From 925845bd49c6de437dfab3bf8dc654ea3ae21d74 Mon Sep 17 00:00:00 2001 From: Myron Stowe Date: Mon, 21 Nov 2011 11:54:13 -0700 Subject: [PATCH] x86/PCI: Infrastructure to maintain a list of FW-assigned BIOS BAR values Commit 58c84eda075 introduced functionality to try and reinstate the original BIOS BAR addresses of a PCI device when normal resource assignment attempts fail. To keep track of the BIOS BAR addresses, struct pci_dev was augmented with an array to hold the BAR addresses of the PCI device: 'resource_size_t fw_addr[DEVICE_COUNT_RESOURCE]'. The reinstatement of BAR addresses is an uncommon event leaving the 'fw_addr' array unused under normal circumstances. This functionality is also currently architecture specific with an implementation limited to x86. As the use of struct pci_dev is so prevalent, having the 'fw_addr' array residing within such seems somewhat wasteful. This patch introduces a stand alone data structure and interfacing routines for maintaining a list of FW-assigned BIOS BAR value entries. Signed-off-by: Myron Stowe Signed-off-by: Jesse Barnes --- arch/x86/pci/i386.c | 79 +++++++++++++++++++++++++++++++++++++++++++++ include/linux/pci.h | 1 + 2 files changed, 80 insertions(+) diff --git a/arch/x86/pci/i386.c b/arch/x86/pci/i386.c index 91821a1a0c3a..5a1edf2b5386 100644 --- a/arch/x86/pci/i386.c +++ b/arch/x86/pci/i386.c @@ -39,6 +39,85 @@ #include +/* + * This list of dynamic mappings is for temporarily maintaining + * original BIOS BAR addresses for possible reinstatement. + */ +struct pcibios_fwaddrmap { + struct list_head list; + struct pci_dev *dev; + resource_size_t fw_addr[DEVICE_COUNT_RESOURCE]; +}; + +static LIST_HEAD(pcibios_fwaddrmappings); +static DEFINE_SPINLOCK(pcibios_fwaddrmap_lock); + +/* Must be called with 'pcibios_fwaddrmap_lock' lock held. */ +static struct pcibios_fwaddrmap *pcibios_fwaddrmap_lookup(struct pci_dev *dev) +{ + struct pcibios_fwaddrmap *map; + + list_for_each_entry(map, &pcibios_fwaddrmappings, list) + if (map->dev == dev) + return map; + + return NULL; +} + +static void +pcibios_save_fw_addr(struct pci_dev *dev, int idx, resource_size_t fw_addr) +{ + unsigned long flags; + struct pcibios_fwaddrmap *map; + + spin_lock_irqsave(&pcibios_fwaddrmap_lock, flags); + map = pcibios_fwaddrmap_lookup(dev); + if (!map) { + spin_unlock_irqrestore(&pcibios_fwaddrmap_lock, flags); + map = kzalloc(sizeof(*map), GFP_KERNEL); + if (!map) + return; + + map->dev = pci_dev_get(dev); + map->fw_addr[idx] = fw_addr; + INIT_LIST_HEAD(&map->list); + + spin_lock_irqsave(&pcibios_fwaddrmap_lock, flags); + list_add_tail(&map->list, &pcibios_fwaddrmappings); + } else + map->fw_addr[idx] = fw_addr; + spin_unlock_irqrestore(&pcibios_fwaddrmap_lock, flags); +} + +resource_size_t pcibios_retrieve_fw_addr(struct pci_dev *dev, int idx) +{ + unsigned long flags; + struct pcibios_fwaddrmap *map; + resource_size_t fw_addr = 0; + + spin_lock_irqsave(&pcibios_fwaddrmap_lock, flags); + map = pcibios_fwaddrmap_lookup(dev); + if (map) + fw_addr = map->fw_addr[idx]; + spin_unlock_irqrestore(&pcibios_fwaddrmap_lock, flags); + + return fw_addr; +} + +static void pcibios_fw_addr_list_del(void) +{ + unsigned long flags; + struct pcibios_fwaddrmap *entry, *next; + + spin_lock_irqsave(&pcibios_fwaddrmap_lock, flags); + list_for_each_entry_safe(entry, next, &pcibios_fwaddrmappings, list) { + list_del(&entry->list); + pci_dev_put(entry->dev); + kfree(entry); + } + spin_unlock_irqrestore(&pcibios_fwaddrmap_lock, flags); +} + static int skip_isa_ioresource_align(struct pci_dev *dev) { diff --git a/include/linux/pci.h b/include/linux/pci.h index a16b1df3deff..8e9a307e58b8 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -891,6 +891,7 @@ ssize_t pci_write_vpd(struct pci_dev *dev, loff_t pos, size_t count, const void int pci_vpd_truncate(struct pci_dev *dev, size_t size); /* Helper functions for low-level code (drivers/pci/setup-[bus,res].c) */ +resource_size_t pcibios_retrieve_fw_addr(struct pci_dev *dev, int idx); void pci_bus_assign_resources(const struct pci_bus *bus); void pci_bus_size_bridges(struct pci_bus *bus); int pci_claim_resource(struct pci_dev *, int); -- 2.20.1