1 files changed, 62 insertions, 0 deletions

diff --git a/drivers/pci/access.c b/drivers/pci/access.c
new file mode 100644
index 000000000000..24a76de49f41
--- /dev/null
+++ b/drivers/pci/access.c
@@ -0,0 +1,62 @@
+#include <linux/pci.h>
+#include <linux/module.h>
+#include <linux/ioport.h>
+
+/*
+ * This interrupt-safe spinlock protects all accesses to PCI
+ * configuration space.
+ */
+
+static DEFINE_SPINLOCK(pci_lock);
+
+/*
+ *  Wrappers for all PCI configuration access functions.  They just check
+ *  alignment, do locking and call the low-level functions pointed to
+ *  by pci_dev->ops.
+ */
+
+#define PCI_byte_BAD 0
+#define PCI_word_BAD (pos & 1)
+#define PCI_dword_BAD (pos & 3)
+
+#define PCI_OP_READ(size,type,len) \
+int pci_bus_read_config_##size \
+        (struct pci_bus *bus, unsigned int devfn, int pos, type *value) \
+{                                                                       \
+        int res;                                                        \
+        unsigned long flags;                                            \
+        u32 data = 0;                                                   \
+        if (PCI_##size##_BAD) return PCIBIOS_BAD_REGISTER_NUMBER;       \
+        spin_lock_irqsave(&pci_lock, flags);                            \
+        res = bus->ops->read(bus, devfn, pos, len, &data);              \
+        *value = (type)data;                                            \
+        spin_unlock_irqrestore(&pci_lock, flags);                       \
+        return res;                                                     \
+}
+
+#define PCI_OP_WRITE(size,type,len) \
+int pci_bus_write_config_##size \
+        (struct pci_bus *bus, unsigned int devfn, int pos, type value)  \
+{                                                                       \
+        int res;                                                        \
+        unsigned long flags;                                            \
+        if (PCI_##size##_BAD) return PCIBIOS_BAD_REGISTER_NUMBER;       \
+        spin_lock_irqsave(&pci_lock, flags);                            \
+        res = bus->ops->write(bus, devfn, pos, len, value);             \
+        spin_unlock_irqrestore(&pci_lock, flags);                       \
+        return res;                                                     \
+}
+
+PCI_OP_READ(byte, u8, 1)
+PCI_OP_READ(word, u16, 2)
+PCI_OP_READ(dword, u32, 4)
+PCI_OP_WRITE(byte, u8, 1)
+PCI_OP_WRITE(word, u16, 2)
+PCI_OP_WRITE(dword, u32, 4)
+
+EXPORT_SYMBOL(pci_bus_read_config_byte);
+EXPORT_SYMBOL(pci_bus_read_config_word);
+EXPORT_SYMBOL(pci_bus_read_config_dword);
+EXPORT_SYMBOL(pci_bus_write_config_byte);
+EXPORT_SYMBOL(pci_bus_write_config_word);
+EXPORT_SYMBOL(pci_bus_write_config_dword);