From 0899d6349c60e4021224b51c8c97f49b829dfefd Mon Sep 17 00:00:00 2001 From: Li Yang Date: Fri, 22 May 2009 16:39:59 +0800 Subject: [PATCH 1/7] fsldma: update mailling list address in MAINTAINERS linuxppc-embedded has been merged into linuxppc-dev. Signed-off-by: Li Yang --- MAINTAINERS | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/MAINTAINERS b/MAINTAINERS index 2b349ba4add4..cac3e3b71d35 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -2241,7 +2241,7 @@ P: Li Yang M: leoli@freescale.com P: Zhang Wei M: zw@zh-kernel.org -L: linuxppc-embedded@ozlabs.org +L: linuxppc-dev@ozlabs.org L: linux-kernel@vger.kernel.org S: Maintained F: drivers/dma/fsldma.* From f47edc6dab11801c2e97088ba7bbce042ded867c Mon Sep 17 00:00:00 2001 From: Roel Kluin Date: Fri, 22 May 2009 16:46:52 +0800 Subject: [PATCH 2/7] fsldma: fix check on potential fdev->chan[] overflow Fix the check of potential array overflow when using corrupted channel device tree nodes. Signed-off-by: Roel Kluin Signed-off-by: Li Yang --- drivers/dma/fsldma.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/dma/fsldma.c b/drivers/dma/fsldma.c index da8a8ed9e411..391b1bd7098b 100644 --- a/drivers/dma/fsldma.c +++ b/drivers/dma/fsldma.c @@ -830,7 +830,7 @@ static int __devinit fsl_dma_chan_probe(struct fsl_dma_device *fdev, new_fsl_chan->reg.end - new_fsl_chan->reg.start + 1); new_fsl_chan->id = ((new_fsl_chan->reg.start - 0x100) & 0xfff) >> 7; - if (new_fsl_chan->id > FSL_DMA_MAX_CHANS_PER_DEVICE) { + if (new_fsl_chan->id >= FSL_DMA_MAX_CHANS_PER_DEVICE) { dev_err(fdev->dev, "There is no %d channel!\n", new_fsl_chan->id); err = -EINVAL; From 138ef0185177a6d221d24b6aa8f12d867fbbef90 Mon Sep 17 00:00:00 2001 From: Ira Snyder Date: Tue, 19 May 2009 15:42:13 -0700 Subject: [PATCH 3/7] fsldma: fix "DMA halt timeout!" errors When using the DMA controller from multiple threads at the same time, it is possible to get lots of "DMA halt timeout!" errors printed to the kernel log. This occurs due to a race between fsl_dma_memcpy_issue_pending() and the interrupt handler, fsl_dma_chan_do_interrupt(). Both call the fsl_chan_xfer_ld_queue() function, which does not protect against concurrent accesses to dma_halt() and dma_start(). The existing spinlock is moved to cover the dma_halt() and dma_start() functions. Testing shows that the "DMA halt timeout!" errors disappear. Signed-off-by: Ira W. Snyder Signed-off-by: Li Yang --- drivers/dma/fsldma.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/drivers/dma/fsldma.c b/drivers/dma/fsldma.c index 391b1bd7098b..a4151c3bb78b 100644 --- a/drivers/dma/fsldma.c +++ b/drivers/dma/fsldma.c @@ -598,15 +598,16 @@ static void fsl_chan_xfer_ld_queue(struct fsl_dma_chan *fsl_chan) dma_addr_t next_dest_addr; unsigned long flags; + spin_lock_irqsave(&fsl_chan->desc_lock, flags); + if (!dma_is_idle(fsl_chan)) - return; + goto out_unlock; dma_halt(fsl_chan); /* If there are some link descriptors * not transfered in queue. We need to start it. */ - spin_lock_irqsave(&fsl_chan->desc_lock, flags); /* Find the first un-transfer desciptor */ for (ld_node = fsl_chan->ld_queue.next; @@ -617,8 +618,6 @@ static void fsl_chan_xfer_ld_queue(struct fsl_dma_chan *fsl_chan) fsl_chan->common.cookie) == DMA_SUCCESS); ld_node = ld_node->next); - spin_unlock_irqrestore(&fsl_chan->desc_lock, flags); - if (ld_node != &fsl_chan->ld_queue) { /* Get the ld start address from ld_queue */ next_dest_addr = to_fsl_desc(ld_node)->async_tx.phys; @@ -630,6 +629,9 @@ static void fsl_chan_xfer_ld_queue(struct fsl_dma_chan *fsl_chan) set_cdar(fsl_chan, 0); set_ndar(fsl_chan, 0); } + +out_unlock: + spin_unlock_irqrestore(&fsl_chan->desc_lock, flags); } /** From bcfb7465c03a8c62c89da374677df56f6b894d44 Mon Sep 17 00:00:00 2001 From: Ira Snyder Date: Fri, 15 May 2009 14:27:16 -0700 Subject: [PATCH 4/7] fsldma: fix infinite loop on multi-descriptor DMA chain completion When creating a DMA