From patchwork Sat Jan 16 00:01:34 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kamal Mostafa X-Patchwork-Id: 568911 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) by ozlabs.org (Postfix) with ESMTP id CEC231401AF; Sat, 16 Jan 2016 11:19:46 +1100 (AEDT) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1aKEal-00046T-F9; Sat, 16 Jan 2016 00:19:43 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.76) (envelope-from ) id 1aKEOw-0005uQ-Gh for kernel-team@lists.ubuntu.com; Sat, 16 Jan 2016 00:07:30 +0000 Received: from 1.general.kamal.us.vpn ([10.172.68.52] helo=fourier) by youngberry.canonical.com with esmtpsa (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:16) (Exim 4.76) (envelope-from ) id 1aKEOv-0008Js-QH; Sat, 16 Jan 2016 00:07:29 +0000 Received: from kamal by fourier with local (Exim 4.82) (envelope-from ) id 1aKEOt-0002Ii-0Y; Fri, 15 Jan 2016 16:07:27 -0800 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Subject: [PATCH 4.2.y-ckt 280/305] dmaengine: bcm2835-dma: Convert to use DMA pool Date: Fri, 15 Jan 2016 16:01:34 -0800 Message-Id: <1452902519-2754-281-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1452902519-2754-1-git-send-email-kamal@canonical.com> References: <1452902519-2754-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 4.2 Cc: Peter Ujfalusi , Vinod Koul , Kamal Mostafa X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.14 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: kernel-team-bounces@lists.ubuntu.com 4.2.8-ckt2 -stable review patch. If anyone has any objections, please let me know. ---8<------------------------------------------------------------ From: Peter Ujfalusi commit 27bc944ca39ff1ed69bc48a38dc057e15ea3d1c0 upstream. f93178291712 dmaengine: bcm2835-dma: Fix memory leak when stopping a running transfer Fixed the memleak, but introduced another issue: the terminate_all callback might be called with interrupts disabled and the dma_free_coherent() is not allowed to be called when IRQs are disabled. Convert the driver to use dma_pool_* for managing the list of control blocks for the transfer. Fixes: f93178291712 ("dmaengine: bcm2835-dma: Fix memory leak when stopping a running transfer") Signed-off-by: Peter Ujfalusi Tested-by: Matthias Reichl Signed-off-by: Vinod Koul Signed-off-by: Kamal Mostafa --- drivers/dma/bcm2835-dma.c | 78 ++++++++++++++++++++++++++++++++--------------- 1 file changed, 54 insertions(+), 24 deletions(-) diff --git a/drivers/dma/bcm2835-dma.c b/drivers/dma/bcm2835-dma.c index c92d6a7..996c4b0 100644 --- a/drivers/dma/bcm2835-dma.c +++ b/drivers/dma/bcm2835-dma.c @@ -31,6 +31,7 @@ */ #include #include +#include #include #include #include @@ -62,6 +63,11 @@ struct bcm2835_dma_cb { uint32_t pad[2]; }; +struct bcm2835_cb_entry { + struct bcm2835_dma_cb *cb; + dma_addr_t paddr; +}; + struct bcm2835_chan { struct virt_dma_chan vc; struct list_head node; @@ -72,18 +78,18 @@ struct bcm2835_chan { int ch; struct bcm2835_desc *desc; + struct dma_pool *cb_pool; void __iomem *chan_base; int irq_number; }; struct bcm2835_desc { + struct bcm2835_chan *c; struct virt_dma_desc vd; enum dma_transfer_direction dir; - unsigned int control_block_size; - struct bcm2835_dma_cb *control_block_base; - dma_addr_t control_block_base_phys; + struct bcm2835_cb_entry *cb_list; unsigned int frames; size_t size; @@ -143,10 +149,13 @@ static inline struct bcm2835_desc *to_bcm2835_dma_desc( static void bcm2835_dma_desc_free(struct virt_dma_desc *vd) { struct bcm2835_desc *desc = container_of(vd, struct bcm2835_desc, vd); - dma_free_coherent(desc->vd.tx.chan->device->dev, - desc->control_block_size, - desc->control_block_base, - desc->control_block_base_phys); + int i; + + for (i = 0; i < desc->frames; i++) + dma_pool_free(desc->c->cb_pool, desc->cb_list[i].cb, + desc->cb_list[i].paddr); + + kfree(desc->cb_list); kfree(desc); } @@ -199,7 +208,7 @@ static void bcm2835_dma_start_desc(struct bcm2835_chan *c) c->desc = d = to_bcm2835_dma_desc(&vd->tx); - writel(d->control_block_base_phys, c->chan_base + BCM2835_DMA_ADDR); + writel(d->cb_list[0].paddr, c->chan_base + BCM2835_DMA_ADDR); writel(BCM2835_DMA_ACTIVE, c->chan_base + BCM2835_DMA_CS); } @@ -232,9 +241,16 @@ static irqreturn_t bcm2835_dma_callback(int irq, void *data) static int bcm2835_dma_alloc_chan_resources(struct dma_chan *chan) { struct bcm2835_chan *c = to_bcm2835_dma_chan(chan); + struct device *dev = c->vc.chan.device->dev; + + dev_dbg(dev, "Allocating DMA channel %d\n", c->ch); - dev_dbg(c->vc.chan.device->dev, - "Allocating DMA channel %d\n", c->ch); + c->cb_pool = dma_pool_create(dev_name(dev), dev, + sizeof(struct bcm2835_dma_cb), 0, 0); + if (!c->cb_pool) { + dev_err(dev, "unable to allocate descriptor pool\n"); + return -ENOMEM; + } return request_irq(c->irq_number, bcm2835_dma_callback, 0, "DMA IRQ", c); @@ -246,6 +262,7 @@ static void bcm2835_dma_free_chan_resources(struct dma_chan *chan) vchan_free_chan_resources(&c->vc); free_irq(c->irq_number, c); + dma_pool_destroy(c->cb_pool); dev_dbg(c->vc.chan.device->dev, "Freeing DMA channel %u\n", c->ch); } @@ -261,8 +278,7 @@ static size_t bcm2835_dma_desc_size_pos(struct bcm2835_desc *d, dma_addr_t addr) size_t size; for (size = i = 0; i < d->frames; i++) { - struct bcm2835_dma_cb *control_block = - &d->control_block_base[i]; + struct bcm2835_dma_cb *control_block = d->cb_list[i].cb; size_t this_size = control_block->length; dma_addr_t dma; @@ -343,6 +359,7 @@ static struct dma_async_tx_descriptor *bcm2835_dma_prep_dma_cyclic( dma_addr_t dev_addr; unsigned int es, sync_type; unsigned int frame; + int i; /* Grab configuration */ if (!is_slave_direction(direction)) { @@ -374,27 +391,31 @@ static struct dma_async_tx_descriptor *bcm2835_dma_prep_dma_cyclic( if (!d) return NULL; + d->c = c; d->dir = direction; d->frames = buf_len / period_len; - /* Allocate memory for control blocks */ - d->control_block_size = d->frames * sizeof(struct bcm2835_dma_cb); - d->control_block_base = dma_zalloc_coherent(chan->device->dev, - d->control_block_size, &d->control_block_base_phys, - GFP_NOWAIT); - - if (!d->control_block_base) { + d->cb_list = kcalloc(d->frames, sizeof(*d->cb_list), GFP_KERNEL); + if (!d->cb_list) { kfree(d); return NULL; } + /* Allocate memory for control blocks */ + for (i = 0; i < d->frames; i++) { + struct bcm2835_cb_entry *cb_entry = &d->cb_list[i]; + + cb_entry->cb = dma_pool_zalloc(c->cb_pool, GFP_ATOMIC, + &cb_entry->paddr); + if (!cb_entry->cb) + goto error_cb; + } /* * Iterate over all frames, create a control block * for each frame and link them together. */ for (frame = 0; frame < d->frames; frame++) { - struct bcm2835_dma_cb *control_block = - &d->control_block_base[frame]; + struct bcm2835_dma_cb *control_block = d->cb_list[frame].cb; /* Setup adresses */ if (d->dir == DMA_DEV_TO_MEM) { @@ -428,12 +449,21 @@ static struct dma_async_tx_descriptor *bcm2835_dma_prep_dma_cyclic( * This DMA engine driver currently only supports cyclic DMA. * Therefore, wrap around at number of frames. */ - control_block->next = d->control_block_base_phys + - sizeof(struct bcm2835_dma_cb) - * ((frame + 1) % d->frames); + control_block->next = d->cb_list[((frame + 1) % d->frames)].paddr; } return vchan_tx_prep(&c->vc, &d->vd, flags); +error_cb: + i--; + for (; i >= 0; i--) { + struct bcm2835_cb_entry *cb_entry = &d->cb_list[i]; + + dma_pool_free(c->cb_pool, cb_entry->cb, cb_entry->paddr); + } + + kfree(d->cb_list); + kfree(d); + return NULL; } static int bcm2835_dma_slave_config(struct dma_chan *chan,