[PATCH v2 06/10] scatterlist: support "page-less" (__pfn_t only) entries
From: Matthew Wilcox
Given that an offset will never be more than PAGE_SIZE, steal the unused
bits of the offset to implement a flags field. Move the existing "this
is a sg_chain() entry" flag to the new flags field, and add a new flag
(SG_FLAGS_PAGE) to indicate that there is a struct page backing for the
entry.
Signed-off-by: Dan Williams
Signed-off-by: Matthew Wilcox
---
block/blk-merge.c |2 -
drivers/dma/ste_dma40.c |5 --
drivers/mmc/card/queue.c |4 +-
include/asm-generic/scatterlist.h |9
include/crypto/scatterwalk.h | 10
include/linux/scatterlist.h | 91 +
6 files changed, 105 insertions(+), 16 deletions(-)
diff --git a/block/blk-merge.c b/block/blk-merge.c
index 218ad1e57a49..82a688551b72 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -267,7 +267,7 @@ int blk_rq_map_sg(struct request_queue *q, struct request
*rq,
if (rq->cmd_flags & REQ_WRITE)
memset(q->dma_drain_buffer, 0, q->dma_drain_size);
- sg->page_link &= ~0x02;
+ sg_unmark_end(sg);
sg = sg_next(sg);
sg_set_page(sg, virt_to_page(q->dma_drain_buffer),
q->dma_drain_size,
diff --git a/drivers/dma/ste_dma40.c b/drivers/dma/ste_dma40.c
index 3c10f034d4b9..e8c00642cacb 100644
--- a/drivers/dma/ste_dma40.c
+++ b/drivers/dma/ste_dma40.c
@@ -2562,10 +2562,7 @@ dma40_prep_dma_cyclic(struct dma_chan *chan, dma_addr_t
dma_addr,
dma_addr += period_len;
}
- sg[periods].offset = 0;
- sg_dma_len([periods]) = 0;
- sg[periods].page_link =
- ((unsigned long)sg | 0x01) & ~0x02;
+ sg_chain(sg, periods + 1, sg);
txd = d40_prep_sg(chan, sg, sg, periods, direction,
DMA_PREP_INTERRUPT);
diff --git a/drivers/mmc/card/queue.c b/drivers/mmc/card/queue.c
index 236d194c2883..127f76294e71 100644
--- a/drivers/mmc/card/queue.c
+++ b/drivers/mmc/card/queue.c
@@ -469,7 +469,7 @@ static unsigned int mmc_queue_packed_map_sg(struct
mmc_queue *mq,
sg_set_buf(__sg, buf + offset, len);
offset += len;
remain -= len;
- (__sg++)->page_link &= ~0x02;
+ sg_unmark_end(__sg++);
sg_len++;
} while (remain);
}
@@ -477,7 +477,7 @@ static unsigned int mmc_queue_packed_map_sg(struct
mmc_queue *mq,
list_for_each_entry(req, >list, queuelist) {
sg_len += blk_rq_map_sg(mq->queue, req, __sg);
__sg = sg + (sg_len - 1);
- (__sg++)->page_link &= ~0x02;
+ sg_unmark_end(__sg++);
}
sg_mark_end(sg + (sg_len - 1));
return sg_len;
diff --git a/include/asm-generic/scatterlist.h
b/include/asm-generic/scatterlist.h
index 5de07355fad4..959f51572a8e 100644
--- a/include/asm-generic/scatterlist.h
+++ b/include/asm-generic/scatterlist.h
@@ -7,8 +7,17 @@ struct scatterlist {
#ifdef CONFIG_DEBUG_SG
unsigned long sg_magic;
#endif
+#ifdef CONFIG_HAVE_DMA_PFN
+ union {
+ __pfn_t pfn;
+ struct scatterlist *next;
+ };
+ unsigned short offset;
+ unsigned short sg_flags;
+#else
unsigned long page_link;
unsigned intoffset;
+#endif
unsigned intlength;
dma_addr_t dma_address;
#ifdef CONFIG_NEED_SG_DMA_LENGTH
diff --git a/include/crypto/scatterwalk.h b/include/crypto/scatterwalk.h
index 20e4226a2e14..7296d89a50b2 100644
--- a/include/crypto/scatterwalk.h
+++ b/include/crypto/scatterwalk.h
@@ -25,6 +25,15 @@
#include
#include
+#ifdef CONFIG_HAVE_DMA_PFN
+/*
+ * If we're using PFNs, the architecture must also have been converted to
+ * support SG_CHAIN. So we can use the generic code instead of custom
+ * code.
+ */
+#define scatterwalk_sg_chain(prv, num, sgl)sg_chain(prv, num, sgl)
+#define scatterwalk_sg_next(sgl) sg_next(sgl)
+#else
static inline void scatterwalk_sg_chain(struct scatterlist *sg1, int num,
struct scatterlist *sg2)
{
@@ -32,6 +41,7 @@ static inline void scatterwalk_sg_chain(struct scatterlist
*sg1, int num,
sg1[num - 1].page_link &= ~0x02;
sg1[num - 1].page_link |= 0x01;
}
+#endif
static inline void scatterwalk_crypto_chain(struct scatterlist *head,
struct scatterlist *sg,
diff --git a/include/linux/scatterlist.h b/include/linux/scatterlist.h
index ed8f9e70df9b..9d423e559bdb 100644
--- a/include/linux/scatterlist.h
+++ b/include/linux/scatterlist.h
@@ -5,6 +5,7 @@
#include
#include
+#include
#include
#include
#include
@@ -18,8 +19,14 @@ struct sg_table {
/*
* Notes on SG table design.
