soc/intel/dnv: Set INT_LINE accouting for PIRQ routing & swizzling

This code also sets unused interrupt lines to the recommended safe
value of 0xff instead of ignoring such devices.

Change-Id: I7582b41eb3288c400a949e20402e9820f6b72434
Signed-off-by: Stephen Douthit <stephend@silicom-usa.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/34714
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>

1 files changed, 259 insertions, 17 deletions

diff --git a/src/soc/intel/denverton_ns/lpc.c b/src/soc/intel/denverton_ns/lpc.c
index 6481cbe00b..8c0a181d0c 100644
--- a/src/soc/intel/denverton_ns/lpc.c
+++ b/src/soc/intel/denverton_ns/lpc.c
@@ -65,6 +65,261 @@ static void pch_enable_ioapic(struct device *dev)
 	io_apic_write((void *)IO_APIC_ADDR, 0x03, 0x01);
 }
 
+/* interrupt router lookup for internal devices */
+struct dnv_ir_lut {
+	/* (dev << 3) | fn */
+	u8 devfn;
+	u8 ir;
+};
+
+#define DEVFN(dev, fn) ((dev << 3) | (fn))
+
+static const struct dnv_ir_lut dnv_ir_lut[] = {
+	{.devfn = DEVFN(0x05, 0), .ir = 3},  /* RCEC */
+	{.devfn = DEVFN(0x06, 0), .ir = 4},  /* Virtual RP to QAT */
+	{.devfn = DEVFN(0x09, 0), .ir = 7},  /* PCIe RP0 */
+	{.devfn = DEVFN(0x0a, 0), .ir = 7},  /* PCIe RP1 */
+	{.devfn = DEVFN(0x0b, 0), .ir = 7},  /* PCIe RP2 */
+	{.devfn = DEVFN(0x0c, 0), .ir = 7},  /* PCIe RP3 */
+	{.devfn = DEVFN(0x0e, 0), .ir = 8},  /* PCIe RP4 */
+	{.devfn = DEVFN(0x0f, 0), .ir = 8},  /* PCIe RP5 */
+	{.devfn = DEVFN(0x10, 0), .ir = 8},  /* PCIe RP6 */
+	{.devfn = DEVFN(0x11, 0), .ir = 8},  /* PCIe RP7 */
+	{.devfn = DEVFN(0x12, 0), .ir = 10}, /* SMBus - Host */
+	{.devfn = DEVFN(0x13, 0), .ir = 6},  /* AHCI0 */
+	{.devfn = DEVFN(0x14, 0), .ir = 11}, /* AHCI1 */
+	{.devfn = DEVFN(0x15, 0), .ir = 9},  /* USB */
+	{.devfn = DEVFN(0x16, 0), .ir = 1},  /* Virtual RP to LAN0 */
+	{.devfn = DEVFN(0x17, 0), .ir = 2},  /* Virtual RP to LAN1 */
+	{.devfn = DEVFN(0x18, 0), .ir = 5},  /* ME HECI1 */
+	{.devfn = DEVFN(0x18, 1), .ir = 5},  /* ME HECI1 */
+	{.devfn = DEVFN(0x18, 2), .ir = 5},  /* ME PTIO-IDER */
+	{.devfn = DEVFN(0x18, 3), .ir = 5},  /* ME PTIO-KT */
+	{.devfn = DEVFN(0x18, 4), .ir = 5},  /* ME HECI3 */
+	{.devfn = DEVFN(0x1a, 0), .ir = 10}, /* HSUART0 */
+	{.devfn = DEVFN(0x1a, 1), .ir = 10}, /* HSUART1 */
+	{.devfn = DEVFN(0x1a, 2), .ir = 10}, /* HSUART2 */
+	{.devfn = DEVFN(0x1b, 0), .ir = 12}, /* IE HECI1 */
+	{.devfn = DEVFN(0x1b, 1), .ir = 12}, /* IE HECI1 */
+	{.devfn = DEVFN(0x1b, 2), .ir = 12}, /* IE PTIO-IDER */
+	{.devfn = DEVFN(0x1b, 3), .ir = 12}, /* IE PTIO-KT */
+	{.devfn = DEVFN(0x1b, 4), .ir = 12}, /* IE HECI3 */
+	{.devfn = DEVFN(0x1c, 0), .ir = 12}, /* SDHCI */
+	{.devfn = DEVFN(0x1f, 0), .ir = 0},  /* LPC */
+	{.devfn = DEVFN(0x1f, 1), .ir = 0},  /* PS2B */
+	{.devfn = DEVFN(0x1f, 4), .ir = 0},  /* SMBus - Legacy */
+	{.devfn = DEVFN(0x1f, 7), .ir = 0},  /* Trace Hub */
+};
+
+/*
+ * Only 6 of the 8 root ports have swizzling, return '1' if this bdf is one of
+ * them, '0' otherwise
+ */
+static int is_dnv_swizzled_rp(uint16_t bdf)
+{
+	switch (bdf) {
+	case DEVFN(10, 0):
+	case DEVFN(11, 0):
+	case DEVFN(12, 0):
+	case DEVFN(15, 0):
+	case DEVFN(16, 0):
+	case DEVFN(17, 0):
+		return 1;
+	}
+
+	return 0;
+}
+
+/*
+ * Figure out which upstream interrupt pin a downstream device gets swizzled to
+ *
+ * config - pointer to chip_info containing routing info
+ * devfn - device/function of root port to check swizzling for
+ * pin - interrupt pin 1-4 = A-D
+ *
+ * Return new pin mapping, 0 if invalid pin
+ */
+static int dnv_get_swizzled_pin(config_t *config, u8 devfn, u8 pin)
+{
+	if (pin < 1 || pin > 4)
+		return 0;
+
+	devfn >>= 3;
+	if (devfn < 13)
+		devfn -= 9;
+	else
+		devfn -= 14;
+
+	return ((pin - 1 + devfn) % 4) + 1;
+}
+
+/*
+ * Figure out which upstream interrupt pin a downstream device gets swizzled to
+ *
+ * config - pointer to chip_info containing routing info
+ * devfn - device/function of root port to check swizzling for
+ * pin - interrupt pin 1-4 = A-D
+ *
+ * Return new pin mapping, 0 if invalid pin
+ */
+static int dnv_get_ir(config_t *config, u8 devfn, u8 pin)
+{
+	int i = 0;
+	int line = 0xff;
+	u16 ir = 0xffff;
+
