This is a note to let you know that I've just added the patch titled
RISC-V: Fix MEMREMAP_WB for systems with Svpbmt
to the 6.0-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
risc-v-fix-memremap_wb-for-systems-with-svpbmt.patch
and it can be found in the queue-6.0 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 709e5012264be30bb6e3491efbbd19de49cfad11
Author: Anup Patel <apatel@xxxxxxxxxxxxxxxx>
Date: Mon Nov 14 14:35:34 2022 +0530
RISC-V: Fix MEMREMAP_WB for systems with Svpbmt
[ Upstream commit b91676fc16cd384a81e3af52c641aa61985cc231 ]
Currently, the memremap() called with MEMREMAP_WB maps memory using
the generic ioremap() function which breaks on system with Svpbmt
because memory mapped using _PAGE_IOREMAP page attributes is treated
as strongly-ordered non-cacheable IO memory.
To address this, we implement RISC-V specific arch_memremap_wb()
which maps memory using _PAGE_KERNEL page attributes resulting in
write-back cacheable mapping on systems with Svpbmt.
Fixes: ff689fd21cb1 ("riscv: add RISC-V Svpbmt extension support")
Co-developed-by: Mayuresh Chitale <mchitale@xxxxxxxxxxxxxxxx>
Signed-off-by: Mayuresh Chitale <mchitale@xxxxxxxxxxxxxxxx>
Signed-off-by: Anup Patel <apatel@xxxxxxxxxxxxxxxx>
Acked-by: Conor Dooley <conor.dooley@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20221114090536.1662624-2-apatel@xxxxxxxxxxxxxxxx
Signed-off-by: Palmer Dabbelt <palmer@xxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/arch/riscv/include/asm/io.h b/arch/riscv/include/asm/io.h
index 92080a227937..42497d487a17 100644
--- a/arch/riscv/include/asm/io.h
+++ b/arch/riscv/include/asm/io.h
@@ -135,4 +135,9 @@ __io_writes_outs(outs, u64, q, __io_pbr(), __io_paw())
#include <asm-generic/io.h>
+#ifdef CONFIG_MMU
+#define arch_memremap_wb(addr, size) \
+ ((__force void *)ioremap_prot((addr), (size), _PAGE_KERNEL))
+#endif
+
#endif /* _ASM_RISCV_IO_H */
