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authorJeff Dike <jdike@addtoit.com>2008-02-04 22:31:17 -0800
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2008-02-05 09:44:30 -0800
commit80e39311ff3d7d2267ea8d259aab8dc9d5a59d61 (patch)
tree141c6adb305a57cc8284580d88a839343f57ee90 /arch/um
parent3a24ebf0cb2ca44fdcdb5cae9ed2e778e5170f97 (diff)
uml: SMP locking commentary
Add some more commentary about various pieces of global data not needing locking. Also got rid of unmap_physmem since that is no longer used. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/um')
-rw-r--r--arch/um/drivers/net_kern.c7
-rw-r--r--arch/um/include/mem_user.h1
-rw-r--r--arch/um/kernel/mem.c13
-rw-r--r--arch/um/kernel/physmem.c6
4 files changed, 17 insertions, 10 deletions
diff --git a/arch/um/drivers/net_kern.c b/arch/um/drivers/net_kern.c
index 3c6c44ca1ff..ca71577f363 100644
--- a/arch/um/drivers/net_kern.c
+++ b/arch/um/drivers/net_kern.c
@@ -368,7 +368,6 @@ static struct platform_driver uml_net_driver = {
.name = DRIVER_NAME,
},
};
-static int driver_registered;
static void net_device_release(struct device *dev)
{
@@ -383,6 +382,12 @@ static void net_device_release(struct device *dev)
free_netdev(netdev);
}
+/*
+ * Ensures that platform_driver_register is called only once by
+ * eth_configure. Will be set in an initcall.
+ */
+static int driver_registered;
+
static void eth_configure(int n, void *init, char *mac,
struct transport *transport)
{
diff --git a/arch/um/include/mem_user.h b/arch/um/include/mem_user.h
index 4e6707bd0a0..46384acd547 100644
--- a/arch/um/include/mem_user.h
+++ b/arch/um/include/mem_user.h
@@ -56,7 +56,6 @@ extern void setup_physmem(unsigned long start, unsigned long usable,
unsigned long len, unsigned long long highmem);
extern void add_iomem(char *name, int fd, unsigned long size);
extern unsigned long phys_offset(unsigned long phys);
-extern void unmap_physmem(void);
extern void map_memory(unsigned long virt, unsigned long phys,
unsigned long len, int r, int w, int x);
diff --git a/arch/um/kernel/mem.c b/arch/um/kernel/mem.c
index 663011c2983..d948babfc67 100644
--- a/arch/um/kernel/mem.c
+++ b/arch/um/kernel/mem.c
@@ -22,17 +22,20 @@
unsigned long *empty_zero_page = NULL;
/* allocated in paging_init and unchanged thereafter */
unsigned long *empty_bad_page = NULL;
+
+/*
+ * Initialized during boot, and readonly for initializing page tables
+ * afterwards
+ */
pgd_t swapper_pg_dir[PTRS_PER_PGD];
+
+/* Initialized at boot time, and readonly after that */
unsigned long long highmem;
int kmalloc_ok = 0;
+/* Used during early boot */
static unsigned long brk_end;
-void unmap_physmem(void)
-{
- os_unmap_memory((void *) brk_end, uml_reserved - brk_end);
-}
-
static void map_cb(void *unused)
{
map_memory(brk_end, __pa(brk_end), uml_reserved - brk_end, 1, 1, 0);
diff --git a/arch/um/kernel/physmem.c b/arch/um/kernel/physmem.c
index 9c929000579..9757085a022 100644
--- a/arch/um/kernel/physmem.c
+++ b/arch/um/kernel/physmem.c
@@ -164,10 +164,10 @@ __uml_setup("iomem=", parse_iomem,
* setup_iomem, both of which run during early boot. Afterwards, it's
* unchanged.
*/
-struct iomem_region *iomem_regions = NULL;
+struct iomem_region *iomem_regions;
-/* Initialized in parse_iomem */
-int iomem_size = 0;
+/* Initialized in parse_iomem and unchanged thereafter */
+int iomem_size;
unsigned long find_iomem(char *driver, unsigned long *len_out)
{