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Date:   Tue, 22 Jun 2021 14:02:58 -0700 (PDT)
From:   Stefano Stabellini <sstabellini@kernel.org>
To:     Claire Chang <tientzu@chromium.org>
cc:     Rob Herring <robh+dt@kernel.org>, mpe@ellerman.id.au,
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Subject: Re: [PATCH v14 01/12] swiotlb: Refactor swiotlb init functions
In-Reply-To: <20210619034043.199220-2-tientzu@chromium.org>
Message-ID: <alpine.DEB.2.21.2106221402390.24906@sstabellini-ThinkPad-T480s>
References: <20210619034043.199220-1-tientzu@chromium.org> <20210619034043.199220-2-tientzu@chromium.org>
User-Agent: Alpine 2.21 (DEB 202 2017-01-01)
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Precedence: bulk

On Sat, 19 Jun 2021, Claire Chang wrote:
> Add a new function, swiotlb_init_io_tlb_mem, for the io_tlb_mem struct
> initialization to make the code reusable.
> 
> Signed-off-by: Claire Chang <tientzu@chromium.org>
> Reviewed-by: Christoph Hellwig <hch@lst.de>
> Tested-by: Stefano Stabellini <sstabellini@kernel.org>
> Tested-by: Will Deacon <will@kernel.org>

Acked-by: Stefano Stabellini <sstabellini@kernel.org>


> ---
>  kernel/dma/swiotlb.c | 50 ++++++++++++++++++++++----------------------
>  1 file changed, 25 insertions(+), 25 deletions(-)
> 
> diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
> index 52e2ac526757..1f9b2b9e7490 100644
> --- a/kernel/dma/swiotlb.c
> +++ b/kernel/dma/swiotlb.c
> @@ -168,9 +168,28 @@ void __init swiotlb_update_mem_attributes(void)
>  	memset(vaddr, 0, bytes);
>  }
>  
> -int __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose)
> +static void swiotlb_init_io_tlb_mem(struct io_tlb_mem *mem, phys_addr_t start,
> +				    unsigned long nslabs, bool late_alloc)
>  {
> +	void *vaddr = phys_to_virt(start);
>  	unsigned long bytes = nslabs << IO_TLB_SHIFT, i;
> +
> +	mem->nslabs = nslabs;
> +	mem->start = start;
> +	mem->end = mem->start + bytes;
> +	mem->index = 0;
> +	mem->late_alloc = late_alloc;
> +	spin_lock_init(&mem->lock);
> +	for (i = 0; i < mem->nslabs; i++) {
> +		mem->slots[i].list = IO_TLB_SEGSIZE - io_tlb_offset(i);
> +		mem->slots[i].orig_addr = INVALID_PHYS_ADDR;
> +		mem->slots[i].alloc_size = 0;
> +	}
> +	memset(vaddr, 0, bytes);
> +}
> +
> +int __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose)
> +{
>  	struct io_tlb_mem *mem;
>  	size_t alloc_size;
>  
> @@ -186,16 +205,8 @@ int __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose)
>  	if (!mem)
>  		panic("%s: Failed to allocate %zu bytes align=0x%lx\n",
>  		      __func__, alloc_size, PAGE_SIZE);
> -	mem->nslabs = nslabs;
> -	mem->start = __pa(tlb);
> -	mem->end = mem->start + bytes;
> -	mem->index = 0;
> -	spin_lock_init(&mem->lock);
> -	for (i = 0; i < mem->nslabs; i++) {
> -		mem->slots[i].list = IO_TLB_SEGSIZE - io_tlb_offset(i);
> -		mem->slots[i].orig_addr = INVALID_PHYS_ADDR;
> -		mem->slots[i].alloc_size = 0;
> -	}
> +
> +	swiotlb_init_io_tlb_mem(mem, __pa(tlb), nslabs, false);
>  
>  	io_tlb_default_mem = mem;
>  	if (verbose)
> @@ -282,8 +293,8 @@ swiotlb_late_init_with_default_size(size_t default_size)
>  int
>  swiotlb_late_init_with_tbl(char *tlb, unsigned long nslabs)
>  {
> -	unsigned long bytes = nslabs << IO_TLB_SHIFT, i;
>  	struct io_tlb_mem *mem;
> +	unsigned long bytes = nslabs << IO_TLB_SHIFT;
>  
>  	if (swiotlb_force == SWIOTLB_NO_FORCE)
>  		return 0;
> @@ -297,20 +308,9 @@ swiotlb_late_init_with_tbl(char *tlb, unsigned long nslabs)
>  	if (!mem)
>  		return -ENOMEM;
>  
> -	mem->nslabs = nslabs;
> -	mem->start = virt_to_phys(tlb);
> -	mem->end = mem->start + bytes;
> -	mem->index = 0;
> -	mem->late_alloc = 1;
> -	spin_lock_init(&mem->lock);
> -	for (i = 0; i < mem->nslabs; i++) {
> -		mem->slots[i].list = IO_TLB_SEGSIZE - io_tlb_offset(i);
> -		mem->slots[i].orig_addr = INVALID_PHYS_ADDR;
> -		mem->slots[i].alloc_size = 0;
> -	}
> -
> +	memset(mem, 0, sizeof(*mem));
>  	set_memory_decrypted((unsigned long)tlb, bytes >> PAGE_SHIFT);
> -	memset(tlb, 0, bytes);
> +	swiotlb_init_io_tlb_mem(mem, virt_to_phys(tlb), nslabs, true);
>  
>  	io_tlb_default_mem = mem;
>  	swiotlb_print_info();
> -- 
> 2.32.0.288.g62a8d224e6-goog
>