2012-04-23 13:51:48

by Jiang Liu

[permalink] [raw]
Subject: [PATCH v1 7/8] dmaengine: enhance ASYNC_TX subsystem to support DMA device hotplug

Enhance ASYNC_TX subsystem to correctly update DMA channel reference counts,
so it won't break DMA device hotplug logic.

Signed-off-by: Jiang Liu <[email protected]>
---
crypto/async_tx/async_memcpy.c | 2 ++
crypto/async_tx/async_memset.c | 2 ++
crypto/async_tx/async_pq.c | 10 ++++++++--
crypto/async_tx/async_raid6_recov.c | 8 ++++++--
crypto/async_tx/async_tx.c | 6 +++---
crypto/async_tx/async_xor.c | 13 +++++++++----
include/linux/async_tx.h | 13 +++++++++++++
include/linux/dmaengine.h | 14 ++++++++++++++
8 files changed, 57 insertions(+), 11 deletions(-)

diff --git a/crypto/async_tx/async_memcpy.c b/crypto/async_tx/async_memcpy.c
index 361b5e8..0cbd90e 100644
--- a/crypto/async_tx/async_memcpy.c
+++ b/crypto/async_tx/async_memcpy.c
@@ -90,6 +90,8 @@ async_memcpy(struct page *dest, struct page *src, unsigned int dest_offset,
async_tx_sync_epilog(submit);
}

+ async_tx_put_channel(chan);
+
return tx;
}
EXPORT_SYMBOL_GPL(async_memcpy);
diff --git a/crypto/async_tx/async_memset.c b/crypto/async_tx/async_memset.c
index 58e4a87..ec568bb 100644
--- a/crypto/async_tx/async_memset.c
+++ b/crypto/async_tx/async_memset.c
@@ -79,6 +79,8 @@ async_memset(struct page *dest, int val, unsigned int offset, size_t len,
async_tx_sync_epilog(submit);
}

+ async_tx_put_channel(chan);
+
return tx;
}
EXPORT_SYMBOL_GPL(async_memset);
diff --git a/crypto/async_tx/async_pq.c b/crypto/async_tx/async_pq.c
index 91d5d38..ae2070c 100644
--- a/crypto/async_tx/async_pq.c
+++ b/crypto/async_tx/async_pq.c
@@ -203,6 +203,7 @@ async_gen_syndrome(struct page **blocks, unsigned int offset, int disks,
blocks, src_cnt, len);
struct dma_device *device = chan ? chan->device : NULL;
dma_addr_t *dma_src = NULL;
+ struct dma_async_tx_descriptor *tx;

BUG_ON(disks > 255 || !(P(blocks, disks) || Q(blocks, disks)));

@@ -218,12 +219,15 @@ async_gen_syndrome(struct page **blocks, unsigned int offset, int disks,
/* run the p+q asynchronously */
pr_debug("%s: (async) disks: %d len: %zu\n",
__func__, disks, len);
- return do_async_gen_syndrome(chan, blocks, raid6_gfexp, offset,
- disks, len, dma_src, submit);
+ tx = do_async_gen_syndrome(chan, blocks, raid6_gfexp, offset,
+ disks, len, dma_src, submit);
+ async_tx_put_channel(chan);
+ return tx;
}

/* run the pq synchronously */
pr_debug("%s: (sync) disks: %d len: %zu\n", __func__, disks, len);
+ async_tx_put_channel(chan);

/* wait for any prerequisite operations */
async_tx_quiesce(&submit->depend_tx);
@@ -331,6 +335,7 @@ async_syndrome_val(struct page **blocks, unsigned int offset, int disks,
dma_async_issue_pending(chan);
}
async_tx_submit(chan, tx, submit);
+ async_tx_put_channel(chan);

return tx;
} else {
@@ -344,6 +349,7 @@ async_syndrome_val(struct page **blocks, unsigned int offset, int disks,

pr_debug("%s: (sync) disks: %d len: %zu\n",
__func__, disks, len);
+ async_tx_put_channel(chan);

