[Patch 1/5] add multi-page allocation to the uncached allocator -v2

Dean Nelson
2008-03-26T16:48:15Z

Enable the uncached allocator to allocate multiple pages of contiguous
uncached memory.

Signed-off-by: Dean Nelson <dcn@sgi.com>

---

arch/ia64/kernel/uncached.c | 21 ++++++++++++---------
drivers/char/mspec.c | 12 ++++++------
include/asm-ia64/uncached.h | 4 ++--
3 files changed, 20 insertions(+), 17 deletions(-)

Index: linux-2.6/arch/ia64/kernel/uncached.c
=================================--- linux-2.6.orig/arch/ia64/kernel/uncached.c 2007-10-04 06:52:20.000000000 -0500
+++ linux-2.6/arch/ia64/kernel/uncached.c 2007-11-08 12:14:31.408258515 -0600
@@ -177,12 +177,13 @@
* uncached_alloc_page
*
* @starting_nid: node id of node to start with, or -1
+ * @n_pages: number of contiguous pages to allocate
*
- * Allocate 1 uncached page. Allocates on the requested node. If no
- * uncached pages are available on the requested node, roundrobin starting
- * with the next higher node.
+ * Allocate the specified number of contiguous uncached pages on the
+ * the requested node. If not enough contiguous uncached pages are available
+ * on the requested node, roundrobin starting with the next higher node.
*/
-unsigned long uncached_alloc_page(int starting_nid)
+unsigned long uncached_alloc_page(int starting_nid, int n_pages)
{
unsigned long uc_addr;
struct uncached_pool *uc_pool;
@@ -202,7 +203,8 @@
if (uc_pool->pool = NULL)
continue;
do {
- uc_addr = gen_pool_alloc(uc_pool->pool, PAGE_SIZE);
+ uc_addr = gen_pool_alloc(uc_pool->pool,
+ n_pages * PAGE_SIZE);
if (uc_addr != 0)
return uc_addr;
} while (uncached_add_chunk(uc_pool, nid) = 0);
@@ -217,11 +219,12 @@
/*
* uncached_free_page
*
- * @uc_addr: uncached address of page to free
+ * @uc_addr: uncached address of first page to free
+ * @n_pages: number of contiguous pages to free
*
- * Free a single uncached page.
+ * Free the specified number of uncached pages.
*/
-void uncached_free_page(unsigned long uc_addr)
+void uncached_free_page(unsigned long uc_addr, int n_pages)
{
int nid = paddr_to_nid(uc_addr - __IA64_UNCACHED_OFFSET);
struct gen_pool *pool = uncached_pools[nid].pool;
@@ -232,7 +235,7 @@
if ((uc_addr & (0XFUL << 60)) != __IA64_UNCACHED_OFFSET)
panic("uncached_free_page invalid address %lx\n", uc_addr);

- gen_pool_free(pool, uc_addr, PAGE_SIZE);
+ gen_pool_free(pool, uc_addr, n_pages * PAGE_SIZE);
}
EXPORT_SYMBOL(uncached_free_page);

Index: linux-2.6/drivers/char/mspec.c
=================================--- linux-2.6.orig/drivers/char/mspec.c 2007-10-04 06:52:21.000000000 -0500
+++ linux-2.6/drivers/char/mspec.c 2007-11-08 12:07:17.458415225 -0600
@@ -180,7 +180,7 @@
my_page = vdata->maddr[index];
vdata->maddr[index] = 0;
if (!mspec_zero_block(my_page, PAGE_SIZE))
- uncached_free_page(my_page);
+ uncached_free_page(my_page, 1);
else
printk(KERN_WARNING "mspec_close(): "
"failed to zero page %ld\n", my_page);
@@ -209,7 +209,7 @@
index = (address - vdata->vm_start) >> PAGE_SHIFT;
maddr = (volatile unsigned long) vdata->maddr[index];
if (maddr = 0) {
- maddr = uncached_alloc_page(numa_node_id());
+ maddr = uncached_alloc_page(numa_node_id(), 1);
if (maddr = 0)
return NOPFN_OOM;

@@ -218,7 +218,7 @@
vdata->count++;
vdata->maddr[index] = maddr;
} else {
- uncached_free_page(maddr);
+ uncached_free_page(maddr, 1);
maddr = vdata->maddr[index];
}
spin_unlock(&vdata->lock);
@@ -367,7 +367,7 @@
int nasid;
unsigned long phys;

- scratch_page[nid] = uncached_alloc_page(nid);
+ scratch_page[nid] = uncached_alloc_page(nid, 1);
if (scratch_page[nid] = 0)
goto free_scratch_pages;
phys = __pa(scratch_page[nid]);
@@ -414,7 +414,7 @@
free_scratch_pages:
for_each_node(nid) {
if (scratch_page[nid] != 0)
- uncached_free_page(scratch_page[nid]);
+ uncached_free_page(scratch_page[nid], 1);
}
return ret;
}
@@ -431,7 +431,7 @@

for_each_node(nid) {
if (scratch_page[nid] != 0)
- uncached_free_page(scratch_page[nid]);
+ uncached_free_page(scratch_page[nid], 1);
}
}
}
Index: linux-2.6/include/asm-ia64/uncached.h
=================================--- linux-2.6.orig/include/asm-ia64/uncached.h 2007-10-04 06:52:25.000000000 -0500
+++ linux-2.6/include/asm-ia64/uncached.h 2007-11-08 12:05:00.633469891 -0600
@@ -8,5 +8,5 @@
* Prototypes for the uncached page allocator
*/

-extern unsigned long uncached_alloc_page(int nid);
-extern void uncached_free_page(unsigned long);
+extern unsigned long uncached_alloc_page(int, int);
+extern void uncached_free_page(unsigned long, int);