On Fri, Mar 22, 2024 at 11:29:10AM +0100, Niklas Cassel wrote: > Hello Mani, > > On Fri, Mar 22, 2024 at 03:50:58PM +0530, Manivannan Sadhasivam wrote: > > On Wed, Mar 20, 2024 at 10:01:05AM +0100, Niklas Cassel wrote: > > > The current code uses writel()/readl(), which has an implicit memory > > > barrier for every single readl()/writel(). > > > > > > Additionally, reading 4 bytes at a time over the PCI bus is not really > > > optimal, considering that this code is running in an ioctl handler. > > > > > > Use memcpy_toio()/memcpy_fromio() for BAR tests. > > > > > > Before patch with a 4MB BAR: > > > $ time /usr/bin/pcitest -b 1 > > > BAR1: OKAY > > > real 0m 1.56s > > > > > > After patch with a 4MB BAR: > > > $ time /usr/bin/pcitest -b 1 > > > BAR1: OKAY > > > real 0m 0.54s > > > > > > Signed-off-by: Niklas Cassel <cassel@xxxxxxxxxx> > > > --- > > > Changes since v2: > > > -Actually free the allocated memory... (thank you Kuppuswamy) > > > > > > drivers/misc/pci_endpoint_test.c | 68 ++++++++++++++++++++++++++------ > > > 1 file changed, 55 insertions(+), 13 deletions(-) > > > > > > diff --git a/drivers/misc/pci_endpoint_test.c b/drivers/misc/pci_endpoint_test.c > > > index 705029ad8eb5..1d361589fb61 100644 > > > --- a/drivers/misc/pci_endpoint_test.c > > > +++ b/drivers/misc/pci_endpoint_test.c > > > @@ -272,33 +272,75 @@ static const u32 bar_test_pattern[] = { > > > 0xA5A5A5A5, > > > }; > > > > > > +static int pci_endpoint_test_bar_memcmp(struct pci_endpoint_test *test, > > > + enum pci_barno barno, int offset, > > > + void *write_buf, void *read_buf, > > > + int size) > > > +{ > > > + memset(write_buf, bar_test_pattern[barno], size); > > > + memcpy_toio(test->bar[barno] + offset, write_buf, size); > > > + > > > + memcpy_fromio(read_buf, test->bar[barno] + offset, size); > > > + > > > + return memcmp(write_buf, read_buf, size); > > > +} > > > + > > > static bool pci_endpoint_test_bar(struct pci_endpoint_test *test, > > > enum pci_barno barno) > > > { > > > - int j; > > > - u32 val; > > > - int size; > > > + int j, bar_size, buf_size, iters, remain; > > > + void *write_buf; > > > + void *read_buf; > > > struct pci_dev *pdev = test->pdev; > > > + bool ret; > > > > > > if (!test->bar[barno]) > > > return false; > > > > > > - size = pci_resource_len(pdev, barno); > > > + bar_size = pci_resource_len(pdev, barno); > > > > > > if (barno == test->test_reg_bar) > > > - size = 0x4; > > > + bar_size = 0x4; > > > > > > - for (j = 0; j < size; j += 4) > > > - pci_endpoint_test_bar_writel(test, barno, j, > > > - bar_test_pattern[barno]); > > > + buf_size = min(SZ_1M, bar_size); > > > > > > - for (j = 0; j < size; j += 4) { > > > - val = pci_endpoint_test_bar_readl(test, barno, j); > > > - if (val != bar_test_pattern[barno]) > > > - return false; > > > + write_buf = kmalloc(buf_size, GFP_KERNEL); > > > + if (!write_buf) > > > + return false; > > > + > > > + read_buf = kmalloc(buf_size, GFP_KERNEL); > > > + if (!read_buf) { > > > + ret = false; > > > + goto err; > > > > This frees read_buf also. Please fix that and also rename the labels to: > > > > err_free_write_buf > > err_free_read_buf > > This was intentional since kfree() handles NULL perfectly fine. > (I was thinking that it would just add extra lines for no good reason.) > > Do you think that there is any point in having two labels in this case? > I know that NULL is ignored, but that's not an excuse to call kfree() for non-existent memory (for code sanity). Please create separate labels. - Mani > > Kind regards, > Niklas > > > > > - Mani > > > > > } > > > > > > - return true; > > > + iters = bar_size / buf_size; > > > + for (j = 0; j < iters; j++) { > > > + if (pci_endpoint_test_bar_memcmp(test, barno, buf_size * j, > > > + write_buf, read_buf, > > > + buf_size)) { > > > + ret = false; > > > + goto err; > > > + } > > > + } > > > + > > > + remain = bar_size % buf_size; > > > + if (remain) { > > > + if (pci_endpoint_test_bar_memcmp(test, barno, buf_size * iters, > > > + write_buf, read_buf, > > > + remain)) { > > > + ret = false; > > > + goto err; > > > + } > > > + } > > > + > > > + ret = true; > > > + > > > +err: > > > + kfree(write_buf); > > > + kfree(read_buf); > > > + > > > + return ret; > > > } > > > > > > static bool pci_endpoint_test_intx_irq(struct pci_endpoint_test *test) > > > -- > > > 2.44.0 > > > > > > > -- > > மணிவண்ணன் சதாசிவம் -- மணிவண்ணன் சதாசிவம்