/* caller must provide a temporary result buffer and
* allow the input parameters to be preserved
diff --git a/crypto/async_tx/async_raid6_recov.c b/crypto/async_tx/async_raid6_recov.c
index a9f08a6..0f54d7c 100644
--- a/crypto/async_tx/async_raid6_recov.c
+++ b/crypto/async_tx/async_raid6_recov.c
@@ -54,6 +54,7 @@ async_sum_product(struct page *dest, struct page **srcs, unsigned char *coef,
len, dma_flags);
if (tx) {
async_tx_submit(chan, tx, submit);
+ async_tx_put_channel(chan);
return tx;
}

@@ -66,6 +67,7 @@ async_sum_product(struct page *dest, struct page **srcs, unsigned char *coef,
}

/* run the operation synchronously */
+ async_tx_put_channel(chan);
async_tx_quiesce(&submit->depend_tx);
amul = raid6_gfmul[coef[0]];
bmul = raid6_gfmul[coef[1]];
@@ -107,6 +109,7 @@ async_mult(struct page *dest, struct page *src, u8 coef, size_t len,
len, dma_flags);
if (tx) {
async_tx_submit(chan, tx, submit);
+ async_tx_put_channel(chan);
return tx;
}

@@ -120,6 +123,7 @@ async_mult(struct page *dest, struct page *src, u8 coef, size_t len,
/* no channel available, or failed to allocate a descriptor, so
* perform the operation synchronously
*/
+ async_tx_put_channel(chan);
async_tx_quiesce(&submit->depend_tx);
qmul = raid6_gfmul[coef];
d = page_address(dest);
@@ -339,7 +343,7 @@ async_raid6_2data_recov(int disks, size_t bytes, int faila, int failb,
* available' case be sure to use the scribble buffer to
* preserve the content of 'blocks' as the caller intended.
*/
- if (!async_dma_find_channel(DMA_PQ) || !scribble) {
+ if (!async_tx_has_capability(DMA_PQ) || !scribble) {
void **ptrs = scribble ? scribble : (void **) blocks;

async_tx_quiesce(&submit->depend_tx);
@@ -415,7 +419,7 @@ async_raid6_datap_recov(int disks, size_t bytes, int faila,
* available' case be sure to use the scribble buffer to
* preserve the content of 'blocks' as the caller intended.
*/
- if (!async_dma_find_channel(DMA_PQ) || !scribble) {
+ if (!async_tx_has_capability(DMA_PQ) || !scribble) {
void **ptrs = scribble ? scribble : (void **) blocks;

async_tx_quiesce(&submit->depend_tx);
diff --git a/crypto/async_tx/async_tx.c b/crypto/async_tx/async_tx.c
index 8421209..6fe6561 100644
--- a/crypto/async_tx/async_tx.c
+++ b/crypto/async_tx/async_tx.c
@@ -47,8 +47,8 @@ module_init(async_tx_init);
module_exit(async_tx_exit);

/**
- * __async_tx_find_channel - find a channel to carry out the operation or let
- * the transaction execute synchronously
+ * __async_tx_find_channel - find and hold a channel to carry out the
+ * operation or let the transaction execute synchronously
* @submit: transaction dependency and submission modifiers
* @tx_type: transaction type
*/
@@ -61,7 +61,7 @@ __async_tx_find_channel(struct async_submit_ctl *submit,
/* see if we can keep the chain on one channel */
if (depend_tx &&
dma_has_cap(tx_type, depend_tx->chan->device->cap_mask))
- return depend_tx->chan;
+ return async_dma_get_channel(depend_tx->chan);
return async_dma_find_channel(tx_type);
}
EXPORT_SYMBOL_GPL(__async_tx_find_channel);
diff --git a/crypto/async_tx/async_xor.c b/crypto/async_tx/async_xor.c
index 154cc84..056e248 100644
--- a/crypto/async_tx/async_xor.c
+++ b/crypto/async_tx/async_xor.c
@@ -190,6 +190,7 @@ async_xor(struct page *dest, struct page **src_list, unsigned int offset,
&dest, 1, src_list,
src_cnt, len);
dma_addr_t *dma_src = NULL;
+ struct dma_async_tx_descriptor *tx = NULL;