transaction with multiple descriptors, the async_tx cookie is set to 0 for each descriptor in the chain, excluding the last descriptor, whose cookie is set to -EBUSY. When fsl_dma_tx_submit() is run, it only assigns a cookie to the first descriptor. All of the remaining descriptors keep their original value, including the last descriptor, which is set to -EBUSY. After the DMA completes, the driver will update the last completed cookie to be -EBUSY, which is an error code instead of a valid cookie. This causes dma_async_is_complete() to always return DMA_IN_PROGRESS. This causes the fsldma driver to never cleanup the queue of link descriptors, and the driver will re-run the DMA transaction on the hardware each time it receives the End-of-Chain interrupt. This causes an infinite loop. With this patch, fsl_dma_tx_submit() is changed to assign a cookie to every descriptor in the chain. The rest of the code then works without problems. Signed-off-by: Ira W. Snyder Signed-off-by: Li Yang --- drivers/dma/fsldma.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) diff --git a/drivers/dma/fsldma.c b/drivers/dma/fsldma.c index a4151c3bb78b..7313a1ae5f83 100644 --- a/drivers/dma/fsldma.c +++ b/drivers/dma/fsldma.c @@ -313,8 +313,8 @@ static void fsl_chan_toggle_ext_start(struct fsl_dma_chan *fsl_chan, int enable) static dma_cookie_t fsl_dma_tx_submit(struct dma_async_tx_descriptor *tx) { - struct fsl_desc_sw *desc = tx_to_fsl_desc(tx); struct fsl_dma_chan *fsl_chan = to_fsl_chan(tx->chan); + struct fsl_desc_sw *desc; unsigned long flags; dma_cookie_t cookie; @@ -322,14 +322,17 @@ static dma_cookie_t fsl_dma_tx_submit(struct dma_async_tx_descriptor *tx) spin_lock_irqsave(&fsl_chan->desc_lock, flags); cookie = fsl_chan->common.cookie; - cookie++; - if (cookie < 0) - cookie = 1; - desc->async_tx.cookie = cookie; - fsl_chan->common.cookie = desc->async_tx.cookie; + list_for_each_entry(desc, &tx->tx_list, node) { + cookie++; + if (cookie < 0) + cookie = 1; - append_ld_queue(fsl_chan, desc); - list_splice_init(&desc->async_tx.tx_list, fsl_chan->ld_queue.prev); + desc->async_tx.cookie = cookie; + } + + fsl_chan->common.cookie = cookie; + append_ld_queue(fsl_chan, tx_to_fsl_desc(tx)); + list_splice_init(&tx->tx_list, fsl_chan->ld_queue.prev); spin_unlock_irqrestore(&fsl_chan->desc_lock, flags); From 776c8943f2766f2819fafd88fdfbaf418ecd6e41 Mon Sep 17 00:00:00 2001 From: Ira Snyder Date: Fri, 15 May 2009 11:33:20 -0700 Subject: [PATCH 5/7] fsldma: snooping is not enabled for last entry in descriptor chain On the 83xx controller, snooping is necessary for the DMA controller to ensure cache coherence with the CPU when transferring to/from RAM. The last descriptor in a chain will always have the End-of-Chain interrupt bit set, so we can set the snoop bit while adding the End-of-Chain interrupt bit. Signed-off-by: Ira W. Snyder Signed-off-by: Li Yang --- drivers/dma/fsldma.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/dma/fsldma.c b/drivers/dma/fsldma.c index 7313a1ae5f83..ff9194d7ebb7 100644 --- a/drivers/dma/fsldma.c +++ b/drivers/dma/fsldma.c @@ -179,9 +179,14 @@ static void dma_halt(struct fsl_dma_chan *fsl_chan) static void set_ld_eol(struct fsl_dma_chan *fsl_chan, struct fsl_desc_sw *desc) { + u64 snoop_bits; + + snoop_bits = ((fsl_chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_83XX) + ? FSL_DMA_SNEN : 0; + desc->hw.next_ln_addr = CPU_TO_DMA(fsl_chan, - DMA_TO_CPU(fsl_chan, desc->hw.next_ln_addr, 64) | FSL_DMA_EOL, - 64); + DMA_TO_CPU(fsl_chan, desc->hw.next_ln_addr, 64) | FSL_DMA_EOL + | snoop_bits, 64); } static void append_ld_queue(struct fsl_dma_chan *fsl_chan, From 2e077f8e8337e52eef3c39c24c31e103b11a0326 Mon Sep 17 00:00:00 2001 From: Ira Snyder Date: Fri, 15 May 2009 09:59:46 -0700 Subject: [PATCH 6/7] fsldma: fix memory leak on error path in fsl_dma_prep_memcpy() When preparing a memcpy operation, if the kernel fails to allocate memory for a link descriptor after the first link descriptor has already been allocated, then some memory will never be released. Fix the problem by walking the list of allocated descriptors backwards, and freeing the allocated descriptors back into the DMA pool. Signed-off-by: Ira W. Snyder Signed-off-by: Li Yang --- drivers/dma/fsldma.