From 7631cb95056f03136c9e0a35484e8bebe7b52650 Mon Sep 17 00:00:00 2001 From: Robin Murphy Date: Wed, 3 Jul 2019 18:42:20 +0100 Subject: [PATCH] of: Make of_dma_get_range() work on bus nodes commit 951d48855d86e72e0d6de73440fe09d363168064 upstream. Since the "dma-ranges" property is only valid for a node representing a bus, of_dma_get_range() currently assumes the node passed in is a leaf representing a device, and starts the walk from its parent. In cases like PCI host controllers on typical FDT systems, however, where the PCI endpoints are probed dynamically the initial leaf node represents the 'bus' itself, and this logic means we fail to consider any "dma-ranges" describing the host bridge itself. Rework the logic such that of_dma_get_range() also works correctly starting from a bus node containing "dma-ranges". While this does mean "dma-ranges" could incorrectly be in a device leaf node, there isn't really any way in this function to ensure that a leaf node is or isn't a bus node. Signed-off-by: Robin Murphy [robh: Allow for the bus child node to still be passed in] Signed-off-by: Rob Herring Reviewed-by: Robin Murphy Reviewed-by: Nicolas Saenz Julienne Tested-by: Nicolas Saenz Julienne --- drivers/of/address.c | 44 ++++++++++++++++++-------------------------- 1 file changed, 18 insertions(+), 26 deletions(-) --- a/drivers/of/address.c +++ b/drivers/of/address.c @@ -940,47 +940,39 @@ int of_dma_get_range(struct device_node const __be32 *ranges = NULL; int len, naddr, nsize, pna; int ret = 0; + bool found_dma_ranges = false; u64 dmaaddr; - if (!node) - return -EINVAL; - - while (1) { - struct device_node *parent; - - naddr = of_n_addr_cells(node); - nsize = of_n_size_cells(node); - - parent = __of_get_dma_parent(node); - of_node_put(node); - - node = parent; - if (!node) - break; - + while (node) { ranges = of_get_property(node, "dma-ranges", &len); /* Ignore empty ranges, they imply no translation required */ if (ranges && len > 0) break; - /* - * At least empty ranges has to be defined for parent node if - * DMA is supported - */ - if (!ranges) - break; + /* Once we find 'dma-ranges', then a missing one is an error */ + if (found_dma_ranges && !ranges) { + ret = -ENODEV; + goto out; + } + found_dma_ranges = true; + + node = of_get_next_dma_parent(node); } - if (!ranges) { + if (!node || !ranges) { pr_debug("no dma-ranges found for node(%pOF)\n", np); ret = -ENODEV; goto out; } - len /= sizeof(u32); - + naddr = of_bus_n_addr_cells(node); + nsize = of_bus_n_size_cells(node); pna = of_n_addr_cells(node); + if ((len / sizeof(__be32)) % (pna + naddr + nsize)) { + ret = -EINVAL; + goto out; + } /* dma-ranges format: * DMA addr : naddr cells @@ -988,7 +980,7 @@ int of_dma_get_range(struct device_node * size : nsize cells */ dmaaddr = of_read_number(ranges, naddr); - *paddr = of_translate_dma_address(np, ranges); + *paddr = of_translate_dma_address(node, ranges + naddr); if (*paddr == OF_BAD_ADDR) { pr_err("translation of DMA address(%pad) to CPU address failed node(%pOF)\n", dma_addr, np);