xhci: Refactor interrupter code for initial multi interrupter support.

xHC supports several interrupters, each with its own mmio register set,
event ring and MSI/MSI-X vector. Transfers can be assigned different
interrupters when queued. See xhci 4.17 for details.
Current driver only supports one interrupter.

Create a xhci_interrupter structure containing an event ring, pointer to
mmio registers for this interrupter, variables to store registers over s3
suspend, erst, etc. Add functions to create and free an interrupter, and
pass an interrupter pointer to functions that deal with events.

Secondary interrupters are also useful without having an interrupt vector.
One use case is the xHCI audio sideband offloading where a DSP can take
care of specific audio endpoints.

When all transfer events of an offloaded endpoint can be mapped to a
separate interrupter event ring the DSP can poll this ring, and we can mask
these events preventing waking up the CPU.

Only minor functional changes such as clearing some of the interrupter
registers when freeing the interrupter.

Still create only one primary interrupter.

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20230202150505.618915-4-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 34 insertions, 20 deletions

diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index f61fda4715cc..8dc3f2c00577 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -613,6 +613,7 @@ static int xhci_init(struct usb_hcd *hcd)
 
 static int xhci_run_finished(struct xhci_hcd *xhci)
 {
+	struct xhci_interrupter *ir = xhci->interrupter;
 	unsigned long	flags;
 	u32		temp;
 
@@ -628,8 +629,8 @@ static int xhci_run_finished(struct xhci_hcd *xhci)
 	writel(temp, &xhci->op_regs->command);
 
 	xhci_dbg_trace(xhci, trace_xhci_dbg_init, "Enable primary interrupter");
-	temp = readl(&xhci->ir_set->irq_pending);
-	writel(ER_IRQ_ENABLE(temp), &xhci->ir_set->irq_pending);
+	temp = readl(&ir->ir_set->irq_pending);
+	writel(ER_IRQ_ENABLE(temp), &ir->ir_set->irq_pending);
 
 	if (xhci_start(xhci)) {
 		xhci_halt(xhci);
@@ -665,7 +666,7 @@ int xhci_run(struct usb_hcd *hcd)
 	u64 temp_64;
 	int ret;
 	struct xhci_hcd *xhci = hcd_to_xhci(hcd);
-
+	struct xhci_interrupter *ir = xhci->interrupter;
 	/* Start the xHCI host controller running only after the USB 2.0 roothub
 	 * is setup.
 	 */
@@ -680,17 +681,17 @@ int xhci_run(struct usb_hcd *hcd)
 	if (ret)
 		return ret;
 
-	temp_64 = xhci_read_64(xhci, &xhci->ir_set->erst_dequeue);
+	temp_64 = xhci_read_64(xhci, &ir->ir_set->erst_dequeue);
 	temp_64 &= ~ERST_PTR_MASK;
 	xhci_dbg_trace(xhci, trace_xhci_dbg_init,
 			"ERST deq = 64'h%0lx", (long unsigned int) temp_64);
 
 	xhci_dbg_trace(xhci, trace_xhci_dbg_init,
 			"// Set the interrupt modulation register");
-	temp = readl(&xhci->ir_set->irq_control);
+	temp = readl(&ir->ir_set->irq_control);
 	temp &= ~ER_IRQ_INTERVAL_MASK;
 	temp |= (xhci->imod_interval / 250) & ER_IRQ_INTERVAL_MASK;
-	writel(temp, &xhci->ir_set->irq_control);
+	writel(temp, &ir->ir_set->irq_control);
 
 	if (xhci->quirks & XHCI_NEC_HOST) {
 		struct xhci_command *command;
@@ -769,8 +770,8 @@ static void xhci_stop(struct usb_hcd *hcd)
 			"// Disabling event ring interrupts");
 	temp = readl(&xhci->op_regs->status);
 	writel((temp & ~0x1fff) | STS_EINT, &xhci->op_regs->status);
-	temp = readl(&xhci->ir_set->irq_pending);
-	writel(ER_IRQ_DISABLE(temp), &xhci->ir_set->irq_pending);
+	temp = readl(&xhci->interrupter->ir_set->irq_pending);
+	writel(ER_IRQ_DISABLE(temp), &xhci->interrupter->ir_set->irq_pending);
 
