diff options
| author |   Rob Herring <robh@kernel.org> | 2020-02-06 14:26:40 +0000 |
|---|---|---|
| committer | Rob Herring <robh@kernel.org> | 2020-02-14 15:27:08 -0600 |
| commit | 9d55bebd9816903b821a403a69a94190442ac043 (patch) | |
| tree | a48b5eb8dea1012bc225b62e0445595b89e5508a /drivers/of | |
| parent | of/address: use range parser for of_dma_get_range (diff) | |
| download | wireguard-linux-9d55bebd9816903b821a403a69a94190442ac043.tar.xz wireguard-linux-9d55bebd9816903b821a403a69a94190442ac043.zip | |
of/address: Support multiple 'dma-ranges' entries
Currently, the DMA offset and mask for a device are set based only on the
first 'dma-ranges' entry. We should really be using all the entries. The
kernel doesn't yet support multiple offsets and sizes, so the best we can
do is to find the biggest size for a single offset. The algorithm is
copied from acpi_dma_get_range().
If there's different offsets from the first entry, then we warn and
continue. It really should be an error, but this will likely break
existing DTs.
Signed-off-by: Rob Herring <robh@kernel.org>
Diffstat (limited to 'drivers/of')
| -rw-r--r-- | drivers/of/address.c | 28 |
1 files changed, 24 insertions, 4 deletions
diff --git a/drivers/of/address.c b/drivers/of/address.c index a2c45812a50e..8eea3f6e29a4 100644 --- a/drivers/of/address.c +++ b/drivers/of/address.c @@ -944,6 +944,7 @@ int of_dma_get_range(struct device_node *np, u64 *dma_addr, u64 *paddr, u64 *siz bool found_dma_ranges = false; struct of_range_parser parser; struct of_range range; + u64 dma_start = U64_MAX, dma_end = 0, dma_offset = 0; while (node) { ranges = of_get_property(node, "dma-ranges", &len); @@ -974,14 +975,33 @@ int of_dma_get_range(struct device_node *np, u64 *dma_addr, u64 *paddr, u64 *siz pr_debug("dma_addr(%llx) cpu_addr(%llx) size(%llx)\n", range.bus_addr, range.cpu_addr, range.size); - *dma_addr = range.bus_addr; - *paddr = range.cpu_addr; - *size = range.size; + if (dma_offset && range.cpu_addr - range.bus_addr != dma_offset) { + pr_warn("Can't handle multiple dma-ranges with different offsets on node(%pOF)\n", node); + /* Don't error out as we'd break some existing DTs */ + continue; + } + dma_offset = range.cpu_addr - range.bus_addr; + + /* Take lower and upper limits */ + if (range.bus_addr < dma_start) + dma_start = range.bus_addr; + if (range.bus_addr + range.size > dma_end) + dma_end = range.bus_addr + range.size; + } + if (dma_start >= dma_end) { + ret = -EINVAL; + pr_debug("Invalid DMA ranges configuration on node(%pOF)\n", + node); goto out; } - pr_err("translation of DMA ranges failed on node(%pOF)\n", np); + *dma_addr = dma_start; + *size = dma_end - dma_start; + *paddr = dma_start + dma_offset; + + pr_debug("final: dma_addr(%llx) cpu_addr(%llx) size(%llx)\n", + *dma_addr, *paddr, *size); out: of_node_put(node); |