Re: [PATCH 2/7] cache: andes_llcache: refactor initialization and cache operations

[Conor Dooley <conor@kernel.org>]

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On Mon, Mar 30, 2026 at 06:27:19PM +0800, Hui Min Mina Chou wrote:
> This patch cleans up the Andes LLC cache driver:
>  - improved error handling in andes_cache_init() by using goto labels

I don't agree that this is an improvement. There's no meaningful
teardown shared.

>  - updated andes_dma_cache_inv/wback() to check for !size instead of
>    start == end
>  - cache-line-size mismatch from an error to a warning
>  - Use ALIGN and ALIGN_DOWN helpers instead of the alignment logic in
>    andes_dma_cache_inv() and andes_dma_cache_wback().
> 
> Signed-off-by: Hui Min Mina Chou <minachou@andestech.com>
> ---
>  drivers/cache/andes_llcache.c | 56 ++++++++++++++++++-----------------
>  1 file changed, 29 insertions(+), 27 deletions(-)
> 
> diff --git a/drivers/cache/andes_llcache.c b/drivers/cache/andes_llcache.c
> index d5e382f3c801..d318b8009f7f 100644
> --- a/drivers/cache/andes_llcache.c
> +++ b/drivers/cache/andes_llcache.c
> @@ -111,21 +111,17 @@ static void andes_dma_cache_inv(phys_addr_t paddr, size_t size)
>  {
>  	unsigned long start = (unsigned long)phys_to_virt(paddr);
>  	unsigned long end = start + size;
> -	unsigned long line_size;
> +	unsigned long line_size = andes_priv.andes_cache_line_size;
>  	unsigned long flags;
>  
> -	if (unlikely(start == end))
> +	if (unlikely(!size))
>  		return;
>  
> -	line_size = andes_priv.andes_cache_line_size;
> -
> -	start = start & (~(line_size - 1));
> -	end = ((end + line_size - 1) & (~(line_size - 1)));
> +	start = ALIGN_DOWN(start, line_size);
> +	end = ALIGN(end, line_size);
>  
>  	local_irq_save(flags);
> -
>  	andes_cpu_dcache_inval_range(start, end);
> -
>  	local_irq_restore(flags);
>  }
>  
> @@ -133,15 +129,15 @@ static void andes_dma_cache_wback(phys_addr_t paddr, size_t size)
>  {
>  	unsigned long start = (unsigned long)phys_to_virt(paddr);
>  	unsigned long end = start + size;
> -	unsigned long line_size;
> +	unsigned long line_size = andes_priv.andes_cache_line_size;
>  	unsigned long flags;
>  
> -	if (unlikely(start == end))
> +	if (unlikely(!size))
>  		return;
>  
> -	line_size = andes_priv.andes_cache_line_size;
> -	start = start & (~(line_size - 1));
> -	end = ((end + line_size - 1) & (~(line_size - 1)));
> +	start = ALIGN_DOWN(start, line_size);
> +	end = ALIGN(end, line_size);
> +
>  	local_irq_save(flags);
>  	andes_cpu_dcache_wb_range(start, end);
>  	local_irq_restore(flags);
> @@ -159,14 +155,13 @@ static int andes_get_llc_line_size(struct device_node *np)
>  
>  	ret = of_property_read_u32(np, "cache-line-size", &andes_priv.andes_cache_line_size);
>  	if (ret) {
> -		pr_err("Failed to get cache-line-size, defaulting to 64 bytes\n");
> +		pr_err("Cache: Failed to get cache-line-size\n");
>  		return ret;
>  	}
>  
>  	if (andes_priv.andes_cache_line_size != ANDES_CACHE_LINE_SIZE) {
> -		pr_err("Expected cache-line-size to be 64 bytes (found:%u)\n",
> -		       andes_priv.andes_cache_line_size);
> -		return -EINVAL;
> +		pr_warn("Cache: Expected cache-line-size to be 64 bytes (found:%u)\n",
> +			andes_priv.andes_cache_line_size);
>  	}
>  
>  	return 0;
> @@ -186,16 +181,18 @@ static const struct of_device_id andes_cache_ids[] = {
>  static int __init andes_cache_init(void)
>  {
>  	struct resource res;
> -	int ret;
> +	int ret = 0;
>  
>  	struct device_node *np __free(device_node) =
>  		of_find_matching_node(NULL, andes_cache_ids);
> -	if (!of_device_is_available(np))
> -		return -ENODEV;
> +	if (!of_device_is_available(np)) {
> +		ret = -ENODEV;
> +		goto err_ret;
> +	}
>  
>  	ret = of_address_to_resource(np, 0, &res);
>  	if (ret)
> -		return ret;
> +		goto err_ret;
>  
>  	/*
>  	 * If IOCP is present on the Andes AX45MP core riscv_cbom_block_size
> @@ -208,17 +205,22 @@ static int __init andes_cache_init(void)
>  		return 0;
>  
>  	andes_priv.llc_base = ioremap(res.start, resource_size(&res));
> -	if (!andes_priv.llc_base)
> -		return -ENOMEM;
> +	if (!andes_priv.llc_base) {
> +		ret = -ENOMEM;
> +		goto err_ret;
> +	}
>  
>  	ret = andes_get_llc_line_size(np);
> -	if (ret) {
> -		iounmap(andes_priv.llc_base);
> -		return ret;
> -	}
> +	if (ret)
> +		goto err_unmap;
>  
>  	riscv_noncoherent_register_cache_ops(&andes_cmo_ops);
>  
>  	return 0;
> +
> +err_unmap:
> +	iounmap(andes_priv.llc_base);
> +err_ret:
> +	return ret;
>  }
>  early_initcall(andes_cache_init);
> -- 
> 2.34.1
> 

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