[PATCH 6.1 0678/1146] RISC-V: Fix MEMREMAP_WB for systems with Svpbmt

Greg Kroah-Hartman
2022-12-28T16:25:41Z

From: Anup Patel <apatel@ventanamicro.com>

[ 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@ventanamicro.com>
Signed-off-by: Mayuresh Chitale <mchitale@ventanamicro.com>
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20221114090536.1662624-2-apatel@ventanamicro.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/riscv/include/asm/io.h | 5 +++++
1 file changed, 5 insertions(+)

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 */
--
2.35.1