BUG_ON(src_cnt <= 1);

@@ -202,8 +203,8 @@ async_xor(struct page *dest, struct page **src_list, unsigned int offset,
/* run the xor asynchronously */
pr_debug("%s (async): len: %zu\n", __func__, len);

- return do_async_xor(chan, dest, src_list, offset, src_cnt, len,
- dma_src, submit);
+ tx = do_async_xor(chan, dest, src_list, offset, src_cnt, len,
+ dma_src, submit);
} else {
/* run the xor synchronously */
pr_debug("%s (sync): len: %zu\n", __func__, len);
@@ -222,9 +223,11 @@ async_xor(struct page *dest, struct page **src_list, unsigned int offset,
async_tx_quiesce(&submit->depend_tx);

do_sync_xor(dest, src_list, offset, src_cnt, len, submit);
-
- return NULL;
}
+
+ async_tx_put_channel(chan);
+
+ return tx;
}
EXPORT_SYMBOL_GPL(async_xor);

@@ -330,6 +333,8 @@ async_xor_val(struct page *dest, struct page **src_list, unsigned int offset,
submit->flags = flags_orig;
}

+ async_tx_put_channel(chan);
+
return tx;
}
EXPORT_SYMBOL_GPL(async_xor_val);
diff --git a/include/linux/async_tx.h b/include/linux/async_tx.h
index a1c486a..35dea72 100644
--- a/include/linux/async_tx.h
+++ b/include/linux/async_tx.h
@@ -104,6 +104,10 @@ static inline void async_tx_issue_pending(struct dma_async_tx_descriptor *tx)
dma->device_issue_pending(chan);
}
}
+
+#define async_tx_put_channel(c) async_dma_put_channel(c)
+#define async_tx_has_capability(c) async_dma_has_capability(c)
+
#ifdef CONFIG_ARCH_HAS_ASYNC_TX_FIND_CHANNEL
#include <asm/async_tx.h>
#else
@@ -132,6 +136,15 @@ async_tx_find_channel(struct async_submit_ctl *submit,
{
return NULL;
}
+
+static inline void async_tx_put_channel(struct dma_chan *chan)
+{
+}
+
+static inline bool async_tx_has_capability(enum dma_transaction_type type)
+{
+ return false;
+}
#endif

/**
diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
index 874f8de..99762a2 100644
--- a/include/linux/dmaengine.h
+++ b/include/linux/dmaengine.h
@@ -789,6 +789,9 @@ static inline void net_dmaengine_put(void)
#else
#define async_dma_find_channel(type) dma_find_channel(type)
#endif /* CONFIG_ASYNC_TX_ENABLE_CHANNEL_SWITCH */
+#define async_dma_get_channel(chan) dma_get_channel(chan)
+#define async_dma_put_channel(chan) dma_put_channel(chan)
+#define async_dma_has_capability(c) dma_has_capability(c)
#else
static inline void async_dmaengine_get(void)
{
@@ -801,6 +804,17 @@ async_dma_find_channel(enum dma_transaction_type type)
{
return NULL;
}
+static inline struct dma_chan *async_dma_get_channel(struct dma_chan *chan)
+{
+ return chan;
+}
+static inline void async_dma_put_channel(struct dma_chan *chan)
+{
+}
+static inline bool async_dma_has_capability(enum dma_transaction_type type)
+{
+ return false;
+}
#endif /* CONFIG_ASYNC_TX_DMA */

dma_cookie_t dma_async_memcpy_buf_to_buf(struct dma_chan *chan,
--
1.7.5.4