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 <myron.stowe@redhat.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
diff --git a/arch/x86/pci/i386.c b/arch/x86/pci/i386.c
index 91821a1..5a1edf2 100644
--- a/arch/x86/pci/i386.c
+++ b/arch/x86/pci/i386.c
@@ -39,6 +39,85 @@
#include <asm/io_apic.h>
+/*
+ * 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) {