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authorKevin Hilman <kevin@hilman.org>2006-01-12 16:12:21 +0000
committerRussell King <rmk+kernel@arm.linux.org.uk>2006-01-12 16:12:21 +0000
commit37134cd55d57e95d3f606c6f2a57fa496bdad333 (patch)
tree0c5c3bb4a52550613eb5f171c5954725b51a1915
parenta3e49436867e6c7acc1b5eed21d30c88d156825b (diff)
[ARM] 3209/1: Configurable DMA-consistent memory region
Patch from Kevin Hilman This patch increase available DMA-consistent memory allocated by dma_coherent_alloc(). The default remains at 2M (defined in asm/memory.h) and each platform has the ability to override in asm/arch-foo/memory.h. Signed-off-by: Kevin Hilman <kevin@hilman.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
-rw-r--r--arch/arm/mm/consistent.c53
-rw-r--r--include/asm-arm/memory.h9
2 files changed, 50 insertions, 12 deletions
diff --git a/arch/arm/mm/consistent.c b/arch/arm/mm/consistent.c
index 0513ed1b2fc..c2ee18d2075 100644
--- a/arch/arm/mm/consistent.c
+++ b/arch/arm/mm/consistent.c
@@ -20,15 +20,25 @@
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>
+#include <asm/sizes.h>
+
+/* Sanity check size */
+#if (CONSISTENT_DMA_SIZE % SZ_2M)
+#error "CONSISTENT_DMA_SIZE must be multiple of 2MiB"
+#endif
-#define CONSISTENT_BASE (0xffc00000)
#define CONSISTENT_END (0xffe00000)
+#define CONSISTENT_BASE (CONSISTENT_END - CONSISTENT_DMA_SIZE)
+
#define CONSISTENT_OFFSET(x) (((unsigned long)(x) - CONSISTENT_BASE) >> PAGE_SHIFT)
+#define CONSISTENT_PTE_INDEX(x) (((unsigned long)(x) - CONSISTENT_BASE) >> PGDIR_SHIFT)
+#define NUM_CONSISTENT_PTES (CONSISTENT_DMA_SIZE >> PGDIR_SHIFT)
+
/*
- * This is the page table (2MB) covering uncached, DMA consistent allocations
+ * These are the page tables (2MB each) covering uncached, DMA consistent allocations
*/
-static pte_t *consistent_pte;
+static pte_t *consistent_pte[NUM_CONSISTENT_PTES];
static DEFINE_SPINLOCK(consistent_lock);
/*
@@ -142,7 +152,7 @@ __dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp,
unsigned long order;
u64 mask = ISA_DMA_THRESHOLD, limit;
- if (!consistent_pte) {
+ if (!consistent_pte[0]) {
printk(KERN_ERR "%s: not initialised\n", __func__);
dump_stack();
return NULL;
@@ -205,9 +215,12 @@ __dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp,
c = vm_region_alloc(&consistent_head, size,
gfp & ~(__GFP_DMA | __GFP_HIGHMEM));
if (c) {
- pte_t *pte = consistent_pte + CONSISTENT_OFFSET(c->vm_start);
+ pte_t *pte;
struct page *end = page + (1 << order);
+ int idx = CONSISTENT_PTE_INDEX(c->vm_start);
+ u32 off = CONSISTENT_OFFSET(c->vm_start) & (PTRS_PER_PTE-1);
+ pte = consistent_pte[idx] + off;
c->vm_pages = page;
/*
@@ -226,6 +239,11 @@ __dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp,
set_pte(pte, mk_pte(page, prot));
page++;
pte++;
+ off++;
+ if (off >= PTRS_PER_PTE) {
+ off = 0;
+ pte = consistent_pte[++idx];
+ }
} while (size -= PAGE_SIZE);
/*
@@ -327,6 +345,8 @@ void dma_free_coherent(struct device *dev, size_t size, void *cpu_addr, dma_addr
struct vm_region *c;
unsigned long flags, addr;
pte_t *ptep;
+ int idx;
+ u32 off;
WARN_ON(irqs_disabled());
@@ -347,7 +367,9 @@ void dma_free_coherent(struct device *dev, size_t size, void *cpu_addr, dma_addr
size = c->vm_end - c->vm_start;
}
- ptep = consistent_pte + CONSISTENT_OFFSET(c->vm_start);
+ idx = CONSISTENT_PTE_INDEX(c->vm_start);
+ off = CONSISTENT_OFFSET(c->vm_start) & (PTRS_PER_PTE-1);
+ ptep = consistent_pte[idx] + off;
addr = c->vm_start;
do {
pte_t pte = ptep_get_and_clear(&init_mm, addr, ptep);
@@ -355,6 +377,11 @@ void dma_free_coherent(struct device *dev, size_t size, void *cpu_addr, dma_addr
ptep++;
addr += PAGE_SIZE;
+ off++;
+ if (off >= PTRS_PER_PTE) {
+ off = 0;
+ ptep = consistent_pte[++idx];
+ }
if (!pte_none(pte) && pte_present(pte)) {
pfn = pte_pfn(pte);
@@ -401,11 +428,12 @@ static int __init consistent_init(void)
pgd_t *pgd;
pmd_t *pmd;
pte_t *pte;
- int ret = 0;
+ int ret = 0, i = 0;
+ u32 base = CONSISTENT_BASE;
do {
- pgd = pgd_offset(&init_mm, CONSISTENT_BASE);
- pmd = pmd_alloc(&init_mm, pgd, CONSISTENT_BASE);
+ pgd = pgd_offset(&init_mm, base);
+ pmd = pmd_alloc(&init_mm, pgd, base);
if (!pmd) {
printk(KERN_ERR "%s: no pmd tables\n", __func__);
ret = -ENOMEM;
@@ -413,15 +441,16 @@ static int __init consistent_init(void)
}
WARN_ON(!pmd_none(*pmd));
- pte = pte_alloc_kernel(pmd, CONSISTENT_BASE);
+ pte = pte_alloc_kernel(pmd, base);
if (!pte) {
printk(KERN_ERR "%s: no pte tables\n", __func__);
ret = -ENOMEM;
break;
}
- consistent_pte = pte;
- } while (0);
+ consistent_pte[i++] = pte;
+ base += (1 << PGDIR_SHIFT);
+ } while (base < CONSISTENT_END);
return ret;
}
diff --git a/include/asm-arm/memory.h b/include/asm-arm/memory.h
index 3d7f08bd903..b4e1146ab68 100644
--- a/include/asm-arm/memory.h
+++ b/include/asm-arm/memory.h
@@ -25,6 +25,7 @@
#include <linux/config.h>
#include <linux/compiler.h>
#include <asm/arch/memory.h>
+#include <asm/sizes.h>
#ifndef TASK_SIZE
/*
@@ -48,6 +49,14 @@
#endif
/*
+ * Size of DMA-consistent memory region. Must be multiple of 2M,
+ * between 2MB and 14MB inclusive.
+ */
+#ifndef CONSISTENT_DMA_SIZE
+#define CONSISTENT_DMA_SIZE SZ_2M
+#endif
+
+/*
* Physical vs virtual RAM address space conversion. These are
* private definitions which should NOT be used outside memory.h
* files. Use virt_to_phys/phys_to_virt/__pa/__va instead.