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authorDmitry Torokhov <dmitry.torokhov@gmail.com>2015-02-10 11:35:36 -0800
committerDmitry Torokhov <dmitry.torokhov@gmail.com>2015-02-10 11:35:36 -0800
commit4ba24fef3eb3b142197135223b90ced2f319cd53 (patch)
treea20c125b27740ec7b4c761b11d801108e1b316b2 /mm/cma.c
parent47c1ffb2b6b630894e9a16442611c056ab21c057 (diff)
parent98a4a59ee31a12105a2b84f5b8b515ac2cb208ef (diff)
Merge branch 'next' into for-linus
Prepare first round of input updates for 3.20.
Diffstat (limited to 'mm/cma.c')
-rw-r--r--mm/cma.c169
1 files changed, 142 insertions, 27 deletions
diff --git a/mm/cma.c b/mm/cma.c
index c17751c0dca..a85ae28709a 100644
--- a/mm/cma.c
+++ b/mm/cma.c
@@ -32,6 +32,8 @@
#include <linux/slab.h>
#include <linux/log2.h>
#include <linux/cma.h>
+#include <linux/highmem.h>
+#include <linux/io.h>
struct cma {
unsigned long base_pfn;
@@ -57,7 +59,20 @@ unsigned long cma_get_size(struct cma *cma)
static unsigned long cma_bitmap_aligned_mask(struct cma *cma, int align_order)
{
- return (1UL << (align_order >> cma->order_per_bit)) - 1;
+ if (align_order <= cma->order_per_bit)
+ return 0;
+ return (1UL << (align_order - cma->order_per_bit)) - 1;
+}
+
+static unsigned long cma_bitmap_aligned_offset(struct cma *cma, int align_order)
+{
+ unsigned int alignment;
+
+ if (align_order <= cma->order_per_bit)
+ return 0;
+ alignment = 1UL << (align_order - cma->order_per_bit);
+ return ALIGN(cma->base_pfn, alignment) -
+ (cma->base_pfn >> cma->order_per_bit);
}
static unsigned long cma_bitmap_maxno(struct cma *cma)
@@ -121,6 +136,7 @@ static int __init cma_activate_area(struct cma *cma)
err:
kfree(cma->bitmap);
+ cma->count = 0;
return -EINVAL;
}
@@ -140,6 +156,54 @@ static int __init cma_init_reserved_areas(void)
core_initcall(cma_init_reserved_areas);
/**
+ * cma_init_reserved_mem() - create custom contiguous area from reserved memory
+ * @base: Base address of the reserved area
+ * @size: Size of the reserved area (in bytes),
+ * @order_per_bit: Order of pages represented by one bit on bitmap.
+ * @res_cma: Pointer to store the created cma region.
+ *
+ * This function creates custom contiguous area from already reserved memory.
+ */
+int __init cma_init_reserved_mem(phys_addr_t base, phys_addr_t size,
+ int order_per_bit, struct cma **res_cma)
+{
+ struct cma *cma;
+ phys_addr_t alignment;
+
+ /* Sanity checks */
+ if (cma_area_count == ARRAY_SIZE(cma_areas)) {
+ pr_err("Not enough slots for CMA reserved regions!\n");
+ return -ENOSPC;
+ }
+
+ if (!size || !memblock_is_region_reserved(base, size))
+ return -EINVAL;
+
+ /* ensure minimal alignment requied by mm core */
+ alignment = PAGE_SIZE << max(MAX_ORDER - 1, pageblock_order);
+
+ /* alignment should be aligned with order_per_bit */
+ if (!IS_ALIGNED(alignment >> PAGE_SHIFT, 1 << order_per_bit))
+ return -EINVAL;
+
+ if (ALIGN(base, alignment) != base || ALIGN(size, alignment) != size)
+ return -EINVAL;
+
+ /*
+ * Each reserved area must be initialised later, when more kernel
+ * subsystems (like slab allocator) are available.
+ */
+ cma = &cma_areas[cma_area_count];
+ cma->base_pfn = PFN_DOWN(base);
+ cma->count = size >> PAGE_SHIFT;
+ cma->order_per_bit = order_per_bit;
+ *res_cma = cma;
+ cma_area_count++;
+
+ return 0;
+}
+
+/**
* cma_declare_contiguous() - reserve custom contiguous area
* @base: Base address of the reserved area optional, use 0 for any
* @size: Size of the reserved area (in bytes),
@@ -162,12 +226,24 @@ int __init cma_declare_contiguous(phys_addr_t base,
phys_addr_t alignment, unsigned int order_per_bit,
bool fixed, struct cma **res_cma)
{
- struct cma *cma;
+ phys_addr_t memblock_end = memblock_end_of_DRAM();
+ phys_addr_t highmem_start;
int ret = 0;
- pr_debug("%s(size %lx, base %08lx, limit %08lx alignment %08lx)\n",
- __func__, (unsigned long)size, (unsigned long)base,
- (unsigned long)limit, (unsigned long)alignment);
+#ifdef CONFIG_X86
+ /*
+ * high_memory isn't direct mapped memory so retrieving its physical
+ * address isn't appropriate. But it would be useful to check the
+ * physical address of the highmem boundary so it's justfiable to get
+ * the physical address from it. On x86 there is a validation check for
+ * this case, so the following workaround is needed to avoid it.
