From 102a0743326a03cd1a1202ceda21e175b7d3575c Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Tue, 20 Feb 2024 01:20:52 +0000
Subject: [PATCH] add new system file
---
kernel/include/linux/scatterlist.h | 108 +++++++++++++++++++++++++++++++++++++----------------
1 files changed, 75 insertions(+), 33 deletions(-)
diff --git a/kernel/include/linux/scatterlist.h b/kernel/include/linux/scatterlist.h
index f2b09fb..36c47e7 100644
--- a/kernel/include/linux/scatterlist.h
+++ b/kernel/include/linux/scatterlist.h
@@ -165,6 +165,22 @@
#define for_each_sgtable_dma_sg(sgt, sg, i) \
for_each_sg((sgt)->sgl, sg, (sgt)->nents, i)
+static inline void __sg_chain(struct scatterlist *chain_sg,
+ struct scatterlist *sgl)
+{
+ /*
+ * offset and length are unused for chain entry. Clear them.
+ */
+ chain_sg->offset = 0;
+ chain_sg->length = 0;
+
+ /*
+ * Set lowest bit to indicate a link pointer, and make sure to clear
+ * the termination bit if it happens to be set.
+ */
+ chain_sg->page_link = ((unsigned long) sgl | SG_CHAIN) & ~SG_END;
+}
+
/**
* sg_chain - Chain two sglists together
* @prv: First scatterlist
@@ -178,18 +194,7 @@
static inline void sg_chain(struct scatterlist *prv, unsigned int prv_nents,
struct scatterlist *sgl)
{
- /*
- * offset and length are unused for chain entry. Clear them.
- */
- prv[prv_nents - 1].offset = 0;
- prv[prv_nents - 1].length = 0;
-
- /*
- * Set lowest bit to indicate a link pointer, and make sure to clear
- * the termination bit if it happens to be set.
- */
- prv[prv_nents - 1].page_link = ((unsigned long) sgl | SG_CHAIN)
- & ~SG_END;
+ __sg_chain(&prv[prv_nents - 1], sgl);
}
/**
@@ -280,15 +285,17 @@
typedef struct scatterlist *(sg_alloc_fn)(unsigned int, gfp_t);
typedef void (sg_free_fn)(struct scatterlist *, unsigned int);
-void __sg_free_table(struct sg_table *, unsigned int, bool, sg_free_fn *);
+void __sg_free_table(struct sg_table *, unsigned int, unsigned int,
+ sg_free_fn *);
void sg_free_table(struct sg_table *);
int __sg_alloc_table(struct sg_table *, unsigned int, unsigned int,
- struct scatterlist *, gfp_t, sg_alloc_fn *);
+ struct scatterlist *, unsigned int, gfp_t, sg_alloc_fn *);
int sg_alloc_table(struct sg_table *, unsigned int, gfp_t);
-int __sg_alloc_table_from_pages(struct sg_table *sgt, struct page **pages,
- unsigned int n_pages, unsigned int offset,
- unsigned long size, unsigned int max_segment,
- gfp_t gfp_mask);
+struct scatterlist *__sg_alloc_table_from_pages(struct sg_table *sgt,
+ struct page **pages, unsigned int n_pages, unsigned int offset,
+ unsigned long size, unsigned int max_segment,
+ struct scatterlist *prv, unsigned int left_pages,
+ gfp_t gfp_mask);
int sg_alloc_table_from_pages(struct sg_table *sgt, struct page **pages,
unsigned int n_pages, unsigned int offset,
unsigned long size, gfp_t gfp_mask);
@@ -338,27 +345,29 @@
* Like SG_CHUNK_SIZE, but for archs that have sg chaining. This limit
* is totally arbitrary, a setting of 2048 will get you at least 8mb ios.
