PCI: Add ability to mmap legacy_io on some platforms

This adds the ability to mmap legacy IO space to the legacy_io files
in sysfs on platforms that support it. This will allow to clean up
X to use this instead of /dev/mem for legacy IO accesses such as
those performed by Int10.

While at it I moved pci_create/remove_legacy_files() to pci-sysfs.c
where I think they belong, thus making more things statis in there
and cleaned up some spurrious prototypes in the ia64 pci.h file

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

1 files changed, 88 insertions, 5 deletions

diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index 2cad6da2e4aa..110022d78689 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -423,7 +423,7 @@ pci_write_vpd(struct kobject *kobj, struct bin_attribute *bin_attr,
  * Reads 1, 2, or 4 bytes from legacy I/O port space using an arch specific
  * callback routine (pci_legacy_read).
  */
-ssize_t
+static ssize_t
 pci_read_legacy_io(struct kobject *kobj, struct bin_attribute *bin_attr,
                    char *buf, loff_t off, size_t count)
 {
@@ -448,7 +448,7 @@ pci_read_legacy_io(struct kobject *kobj, struct bin_attribute *bin_attr,
  * Writes 1, 2, or 4 bytes from legacy I/O port space using an arch specific
  * callback routine (pci_legacy_write).
  */
-ssize_t
+static ssize_t
 pci_write_legacy_io(struct kobject *kobj, struct bin_attribute *bin_attr,
                     char *buf, loff_t off, size_t count)
 {
@@ -468,11 +468,11 @@ pci_write_legacy_io(struct kobject *kobj, struct bin_attribute *bin_attr,
  * @attr: struct bin_attribute for this file
  * @vma: struct vm_area_struct passed to mmap
  *
- * Uses an arch specific callback, pci_mmap_legacy_page_range, to mmap
+ * Uses an arch specific callback, pci_mmap_legacy_mem_page_range, to mmap
  * legacy memory space (first meg of bus space) into application virtual
  * memory space.
  */
-int
+static int
 pci_mmap_legacy_mem(struct kobject *kobj, struct bin_attribute *attr,
                     struct vm_area_struct *vma)
 {
@@ -480,7 +480,90 @@ pci_mmap_legacy_mem(struct kobject *kobj, struct bin_attribute *attr,
                                                       struct device,
                                                       kobj));
 
-        return pci_mmap_legacy_page_range(bus, vma);
+        return pci_mmap_legacy_page_range(bus, vma, pci_mmap_mem);
+}
+
+/**
+ * pci_mmap_legacy_io - map legacy PCI IO into user memory space
+ * @kobj: kobject corresponding to device to be mapped
+ * @attr: struct bin_attribute for this file
+ * @vma: struct vm_area_struct passed to mmap
+ *
+ * Uses an arch specific callback, pci_mmap_legacy_io_page_range, to mmap
+ * legacy IO space (first meg of bus space) into application virtual
+ * memory space. Returns -ENOSYS if the operation isn't supported
+ */
+static int
+pci_mmap_legacy_io(struct kobject *kobj, struct bin_attribute *attr,
+                   struct vm_area_struct *vma)
+{
+        struct pci_bus *bus = to_pci_bus(container_of(kobj,
+                                                      struct device,
+                                                      kobj));
+
+        return pci_mmap_legacy_page_range(bus, vma, pci_mmap_io);
+}
+
+/**
+ * pci_create_legacy_files - create legacy I/O port and memory files
+ * @b: bus to create files under
+ *
+ * Some platforms allow access to legacy I/O port and ISA memory space on
+ * a per-bus basis.  This routine creates the files and ties them into
+ * their associated read, write and mmap files from pci-sysfs.c
+ *
+ * On error unwind, but don't propogate the error to the caller
+ * as it is ok to set up the PCI bus without these files.
+ */
+void pci_create_legacy_files(struct pci_bus *b)
+{
+        int error;
+
+        b->legacy_io = kzalloc(sizeof(struct bin_attribute) * 2,
+                               GFP_ATOMIC);
+        if (!b->legacy_io)
+                goto kzalloc_err;
+
+        b->legacy_io->attr.name = "legacy_io";
+        b->legacy_io->size = 0xffff;
+        b->legacy_io->attr.mode = S_IRUSR | S_IWUSR;
+        b->legacy_io->read = pci_read_legacy_io;
+        b->legacy_io->write = pci_write_legacy_io;
+        b->legacy_io->mmap = pci_mmap_legacy_io;
+        error = device_create_bin_file(&b->dev, b->legacy_io);
+        if (error)
+                goto legacy_io_err;
+
+        /* Allocated above after the legacy_io struct */
+        b->legacy_mem = b->legacy_io + 1;
+        b->legacy_mem->attr.name = "legacy_mem";
+        b->legacy_mem->size = 1024*1024;
+        b->legacy_mem->attr.mode = S_IRUSR | S_IWUSR;
+        b->legacy_mem->mmap = pci_mmap_legacy_mem;
+        error = device_create_bin_file(&b->dev, b->legacy_mem);
+        if (error)
+                goto legacy_mem_err;
+
+        return;
+
+legacy_mem_err:
+        device_remove_bin_file(&b->dev, b->legacy_io);
+legacy_io_err:
+        kfree(b->legacy_io);
+        b->legacy_io = NULL;
+kzalloc_err:
+        printk(KERN_WARNING "pci: warning: could not create legacy I/O port "
+               "and ISA memory resources to sysfs\n");
+        return;
+}
+
+void pci_remove_legacy_files(struct pci_bus *b)
+{
+        if (b->legacy_io) {
+                device_remove_bin_file(&b->dev, b->legacy_io);
+                device_remove_bin_file(&b->dev, b->legacy_mem);
+                kfree(b->legacy_io); /* both are allocated here */
+        }
 }
 #endif /* HAVE_PCI_LEGACY */