[PATCH v2 5/9] PCI: endpoint: pci-epf-test: Simplify pci_epf_test_set_bar() loop

Niklas Cassel
2024-03-12T10:52:40Z

Simplify the loop in pci_epf_test_set_bar().
If we allocated memory for the BAR, we need to call set_bar() for that
BAR, if we did not allocated memory for that BAR, we need to skip.
It is as simple as that. This also matches the logic in
pci_epf_test_unbind().

A 64-bit BAR will still only be one allocation, with the BAR succeeding
the 64-bit BAR being null.

While at it, remove the misleading comment.
A EPC .set_bar() callback should never change the epf_bar->flags.
(E.g. to set a 64-bit BAR if we requested a 32-bit BAR.)

A .set_bar() callback should do what we request it to do.
If it can't satisfy the request, it should return an error.

If platform has a specific requirement, e.g. that a certain BAR has to
be a 64-bit BAR, then it should specify that by setting the .only_64bit
flag for that specific BAR in epc_features->bar[], such that
pci_epf_alloc_space() will return a epf_bar with the 64-bit flag set.
(Such that .set_bar() will receive a request to set a 64-bit BAR.)

Signed-off-by: Niklas Cassel <cassel@kernel.org>
---
drivers/pci/endpoint/functions/pci-epf-test.c | 18 ++++--------------
1 file changed, 4 insertions(+), 14 deletions(-)

diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c
index 20c79610712d..05b9bc1e89cd 100644
--- a/drivers/pci/endpoint/functions/pci-epf-test.c
+++ b/drivers/pci/endpoint/functions/pci-epf-test.c
@@ -709,9 +709,7 @@ static void pci_epf_test_unbind(struct pci_epf *epf)

static int pci_epf_test_set_bar(struct pci_epf *epf)
{
- int bar, add;
- int ret;
- struct pci_epf_bar *epf_bar;
+ int bar, ret;
struct pci_epc *epc = epf->epc;
struct device *dev = &epf->dev;
struct pci_epf_test *epf_test = epf_get_drvdata(epf);
@@ -720,20 +718,12 @@ static int pci_epf_test_set_bar(struct pci_epf *epf)

epc_features = epf_test->epc_features;

- for (bar = 0; bar < PCI_STD_NUM_BARS; 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->bar[bar].type == BAR_RESERVED)
+ for (bar = 0; bar < PCI_STD_NUM_BARS; bar++) {
+ if (!epf_test->reg[bar])
continue;

ret = pci_epc_set_bar(epc, epf->func_no, epf->vfunc_no,
- epf_bar);
+ &epf->bar[bar]);
if (ret) {
pci_epf_free_space(epf, epf_test->reg[bar], bar,
PRIMARY_INTERFACE);
--
2.44.0