*/
-#ifdef CONFIG_ARCH_HAS_SG_CHAIN
-#define SG_MAX_SEGMENTS 2048
-#else
+#ifdef CONFIG_ARCH_NO_SG_CHAIN
#define SG_MAX_SEGMENTS SG_CHUNK_SIZE
+#else
+#define SG_MAX_SEGMENTS 2048
#endif
#ifdef CONFIG_SG_POOL
-void sg_free_table_chained(struct sg_table *table, bool first_chunk);
+void sg_free_table_chained(struct sg_table *table,
+ unsigned nents_first_chunk);
int sg_alloc_table_chained(struct sg_table *table, int nents,
- struct scatterlist *first_chunk);
+ struct scatterlist *first_chunk,
+ unsigned nents_first_chunk);
#endif
/*
* sg page iterator
*
- * Iterates over sg entries page-by-page. On each successful iteration,
- * you can call sg_page_iter_page(@piter) and sg_page_iter_dma_address(@piter)
- * to get the current page and its dma address. @piter->sg will point to the
- * sg holding this page and @piter->sg_pgoffset to the page's page offset
- * within the sg. The iteration will stop either when a maximum number of sg
- * entries was reached or a terminating sg (sg_last(sg) == true) was reached.
+ * Iterates over sg entries page-by-page. On each successful iteration, you
+ * can call sg_page_iter_page(@piter) to get the current page.
+ * @piter->sg will point to the sg holding this page and @piter->sg_pgoffset to
+ * the page's page offset within the sg. The iteration will stop either when a
+ * maximum number of sg entries was reached or a terminating sg
+ * (sg_last(sg) == true) was reached.
*/
struct sg_page_iter {
struct scatterlist *sg; /* sg holding the page */
@@ -370,7 +379,19 @@
* next step */
};
+/*
+ * sg page iterator for DMA addresses
+ *
+ * This is the same as sg_page_iter however you can call
+ * sg_page_iter_dma_address(@dma_iter) to get the page's DMA
+ * address. sg_page_iter_page() cannot be called on this iterator.
+ */
+struct sg_dma_page_iter {
+ struct sg_page_iter base;
+};
+
bool __sg_page_iter_next(struct sg_page_iter *piter);
+bool __sg_page_iter_dma_next(struct sg_dma_page_iter *dma_iter);
void __sg_page_iter_start(struct sg_page_iter *piter,
struct scatterlist *sglist, unsigned int nents,
unsigned long pgoffset);
@@ -386,11 +407,13 @@
/**
* sg_page_iter_dma_address - get the dma address of the current page held by
* the page iterator.
- * @piter: page iterator holding the page
+ * @dma_iter: page iterator holding the page
*/
-static inline dma_addr_t sg_page_iter_dma_address(struct sg_page_iter *piter)
+static inline dma_addr_t
+sg_page_iter_dma_address(struct sg_dma_page_iter *dma_iter)
{
- return sg_dma_address(piter->sg) + (piter->sg_pgoffset << PAGE_SHIFT);
+ return sg_dma_address(dma_iter->base.sg) +
+ (dma_iter->base.sg_pgoffset << PAGE_SHIFT);
}
/**
@@ -398,13 +421,32 @@
* @sglist: sglist to iterate over
* @piter: page iterator to hold current page, sg, sg_pgoffset
* @nents: maximum number of sg entries to iterate over
- * @pgoffset: starting page offset
+ * @pgoffset: starting page offset (in pages)
+ *
+ * Callers may use sg_page_iter_page() to get each page pointer.
+ * In each loop it operates on PAGE_SIZE unit.
*/
#define for_each_sg_page(sglist, piter, nents, pgoffset) \
for (__sg_page_iter_start((piter), (sglist), (nents), (pgoffset)); \
__sg_page_iter_next(piter);)
/**
+ * for_each_sg_dma_page - iterate over the pages of the given sg list
+ * @sglist: sglist to iterate over
+ * @dma_iter: DMA page iterator to hold current page
+ * @dma_nents: maximum number of sg entries to iterate over, this is the value
+ * returned from dma_map_sg
+ * @pgoffset: starting page offset (in pages)
+ *
+ * Callers may use sg_page_iter_dma_address() to get each page's DMA address.
+ * In each loop it operates on PAGE_SIZE unit.
+ */
+#define for_each_sg_dma_page(sglist, dma_iter, dma_nents, pgoffset) \
+ for (__sg_page_iter_start(&(dma_iter)->base, sglist, dma_nents, \
+ pgoffset); \
+ __sg_page_iter_dma_next(dma_iter);)
+
+/**
* for_each_sgtable_page - iterate over all pages in the sg_table object
* @sgt: sg_table object to iterate over
* @piter: page iterator to hold current page
--
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