From: Heiko Stuebner <heiko@sntech.de>
To: palmer@dabbelt.com, paul.walmsley@sifive.com
Cc: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org,
wefu@redhat.com, guoren@kernel.org, cmuellner@linux.com,
philipp.tomsich@vrull.eu, hch@lst.de, samuel@sholland.org,
atishp@atishpatra.org, anup@brainfault.org, mick@ics.forth.gr,
robh+dt@kernel.org, krzk+dt@kernel.org,
devicetree@vger.kernel.org, drew@beagleboard.org,
rdunlap@infradead.org, Heiko Stuebner <heiko@sntech.de>
Subject: [PATCH 1/4] of: also handle dma-noncoherent in of_dma_is_coherent()
Date: Sun, 19 Jun 2022 22:32:09 +0200 [thread overview]
Message-ID: <20220619203212.3604485-2-heiko@sntech.de> (raw)
In-Reply-To: <20220619203212.3604485-1-heiko@sntech.de>
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.
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
---
drivers/of/address.c | 16 +++++++++++-----
1 file changed, 11 insertions(+), 5 deletions(-)
diff --git a/drivers/of/address.c b/drivers/of/address.c
index 94f017d808c4..1c362d09983d 100644
--- a/drivers/of/address.c
+++ b/drivers/of/address.c
@@ -1045,26 +1045,32 @@ 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;
+ bool ret = false;
if (IS_ENABLED(CONFIG_OF_DMA_DEFAULT_COHERENT))
- return true;
+ ret = true;
node = of_node_get(np);
while (node) {
if (of_property_read_bool(node, "dma-coherent")) {
- of_node_put(node);
- return true;
+ ret = true;
+ break;
+ }
+ if (of_property_read_bool(node, "dma-noncoherent")) {
+ ret = false;
+ break;
}
node = of_get_next_dma_parent(node);
}
of_node_put(node);
- return false;
+ return ret;
}
EXPORT_SYMBOL_GPL(of_dma_is_coherent);
--
2.35.1
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next prev parent reply other threads:[~2022-06-19 20:32 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-06-19 20:32 [PATCH v4 0/4] riscv: implement Zicbom-based CMO instructions + the t-head variant Heiko Stuebner
2022-06-19 20:32 ` Heiko Stuebner [this message]
2022-06-20 6:01 ` [PATCH 1/4] of: also handle dma-noncoherent in of_dma_is_coherent() Christoph Hellwig
2022-06-20 16:33 ` Atish Patra
2022-06-20 18:11 ` Heiko Stuebner
2022-06-20 19:41 ` Atish Patra
2022-06-19 20:32 ` [PATCH 2/4] dt-bindings: riscv: document cbom-block-size Heiko Stuebner
2022-06-19 20:32 ` [PATCH 3/4] riscv: Implement Zicbom-based cache management operations Heiko Stuebner
2022-06-20 6:16 ` Christoph Hellwig
2022-06-24 7:49 ` Heiko Stuebner
2022-06-19 20:32 ` [PATCH 4/4] riscv: implement cache-management errata for T-Head SoCs Heiko Stuebner
2022-06-29 1:29 ` Samuel Holland
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