+ */
+ highmem_start = __pa_nodebug(high_memory);
+#else
+ highmem_start = __pa(high_memory);
+#endif
+ pr_debug("%s(size %pa, base %pa, limit %pa alignment %pa)\n",
+ __func__, &size, &base, &limit, &alignment);
if (cma_area_count == ARRAY_SIZE(cma_areas)) {
pr_err("Not enough slots for CMA reserved regions!\n");
@@ -192,41 +268,78 @@ int __init cma_declare_contiguous(phys_addr_t base,
size = ALIGN(size, alignment);
limit &= ~(alignment - 1);
+ if (!base)
+ fixed = false;
+
/* size should be aligned with order_per_bit */
if (!IS_ALIGNED(size >> PAGE_SHIFT, 1 << order_per_bit))
return -EINVAL;
+ /*
+ * If allocating at a fixed base the request region must not cross the
+ * low/high memory boundary.
+ */
+ if (fixed && base < highmem_start && base + size > highmem_start) {
+ ret = -EINVAL;
+ pr_err("Region at %pa defined on low/high memory boundary (%pa)\n",
+ &base, &highmem_start);
+ goto err;
+ }
+
+ /*
+ * If the limit is unspecified or above the memblock end, its effective
+ * value will be the memblock end. Set it explicitly to simplify further
+ * checks.
+ */
+ if (limit == 0 || limit > memblock_end)
+ limit = memblock_end;
+
/* Reserve memory */
- if (base && fixed) {
+ if (fixed) {
if (memblock_is_region_reserved(base, size) ||
memblock_reserve(base, size) < 0) {
ret = -EBUSY;
goto err;
}
} else {
- phys_addr_t addr = memblock_alloc_range(size, alignment, base,
- limit);
+ phys_addr_t addr = 0;
+
+ /*
+ * All pages in the reserved area must come from the same zone.
+ * If the requested region crosses the low/high memory boundary,
+ * try allocating from high memory first and fall back to low
+ * memory in case of failure.
+ */
+ if (base < highmem_start && limit > highmem_start) {
+ addr = memblock_alloc_range(size, alignment,
+ highmem_start, limit);
+ limit = highmem_start;
+ }
+
if (!addr) {
- ret = -ENOMEM;
- goto err;
- } else {
- base = addr;
+ addr = memblock_alloc_range(size, alignment, base,
+ limit);
+ if (!addr) {
+ ret = -ENOMEM;
+ goto err;
+ }
}
+
+ /*
+ * kmemleak scans/reads tracked objects for pointers to other
+ * objects but this address isn't mapped and accessible
+ */
+ kmemleak_ignore(phys_to_virt(addr));
+ base = addr;
}
- /*
- * Each reserved area must be initialised later, when more kernel
- * subsystems (like slab allocator) are available.
- */
- cma = &cma_areas[cma_area_count];
- cma->base_pfn = PFN_DOWN(base);
- cma->count = size >> PAGE_SHIFT;
- cma->order_per_bit = order_per_bit;
- *res_cma = cma;
- cma_area_count++;
+ ret = cma_init_reserved_mem(base, size, order_per_bit, res_cma);
+ if (ret)
+ goto err;
- pr_info("Reserved %ld MiB at %08lx\n", (unsigned long)size / SZ_1M,
- (unsigned long)base);
+ totalcma_pages += (size / PAGE_SIZE);
+ pr_info("Reserved %ld MiB at %pa\n", (unsigned long)size / SZ_1M,
+ &base);
return 0;
err:
@@ -245,7 +358,7 @@ err:
*/
struct page *cma_alloc(struct cma *cma, int count, unsigned int align)
{
- unsigned long mask, pfn, start = 0;
+ unsigned long mask, offset, pfn, start = 0;
unsigned long bitmap_maxno, bitmap_no, bitmap_count;
struct page *page = NULL;
int ret;
@@ -260,13 +373,15 @@ struct page *cma_alloc(struct cma *cma, int count, unsigned int align)
return NULL;
mask = cma_bitmap_aligned_mask(cma, align);
+ offset = cma_bitmap_aligned_offset(cma, align);
bitmap_maxno = cma_bitmap_maxno(cma);
bitmap_count = cma_bitmap_pages_to_bits(cma, count);
for (;;) {
mutex_lock(&cma->lock);
- bitmap_no = bitmap_find_next_zero_area(cma->bitmap,
- bitmap_maxno, start, bitmap_count, mask);
+ bitmap_no = bitmap_find_next_zero_area_off(cma->bitmap,
+ bitmap_maxno, start, bitmap_count, mask,
+ offset);
if (bitmap_no >= bitmap_maxno) {
mutex_unlock(&cma->lock);
break;