From ce3aca0465e31c20ada1270ac6547ba28b610ab2 Mon Sep 17 00:00:00 2001 From: Kefeng Wang <wangkefeng.wang@huawei.com> Date: Wed, 2 Jun 2021 16:55:16 +0800 Subject: [PATCH] riscv: Only initialize swiotlb when necessary The SWIOTLB buffer is not needed unless the physical address space is beyond the limit of dma, only initialize swiotlb when swiotlb_force is true or not all system memory is DMA-able. Also move the swiotlb_init() into mem_init(). Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com> --- arch/riscv/kernel/setup.c | 5 ----- arch/riscv/mm/init.c | 8 ++++++++ 2 files changed, 8 insertions(+), 5 deletions(-) diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c index 4db4d0b5911fd..5c6d2a1fdbc74 100644 --- a/arch/riscv/kernel/setup.c +++ b/arch/riscv/kernel/setup.c @@ -17,7 +17,6 @@ #include <linux/of_fdt.h> #include <linux/of_platform.h> #include <linux/sched/task.h> -#include <linux/swiotlb.h> #include <linux/smp.h> #include <linux/efi.h> #include <linux/crash_dump.h> @@ -295,10 +294,6 @@ void __init setup_arch(char **cmdline_p) protect_kernel_linear_mapping_text_rodata(); } -#ifdef CONFIG_SWIOTLB - swiotlb_init(1); -#endif - #ifdef CONFIG_KASAN kasan_init(); #endif diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c index e7b136abf90c8..30b204546cebd 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -11,6 +11,7 @@ #include <linux/memblock.h> #include <linux/initrd.h> #include <linux/swap.h> +#include <linux/swiotlb.h> #include <linux/sizes.h> #include <linux/of_fdt.h> #include <linux/of_reserved_mem.h> @@ -109,6 +110,13 @@ void __init mem_init(void) BUG_ON(!mem_map); #endif /* CONFIG_FLATMEM */ +#ifdef CONFIG_SWIOTLB + if (swiotlb_force == SWIOTLB_FORCE || + max_pfn > PFN_DOWN(dma32_phys_limit)) + swiotlb_init(1); + else + swiotlb_force = SWIOTLB_NO_FORCE; +#endif high_memory = (void *)(__va(PFN_PHYS(max_low_pfn))); memblock_free_all(); -- GitLab