DMA_DIRECT_REMAP allows the kernel to make pages coherent for DMA by remapping them in the page tables with a different pgprot_t value. On RISC-V, this is supported by the page-based memory type extensions (Svpbmt and Xtheadmae). It is independent from the software cache maintenance extensions (Zicbom and Xtheadcmo). Signed-off-by: Samuel Holland --- Changes in v3: - New patch for v3 arch/riscv/Kconfig | 2 +- arch/riscv/Kconfig.errata | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index fadec20b87a8..cf5a4b5cdcd4 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -598,6 +598,7 @@ config RISCV_ISA_SVPBMT depends on 64BIT && MMU depends on RISCV_ALTERNATIVE default y + select DMA_DIRECT_REMAP help Add support for the Svpbmt ISA-extension (Supervisor-mode: page-based memory types) in the kernel when it is detected at boot. @@ -811,7 +812,6 @@ config RISCV_ISA_ZICBOM depends on RISCV_ALTERNATIVE default y select RISCV_DMA_NONCOHERENT - select DMA_DIRECT_REMAP help Add support for the Zicbom extension (Cache Block Management Operations) and enable its use in the kernel when it is detected diff --git a/arch/riscv/Kconfig.errata b/arch/riscv/Kconfig.errata index aca9b0cfcfec..46a353a266e5 100644 --- a/arch/riscv/Kconfig.errata +++ b/arch/riscv/Kconfig.errata @@ -108,6 +108,7 @@ config ERRATA_THEAD config ERRATA_THEAD_MAE bool "Apply T-Head's memory attribute extension (XTheadMae) errata" depends on ERRATA_THEAD && 64BIT && MMU + select DMA_DIRECT_REMAP select RISCV_ALTERNATIVE_EARLY default y help @@ -119,7 +120,6 @@ config ERRATA_THEAD_MAE config ERRATA_THEAD_CMO bool "Apply T-Head cache management errata" depends on ERRATA_THEAD && MMU - select DMA_DIRECT_REMAP select RISCV_DMA_NONCOHERENT select RISCV_NONSTANDARD_CACHE_OPS default y -- 2.47.2