = vpd;
+	return 0;
+}
+
+void pci_vpd_release(struct pci_dev *dev)
+{
+	kfree(dev->vpd);
+}
 
 int pci_vpd_find_tag(const u8 *buf, unsigned int off, unsigned int len, u8 rdt)
 {