device/pci_ops: Simplify logic for PCI bus ops

Nobody ever sets ops_pci_bus. This implies pci_bus_ops() always
returns pci_bus_default_ops() and get_pbus returns NULL.

Change-Id: Ia30d579e1efe6542dc58714f2e7077507847c0de
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/31684
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

1 files changed, 20 insertions, 54 deletions

diff --git a/src/device/pci_ops.c b/src/device/pci_ops.c
index b7c8942ae0..12c4e26d0e 100644
--- a/src/device/pci_ops.c
+++ b/src/device/pci_ops.c
@@ -15,96 +15,62 @@
  * GNU General Public License for more details.
  */
 
+#include <stdint.h>
 #include <console/console.h>
+#include <device/device.h>
 #include <device/pci.h>
 #include <device/pci_ops.h>
 
-static const struct pci_bus_operations *pci_bus_ops(struct bus *bus, struct device *dev)
+static __always_inline const struct pci_bus_operations *pci_bus_ops(void)
 {
-	const struct pci_bus_operations *bops;
-	bops = NULL;
-	if (bus && bus->dev && bus->dev->ops && bus->dev->ops->ops_pci_bus) {
-		bops = bus->dev->ops->ops_pci_bus(dev);
-	}
-	if (!bops)
-		bops = pci_bus_default_ops();
-	return bops;
+	return pci_bus_default_ops();
 }
 
-/*
- * The only consumer of the return value of get_pbus() is pci_bus_ops().
- * pci_bus_ops() can handle being passed NULL and auto-picks working ops.
- */
-static struct bus *get_pbus(struct device *dev)
+static void pcidev_assert(const struct device *dev)
 {
-	struct bus *pbus = NULL;
-
-	if (!dev)
-		die("get_pbus: dev is NULL!\n");
-	else
-		pbus = dev->bus;
-
-	while (pbus && pbus->dev && !pci_bus_ops(pbus, dev)) {
-		if (pbus == pbus->dev->bus) {
-			printk(BIOS_ALERT, "%s in endless loop looking for a "
-			       "parent bus with pci_bus_ops for %s, breaking "
-			       "out.\n", __func__, dev_path(dev));
-			break;
-		}
-		pbus = pbus->dev->bus;
-	}
-
-	if (!pbus || !pbus->dev || !pbus->dev->ops
-	    || !pbus->dev->ops->ops_pci_bus) {
-		/* This can happen before the device tree is fully set up. */
-
-		// printk(BIOS_EMERG, "%s: Cannot find PCI bus operations.\n",
-		// dev_path(dev));
-
-		pbus = NULL;
-	}
-
-	return pbus;
+	if (dev)
+		return;
+	die("PCI: dev is NULL!\n");
 }
 
 u8 pci_read_config8(struct device *dev, unsigned int where)
 {
-	struct bus *pbus = get_pbus(dev);
-	return pci_bus_ops(pbus, dev)->read8(dev->bus->secondary,
+	pcidev_assert(dev);
+	return pci_bus_ops()->read8(dev->bus->secondary,
 					dev->path.pci.devfn, where);
 }
 
 u16 pci_read_config16(struct device *dev, unsigned int where)
 {
-	struct bus *pbus = get_pbus(dev);
-	return pci_bus_ops(pbus, dev)->read16(dev->bus->secondary,
+	pcidev_assert(dev);
+	return pci_bus_ops()->read16(dev->bus->secondary,
 					 dev->path.pci.devfn, where);
 }
 
 u32 pci_read_config32(struct device *dev, unsigned int where)
 {
-	struct bus *pbus = get_pbus(dev);
-	return pci_bus_ops(pbus, dev)->read32(dev->bus->secondary,
+	pcidev_assert(dev);
+	return pci_bus_ops()->read32(dev->bus->secondary,
 					 dev->path.pci.devfn, where);
 }
 
 void pci_write_config8(struct device *dev, unsigned int where, u8 val)
 {
-	struct bus *pbus = get_pbus(dev);
-	pci_bus_ops(pbus, dev)->write8(dev->bus->secondary,
+	pcidev_assert(dev);
+	pci_bus_ops()->write8(dev->bus->secondary,
 				  dev->path.pci.devfn, where, val);
 }
 
 void pci_write_config16(struct device *dev, unsigned int where, u16 val)
 {
-	struct bus *pbus = get_pbus(dev);
-	pci_bus_ops(pbus, dev)->write16(dev->bus->secondary,
+	pcidev_assert(dev);
+	pci_bus_ops()->write16(dev->bus->secondary,
 				   dev->path.pci.devfn, where, val);
 }
 
 void pci_write_config32(struct device *dev, unsigned int where, u32 val)
 {
-	struct bus *pbus = get_pbus(dev);
-	pci_bus_ops(pbus, dev)->write32(dev->bus->secondary,
+	pcidev_assert(dev);
+	pci_bus_ops()->write32(dev->bus->secondary,
 				   dev->path.pci.devfn, where, val);
 }