*
- * Architectures must provide an unsigned long
[PATCH v2 06/10] scatterlist: support page-less (__pfn_t only) entries
From: Matthew Wilcox wi...@linux.intel.com
Given that an offset will never be more than PAGE_SIZE, steal the unused
bits of the offset to implement a flags field. Move the existing this
is a sg_chain() entry flag to the new flags field, and add a new flag
(SG_FLAGS_PAGE) to indicate that there is a struct page backing for the
entry.
Signed-off-by: Dan Williams dan.j.willi...@intel.com
Signed-off-by: Matthew Wilcox wi...@linux.intel.com
---
block/blk-merge.c |2 -
drivers/dma/ste_dma40.c |5 --
drivers/mmc/card/queue.c |4 +-
include/asm-generic/scatterlist.h |9
include/crypto/scatterwalk.h | 10
include/linux/scatterlist.h | 91 +
6 files changed, 105 insertions(+), 16 deletions(-)
diff --git a/block/blk-merge.c b/block/blk-merge.c
index 218ad1e57a49..82a688551b72 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -267,7 +267,7 @@ int blk_rq_map_sg(struct request_queue *q, struct request
*rq,
if (rq-cmd_flags REQ_WRITE)
memset(q-dma_drain_buffer, 0, q-dma_drain_size);
- sg-page_link = ~0x02;
+ sg_unmark_end(sg);
sg = sg_next(sg);
sg_set_page(sg, virt_to_page(q-dma_drain_buffer),
q-dma_drain_size,
diff --git a/drivers/dma/ste_dma40.c b/drivers/dma/ste_dma40.c
index 3c10f034d4b9..e8c00642cacb 100644
--- a/drivers/dma/ste_dma40.c
+++ b/drivers/dma/ste_dma40.c
@@ -2562,10 +2562,7 @@ dma40_prep_dma_cyclic(struct dma_chan *chan, dma_addr_t
dma_addr,
dma_addr += period_len;
}
- sg[periods].offset = 0;
- sg_dma_len(sg[periods]) = 0;
- sg[periods].page_link =
- ((unsigned long)sg | 0x01) ~0x02;
+ sg_chain(sg, periods + 1, sg);
txd = d40_prep_sg(chan, sg, sg, periods, direction,
DMA_PREP_INTERRUPT);
diff --git a/drivers/mmc/card/queue.c b/drivers/mmc/card/queue.c
index 236d194c2883..127f76294e71 100644
--- a/drivers/mmc/card/queue.c
+++ b/drivers/mmc/card/queue.c
@@ -469,7 +469,7 @@ static unsigned int mmc_queue_packed_map_sg(struct
mmc_queue *mq,
sg_set_buf(__sg, buf + offset, len);
offset += len;
remain -= len;
- (__sg++)-page_link = ~0x02;
+ sg_unmark_end(__sg++);
sg_len++;
} while (remain);
}
@@ -477,7 +477,7 @@ static unsigned int mmc_queue_packed_map_sg(struct
mmc_queue *mq,
list_for_each_entry(req, packed-list, queuelist) {
sg_len += blk_rq_map_sg(mq-queue, req, __sg);
__sg = sg + (sg_len - 1);
- (__sg++)-page_link = ~0x02;
+ sg_unmark_end(__sg++);
}
sg_mark_end(sg + (sg_len - 1));
return sg_len;
diff --git a/include/asm-generic/scatterlist.h
b/include/asm-generic/scatterlist.h
index 5de07355fad4..959f51572a8e 100644
--- a/include/asm-generic/scatterlist.h
+++ b/include/asm-generic/scatterlist.h
@@ -7,8 +7,17 @@ struct scatterlist {
#ifdef CONFIG_DEBUG_SG
unsigned long sg_magic;
#endif
+#ifdef CONFIG_HAVE_DMA_PFN
+ union {
+ __pfn_t pfn;
+ struct scatterlist *next;
+ };
+ unsigned short offset;
+ unsigned short sg_flags;
+#else
unsigned long page_link;
unsigned intoffset;
+#endif
unsigned intlength;
dma_addr_t dma_address;
#ifdef CONFIG_NEED_SG_DMA_LENGTH
diff --git a/include/crypto/scatterwalk.h b/include/crypto/scatterwalk.h
index 20e4226a2e14..7296d89a50b2 100644
--- a/include/crypto/scatterwalk.h
+++ b/include/crypto/scatterwalk.h
@@ -25,6 +25,15 @@
#include linux/scatterlist.h
#include linux/sched.h
+#ifdef CONFIG_HAVE_DMA_PFN
+/*
+ * If we're using PFNs, the architecture must also have been converted to
+ * support SG_CHAIN. So we can use the generic code instead of custom
+ * code.
+ */
+#define scatterwalk_sg_chain(prv, num, sgl)sg_chain(prv, num, sgl)
+#define scatterwalk_sg_next(sgl) sg_next(sgl)
+#else
static inline void scatterwalk_sg_chain(struct scatterlist *sg1, int num,
struct scatterlist *sg2)
{
@@ -32,6 +41,7 @@ static inline void scatterwalk_sg_chain(struct scatterlist
*sg1, int num,
sg1[num - 1].page_link = ~0x02;
sg1[num - 1].page_link |= 0x01;
}
+#endif
static inline void scatterwalk_crypto_chain(struct scatterlist *head,
struct scatterlist *sg,
diff --git a/include/linux/scatterlist.h b/include/linux/scatterlist.h
index ed8f9e70df9b..9d423e559bdb 100644
--- a/include/linux/scatterlist.h
+++ b/include/linux/scatterlist.h
@@ -5,6 +5,7 @@
#include linux/bug.h
#include linux/mm.h
+#include asm/page.h
#include asm/types.h
#include
