diff options
Diffstat (limited to 'drivers/pci/access.c')
| -rw-r--r-- | drivers/pci/access.c | 166 |
1 files changed, 166 insertions, 0 deletions
diff --git a/drivers/pci/access.c b/drivers/pci/access.c index fc405f0165d..ec8f7002b09 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 |