[RFC/PATCH 1/2] pci: Add ability to mmap legacy_io on some platforms
Benjamin Herrenschmidt
benh at kernel.crashing.org
Fri Oct 3 19:49:32 EST 2008
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 at kernel.crashing.org>
---
I didn't have a chance to test that I didn't break ia64, so I would
be if somebody could give it a spin there ! Thanks !
arch/ia64/include/asm/pci.h | 12 -----
arch/ia64/pci/pci.c | 7 ++-
drivers/pci/pci-sysfs.c | 93 +++++++++++++++++++++++++++++++++++++++++---
drivers/pci/pci.h | 6 ++
drivers/pci/probe.c | 66 -------------------------------
5 files changed, 102 insertions(+), 82 deletions(-)
--- linux-work.orig/arch/ia64/include/asm/pci.h 2008-10-03 11:24:12.000000000 +1000
+++ linux-work/arch/ia64/include/asm/pci.h 2008-10-03 11:25:08.000000000 +1000
@@ -95,16 +95,8 @@ extern int pci_mmap_page_range (struct p
enum pci_mmap_state mmap_state, int write_combine);
#define HAVE_PCI_LEGACY
extern int pci_mmap_legacy_page_range(struct pci_bus *bus,
- struct vm_area_struct *vma);
-extern ssize_t pci_read_legacy_io(struct kobject *kobj,
- struct bin_attribute *bin_attr,
- char *buf, loff_t off, size_t count);
-extern ssize_t pci_write_legacy_io(struct kobject *kobj,
- struct bin_attribute *bin_attr,
- char *buf, loff_t off, size_t count);
-extern int pci_mmap_legacy_mem(struct kobject *kobj,
- struct bin_attribute *attr,
- struct vm_area_struct *vma);
+ struct vm_area_struct *vma,
+ enum pci_mmap_state mmap_state);
#define pci_get_legacy_mem platform_pci_get_legacy_mem
#define pci_legacy_read platform_pci_legacy_read
Index: linux-work/arch/ia64/pci/pci.c
===================================================================
--- linux-work.orig/arch/ia64/pci/pci.c 2008-10-03 11:23:35.000000000 +1000
+++ linux-work/arch/ia64/pci/pci.c 2008-10-03 11:47:17.000000000 +1000
@@ -614,12 +614,17 @@ char *ia64_pci_get_legacy_mem(struct pci
* vector to get the base address.
*/
int
-pci_mmap_legacy_page_range(struct pci_bus *bus, struct vm_area_struct *vma)
+pci_mmap_legacy_page_range(struct pci_bus *bus, struct vm_area_struct *vma,
+ enum pci_mmap_state mmap_state)
{
unsigned long size = vma->vm_end - vma->vm_start;
pgprot_t prot;
char *addr;
+ /* We only support mmap'ing of legacy memory space */
+ if (mmap_state != pci_mmap_mem)
+ return -ENOSYS;
+
/*
* Avoid attribute aliasing. See Documentation/ia64/aliasing.txt
* for more details.
Index: linux-work/drivers/pci/pci-sysfs.c
===================================================================
--- linux-work.orig/drivers/pci/pci-sysfs.c 2008-10-03 11:12:22.000000000 +1000
+++ linux-work/drivers/pci/pci-sysfs.c 2008-10-03 11:45:34.000000000 +1000
@@ -422,7 +422,7 @@ pci_write_vpd(struct kobject *kobj, stru
* 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)
{
@@ -447,7 +447,7 @@ pci_read_legacy_io(struct kobject *kobj,
* 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)
{
@@ -467,11 +467,11 @@ pci_write_legacy_io(struct kobject *kobj
* @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)
{
@@ -479,7 +479,90 @@ pci_mmap_legacy_mem(struct kobject *kobj
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 */
Index: linux-work/drivers/pci/pci.h
===================================================================
--- linux-work.orig/drivers/pci/pci.h 2008-10-03 11:17:53.000000000 +1000
+++ linux-work/drivers/pci/pci.h 2008-10-03 11:18:32.000000000 +1000
@@ -76,7 +76,13 @@ static inline int pci_proc_detach_bus(st
/* Functions for PCI Hotplug drivers to use */
extern unsigned int pci_do_scan_bus(struct pci_bus *bus);
+#ifdef HAVE_PCI_LEGACY
+extern void pci_create_legacy_files(struct pci_bus *bus);
extern void pci_remove_legacy_files(struct pci_bus *bus);
+#else
+static inline void pci_create_legacy_files(struct pci_bus *bus) { return; }
+static inline void pci_remove_legacy_files(struct pci_bus *bus) { return; }
+#endif
/* Lock for read/write access to pci device and bus lists */
extern struct rw_semaphore pci_bus_sem;
Index: linux-work/drivers/pci/probe.c
===================================================================
--- linux-work.orig/drivers/pci/probe.c 2008-10-03 11:19:26.000000000 +1000
+++ linux-work/drivers/pci/probe.c 2008-10-03 11:19:57.000000000 +1000
@@ -44,72 +44,6 @@ int no_pci_devices(void)
}
EXPORT_SYMBOL(no_pci_devices);
-#ifdef HAVE_PCI_LEGACY
-/**
- * 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.
- */
-static 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;
- 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 */
- }
-}
-#else /* !HAVE_PCI_LEGACY */
-static inline void pci_create_legacy_files(struct pci_bus *bus) { return; }
-void pci_remove_legacy_files(struct pci_bus *bus) { return; }
-#endif /* HAVE_PCI_LEGACY */
-
/*
* PCI Bus Class Devices
*/
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