From: Eric W. Biederman Date: Thu, 8 Mar 2007 20:06:13 +0000 (-0700) Subject: [PATCH] pci: Repair pci_save/restore_state so we can restore one save many times. X-Git-Tag: v2.6.21-rc4~46 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=9f35575dfc172f0a93fb464761883c8f49599b7a;p=linux-2.6 [PATCH] pci: Repair pci_save/restore_state so we can restore one save many times. Because we do not reserve space for the pci-x and pci-e state in struct pci dev we need to dynamically allocate it. However because we need to support restore being called multiple times after a single save it is never safe to free the buffers we have allocated to hold the state. So this patch modifies the save routines to first check to see if we have already allocated a state buffer before allocating a new one. Then the restore routines are modified to not free the state after restoring it. Simple and it fixes some subtle error path handling bugs, that are hard to test for. Signed-off-by: Eric W. Biederman Signed-off-by: Greg Kroah-Hartman Acked-by: Auke Kok Signed-off-by: Linus Torvalds --- diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 6048c0c637..d3eab057b2 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -551,7 +551,9 @@ static int pci_save_pcie_state(struct pci_dev *dev) if (pos <= 0) return 0; - save_state = kzalloc(sizeof(*save_state) + sizeof(u16) * 4, GFP_KERNEL); + 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); if (!save_state) { dev_err(&dev->dev, "Out of memory in pci_save_pcie_state\n"); return -ENOMEM; @@ -582,8 +584,6 @@ static void pci_restore_pcie_state(struct pci_dev *dev) pci_write_config_word(dev, pos + PCI_EXP_LNKCTL, cap[i++]); pci_write_config_word(dev, pos + PCI_EXP_SLTCTL, cap[i++]); pci_write_config_word(dev, pos + PCI_EXP_RTCTL, cap[i++]); - pci_remove_saved_cap(save_state); - kfree(save_state); } @@ -597,7 +597,9 @@ static int pci_save_pcix_state(struct pci_dev *dev) if (pos <= 0) return 0; - save_state = kzalloc(sizeof(*save_state) + sizeof(u16), GFP_KERNEL); + save_state = pci_find_saved_cap(dev, PCI_CAP_ID_EXP); + if (!save_state) + save_state = kzalloc(sizeof(*save_state) + sizeof(u16), GFP_KERNEL); if (!save_state) { dev_err(&dev->dev, "Out of memory in pci_save_pcie_state\n"); return -ENOMEM; @@ -622,8 +624,6 @@ static void pci_restore_pcix_state(struct pci_dev *dev) cap = (u16 *)&save_state->data[0]; pci_write_config_word(dev, pos + PCI_X_CMD, cap[i++]); - pci_remove_saved_cap(save_state); - kfree(save_state); } diff --git a/include/linux/pci.h b/include/linux/pci.h index 78417e421b..481ea0663f 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -209,11 +209,6 @@ static inline void pci_add_saved_cap(struct pci_dev *pci_dev, hlist_add_head(&new_cap->next, &pci_dev->saved_cap_space); } -static inline void pci_remove_saved_cap(struct pci_cap_saved_state *cap) -{ - hlist_del(&cap->next); -} - /* * For PCI devices, the region numbers are assigned this way: *