[PATCH 2/2] agp/intel: use dma_alloc_coherent for special cursormemory

From: Jeremy Fitzhardinge
Date: Tue Mar 24 2009 - 14:00:16 EST


Impact: make i810 work under Xen

Given that i810 wants special physically contiguous memory for its
cursor, we should allocate it with dma_alloc_coherent, which will
give us memory with the right properties. This is particularly for
Xen, which won't normally give us physically contiuous memory.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@xxxxxxxxxx>
Cc: David Airlie <airlied@xxxxxxxx>

diff --git a/drivers/char/agp/intel-agp.c b/drivers/char/agp/intel-agp.c
index 4373adb..8ba6808 100644
--- a/drivers/char/agp/intel-agp.c
+++ b/drivers/char/agp/intel-agp.c
@@ -244,33 +244,29 @@ static void intel_i810_agp_enable(struct agp_bridge_data *bridge, u32 mode)
/* Exists to support ARGB cursors */
static void *i8xx_alloc_pages(void)
{
- struct page *page;
-
- page = alloc_pages(GFP_KERNEL | GFP_DMA32, 2);
- if (page == NULL)
+ void *addr;
+ dma_addr_t _d;
+
+ addr = dma_alloc_coherent(NULL, 4 * PAGE_SIZE, &_d, GFP_KERNEL);
+ if (addr == NULL)
return NULL;

- if (set_pages_uc(page, 4) < 0) {
- set_pages_wb(page, 4);
- __free_pages(page, 2);
+ if (set_memory_uc((unsigned long)addr, 4) < 0) {
+ set_memory_wb((unsigned long)addr, 4);
+ dma_free_coherent(NULL, 4 * PAGE_SIZE, addr, _d);
return NULL;
}
- get_page(page);
atomic_inc(&agp_bridge->current_memory_agp);
- return page_address(page);
+ return addr;
}

static void i8xx_destroy_pages(void *addr)
{
- struct page *page;
-
if (addr == NULL)
return;

- page = virt_to_page(addr);
- set_pages_wb(page, 4);
- put_page(page);
- __free_pages(page, 2);
+ set_memory_wb((unsigned long)addr, 4);
+ dma_free_coherent(NULL, 4 * PAGE_SIZE, addr, virt_to_bus(addr));
atomic_dec(&agp_bridge->current_memory_agp);
}



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