From 63f4898ace2788a89ed685672aab092e1c3e50e6 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Sun, 7 Dec 2008 22:02:58 +0100 Subject: [PATCH] PCI: handle PCI state saving with interrupts disabled Since interrupts will soon be disabled at PCI resume time, we need to pre-allocate memory to save/restore PCI config space (or use GFP_ATOMIC, but this is safer). Reported-by: Linus Torvalds Signed-off-by: "Rafael J. Wysocki" Signed-off-by: Jesse Barnes --- drivers/pci/pci.c | 73 +++++++++++++++++++++++++++++++-------------- drivers/pci/pci.h | 1 + drivers/pci/probe.c | 3 ++ 3 files changed, 55 insertions(+), 22 deletions(-) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 47663dc0daf7..3222f9022707 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -640,19 +640,14 @@ static int pci_save_pcie_state(struct pci_dev *dev) int pos, i = 0; struct pci_cap_saved_state *save_state; u16 *cap; - int found = 0; pos = pci_find_capability(dev, PCI_CAP_ID_EXP); if (pos <= 0) return 0; save_state = pci_find_saved_cap(dev, PCI_CAP_ID_EXP); - if (!save_state) - save_state = kzalloc(sizeof(*save_state) + sizeof(u16) * 4, GFP_KERNEL); - else - found = 1; if (!save_state) { - dev_err(&dev->dev, "out of memory in pci_save_pcie_state\n"); + dev_err(&dev->dev, "buffer not found in %s\n", __FUNCTION__); return -ENOMEM; } cap = (u16 *)&save_state->data[0]; @@ -661,9 +656,7 @@ static int pci_save_pcie_state(struct pci_dev *dev) pci_read_config_word(dev, pos + PCI_EXP_LNKCTL, &cap[i++]); pci_read_config_word(dev, pos + PCI_EXP_SLTCTL, &cap[i++]); pci_read_config_word(dev, pos + PCI_EXP_RTCTL, &cap[i++]); - save_state->cap_nr = PCI_CAP_ID_EXP; - if (!found) - pci_add_saved_cap(dev, save_state); + return 0; } @@ -688,30 +681,21 @@ static void pci_restore_pcie_state(struct pci_dev *dev) static int pci_save_pcix_state(struct pci_dev *dev) { - int pos, i = 0; + int pos; struct pci_cap_saved_state *save_state; - u16 *cap; - int found = 0; pos = pci_find_capability(dev, PCI_CAP_ID_PCIX); if (pos <= 0) return 0; save_state = pci_find_saved_cap(dev, PCI_CAP_ID_PCIX); - if (!save_state) - save_state = kzalloc(sizeof(*save_state) + sizeof(u16), GFP_KERNEL); - else - found = 1; if (!save_state) { - dev_err(&dev->dev, "out of memory in pci_save_pcie_state\n"); + dev_err(&dev->dev, "buffer not found in %s\n", __FUNCTION__); return -ENOMEM; } - cap = (u16 *)&save_state->data[0]; - pci_read_config_word(dev, pos + PCI_X_CMD, &cap[i++]); - save_state->cap_nr = PCI_CAP_ID_PCIX; - if (!found) - pci_add_saved_cap(dev, save_state); + pci_read_config_word(dev, pos + PCI_X_CMD, (u16 *)save_state->data); + return 0; } @@ -1300,6 +1284,51 @@ void pci_pm_init(struct pci_dev *dev) } } +/** + * pci_add_save_buffer - allocate buffer for saving given capability registers + * @dev: the PCI device + * @cap: the capability to allocate the buffer for + * @size: requested size of the buffer + */ +static int pci_add_cap_save_buffer( + struct pci_dev *dev, char cap, unsigned int size) +{ + int pos; + struct pci_cap_saved_state *save_state; + + pos = pci_find_capability(dev, cap); + if (pos <= 0) + return 0; + + save_state = kzalloc(sizeof(*save_state) + size, GFP_KERNEL); + if (!save_state) + return -ENOMEM; + + save_state->cap_nr = cap; + pci_add_saved_cap(dev, save_state); + + return 0; +} + +/** + * pci_allocate_cap_save_buffers - allocate buffers for saving capabilities + * @dev: the PCI device + */ +void pci_allocate_cap_save_buffers(struct pci_dev *dev) +{ + int error; + + error = pci_add_cap_save_buffer(dev, PCI_CAP_ID_EXP, 4 * sizeof(u16)); + if (error) + dev_err(&dev->dev, + "unable to preallocate PCI Express save buffer\n"); + + error = pci_add_cap_save_buffer(dev, PCI_CAP_ID_PCIX, sizeof(u16)); + if (error) + dev_err(&dev->dev, + "unable to preallocate PCI-X save buffer\n"); +} + /** * pci_enable_ari - enable ARI forwarding if hardware support it * @dev: the PCI device diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index 9162e242b99e..7242b511a93f 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -45,6 +45,7 @@ struct pci_platform_pm_ops { extern int pci_set_platform_pm(struct pci_platform_pm_ops *ops); extern void pci_pm_init(struct pci_dev *dev); +extern void pci_allocate_cap_save_buffers(struct pci_dev *dev); extern int pci_user_read_config_byte(struct pci_dev *dev, int where, u8 *val); extern int pci_user_read_config_word(struct pci_dev *dev, int where, u16 *val); diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index eb2b985beb48..5dcf2b65e3f9 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -958,6 +958,9 @@ static void pci_init_capabilities(struct pci_dev *dev) /* MSI/MSI-X list */ pci_msi_init_pci_dev(dev); + /* Buffers for saving PCIe and PCI-X capabilities */ + pci_allocate_cap_save_buffers(dev); + /* Power Management */ pci_pm_init(dev); -- 2.30.2