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<title>kernel/linux.git/drivers/cache/ax45mp_cache.c, branch v6.6.132</title>
<subtitle>Linux kernel stable tree (mirror)</subtitle>
<id>https://git.radix-linux.su/kernel/linux.git/atom?h=v6.6.132</id>
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<updated>2026-03-25T10:06:05+00:00</updated>
<entry>
<title>cache: ax45mp: Fix device node reference leak in ax45mp_cache_init()</title>
<updated>2026-03-25T10:06:05+00:00</updated>
<author>
<name>Felix Gu</name>
<email>ustc.gu@gmail.com</email>
</author>
<published>2026-01-30T17:49:09+00:00</published>
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<id>urn:sha1:d0a466caf4ace74188db9d22d26a097b3e600bcc</id>
<content type='text'>
[ Upstream commit 0528a348b04b327a4611e29589beb4c9ae81304a ]

In ax45mp_cache_init(), of_find_matching_node() returns a device node
with an incremented reference count that must be released with
of_node_put(). The current code fails to call of_node_put() which
causes a reference leak.

Use the __free(device_node) attribute to ensure automatic cleanup when
the variable goes out of scope.

Fixes: d34599bcd2e4 ("cache: Add L2 cache management for Andes AX45MP RISC-V core")
Signed-off-by: Felix Gu &lt;ustc.gu@gmail.com&gt;
Signed-off-by: Conor Dooley &lt;conor.dooley@microchip.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>cache: ax45mp_cache: Align end size to cache boundary in ax45mp_dma_cache_wback()</title>
<updated>2024-03-01T12:35:08+00:00</updated>
<author>
<name>Lad Prabhakar</name>
<email>prabhakar.mahadev-lad.rj@bp.renesas.com</email>
</author>
<published>2024-02-03T21:26:40+00:00</published>
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<id>urn:sha1:50b30655b2246ac21352d2ae5ea4690e75cecf37</id>
<content type='text'>
[ Upstream commit 9bd405c48b0ac4de087c0c4440fd79597201b8a7 ]

Align the end size to cache boundary size in ax45mp_dma_cache_wback()
callback likewise done in ax45mp_dma_cache_inv() callback.

Additionally return early in case of start == end.

Fixes: d34599bcd2e4 ("cache: Add L2 cache management for Andes AX45MP RISC-V core")
Reported-by: Pavel Machek &lt;pavel@denx.de&gt;
Link: https://lore.kernel.org/cip-dev/ZYsdKDiw7G+kxQ3m@duo.ucw.cz/
Signed-off-by: Lad Prabhakar &lt;prabhakar.mahadev-lad.rj@bp.renesas.com&gt;
Signed-off-by: Conor Dooley &lt;conor.dooley@microchip.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>cache: Add L2 cache management for Andes AX45MP RISC-V core</title>
<updated>2023-09-01T16:08:59+00:00</updated>
<author>
<name>Lad Prabhakar</name>
<email>prabhakar.mahadev-lad.rj@bp.renesas.com</email>
</author>
<published>2023-08-18T13:57:22+00:00</published>
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<id>urn:sha1:d34599bcd2e4e93a28d5904bf94bc7dafc511f04</id>
<content type='text'>
I/O Coherence Port (IOCP) provides an AXI interface for connecting
external non-caching masters, such as DMA controllers. The accesses
from IOCP are coherent with D-Caches and L2 Cache.

IOCP is a specification option and is disabled on the Renesas RZ/Five
SoC due to this reason IP blocks using DMA will fail.

The Andes AX45MP core has a Programmable Physical Memory Attributes (PMA)
block that allows dynamic adjustment of memory attributes in the runtime.
It contains a configurable amount of PMA entries implemented as CSR
registers to control the attributes of memory locations in interest.
Below are the memory attributes supported:
* Device, Non-bufferable
* Device, bufferable
* Memory, Non-cacheable, Non-bufferable
* Memory, Non-cacheable, Bufferable
* Memory, Write-back, No-allocate
* Memory, Write-back, Read-allocate
* Memory, Write-back, Write-allocate
* Memory, Write-back, Read and Write-allocate

More info about PMA (section 10.3):
Link: http://www.andestech.com/wp-content/uploads/AX45MP-1C-Rev.-5.0.0-Datasheet.pdf

As a workaround for SoCs with IOCP disabled CMO needs to be handled by
software. Firstly OpenSBI configures the memory region as
"Memory, Non-cacheable, Bufferable" and passes this region as a global
shared dma pool as a DT node. With DMA_GLOBAL_POOL enabled all DMA
allocations happen from this region and synchronization callbacks are
implemented to synchronize when doing DMA transactions.

Example PMA region passes as a DT node from OpenSBI:
    reserved-memory {
        #address-cells = &lt;2&gt;;
        #size-cells = &lt;2&gt;;
        ranges;

        pma_resv0@58000000 {
            compatible = "shared-dma-pool";
            reg = &lt;0x0 0x58000000 0x0 0x08000000&gt;;
            no-map;
            linux,dma-default;
        };
    };

Signed-off-by: Lad Prabhakar &lt;prabhakar.mahadev-lad.rj@bp.renesas.com&gt;
Reviewed-by: Conor Dooley &lt;conor.dooley@microchip.com&gt;
Tested-by: Conor Dooley &lt;conor.dooley@microchip.com&gt; # tyre-kicking on a d1
Link: https://lore.kernel.org/r/20230818135723.80612-6-prabhakar.mahadev-lad.rj@bp.renesas.com
Signed-off-by: Palmer Dabbelt &lt;palmer@rivosinc.com&gt;
</content>
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