xhci: change 'msix_count' to encompass MSI or MSI-X vectors

Instead of variable 'msix_count' containing the number of MSI-X vectors,
now it can contains MSI or MSI-X vector amount. Because both interrupt
methods allow several vectors. Thus, 'msix_count' is renamed to 'nvecs'.

Additionally, instead of storing the maximum possible vector amount,
now it stores the amount of successfully allocated vectors, or negative
integer on allocation failure.
Signed-off-by: Niklas Neronin <niklas.neronin@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20231201150647.1307406-16-mathias.nyman@linux.intel.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/host/xhci-pci.c

@@ -142,12 +142,12 @@ static int xhci_try_enable_msi(struct usb_hcd *hcd)
 	 * - num_online_cpus: maximum MSI-X vectors per CPUs core.
 	 *   Add additional 1 vector to ensure always available interrupt.
 	 */
-	xhci->msix_count = min(num_online_cpus() + 1,
+	xhci->nvecs = min(num_online_cpus() + 1,
 			  HCS_MAX_INTRS(xhci->hcs_params1));
 
-	ret = pci_alloc_irq_vectors(pdev, xhci->msix_count, xhci->msix_count,
+	xhci->nvecs = pci_alloc_irq_vectors(pdev, xhci->nvecs, xhci->nvecs,
 					    PCI_IRQ_MSIX);
-	if (ret < 0) {
+	if (xhci->nvecs < 0) {
 		xhci_dbg_trace(xhci, trace_xhci_dbg_init, "Failed to enable MSI-X");
 		goto setup_msi;
 	}
@@ -166,8 +166,8 @@ static int xhci_try_enable_msi(struct usb_hcd *hcd)
 
 setup_msi:
 	/* TODO: Check with MSI Soc for sysdev */
-	ret = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_MSI);
-	if (ret < 0) {
+	xhci->nvecs = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_MSI);
+	if (xhci->nvecs < 0) {
 		xhci_dbg_trace(xhci, trace_xhci_dbg_init, "failed to allocate MSI entry");
 		goto legacy_irq;
 	}

drivers/usb/host/xhci.h

@@ -1765,8 +1765,8 @@ struct xhci_hcd {
 	int		page_size;
 	/* Valid values are 12 to 20, inclusive */
 	int		page_shift;
-	/* msi-x vectors */
-	int		msix_count;
+	/* MSI-X/MSI vectors */
+	int		nvecs;
 	/* optional clocks */
 	struct clk		*clk;
 	struct clk		*reg_clk;