On 2024/8/12 5:21, Yu Zhao wrote:
With alloc_contig_range() and free_contig_range() supporting large
folios, CMA can allocate and free large folios too, by
cma_alloc_folio() and cma_release().
Signed-off-by: Yu Zhao <yuzhao@xxxxxxxxxx>
---
include/linux/cma.h | 1 +
mm/cma.c | 47 ++++++++++++++++++++++++++++++---------------
2 files changed, 33 insertions(+), 15 deletions(-)
diff --git a/include/linux/cma.h b/include/linux/cma.h
index 9db877506ea8..086553fbda73 100644
--- a/include/linux/cma.h
+++ b/include/linux/cma.h
@@ -46,6 +46,7 @@ extern int cma_init_reserved_mem(phys_addr_t base, phys_addr_t size,
struct cma **res_cma);
extern struct page *cma_alloc(struct cma *cma, unsigned long count, unsigned int align,
bool no_warn);
+extern struct folio *cma_alloc_folio(struct cma *cma, int order, gfp_t gfp);
extern bool cma_pages_valid(struct cma *cma, const struct page *pages, unsigned long count);
extern bool cma_release(struct cma *cma, const struct page *pages, unsigned long count);
diff --git a/mm/cma.c b/mm/cma.c
index 95d6950e177b..46feb06db8e7 100644
--- a/mm/cma.c
+++ b/mm/cma.c
@@ -403,18 +403,8 @@ static void cma_debug_show_areas(struct cma *cma)
spin_unlock_irq(&cma->lock);
}
-/**
- * cma_alloc() - allocate pages from contiguous area
- * @cma: Contiguous memory region for which the allocation is performed.
- * @count: Requested number of pages.
- * @align: Requested alignment of pages (in PAGE_SIZE order).
- * @no_warn: Avoid printing message about failed allocation
- *
- * This function allocates part of contiguous memory on specific
- * contiguous memory area.
- */
-struct page *cma_alloc(struct cma *cma, unsigned long count,
- unsigned int align, bool no_warn)
+static struct page *__cma_alloc(struct cma *cma, unsigned long count,
+ unsigned int align, gfp_t gfp)
{
unsigned long mask, offset;
unsigned long pfn = -1;
@@ -463,8 +453,7 @@ struct page *cma_alloc(struct cma *cma, unsigned long count,
pfn = cma->base_pfn + (bitmap_no << cma->order_per_bit);
mutex_lock(&cma_mutex);
- ret = alloc_contig_range(pfn, pfn + count, MIGRATE_CMA,
- GFP_KERNEL | (no_warn ? __GFP_NOWARN : 0));
+ ret = alloc_contig_range(pfn, pfn + count, MIGRATE_CMA, gfp);
mutex_unlock(&cma_mutex);
if (ret == 0) {
page = pfn_to_page(pfn);
@@ -494,7 +483,7 @@ struct page *cma_alloc(struct cma *cma, unsigned long count,
page_kasan_tag_reset(nth_page(page, i));
}
- if (ret && !no_warn) {
+ if (ret && !(gfp & __GFP_NOWARN)) {
pr_err_ratelimited("%s: %s: alloc failed, req-size: %lu pages, ret: %d\n",
__func__, cma->name, count, ret);
cma_debug_show_areas(cma);
@@ -513,6 +502,34 @@ struct page *cma_alloc(struct cma *cma, unsigned long count,
return page;
}
+/**
+ * cma_alloc() - allocate pages from contiguous area
+ * @cma: Contiguous memory region for which the allocation is performed.
+ * @count: Requested number of pages.
+ * @align: Requested alignment of pages (in PAGE_SIZE order).
+ * @no_warn: Avoid printing message about failed allocation
+ *
+ * This function allocates part of contiguous memory on specific
+ * contiguous memory area.
+ */
+struct page *cma_alloc(struct cma *cma, unsigned long count,
+ unsigned int align, bool no_warn)
+{
+ return __cma_alloc(cma, count, align, GFP_KERNEL | (no_warn ? __GFP_NOWARN : 0));
+}
+
+struct folio *cma_alloc_folio(struct cma *cma, int order, gfp_t gfp)
+{
+ struct page *page;
+
+ if (WARN_ON(order && !(gfp | __GFP_COMP)))
+ return NULL;
+
+ page = __cma_alloc(cma, 1 << order, order, gfp);
+
+ return page ? page_folio(page) : NULL;
We don't set large_rmappable for cma alloc folio, which is not consistent
with other folio allocation, eg folio_alloc/folio_alloc_mpol(),
there is no issue for HugeTLB folio, and for HugeTLB folio must without
large_rmappable, but once we use it for mTHP/THP, it need some extra
handle, maybe we set large_rmappable here, and clear it in
init_new_hugetlb_folio()?
+}
+
bool cma_pages_valid(struct cma *cma, const struct page *pages,
unsigned long count)
{
