PCI: endpoint: pci-epf-test: Simplify pci_epf_test_set_bar() loop

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.)

Link: https://lore.kernel.org/linux-pci/20240320113157.322695-5-cassel@kernel.org
Signed-off-by: Niklas Cassel <cassel@kernel.org>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c
index 0a83a1901bb78f56ad44fb7129ccd0ae162b8411..faf347216b6bd9c68692450a88543f86adb6adf0 100644 (file)
--- a/drivers/pci/endpoint/functions/pci-epf-test.c
+++ b/drivers/pci/endpoint/functions/pci-epf-test.c
@@ -709,31 +709,18 @@ 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);
        enum pci_barno test_reg_bar = epf_test->test_reg_bar;
-       const struct pci_epc_features *epc_features;
 
-       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);