PCI: endpoint: pci-epf-test: Make use of cached 'epc_features' in pci_epf_test_core_i...

Instead of getting the epc_features from pci_epc_get_features() API, use
the cached pci_epf_test::epc_features value to avoid the NULL check. Since
the NULL check is already performed in pci_epf_test_bind(), having one more
check in pci_epf_test_core_init() is redundant and it is not possible to
hit the NULL pointer dereference.

Also with commit a01e7214bef9 ("PCI: endpoint: Remove "core_init_notifier"
flag"), 'epc_features' got dereferenced without the NULL check, leading to
the following false positive Smatch warning:

  drivers/pci/endpoint/functions/pci-epf-test.c:784 pci_epf_test_core_init() error: we previously assumed 'epc_features' could be null (see line 747)

Thus, remove the redundant NULL check and also use the epc_features::
{msix_capable/msi_capable} flags directly to avoid local variables.

[kwilczynski: commit log]
Fixes: 5e50ee27d4a5 ("PCI: pci-epf-test: Add support to defer core initialization")
Closes: https://lore.kernel.org/linux-pci/024b5826-7180-4076-ae08-57d2584cca3f@moroto.mountain
Link: https://lore.kernel.org/linux-pci/20240418-pci-epf-test-fix-v2-1-eacd54831444@linaro.org
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Reviewed-by: Niklas Cassel <cassel@kernel.org>

diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c
index 977fb79c15677e749306a29d7f7696834f935a69..546d2a27955cf2600f89ed6602201df941437994 100644 (file)
--- a/drivers/pci/endpoint/functions/pci-epf-test.c
+++ b/drivers/pci/endpoint/functions/pci-epf-test.c
@@ -735,20 +735,12 @@ static int pci_epf_test_core_init(struct pci_epf *epf)
 {
        struct pci_epf_test *epf_test = epf_get_drvdata(epf);
        struct pci_epf_header *header = epf->header;
-       const struct pci_epc_features *epc_features;
+       const struct pci_epc_features *epc_features = epf_test->epc_features;
        struct pci_epc *epc = epf->epc;
        struct device *dev = &epf->dev;
        bool linkup_notifier = false;
-       bool msix_capable = false;
-       bool msi_capable = true;
        int ret;
 
-       epc_features = pci_epc_get_features(epc, epf->func_no, epf->vfunc_no);
-       if (epc_features) {
-               msix_capable = epc_features->msix_capable;
-               msi_capable = epc_features->msi_capable;
-       }
-
        if (epf->vfunc_no <= 1) {
                ret = pci_epc_write_header(epc, epf->func_no, epf->vfunc_no, header);
                if (ret) {
@@ -761,7 +753,7 @@ static int pci_epf_test_core_init(struct pci_epf *epf)
        if (ret)
                return ret;
 
-       if (msi_capable) {
+       if (epc_features->msi_capable) {
                ret = pci_epc_set_msi(epc, epf->func_no, epf->vfunc_no,
                                      epf->msi_interrupts);
                if (ret) {
@@ -770,7 +762,7 @@ static int pci_epf_test_core_init(struct pci_epf *epf)
                }
        }
 
-       if (msix_capable) {
+       if (epc_features->msix_capable) {
                ret = pci_epc_set_msix(epc, epf->func_no, epf->vfunc_no,
                                       epf->msix_interrupts,
                                       epf_test->test_reg_bar,