Re: [PATCH v2 11/16] PCI: epf-test: Simplify dma support checks

[Manivannan Sadhasivam <mani@kernel.org>]

On Wed, Mar 08, 2023 at 06:03:08PM +0900, Damien Le Moal wrote:
> There is no need to have each read, write and copy test functions check
> for the FLAG_USE_DMA flag against the dma support status indicated by
> epf_test->dma_supported. Move this test to the command handler function
> pci_epf_test_cmd_handler() to check once for all cases.
> 
> Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>

Reviewed-by: Manivannan Sadhasivam <mani@kernel.org>

Thanks,
Mani

> ---
>  drivers/pci/endpoint/functions/pci-epf-test.c | 45 +++++++------------
>  1 file changed, 15 insertions(+), 30 deletions(-)
> 
> diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c
> index d1b5441391fb..eaa252a170a2 100644
> --- a/drivers/pci/endpoint/functions/pci-epf-test.c
> +++ b/drivers/pci/endpoint/functions/pci-epf-test.c
> @@ -331,7 +331,6 @@ static int pci_epf_test_copy(struct pci_epf_test *epf_test,
>  			     struct pci_epf_test_reg *reg)
>  {
>  	int ret;
> -	bool use_dma;
>  	void __iomem *src_addr;
>  	void __iomem *dst_addr;
>  	phys_addr_t src_phys_addr;
> @@ -374,14 +373,7 @@ static int pci_epf_test_copy(struct pci_epf_test *epf_test,
>  	}
>  
>  	ktime_get_ts64(&start);
> -	use_dma = !!(reg->flags & FLAG_USE_DMA);
> -	if (use_dma) {
> -		if (!epf_test->dma_supported) {
> -			dev_err(dev, "Cannot transfer data using DMA\n");
> -			ret = -EINVAL;
> -			goto err_map_addr;
> -		}
> -
> +	if (reg->flags & FLAG_USE_DMA) {
>  		if (epf_test->dma_private) {
>  			dev_err(dev, "Cannot transfer data using DMA\n");
>  			ret = -EINVAL;
> @@ -407,7 +399,8 @@ static int pci_epf_test_copy(struct pci_epf_test *epf_test,
>  		kfree(buf);
>  	}
>  	ktime_get_ts64(&end);
> -	pci_epf_test_print_rate("COPY", reg->size, &start, &end, use_dma);
> +	pci_epf_test_print_rate("COPY", reg->size, &start, &end,
> +				reg->flags & FLAG_USE_DMA);
>  
>  err_map_addr:
>  	pci_epc_unmap_addr(epc, epf->func_no, epf->vfunc_no, dst_phys_addr);
> @@ -432,7 +425,6 @@ static int pci_epf_test_read(struct pci_epf_test *epf_test,
>  	void __iomem *src_addr;
>  	void *buf;
>  	u32 crc32;
> -	bool use_dma;
>  	phys_addr_t phys_addr;
>  	phys_addr_t dst_phys_addr;
>  	struct timespec64 start, end;
> @@ -463,14 +455,7 @@ static int pci_epf_test_read(struct pci_epf_test *epf_test,
>  		goto err_map_addr;
>  	}
>  
> -	use_dma = !!(reg->flags & FLAG_USE_DMA);
> -	if (use_dma) {
> -		if (!epf_test->dma_supported) {
> -			dev_err(dev, "Cannot transfer data using DMA\n");
> -			ret = -EINVAL;
> -			goto err_dma_map;
> -		}
> -
> +	if (reg->flags & FLAG_USE_DMA) {
>  		dst_phys_addr = dma_map_single(dma_dev, buf, reg->size,
>  					       DMA_FROM_DEVICE);
>  		if (dma_mapping_error(dma_dev, dst_phys_addr)) {
> @@ -495,7 +480,8 @@ static int pci_epf_test_read(struct pci_epf_test *epf_test,
>  		ktime_get_ts64(&end);
>  	}
>  
> -	pci_epf_test_print_rate("READ", reg->size, &start, &end, use_dma);
> +	pci_epf_test_print_rate("READ", reg->size, &start, &end,
> +				reg->flags & FLAG_USE_DMA);
>  
>  	crc32 = crc32_le(~0, buf, reg->size);
>  	if (crc32 != reg->checksum)
> @@ -520,7 +506,6 @@ static int pci_epf_test_write(struct pci_epf_test *epf_test,
>  	int ret;
>  	void __iomem *dst_addr;
>  	void *buf;
> -	bool use_dma;
>  	phys_addr_t phys_addr;
>  	phys_addr_t src_phys_addr;
>  	struct timespec64 start, end;
> @@ -554,14 +539,7 @@ static int pci_epf_test_write(struct pci_epf_test *epf_test,
>  	get_random_bytes(buf, reg->size);
>  	reg->checksum = crc32_le(~0, buf, reg->size);
>  
> -	use_dma = !!(reg->flags & FLAG_USE_DMA);
> -	if (use_dma) {
> -		if (!epf_test->dma_supported) {
> -			dev_err(dev, "Cannot transfer data using DMA\n");
> -			ret = -EINVAL;
> -			goto err_dma_map;
> -		}
> -
> +	if (reg->flags & FLAG_USE_DMA) {
>  		src_phys_addr = dma_map_single(dma_dev, buf, reg->size,
>  					       DMA_TO_DEVICE);
>  		if (dma_mapping_error(dma_dev, src_phys_addr)) {
> @@ -588,7 +566,8 @@ static int pci_epf_test_write(struct pci_epf_test *epf_test,
>  		ktime_get_ts64(&end);
>  	}
>  
> -	pci_epf_test_print_rate("WRITE", reg->size, &start, &end, use_dma);
> +	pci_epf_test_print_rate("WRITE", reg->size, &start, &end,
> +				reg->flags & FLAG_USE_DMA);
>  
>  	/*
>  	 * wait 1ms inorder for the write to complete. Without this delay L3
> @@ -673,6 +652,12 @@ static void pci_epf_test_cmd_handler(struct work_struct *work)
>  	WRITE_ONCE(reg->command, 0);
>  	WRITE_ONCE(reg->status, 0);
>  
> +	if ((READ_ONCE(reg->flags) & FLAG_USE_DMA) &&
> +	    !epf_test->dma_supported) {
> +		dev_err(dev, "Cannot transfer data using DMA\n");
> +		goto reset_handler;
> +	}
> +
>  	if (reg->irq_type > IRQ_TYPE_MSIX) {
>  		dev_err(dev, "Failed to detect IRQ type\n");
>  		goto reset_handler;
> -- 
> 2.39.2
> 

-- 
மணிவண்ணன் சதாசிவம்