diff options
author | Heiko Stuebner <heiko@sntech.de> | 2022-07-07 01:15:33 +0200 |
---|---|---|
committer | Palmer Dabbelt <palmer@rivosinc.com> | 2022-07-28 15:30:20 -0700 |
commit | 12b827758f51d4b614a677dd453b0e854e46aa65 (patch) | |
tree | ac1a5426c5da997208039af6bf9859f96fef889f /drivers/of | |
parent | 73448ae6204faa636292ae0d7ba8b2f6eb48179d (diff) | |
download | linux-12b827758f51d4b614a677dd453b0e854e46aa65.tar.gz linux-12b827758f51d4b614a677dd453b0e854e46aa65.tar.bz2 linux-12b827758f51d4b614a677dd453b0e854e46aa65.zip |
of: also handle dma-noncoherent in of_dma_is_coherent()
of_dma_is_coherent() currently expects the architecture to be
non-coherent and some devices being coherent getting marked
as such with the dma-coherent devicetree property.
For PowerPC CONFIG_OF_DMA_DEFAULT_COHERENT was added which currently
makes of_dma_is_coherent() always return true but doesn't handle
the case of the architecture being coherent but some devices not.
So modify the function to also check for dma-noncoherent and
set a suitable default return value. If CONFIG_OF_DMA_DEFAULT_COHERENT
is set the value starts with true and finding dma-noncoherent will
set it to false and without CONFIG_OF_DMA_DEFAULT_COHERENT, the
behaviour is reversed.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Guo Ren <guoren@kernel.org>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Link: https://lore.kernel.org/r/20220706231536.2041855-2-heiko@sntech.de
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Diffstat (limited to 'drivers/of')
-rw-r--r-- | drivers/of/address.c | 17 |
1 files changed, 10 insertions, 7 deletions
diff --git a/drivers/of/address.c b/drivers/of/address.c index 94f017d808c4..96f0a12e507c 100644 --- a/drivers/of/address.c +++ b/drivers/of/address.c @@ -1045,26 +1045,29 @@ phys_addr_t __init of_dma_get_max_cpu_address(struct device_node *np) * * It returns true if "dma-coherent" property was found * for this device in the DT, or if DMA is coherent by - * default for OF devices on the current platform. + * default for OF devices on the current platform and no + * "dma-noncoherent" property was found for this device. */ bool of_dma_is_coherent(struct device_node *np) { struct device_node *node; - - if (IS_ENABLED(CONFIG_OF_DMA_DEFAULT_COHERENT)) - return true; + bool is_coherent = IS_ENABLED(CONFIG_OF_DMA_DEFAULT_COHERENT); node = of_node_get(np); while (node) { if (of_property_read_bool(node, "dma-coherent")) { - of_node_put(node); - return true; + is_coherent = true; + break; + } + if (of_property_read_bool(node, "dma-noncoherent")) { + is_coherent = false; + break; } node = of_get_next_dma_parent(node); } of_node_put(node); - return false; + return is_coherent; } EXPORT_SYMBOL_GPL(of_dma_is_coherent); |