[PATCH] riscv: Enable CMA support

[Kefeng Wang]

Any comments, kindly ping...

On 2020/10/31 14:01, Kefeng Wang wrote:
> riscv has selected HAVE_DMA_CONTIGUOUS, but don't call
> dma_contiguous_reserve(). let's enable CMA as expect.
>
> Signed-off-by: Kefeng Wang <wangkefeng.wang at huawei.com>
> ---
>   arch/riscv/mm/init.c | 8 ++++++--
>   1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
> index ea933b789a88..87ae4b99442a 100644
> --- a/arch/riscv/mm/init.c
> +++ b/arch/riscv/mm/init.c
> @@ -13,6 +13,7 @@
>   #include <linux/of_fdt.h>
>   #include <linux/libfdt.h>
>   #include <linux/set_memory.h>
> +#include <linux/dma-map-ops.h>
>   
>   #include <asm/fixmap.h>
>   #include <asm/tlbflush.h>
> @@ -41,13 +42,14 @@ struct pt_alloc_ops {
>   #endif
>   };
>   
> +static phys_addr_t dma32_phys_limit __ro_after_init;
> +
>   static void __init zone_sizes_init(void)
>   {
>   	unsigned long max_zone_pfns[MAX_NR_ZONES] = { 0, };
>   
>   #ifdef CONFIG_ZONE_DMA32
> -	max_zone_pfns[ZONE_DMA32] = PFN_DOWN(min(4UL * SZ_1G,
> -			(unsigned long) PFN_PHYS(max_low_pfn)));
> +	max_zone_pfns[ZONE_DMA32] = PFN_DOWN(dma32_phys_limit);
>   #endif
>   	max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
>   
> @@ -185,6 +187,7 @@ void __init setup_bootmem(void)
>   
>   	max_pfn = PFN_DOWN(memblock_end_of_DRAM());
>   	max_low_pfn = max_pfn;
> +	dma32_phys_limit = min(4UL * SZ_1G, (unsigned long)PFN_PHYS(max_low_pfn));
>   	set_max_mapnr(max_low_pfn);
>   
>   #ifdef CONFIG_BLK_DEV_INITRD
> @@ -198,6 +201,7 @@ void __init setup_bootmem(void)
>   	memblock_reserve(dtb_early_pa, fdt_totalsize(dtb_early_va));
>   
>   	early_init_fdt_scan_reserved_mem();
> +	dma_contiguous_reserve(dma32_phys_limit);
>   	memblock_allow_resize();
>   	memblock_dump_all();
>   }