Re: [PATCH 04/12] pci: epf-test: Use driver registers as volatile

[Manivannan Sadhasivam <mani@kernel.org>]

On Wed, Feb 15, 2023 at 12:21:47PM +0900, Damien Le Moal wrote:
> The pci-epf-test driver uses struct pci_epf_test_reg directly from the
> test register bar memory to execute tests cases sent by the RC side.
> Make sure to declare pci_epf_test_reg use as volatile to ensure that
> modifications to the fields of that structure make it to memory to be
> seen by the RC side on completion.
> 
> Also initialize the test register bar to 0 when it is allocated.
> 

Again, please split this into a separate commit.

Rest LGTM!

Thanks,
Mani

> Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
> ---
>  drivers/pci/endpoint/functions/pci-epf-test.c | 11 ++++++-----
>  1 file changed, 6 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c
> index 030769893efb..df3074667bbc 100644
> --- a/drivers/pci/endpoint/functions/pci-epf-test.c
> +++ b/drivers/pci/endpoint/functions/pci-epf-test.c
> @@ -340,7 +340,7 @@ static int pci_epf_test_copy(struct pci_epf_test *epf_test)
>  	struct device *dev = &epf->dev;
>  	struct pci_epc *epc = epf->epc;
>  	enum pci_barno test_reg_bar = epf_test->test_reg_bar;
> -	struct pci_epf_test_reg *reg = epf_test->reg[test_reg_bar];
> +	volatile struct pci_epf_test_reg *reg = epf_test->reg[test_reg_bar];
>  
>  	src_addr = pci_epc_mem_alloc_addr(epc, &src_phys_addr, reg->size);
>  	if (!src_addr) {
> @@ -441,7 +441,7 @@ static int pci_epf_test_read(struct pci_epf_test *epf_test)
>  	struct pci_epc *epc = epf->epc;
>  	struct device *dma_dev = epf->epc->dev.parent;
>  	enum pci_barno test_reg_bar = epf_test->test_reg_bar;
> -	struct pci_epf_test_reg *reg = epf_test->reg[test_reg_bar];
> +	volatile struct pci_epf_test_reg *reg = epf_test->reg[test_reg_bar];
>  
>  	src_addr = pci_epc_mem_alloc_addr(epc, &phys_addr, reg->size);
>  	if (!src_addr) {
> @@ -530,7 +530,7 @@ static int pci_epf_test_write(struct pci_epf_test *epf_test)
>  	struct pci_epc *epc = epf->epc;
>  	struct device *dma_dev = epf->epc->dev.parent;
>  	enum pci_barno test_reg_bar = epf_test->test_reg_bar;
> -	struct pci_epf_test_reg *reg = epf_test->reg[test_reg_bar];
> +	volatile struct pci_epf_test_reg *reg = epf_test->reg[test_reg_bar];
>  
>  	dst_addr = pci_epc_mem_alloc_addr(epc, &phys_addr, reg->size);
>  	if (!dst_addr) {
> @@ -619,7 +619,7 @@ static void pci_epf_test_raise_irq(struct pci_epf_test *epf_test, u8 irq_type,
>  	struct device *dev = &epf->dev;
>  	struct pci_epc *epc = epf->epc;
>  	enum pci_barno test_reg_bar = epf_test->test_reg_bar;
> -	struct pci_epf_test_reg *reg = epf_test->reg[test_reg_bar];
> +	volatile struct pci_epf_test_reg *reg = epf_test->reg[test_reg_bar];
>  
>  	reg->status |= STATUS_IRQ_RAISED;
>  
> @@ -653,7 +653,7 @@ static void pci_epf_test_cmd_handler(struct work_struct *work)
>  	struct device *dev = &epf->dev;
>  	struct pci_epc *epc = epf->epc;
>  	enum pci_barno test_reg_bar = epf_test->test_reg_bar;
> -	struct pci_epf_test_reg *reg = epf_test->reg[test_reg_bar];
> +	volatile struct pci_epf_test_reg *reg = epf_test->reg[test_reg_bar];
>  
>  	command = reg->command;
>  	if (!command)
> @@ -911,6 +911,7 @@ static int pci_epf_test_alloc_space(struct pci_epf *epf)
>  		dev_err(dev, "Failed to allocated register space\n");
>  		return -ENOMEM;
>  	}
> +	memset(base, 0, test_reg_size);
>  	epf_test->reg[test_reg_bar] = base;
>  
>  	for (bar = 0; bar < PCI_STD_NUM_BARS; bar += add) {
> -- 
> 2.39.1
> 

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