+	/* The only valid pin values are 1-4 for A-D */
+	if (pin < 1 || pin > 4) {
+		printk(BIOS_WARNING, "%s: pin %d is invalid\n", __func__, pin);
+		goto dnv_get_ir_done;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(dnv_ir_lut); i++) {
+		if (dnv_ir_lut[i].devfn == devfn)
+			break;
+	}
+
+	if (i == ARRAY_SIZE(dnv_ir_lut)) {
+		printk(BIOS_WARNING, "%s: no entry\n", __func__);
+		goto dnv_get_ir_done;
+	}
+
+	switch (dnv_ir_lut[i].ir) {
+	case 0:
+		ir = config->ir00_routing;
+		break;
+	case 1:
+		ir = config->ir01_routing;
+		break;
+	case 2:
+		ir = config->ir02_routing;
+		break;
+	case 3:
+		ir = config->ir03_routing;
+		break;
+	case 4:
+		ir = config->ir04_routing;
+		break;
+	case 5:
+		ir = config->ir05_routing;
+		break;
+	case 6:
+		ir = config->ir06_routing;
+		break;
+	case 7:
+		ir = config->ir07_routing;
+		break;
+	case 8:
+		ir = config->ir08_routing;
+		break;
+	case 9:
+		ir = config->ir09_routing;
+		break;
+	case 10:
+		ir = config->ir10_routing;
+		break;
+	case 11:
+		ir = config->ir11_routing;
+		break;
+	case 12:
+		ir = config->ir12_routing;
+		break;
+	default:
+		printk(BIOS_ERR, "%s: invalid ir %d for entry %d\n", __func__, dnv_ir_lut[i].ir,
+		       i);
+		goto dnv_get_ir_done;
+	}
+
+	ir >>= (pin - 1) * 4;
+	ir &= 0xf;
+	switch (ir) {
+	case 0:
+		line = config->pirqa_routing;
+		break;
+	case 1:
+		line = config->pirqb_routing;
+		break;
+	case 2:
+		line = config->pirqc_routing;
+		break;
+	case 3:
+		line = config->pirqd_routing;
+		break;
+	case 4:
+		line = config->pirqe_routing;
+		break;
+	case 5:
+		line = config->pirqf_routing;
+		break;
+	case 6:
+		line = config->pirqg_routing;
+		break;
+	case 7:
+		line = config->pirqh_routing;
+		break;
+	default:
+		printk(BIOS_ERR, "%s: invalid ir pirq %d for entry %d\n", __func__, ir, i);
+		break;
+	}
+
+dnv_get_ir_done:
+	return line;
+}
+
+/*
+ * PCI devices have the INT_LINE (0x3C) and INT_PIN (0x3D) registers which
+ * report interrupt routing information to operating systems and drivers.  The
+ * INT_PIN register is generally read only and reports which interrupt pin
+ * A - D it uses.  The INT_LINE register is configurable and reports which IRQ
+ * (generally the PIC IRQs 1 - 15) it will use.  This needs to take interrupt
+ * pin swizzling on devices that are downstream on a PCI bridge into account.
+ */
+static u8 dnv_get_int_line(struct device *irq_dev)
+{
+	config_t *config;
+	struct device *targ_dev = NULL;
+	uint16_t parent_bdf = 0;
+	int8_t original_int_pin = 0, new_int_pin = 0, swiz_int_pin = 0;
+	uint8_t int_line = 0xff;
+
+	if (irq_dev->path.type != DEVICE_PATH_PCI || !irq_dev->enabled) {
+		printk(BIOS_ERR, "%s for non pci device?\n", __func__);
+		goto dnv_get_int_line_done;
+	}
+
+	/*
+	 * Get the INT_PIN swizzled up to the root port if necessary
+	 * using the existing coreboot pci_device code
+	 */
+	original_int_pin = pci_read_config8(irq_dev, PCI_INTERRUPT_PIN);
+	new_int_pin = get_pci_irq_pins(irq_dev, &targ_dev);
+	if (targ_dev == NULL || new_int_pin < 1)
+		goto dnv_get_int_line_done;
+
+	printk(BIOS_DEBUG, "%s: irq_dev %s, targ_dev %s:\n", __func__, dev_path(irq_dev),
+	       dev_path(targ_dev));
+	printk(BIOS_DEBUG, "%s: std swizzle %s from %c to %c\n", __func__, dev_path(targ_dev),
+	       '@' + original_int_pin, '@' + new_int_pin);
+
+	/* Swizzle this device if needed */
+	config = targ_dev->chip_info;
+	parent_bdf = targ_dev->path.pci.devfn | targ_dev->bus->secondary << 8;
+	if (is_dnv_swizzled_rp(parent_bdf) && irq_dev != targ_dev) {
+		swiz_int_pin = dnv_get_swizzled_pin(config, parent_bdf, new_int_pin);
+		printk(BIOS_DEBUG, "%s: dnv swizzle %s from %c to %c\n", __func__,
+		       dev_path(targ_dev), '@' + new_int_pin, '@' + swiz_int_pin);
+	} else {
+		swiz_int_pin = new_int_pin;
+	}
+
+	/* Look up the routing for the pin */
+	int_line = dnv_get_ir(config, parent_bdf, swiz_int_pin);
+
+dnv_get_int_line_done:
+	printk(BIOS_DEBUG, "\tINT_LINE\t\t: %d\n", int_line);
+	return int_line;
+}
+
 /* PIRQ[n]_ROUT[3:0] - PIRQ Routing Control
  * 0x00 - 0000 = Reserved
  * 0x01 - 0001 = Reserved
@@ -150,6 +405,7 @@ static void pch_pirq_init(struct device *dev)
 		config->ipc3);
 
