summaryrefslogtreecommitdiffstats
path: root/drivers/pci/access.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/pci/access.c')
-rw-r--r--drivers/pci/access.c166
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