Convert the separately-allocated lch_map pointer array to a C99 flexible array member at the end of struct omap_dmadev and annotate it with __counted_by(lch_count). The probe is reordered so platform_data lookup and the lch_count determination happen before the parent allocation, letting struct_size() size the FAM and the dedicated devm_kcalloc() for lch_map go away.
Two allocations collapse into one and the runtime bounds checks from __counted_by now apply to every lch_map[] access. Assisted-by: Claude:Opus-4.7 Signed-off-by: Rosen Penev <[email protected]> --- drivers/dma/ti/omap-dma.c | 68 +++++++++++++++++++-------------------- 1 file changed, 33 insertions(+), 35 deletions(-) diff --git a/drivers/dma/ti/omap-dma.c b/drivers/dma/ti/omap-dma.c index 55ece7fd0d99..901e38b08962 100644 --- a/drivers/dma/ti/omap-dma.c +++ b/drivers/dma/ti/omap-dma.c @@ -57,7 +57,7 @@ struct omap_dmadev { unsigned dma_requests; spinlock_t irq_lock; uint32_t irq_enable_mask; - struct omap_chan **lch_map; + struct omap_chan *lch_map[] __counted_by(lch_count); }; struct omap_chan { @@ -1656,36 +1656,53 @@ static const struct omap_dma_config default_cfg; static int omap_dma_probe(struct platform_device *pdev) { const struct omap_dma_config *conf; + struct omap_system_dma_plat_info *plat; struct omap_dmadev *od; + int lch_count; int rc, i, irq; u32 val; - od = devm_kzalloc(&pdev->dev, sizeof(*od), GFP_KERNEL); - if (!od) - return -ENOMEM; - - od->base = devm_platform_ioremap_resource(pdev, 0); - if (IS_ERR(od->base)) - return PTR_ERR(od->base); - conf = of_device_get_match_data(&pdev->dev); if (conf) { - od->cfg = conf; - od->plat = dev_get_platdata(&pdev->dev); - if (!od->plat) { + plat = dev_get_platdata(&pdev->dev); + if (!plat) { dev_err(&pdev->dev, "omap_system_dma_plat_info is missing"); return -ENODEV; } } else if (IS_ENABLED(CONFIG_ARCH_OMAP1)) { - od->cfg = &default_cfg; - - od->plat = omap_get_plat_info(); - if (!od->plat) + plat = omap_get_plat_info(); + if (!plat) return -EPROBE_DEFER; } else { return -ENODEV; } + /* Number of available logical channels */ + if (!pdev->dev.of_node) { + lch_count = plat->dma_attr->lch_count; + if (unlikely(!lch_count)) + lch_count = OMAP_SDMA_CHANNELS; + } else if (of_property_read_u32(pdev->dev.of_node, "dma-channels", + &lch_count)) { + dev_info(&pdev->dev, + "Missing dma-channels property, using %u.\n", + OMAP_SDMA_CHANNELS); + lch_count = OMAP_SDMA_CHANNELS; + } + + od = devm_kzalloc(&pdev->dev, struct_size(od, lch_map, lch_count), + GFP_KERNEL); + if (!od) + return -ENOMEM; + + od->lch_count = lch_count; + od->plat = plat; + od->cfg = conf ? conf : &default_cfg; + + od->base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(od->base)) + return PTR_ERR(od->base); + od->reg_map = od->plat->reg_map; dma_cap_set(DMA_SLAVE, od->ddev.cap_mask); @@ -1730,19 +1747,6 @@ static int omap_dma_probe(struct platform_device *pdev) OMAP_SDMA_REQUESTS); } - /* Number of available logical channels */ - if (!pdev->dev.of_node) { - od->lch_count = od->plat->dma_attr->lch_count; - if (unlikely(!od->lch_count)) - od->lch_count = OMAP_SDMA_CHANNELS; - } else if (of_property_read_u32(pdev->dev.of_node, "dma-channels", - &od->lch_count)) { - dev_info(&pdev->dev, - "Missing dma-channels property, using %u.\n", - OMAP_SDMA_CHANNELS); - od->lch_count = OMAP_SDMA_CHANNELS; - } - /* Mask of allowed logical channels */ if (pdev->dev.of_node && !of_property_read_u32(pdev->dev.of_node, "dma-channel-mask", @@ -1754,12 +1758,6 @@ static int omap_dma_probe(struct platform_device *pdev) if (od->plat->dma_attr->dev_caps & HS_CHANNELS_RESERVED) bitmap_set(od->lch_bitmap, 0, 2); - od->lch_map = devm_kcalloc(&pdev->dev, od->lch_count, - sizeof(*od->lch_map), - GFP_KERNEL); - if (!od->lch_map) - return -ENOMEM; - for (i = 0; i < od->dma_requests; i++) { rc = omap_dma_chan_init(od); if (rc) { -- 2.54.0