 	xhci_dbg_trace(xhci, trace_xhci_dbg_init, "cleaning up memory");
 	xhci_mem_cleanup(xhci);
@@ -832,28 +833,36 @@ EXPORT_SYMBOL_GPL(xhci_shutdown);
 #ifdef CONFIG_PM
 static void xhci_save_registers(struct xhci_hcd *xhci)
 {
+	struct xhci_interrupter *ir = xhci->interrupter;
+
 	xhci->s3.command = readl(&xhci->op_regs->command);
 	xhci->s3.dev_nt = readl(&xhci->op_regs->dev_notification);
 	xhci->s3.dcbaa_ptr = xhci_read_64(xhci, &xhci->op_regs->dcbaa_ptr);
 	xhci->s3.config_reg = readl(&xhci->op_regs->config_reg);
-	xhci->s3.erst_size = readl(&xhci->ir_set->erst_size);
-	xhci->s3.erst_base = xhci_read_64(xhci, &xhci->ir_set->erst_base);
-	xhci->s3.erst_dequeue = xhci_read_64(xhci, &xhci->ir_set->erst_dequeue);
-	xhci->s3.irq_pending = readl(&xhci->ir_set->irq_pending);
-	xhci->s3.irq_control = readl(&xhci->ir_set->irq_control);
+
+	if (!ir)
+		return;
+
+	ir->s3_erst_size = readl(&ir->ir_set->erst_size);
+	ir->s3_erst_base = xhci_read_64(xhci, &ir->ir_set->erst_base);
+	ir->s3_erst_dequeue = xhci_read_64(xhci, &ir->ir_set->erst_dequeue);
+	ir->s3_irq_pending = readl(&ir->ir_set->irq_pending);
+	ir->s3_irq_control = readl(&ir->ir_set->irq_control);
 }
 
 static void xhci_restore_registers(struct xhci_hcd *xhci)
 {
+	struct xhci_interrupter *ir = xhci->interrupter;
+
 	writel(xhci->s3.command, &xhci->op_regs->command);
 	writel(xhci->s3.dev_nt, &xhci->op_regs->dev_notification);
 	xhci_write_64(xhci, xhci->s3.dcbaa_ptr, &xhci->op_regs->dcbaa_ptr);
 	writel(xhci->s3.config_reg, &xhci->op_regs->config_reg);
-	writel(xhci->s3.erst_size, &xhci->ir_set->erst_size);
-	xhci_write_64(xhci, xhci->s3.erst_base, &xhci->ir_set->erst_base);
-	xhci_write_64(xhci, xhci->s3.erst_dequeue, &xhci->ir_set->erst_dequeue);
-	writel(xhci->s3.irq_pending, &xhci->ir_set->irq_pending);
-	writel(xhci->s3.irq_control, &xhci->ir_set->irq_control);
+	writel(ir->s3_erst_size, &ir->ir_set->erst_size);
+	xhci_write_64(xhci, ir->s3_erst_base, &ir->ir_set->erst_base);
+	xhci_write_64(xhci, ir->s3_erst_dequeue, &ir->ir_set->erst_dequeue);
+	writel(ir->s3_irq_pending, &ir->ir_set->irq_pending);
+	writel(ir->s3_irq_control, &ir->ir_set->irq_control);
 }
 
 static void xhci_set_cmd_ring_deq(struct xhci_hcd *xhci)
@@ -1218,8 +1227,8 @@ int xhci_resume(struct xhci_hcd *xhci, bool hibernated)
 		xhci_dbg(xhci, "// Disabling event ring interrupts\n");
 		temp = readl(&xhci->op_regs->status);
 		writel((temp & ~0x1fff) | STS_EINT, &xhci->op_regs->status);
-		temp = readl(&xhci->ir_set->irq_pending);
-		writel(ER_IRQ_DISABLE(temp), &xhci->ir_set->irq_pending);
+		temp = readl(&xhci->interrupter->ir_set->irq_pending);
+		writel(ER_IRQ_DISABLE(temp), &xhci->interrupter->ir_set->irq_pending);
 
 		xhci_dbg(xhci, "cleaning up memory\n");
 		xhci_mem_cleanup(xhci);
@@ -5334,6 +5343,11 @@ int xhci_gen_setup(struct usb_hcd *hcd, xhci_get_quirks_t get_quirks)
 	if (xhci->hci_version > 0x100)
 		xhci->hcc_params2 = readl(&xhci->cap_regs->hcc_params2);
 
+	/* xhci-plat or xhci-pci might have set max_interrupters already */
+	if ((!xhci->max_interrupters) ||
+	    xhci->max_interrupters > HCS_MAX_INTRS(xhci->hcs_params1))
+		xhci->max_interrupters = HCS_MAX_INTRS(xhci->hcs_params1);
+
 	xhci->quirks |= quirks;
 
 	get_quirks(dev, xhci);