Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752070AbcDWJgU (ORCPT ); Sat, 23 Apr 2016 05:36:20 -0400 Received: from hqemgate15.nvidia.com ([216.228.121.64]:5304 "EHLO hqemgate15.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751681AbcDWJgR (ORCPT ); Sat, 23 Apr 2016 05:36:17 -0400 X-PGP-Universal: processed; by hqnvupgp07.nvidia.com on Sat, 23 Apr 2016 02:36:02 -0700 From: Shardar Shariff Md To: , , , , , , , , , CC: Shardar Shariff Md Subject: [PATCH v4] dmaengine: tegra-apb: proper default init of channel slave_id Date: Sat, 23 Apr 2016 15:06:00 +0530 Message-ID: <1461404160-19612-1-git-send-email-smohammed@nvidia.com> X-Mailer: git-send-email 1.8.1.5 MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2864 Lines: 91 Initialize default channel slave_id(req_sel) to invalid id (i.e max supported slave id + 1) to avoid overwriting of slave_id during tegra_dma_slave_config() with client data if slave_id is not initialized through DT Signed-off-by: Shardar Shariff Md --- Changes from v1: - Instead of initializing the slave id to -1 define macros for max slave id and invalid slave id and do the checks accordingly. Changes from v2: - Check slave id boundary before dma channel is allocated to avoid channel leakage. - Calculate the max slave id from the CSR slave id(req sel) mask bits. Changes from v3: - Remove *MAX_SLAVD_ID macro and instead use *REQ_SEL_MASK - During tegra_dma_slave_config() check for slave_id boundary condition --- drivers/dma/tegra20-apb-dma.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) diff --git a/drivers/dma/tegra20-apb-dma.c b/drivers/dma/tegra20-apb-dma.c index 3871f29..01e316f 100644 --- a/drivers/dma/tegra20-apb-dma.c +++ b/drivers/dma/tegra20-apb-dma.c @@ -54,6 +54,7 @@ #define TEGRA_APBDMA_CSR_ONCE BIT(27) #define TEGRA_APBDMA_CSR_FLOW BIT(21) #define TEGRA_APBDMA_CSR_REQ_SEL_SHIFT 16 +#define TEGRA_APBDMA_CSR_REQ_SEL_MASK 0x1F #define TEGRA_APBDMA_CSR_WCOUNT_MASK 0xFFFC /* STATUS register */ @@ -114,6 +115,8 @@ /* Channel base address offset from APBDMA base address */ #define TEGRA_APBDMA_CHANNEL_BASE_ADD_OFFSET 0x1000 +#define TEGRA_APBDMA_SLAVE_ID_INVALID (TEGRA_APBDMA_CSR_REQ_SEL_MASK + 1) + struct tegra_dma; /* @@ -353,8 +356,11 @@ static int tegra_dma_slave_config(struct dma_chan *dc, } memcpy(&tdc->dma_sconfig, sconfig, sizeof(*sconfig)); - if (!tdc->slave_id) + if (tdc->slave_id == TEGRA_APBDMA_SLAVE_ID_INVALID) { + if (sconfig->slave_id > TEGRA_APBDMA_CSR_REQ_SEL_MASK) + return -EINVAL; tdc->slave_id = sconfig->slave_id; + } tdc->config_init = true; return 0; } @@ -1236,7 +1242,7 @@ static void tegra_dma_free_chan_resources(struct dma_chan *dc) } pm_runtime_put(tdma->dev); - tdc->slave_id = 0; + tdc->slave_id = TEGRA_APBDMA_SLAVE_ID_INVALID; } static struct dma_chan *tegra_dma_of_xlate(struct of_phandle_args *dma_spec, @@ -1246,6 +1252,11 @@ static struct dma_chan *tegra_dma_of_xlate(struct of_phandle_args *dma_spec, struct dma_chan *chan; struct tegra_dma_channel *tdc; + if (dma_spec->args[0] > TEGRA_APBDMA_CSR_REQ_SEL_MASK) { + dev_err(tdma->dev, "Invalid slave id: %d\n", dma_spec->args[0]); + return NULL; + } + chan = dma_get_any_slave_channel(&tdma->dma_dev); if (!chan) return NULL; @@ -1389,6 +1400,7 @@ static int tegra_dma_probe(struct platform_device *pdev) &tdma->dma_dev.channels); tdc->tdma = tdma; tdc->id = i; + tdc->slave_id = TEGRA_APBDMA_SLAVE_ID_INVALID; tasklet_init(&tdc->tasklet, tegra_dma_tasklet, (unsigned long)tdc); -- 1.8.1.5