agp: efficeon: no need to set PG_reserved on GATT tables
Patch series "mm: PG_reserved cleanups and documentation", v2.
I was recently going over all users of PG_reserved. Short story: it is
difficult and sometimes not really clear if setting/checking for
PG_reserved is only a relict from the past. Easy to break things. I
guess I now have a pretty good idea wh things are like that nowadays and
how they evolved.
I had way more cleanups in this series inititally, but some
architectures take PG_reserved as a way to apply a different caching
strategy (for MMIO pages). So I decided to only include the most
obvious changes (that are less likely to break something). So the big
chunk of manual SetPageReserved users are MMIO/DMA related things on
device buffers.
Most notably, for device memory we will hopefully soon stop setting
PG_reserved. Then the documentation has to be updated.
This patch (of 9):
The l1 GATT page table is kept in a special on-chip page with 64
entries. We allocate the l2 page table pages via get_zeroed_page() and
enter them into the table. These l2 pages are modified accordingly when
inserting/removing memory via efficeon_insert_memory and
efficeon_remove_memory.
Apart from that, these pages are not exposed or ioremap'ed. We can stop
setting them reserved (propably copied from generic code).
Link: http://lkml.kernel.org/r/20190114125903.24845-2-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/char/agp/efficeon-agp.c b/drivers/char/agp/efficeon-agp.c
index 7f88490..c53f0f9 100644
--- a/drivers/char/agp/efficeon-agp.c
+++ b/drivers/char/agp/efficeon-agp.c
@@ -163,7 +163,6 @@
unsigned long page = efficeon_private.l1_table[index];
if (page) {
efficeon_private.l1_table[index] = 0;
- ClearPageReserved(virt_to_page((char *)page));
free_page(page);
freed++;
}
@@ -219,7 +218,6 @@
efficeon_free_gatt_table(agp_bridge);
return -ENOMEM;
}
- SetPageReserved(virt_to_page((char *)page));
for (offset = 0; offset < PAGE_SIZE; offset += clflush_chunk)
clflush((char *)page+offset);