 	for (irq_dev = all_devices; irq_dev; irq_dev = irq_dev->next) {
+		int devfn = irq_dev->path.pci.devfn;
 		u8 int_pin = 0, int_line = 0;
 
 		if (!irq_dev->enabled || irq_dev->path.type != DEVICE_PATH_PCI)
@@ -157,23 +413,9 @@ static void pch_pirq_init(struct device *dev)
 
 		int_pin = pci_read_config8(irq_dev, PCI_INTERRUPT_PIN);
 
-		switch (int_pin) {
-		case 1: /* INTA# */
-			int_line = config->pirqa_routing;
-			break;
-		case 2: /* INTB# */
-			int_line = config->pirqb_routing;
-			break;
-		case 3: /* INTC# */
-			int_line = config->pirqc_routing;
-			break;
-		case 4: /* INTD# */
-			int_line = config->pirqd_routing;
-			break;
-		}
-
-		if (!int_line)
-			continue;
+		int_line = dnv_get_int_line(irq_dev);
+		printk(BIOS_DEBUG, "%s: %02x:%02x.%d pin %d int line %d\n", __func__,
+		       irq_dev->bus->secondary, devfn >> 3, devfn & 0x7, int_pin, int_line);
 
 		pci_write_config8(irq_dev, PCI_INTERRUPT_LINE, int_line);
 	}