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Date:   Tue, 16 May 2023 09:55:46 +0800
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Subject: Re: [PATCH] dma-contiguous: support per-numa CMA for all
 architectures
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References: <20230512094210.141540-1-yajun.deng@linux.dev>
From:   Yajun Deng <yajun.deng@linux.dev>
In-Reply-To: <20230512094210.141540-1-yajun.deng@linux.dev>
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Hello,  Barry

This patch changed the caller of dma_pernuma_cma_reserve() from

bootmem_init() to dma_contiguous_reserve(), do you think

would there be something wrong?

On 2023/5/12 17:42, Yajun Deng wrote:
> In the commit b7176c261cdb ("dma-contiguous: provide the ability to
> reserve per-numa CMA"), Barry adds DMA_PERNUMA_CMA for ARM64.
>
> But this feature is architecture independent, so support per-numa CMA
> for all architectures, and enable it by default if NUMA.
>
> Signed-off-by: Yajun Deng <yajun.deng@linux.dev>
> ---
>   Documentation/admin-guide/kernel-parameters.txt | 2 +-
>   arch/arm64/mm/init.c                            | 2 --
>   include/linux/dma-map-ops.h                     | 6 ------
>   kernel/dma/Kconfig                              | 6 +++---
>   kernel/dma/contiguous.c                         | 8 +++++++-
>   5 files changed, 11 insertions(+), 13 deletions(-)
>
> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
> index 56d9458276a6..ac0002b2e323 100644
> --- a/Documentation/admin-guide/kernel-parameters.txt
> +++ b/Documentation/admin-guide/kernel-parameters.txt
> @@ -692,7 +692,7 @@
>   			kernel/dma/contiguous.c
>   
>   	cma_pernuma=nn[MG]
> -			[ARM64,KNL,CMA]
> +			[KNL,CMA]
>   			Sets the size of kernel per-numa memory area for
>   			contiguous memory allocations. A value of 0 disables
>   			per-numa CMA altogether. And If this option is not
> diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
> index 66e70ca47680..d560aef6aafa 100644
> --- a/arch/arm64/mm/init.c
> +++ b/arch/arm64/mm/init.c
> @@ -410,8 +410,6 @@ void __init bootmem_init(void)
>   	arm64_hugetlb_cma_reserve();
>   #endif
>   
> -	dma_pernuma_cma_reserve();
> -
>   	kvm_hyp_reserve();
>   
>   	/*
> diff --git a/include/linux/dma-map-ops.h b/include/linux/dma-map-ops.h
> index 31f114f486c4..7af9949828ff 100644
> --- a/include/linux/dma-map-ops.h
> +++ b/include/linux/dma-map-ops.h
> @@ -168,12 +168,6 @@ static inline void dma_free_contiguous(struct device *dev, struct page *page,
>   }
>   #endif /* CONFIG_DMA_CMA*/
>   
> -#ifdef CONFIG_DMA_PERNUMA_CMA
> -void dma_pernuma_cma_reserve(void);
> -#else
> -static inline void dma_pernuma_cma_reserve(void) { }
> -#endif /* CONFIG_DMA_PERNUMA_CMA */
> -
>   #ifdef CONFIG_DMA_DECLARE_COHERENT
>   int dma_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr,
>   		dma_addr_t device_addr, size_t size);
> diff --git a/kernel/dma/Kconfig b/kernel/dma/Kconfig
> index 6677d0e64d27..79f83091e3a2 100644
> --- a/kernel/dma/Kconfig
> +++ b/kernel/dma/Kconfig
> @@ -140,10 +140,10 @@ if  DMA_CMA
>   
>   config DMA_PERNUMA_CMA
>   	bool "Enable separate DMA Contiguous Memory Area for each NUMA Node"
> -	default NUMA && ARM64
> +	default NUMA
>   	help
> -	  Enable this option to get pernuma CMA areas so that devices like
> -	  ARM64 SMMU can get local memory by DMA coherent APIs.
> +	  Enable this option to get pernuma CMA areas so that NUMA devices
> +	  can get local memory by DMA coherent APIs.
>   
>   	  You can set the size of pernuma CMA by specifying "cma_pernuma=size"
>   	  on the kernel's command line.
> diff --git a/kernel/dma/contiguous.c b/kernel/dma/contiguous.c
> index 6ea80ae42622..26a8e5365fcd 100644
> --- a/kernel/dma/contiguous.c
> +++ b/kernel/dma/contiguous.c
> @@ -128,7 +128,7 @@ static inline __maybe_unused phys_addr_t cma_early_percent_memory(void)
>   #endif
>   
>   #ifdef CONFIG_DMA_PERNUMA_CMA
> -void __init dma_pernuma_cma_reserve(void)
> +static void __init dma_pernuma_cma_reserve(void)
>   {
>   	int nid;
>   
> @@ -153,6 +153,10 @@ void __init dma_pernuma_cma_reserve(void)
>   			(unsigned long long)pernuma_size_bytes / SZ_1M, nid);
>   	}
>   }
> +#else
> +static inline void __init dma_pernuma_cma_reserve(void)
> +{
> +}
>   #endif
>   
>   /**
> @@ -171,6 +175,8 @@ void __init dma_contiguous_reserve(phys_addr_t limit)
>   	phys_addr_t selected_limit = limit;
>   	bool fixed = false;
>   
> +	dma_pernuma_cma_reserve();
> +
>   	pr_debug("%s(limit %08lx)\n", __func__, (unsigned long)limit);
>   
>   	if (size_cmdline != -1) {