Re: [PATCH v2] PCI: endpoint: Skip odd BAR when skipping 64bit BAR

From: Alan Mikhak
Date: Thu May 23 2019 - 19:58:13 EST


+Bjorn Helgaas, +Gustavo Pimentel, +Wen Yang, +Kangjie Lu

On Thu, May 23, 2019 at 2:55 PM Alan Mikhak <alan.mikhak@xxxxxxxxxx> wrote:
>
> Always skip odd bar when skipping 64bit BARs in pci_epf_test_set_bar()
> and pci_epf_test_alloc_space().
>
> Otherwise, pci_epf_test_set_bar() will call pci_epc_set_bar() on odd loop
> index when skipping reserved 64bit BAR. Moreover, pci_epf_test_alloc_space()
> will call pci_epf_alloc_space() on bind for odd loop index when BAR is 64bit
> but leaks on subsequent unbind by not calling pci_epf_free_space().
>
> Signed-off-by: Alan Mikhak <alan.mikhak@xxxxxxxxxx>
> Reviewed-by: Paul Walmsley <paul.walmsley@xxxxxxxxxx>
> ---
> drivers/pci/endpoint/functions/pci-epf-test.c | 25 ++++++++++++-------------
> 1 file changed, 12 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c
> index 27806987e93b..96156a537922 100644
> --- a/drivers/pci/endpoint/functions/pci-epf-test.c
> +++ b/drivers/pci/endpoint/functions/pci-epf-test.c
> @@ -389,7 +389,7 @@ static void pci_epf_test_unbind(struct pci_epf *epf)
>
> static int pci_epf_test_set_bar(struct pci_epf *epf)
> {
> - int bar;
> + int bar, add;
> int ret;
> struct pci_epf_bar *epf_bar;
> struct pci_epc *epc = epf->epc;
> @@ -400,8 +400,14 @@ static int pci_epf_test_set_bar(struct pci_epf *epf)
>
> epc_features = epf_test->epc_features;
>
> - for (bar = BAR_0; bar <= BAR_5; bar++) {
> + for (bar = BAR_0; bar <= BAR_5; bar += add) {
> epf_bar = &epf->bar[bar];
> + /*
> + * pci_epc_set_bar() sets PCI_BASE_ADDRESS_MEM_TYPE_64
> + * if the specific implementation required a 64-bit BAR,
> + * even if we only requested a 32-bit BAR.
> + */
> + add = (epf_bar->flags & PCI_BASE_ADDRESS_MEM_TYPE_64) ? 2 : 1;
>
> if (!!(epc_features->reserved_bar & (1 << bar)))
> continue;
> @@ -413,13 +419,6 @@ static int pci_epf_test_set_bar(struct pci_epf *epf)
> if (bar == test_reg_bar)
> return ret;
> }
> - /*
> - * pci_epc_set_bar() sets PCI_BASE_ADDRESS_MEM_TYPE_64
> - * if the specific implementation required a 64-bit BAR,
> - * even if we only requested a 32-bit BAR.
> - */
> - if (epf_bar->flags & PCI_BASE_ADDRESS_MEM_TYPE_64)
> - bar++;
> }
>
> return 0;
> @@ -431,7 +430,7 @@ static int pci_epf_test_alloc_space(struct pci_epf *epf)
> struct device *dev = &epf->dev;
> struct pci_epf_bar *epf_bar;
> void *base;
> - int bar;
> + int bar, add;
> enum pci_barno test_reg_bar = epf_test->test_reg_bar;
> const struct pci_epc_features *epc_features;
>
> @@ -445,8 +444,10 @@ static int pci_epf_test_alloc_space(struct pci_epf *epf)
> }
> epf_test->reg[test_reg_bar] = base;
>
> - for (bar = BAR_0; bar <= BAR_5; bar++) {
> + for (bar = BAR_0; bar <= BAR_5; bar += add) {
> epf_bar = &epf->bar[bar];
> + add = (epf_bar->flags & PCI_BASE_ADDRESS_MEM_TYPE_64) ? 2 : 1;
> +
> if (bar == test_reg_bar)
> continue;
>
> @@ -459,8 +460,6 @@ static int pci_epf_test_alloc_space(struct pci_epf *epf)
> dev_err(dev, "Failed to allocate space for BAR%d\n",
> bar);
> epf_test->reg[bar] = base;
> - if (epf_bar->flags & PCI_BASE_ADDRESS_MEM_TYPE_64)
> - bar++;
> }
>
> return 0;
> --
> 2.7.4
>