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) diff --git a/drivers/dma/fsldma.c b/drivers/dma/fsldma.c index ff9194d7ebb7..15783102bf17 100644 --- a/drivers/dma/fsldma.c +++ b/drivers/dma/fsldma.c @@ -462,8 +462,8 @@ static struct dma_async_tx_descriptor *fsl_dma_prep_memcpy( { struct fsl_dma_chan *fsl_chan; struct fsl_desc_sw *first = NULL, *prev = NULL, *new; + struct list_head *list; size_t copy; - LIST_HEAD(link_chain); if (!chan) return NULL; @@ -480,7 +480,7 @@ static struct dma_async_tx_descriptor *fsl_dma_prep_memcpy( if (!new) { dev_err(fsl_chan->dev, "No free memory for link descriptor\n"); - return NULL; + goto fail; } #ifdef FSL_DMA_LD_DEBUG dev_dbg(fsl_chan->dev, "new link desc alloc %p\n", new); @@ -515,7 +515,19 @@ static struct dma_async_tx_descriptor *fsl_dma_prep_memcpy( /* Set End-of-link to the last link descriptor of new list*/ set_ld_eol(fsl_chan, new); - return first ? &first->async_tx : NULL; + return &first->async_tx; + +fail: + if (!first) + return NULL; + + list = &first->async_tx.tx_list; + list_for_each_entry_safe_reverse(new, prev, list, node) { + list_del(&new->node); + dma_pool_free(fsl_chan->desc_pool, new, new->async_tx.phys); + } + + return NULL; } /** From b787f2e2a37a373a045f4d9b9bed941ccff01663 Mon Sep 17 00:00:00 2001 From: Kumar Gala Date: Wed, 13 May 2009 16:25:57 -0500 Subject: [PATCH 7/7] fsldma: Fix compile warnings We we build with dma_addr_t as a 64-bit quantity we get: drivers/dma/fsldma.c: In function 'fsl_chan_xfer_ld_queue': drivers/dma/fsldma.c:625: warning: cast to pointer from integer of different size drivers/dma/fsldma.c: In function 'fsl_dma_chan_do_interrupt': drivers/dma/fsldma.c:737: warning: cast to pointer from integer of different size drivers/dma/fsldma.c:737: warning: cast to pointer from integer of different size drivers/dma/fsldma.c: In function 'of_fsl_dma_probe': drivers/dma/fsldma.c:927: warning: cast to pointer from integer of different Signed-off-by: Kumar Gala Signed-off-by: Dan Williams --- drivers/dma/fsldma.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) diff --git a/drivers/dma/fsldma.c b/drivers/dma/fsldma.c index 15783102bf17..f18d1bde0439 100644 --- a/drivers/dma/fsldma.c +++ b/drivers/dma/fsldma.c @@ -641,8 +641,8 @@ static void fsl_chan_xfer_ld_queue(struct fsl_dma_chan *fsl_chan) if (ld_node != &fsl_chan->ld_queue) { /* Get the ld start address from ld_queue */ next_dest_addr = to_fsl_desc(ld_node)->async_tx.phys; - dev_dbg(fsl_chan->dev, "xfer LDs staring from %p\n", - (void *)next_dest_addr); + dev_dbg(fsl_chan->dev, "xfer LDs staring from 0x%llx\n", + (unsigned long long)next_dest_addr); set_cdar(fsl_chan, next_dest_addr); dma_start(fsl_chan); } else { @@ -756,8 +756,9 @@ static irqreturn_t fsl_dma_chan_do_interrupt(int irq, void *data) */ if (stat & FSL_DMA_SR_EOSI) { dev_dbg(fsl_chan->dev, "event: End-of-segments INT\n"); - dev_dbg(fsl_chan->dev, "event: clndar %p, nlndar %p\n", - (void *)get_cdar(fsl_chan), (void *)get_ndar(fsl_chan)); + dev_dbg(fsl_chan->dev, "event: clndar 0x%llx, nlndar 0x%llx\n", + (unsigned long long)get_cdar(fsl_chan), + (unsigned long long)get_ndar(fsl_chan)); stat &= ~FSL_DMA_SR_EOSI; update_cookie = 1; } @@ -947,8 +948,8 @@ static int __devinit of_fsl_dma_probe(struct of_device *dev, } dev_info(&dev->dev, "Probe the Freescale DMA driver for %s " - "controller at %p...\n", - match->compatible, (void *)fdev->reg.start); + "controller at 0x%llx...\n", + match->compatible, (unsigned long long)fdev->reg.start); fdev->reg_base = ioremap(fdev->reg.start, fdev->reg.end - fdev->reg.start + 1);