1 files changed, 166 insertions, 0 deletions

diff --git a/drivers/pci/access.c b/drivers/pci/access.c
index fc405f0165d9..ec8f7002b09d 100644
--- a/drivers/pci/access.c
+++ b/drivers/pci/access.c
@@ -1,3 +1,4 @@
+#include <linux/delay.h>
 #include <linux/pci.h>
 #include <linux/module.h>
 #include <linux/sched.h>
@@ -126,6 +127,171 @@ 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;
+        spinlock_t lock; /* controls access to hardware and the flags */
+        u8      cap;
+        bool    busy;
+        bool    flag; /* value of F bit to wait for */
+};
+
+/* Wait for last operation to complete */
+static int pci_vpd_pci22_wait(struct pci_dev *dev)
+{
+        struct pci_vpd_pci22 *vpd =
+                container_of(dev->vpd, struct pci_vpd_pci22, base);
+        u16 flag, status;
+        int wait;
+        int ret;
+
+        if (!vpd->busy)
+                return 0;
+
+        flag = vpd->flag ? PCI_VPD_ADDR_F : 0;
+        wait = vpd->flag ? 10 : 1000; /* read: 100 us; write: 10 ms */
+        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) == flag) {
+                        vpd->busy = false;
+                        return 0;
+                }
+                if (wait-- == 0)
+                        return -ETIMEDOUT;
+                udelay(10);
+        }
+}
+
+static int pci_vpd_pci22_read(struct pci_dev *dev, int pos, int size,
+                              char *buf)
+{
+        struct pci_vpd_pci22 *vpd =
+                container_of(dev->vpd, struct pci_vpd_pci22, base);
+        u32 val;
+        int ret;
+        int begin, end, i;
+
+        if (pos < 0 || pos > PCI_VPD_PCI22_SIZE ||
+            size > PCI_VPD_PCI22_SIZE  - pos)
+                return -EINVAL;
+        if (size == 0)
+                return 0;
+
+        spin_lock_irq(&vpd->lock);
+        ret = pci_vpd_pci22_wait(dev);
+        if (ret < 0)
+                goto out;
+        ret = pci_user_write_config_word(dev, vpd->cap + PCI_VPD_ADDR,
+                                         pos & ~3);
+        if (ret < 0)
+                goto out;
+        vpd->busy = true;
+        vpd->flag = 1;
+        ret = pci_vpd_pci22_wait(dev);
+        if (ret < 0)
+                goto out;
+        ret = pci_user_read_config_dword(dev, vpd->cap + PCI_VPD_DATA,
+                                         &val);
+out:
+        spin_unlock_irq(&vpd->lock);
+        if (ret < 0)
+                return ret;
+
+        /* Convert to bytes */
+        begin = pos & 3;
+        end = min(4, begin + size);
+        for (i = 0; i < end; ++i) {
+                if (i >= begin)
+                        *buf++ = val;
+                val >>= 8;
+        }
+        return end - begin;
+}
+
+static int pci_vpd_pci22_write(struct pci_dev *dev, int pos, int size,
+                               const char *buf)
+{
+        struct pci_vpd_pci22 *vpd =
+                container_of(dev->vpd, struct pci_vpd_pci22, base);
+        u32 val;
+        int ret;
+
+        if (pos < 0 || pos > PCI_VPD_PCI22_SIZE || pos & 3 ||
+            size > PCI_VPD_PCI22_SIZE - pos || size < 4)
+                return -EINVAL;
+
+        val = (u8) *buf++;
+        val |= ((u8) *buf++) << 8;
+        val |= ((u8) *buf++) << 16;
+        val |= ((u32)(u8) *buf++) << 24;
+
+        spin_lock_irq(&vpd->lock);
+        ret = pci_vpd_pci22_wait(dev);
+        if (ret < 0)
+                goto out;
+        ret = pci_user_write_config_dword(dev, vpd->cap + PCI_VPD_DATA,
+                                          val);
+        if (ret < 0)
+                goto out;
+        ret = pci_user_write_config_word(dev, vpd->cap + PCI_VPD_ADDR,
+                                         pos | PCI_VPD_ADDR_F);
+        if (ret < 0)
+                goto out;
+        vpd->busy = true;
+        vpd->flag = 0;
+        ret = pci_vpd_pci22_wait(dev);
+out:
+        spin_unlock_irq(&vpd->lock);
+        if (ret < 0)
+                return ret;
+
+        return 4;
+}
+
+static int pci_vpd_pci22_get_size(struct pci_dev *dev)
+{
+        return PCI_VPD_PCI22_SIZE;
+}
+
+static void pci_vpd_pci22_release(struct pci_dev *dev)
+{
+        kfree(container_of(dev->vpd, struct pci_vpd_pci22, base));
+}
+
+static struct pci_vpd_ops pci_vpd_pci22_ops = {
+        .read = pci_vpd_pci22_read,
+        .write = pci_vpd_pci22_write,
+        .get_size = pci_vpd_pci22_get_size,
+        .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.ops = &pci_vpd_pci22_ops;
+        spin_lock_init(&vpd->lock);
+        vpd->cap = cap;
+        vpd->busy = false;
+        dev->vpd = &vpd->base;
+        return 0;
+}
+
 /**
  * pci_block_user_cfg_access - Block userspace PCI config reads/writes
  * @dev:        pci device struct