diff options
| author | Jisheng Zhang <jszhang@kernel.org> | 2023-07-18 23:22:14 +0800 |
|---|---|---|
| committer | Palmer Dabbelt <palmer@rivosinc.com> | 2023-08-23 14:22:01 -0700 |
| commit | f51f7a0fc2f4a6cd786327f485e5aba4c9006866 (patch) | |
| tree | 2bc04d008963fe585807fb0fa3677ba727fea746 /arch/riscv | |
| parent | 2926715163cfacea481d218f9151d091f5c0c27a (diff) | |
riscv: enable DMA_BOUNCE_UNALIGNED_KMALLOC for !dma_coherent
With the DMA bouncing of unaligned kmalloc() buffers now in place,
enable it for riscv when RISCV_DMA_NONCOHERENT=y to allow the
kmalloc-{8,16,32,96} caches. Since RV32 doesn't enable SWIOTLB
yet, and I didn't see any dma noncoherent RV32 platforms in the
mainline, so skip RV32 now by only enabling
DMA_BOUNCE_UNALIGNED_KMALLOC if SWIOTLB is available. Once we see
such requirement on RV32, we can enable it then.
NOTE: we didn't force to create the swiotlb buffer even when the
end of RAM is within the 32-bit physical address range. That's to
say:
For RV64 with > 4GB memory, the feature is enabled.
For RV64 with <= 4GB memory, the feature isn't enabled by default. We
rely on users to pass "swiotlb=mmnn,force" where mmnn is the Number of
I/O TLB slabs, see kernel-parameters.txt for details.
Tested on Sipeed Lichee Pi 4A with 8GB DDR and Sipeed M1S BL808 Dock
board.
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20230718152214.2907-3-jszhang@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Diffstat (limited to 'arch/riscv')
| -rw-r--r-- | arch/riscv/Kconfig | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index 4c07b9189c86..6681bd6ed2d7 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -267,6 +267,7 @@ config RISCV_DMA_NONCOHERENT select ARCH_HAS_SETUP_DMA_OPS select ARCH_HAS_SYNC_DMA_FOR_CPU select ARCH_HAS_SYNC_DMA_FOR_DEVICE + select DMA_BOUNCE_UNALIGNED_KMALLOC if SWIOTLB select DMA_DIRECT_REMAP config AS_HAS_INSN |