[cip-dev] [RFC PATCH 4.19.y-cip 20/50] PCI: endpoint: Skip odd BAR when skipping 64bit BAR

Lad Prabhakar
2020-10-12T14:20:34Z

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From: Alan Mikhak <alan.mikhak@sifive.com>

commit 3041a643613a2530ade35a9ae97709a9da4c0c72 upstream.

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 an odd loop index when skipping reserved 64bit
BAR.

Moreover, pci_epf_test_alloc_space() will call pci_epf_alloc_space() on
bind for an 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@sifive.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Kishon Vijay Abraham I <kishon@ti.com>
Reviewed-by: Paul Walmsley <paul.walmsley@sifive.com>
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
---
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 7d41e6684b87..e8bcc924dbf8 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;
size_t test_reg_size;
@@ -451,8 +450,10 @@ 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;

@@ -465,8 +466,6 @@ 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;
--
2.17.1

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