[WIP PATCH v3 5/7] PCI: endpoint: pci-epf-test: Use hardware-owned MSI-X layout

[Koichiro Den]

pci-epf-test always allocates an MSI-X Table and PBA in its test register
BAR. This duplicates fixed regions provided by endpoint controllers that
own the MSI-X layout.

Use the hardware-owned layout when it can hold the configured MSI-X
entries and omit the duplicate regions from the test register BAR. Keep
the existing EPF-owned layout as the fallback.

Signed-off-by: Koichiro Den <den@xxxxxxxxxxxxx>
---
Changes in v3:
  - New patch.
---
 drivers/pci/endpoint/functions/pci-epf-test.c | 36 +++++++++++++------
 1 file changed, 26 insertions(+), 10 deletions(-)

diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c
index 360df7775110..02505f7ca6c8 100644
--- a/drivers/pci/endpoint/functions/pci-epf-test.c
+++ b/drivers/pci/endpoint/functions/pci-epf-test.c
@@ -1278,20 +1278,36 @@ static int pci_epf_test_alloc_space(struct pci_epf *epf)
 	enum pci_barno bar;
 	const struct pci_epc_features *epc_features = epf_test->epc_features;
 	size_t test_reg_size;
+	int ret;
 
 	test_reg_bar_size = ALIGN(sizeof(struct pci_epf_test_reg), 128);
 
 	if (epc_features->msix_capable) {
-		msix_table_size = PCI_MSIX_ENTRY_SIZE * epf->msix_interrupts;
-		pba_size = BITS_TO_U64(epf->msix_interrupts) * sizeof(u64);
-
-		epf_test->msix_layout.table_bar = test_reg_bar;
-		epf_test->msix_layout.table_offset = test_reg_bar_size;
-		epf_test->msix_layout.table_size = msix_table_size;
-		epf_test->msix_layout.pba_bar = test_reg_bar;
-		epf_test->msix_layout.pba_offset = test_reg_bar_size +
-						   msix_table_size;
-		epf_test->msix_layout.pba_size = pba_size;
+		ret = pci_epc_get_hw_msix_layout(epc_features,
+						 &epf_test->msix_layout);
+		if (ret && ret != -ENOENT) {
+			dev_err(dev, "Invalid hardware-owned MSI-X layout\n");
+			return ret;
+		}
+
+		if (ret == -ENOENT ||
+		    epf_test->msix_layout.table_size <
+			    PCI_MSIX_ENTRY_SIZE * epf->msix_interrupts ||
+		    epf_test->msix_layout.pba_size <
+			    BITS_TO_U64(epf->msix_interrupts) * sizeof(u64)) {
+			msix_table_size =
+				PCI_MSIX_ENTRY_SIZE * epf->msix_interrupts;
+			pba_size = BITS_TO_U64(epf->msix_interrupts) *
+				   sizeof(u64);
+
+			epf_test->msix_layout.table_bar = test_reg_bar;
+			epf_test->msix_layout.table_offset = test_reg_bar_size;
+			epf_test->msix_layout.table_size = msix_table_size;
+			epf_test->msix_layout.pba_bar = test_reg_bar;
+			epf_test->msix_layout.pba_offset =
+				test_reg_bar_size + msix_table_size;
+			epf_test->msix_layout.pba_size = pba_size;
+		}
 	}
 	test_reg_size = test_reg_bar_size + msix_table_size + pba_size;
 
-- 
2.51.0