sb/intel/common/pirq_gen: Rework generating pin-route tables

This creates a pin-route matrix first and then generates the ACPI
entries based on that. This approach has the advantage of being
simpler (no need for checks on double entries) and requiring less
access to the pci config space.

A few thing that are also fixed:
* Don't declare DEFAULT_RCBA redundantly.
* Only loop over PCI devices on bus 0
* Add a license header to rcba_pirq.c
* Remove inappropriate use of typedefs
* Fix the pin field: needs to be a byte
* Fix the source field: it should either be a byte or a path
(according to Advanced Configuration and Power Interface Specification
rev 2.0c)

Change-Id: Ic68a91d0cb55942a4d928b30f73e1c779142420d
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/22979
Reviewed-by: Nico Huber <nico.h@gmx.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

1 files changed, 44 insertions, 40 deletions

diff --git a/src/southbridge/intel/common/acpi_pirq_gen.c b/src/southbridge/intel/common/acpi_pirq_gen.c
index fc26d1aa95..1f1a2ab258 100644
--- a/src/southbridge/intel/common/acpi_pirq_gen.c
+++ b/src/southbridge/intel/common/acpi_pirq_gen.c
@@ -23,57 +23,55 @@
 #include "acpi_pirq_gen.h"
 
 enum emit_type {
-	EMIT_NONE,
 	EMIT_APIC,
 	EMIT_PICM,
 };
 
-static size_t enumerate_root_pci_pins(const enum emit_type emit,
-				      const char *lpcb_path)
+static int create_pirq_matrix(char matrix[32][4])
 {
-	char buffer[DEVICE_PATH_MAX];
-	device_t dev;
-	pci_pin_t prev_int_pin = PCI_INT_NONE;
-	u8 prev_pci_dev = 0;
-	size_t num_devs = 0;
+	struct device *dev;
+	int num_devs = 0;
 
-	for (dev = all_devices; dev; dev = dev->next) {
+	for (dev = dev_find_slot(0, PCI_DEVFN(0, 0)); dev; dev = dev->sibling) {
 		u8 pci_dev;
 		u8 int_pin;
-		pirq_t pirq;
-
-		if (dev->path.type != DEVICE_PATH_PCI ||
-		    dev->bus->secondary != 0)
-			continue;
 
 		pci_dev = PCI_SLOT(dev->path.pci.devfn);
 		int_pin = pci_read_config8(dev, PCI_INTERRUPT_PIN);
 
-		if (int_pin == PCI_INT_NONE || int_pin > PCI_INT_D)
+		if (int_pin == PCI_INT_NONE || int_pin > PCI_INT_D ||
+				matrix[pci_dev][int_pin - PCI_INT_A]
+				!= PIRQ_NONE)
 			continue;
 
-		pirq = intel_common_map_pirq(dev, int_pin);
-		if (emit == EMIT_NONE)  /* Only print on the first pass */
-			printk(BIOS_SPEW, "ACPI_PIRQ_GEN: %s: pin=%d pirq=%d\n",
-				dev_path(dev), int_pin, pirq);
+		matrix[pci_dev][int_pin - PCI_INT_A] =
+			intel_common_map_pirq(dev, int_pin);
+		printk(BIOS_SPEW, "ACPI_PIRQ_GEN: %s: pin=%d pirq=%d\n",
+			dev_path(dev), int_pin - PCI_INT_A,
+			matrix[pci_dev][int_pin - PCI_INT_A] - PIRQ_A);
+		num_devs++;
+	}
+	return num_devs;
+}
 
-		if (pirq == PIRQ_NONE)
-			continue;
+static void gen_pirq_route(const enum emit_type emit, const char *lpcb_path,
+			char pci_int_mapping[32][4])
+{
+	int pci_dev, int_pin;
+	char buffer[DEVICE_PATH_MAX];
+	char pirq;
 
-		/* Avoid duplicate entries */
-		if (prev_pci_dev == pci_dev && prev_int_pin == int_pin) {
-			continue;
-		} else {
-			prev_int_pin = int_pin;
-			prev_pci_dev = pci_dev;
-		}
-		if (emit != EMIT_NONE) {
+	for (pci_dev = 0; pci_dev < 32; pci_dev++) {
+		for (int_pin = 0; int_pin < 4; int_pin++) {
+			pirq = pci_int_mapping[pci_dev][int_pin];
+			if (pirq == PIRQ_NONE)
+				continue;
 			acpigen_write_package(4);
 			acpigen_write_dword((pci_dev << 16) | 0xffff);
-			acpigen_write_dword(int_pin - PCI_INT_A);
+			acpigen_write_byte(int_pin);
 			if (emit == EMIT_APIC) {
-				acpigen_write_dword(0);
-				acpigen_write_dword(16 + (pirq - PIRQ_A));
+				acpigen_write_zero();
+				acpigen_write_dword(16 + pirq - PIRQ_A);
 			} else {
 				snprintf(buffer, sizeof(buffer),
 					"%s.LNK%c",
@@ -83,18 +81,24 @@ static size_t enumerate_root_pci_pins(const enum emit_type emit,
 			}
 			acpigen_pop_len();
 		}
-		num_devs++;
 	}
-	return num_devs;
 }
 
-void intel_acpi_gen_def_acpi_pirq(device_t dev)
+void intel_acpi_gen_def_acpi_pirq(struct device *dev)
 {
 	const char *lpcb_path = acpi_device_path(dev);
-	const size_t num_devs = enumerate_root_pci_pins(EMIT_NONE, lpcb_path);
+	char pci_int_mapping[32][4];
+	int num_devs;
+
+	printk(BIOS_DEBUG, "Generating ACPI PIRQ entries\n");
+
+	if (!lpcb_path) {
+		printk(BIOS_ERR, "ACPI_PIRQ_GEN: Missing LPCB ACPI path\n");
+		return;
+	}
 
-	if (!lpcb_path)
-		die("ACPI_PIRQ_GEN: Missing LPCB ACPI path\n");
+	memset(pci_int_mapping, 0, sizeof(pci_int_mapping));
+	num_devs = create_pirq_matrix(pci_int_mapping);
 
 	acpigen_write_scope("\\_SB.PCI0");
 	acpigen_write_method("_PRT", 0);
@@ -102,13 +106,13 @@ void intel_acpi_gen_def_acpi_pirq(device_t dev)
 	acpigen_emit_namestring("PICM");
 	acpigen_emit_byte(RETURN_OP);
 	acpigen_write_package(num_devs);
-	enumerate_root_pci_pins(EMIT_APIC, lpcb_path);
+	gen_pirq_route(EMIT_APIC, lpcb_path, pci_int_mapping);
 	acpigen_pop_len(); /* package */
 	acpigen_pop_len(); /* if PICM */
 	acpigen_write_else();
 	acpigen_emit_byte(RETURN_OP);
 	acpigen_write_package(num_devs);
-	enumerate_root_pci_pins(EMIT_PICM, lpcb_path);
+	gen_pirq_route(EMIT_PICM, lpcb_path, pci_int_mapping);
 	acpigen_pop_len(); /* package */
 	acpigen_pop_len(); /* else PICM */
 	acpigen_pop_len(); /* _PRT */