[coreboot-gerrit] Change in coreboot[master]: device/pci: Don't enabled unassigned resources

[Nico Huber (Code Review)]

Hello Furquan Shaikh, Arthur Heymans, Kyösti Mälkki, Aaron Durbin,

I'd like you to do a code review. Please visit

https://review.coreboot.org/c/coreboot/+/41553

to review the following change.

Change subject: device/pci: Don't enabled unassigned resources
......................................................................

device/pci: Don't enabled unassigned resources

We only have a single bit in the PCI_COMMAND register to enable
or disable resources of one type. If any resource of a type is
unassigned, we have to disable all of them.

Change-Id: I7a7e9c5c382358446b60a7bd5b29954f80cce07e
Signed-off-by: Nico Huber 
---
M src/device/pci_device.c
1 file changed, 12 insertions(+), 2 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/53/41553/1

diff --git a/src/device/pci_device.c b/src/device/pci_device.c
index 5afbfa9..8df44df 100644
--- a/src/device/pci_device.c
+++ b/src/device/pci_device.c
@@ -506,7 +506,8 @@
    }
 }

-static void pci_set_resource(struct device *dev, struct resource *resource)
+static void pci_set_resource(struct device *const dev, struct resource *const resource,
+			     uint16_t *const command_mask)
 {
    /* Make certain the resource has actually been assigned a value. */
    if (!(resource->flags & IORESOURCE_ASSIGNED)) {
@@ -518,6 +519,11 @@
    		printk(BIOS_ERR, "ERROR: %s %02lx %s size: 0x%010llx not "
    		       "assigned\n", dev_path(dev), resource->index,
    		       resource_type(resource), resource->size);
+			/* We'll have to disable all resources of this type. */
+			if (resource->flags & IORESOURCE_MEM)
+				*command_mask &= ~PCI_COMMAND_MEMORY;
+			if (resource->flags & IORESOURCE_IO)
+				*command_mask &= ~PCI_COMMAND_IO;
    		return;
    	}
    }
@@ -561,12 +567,16 @@

void pci_dev_set_resources(struct device *dev)
 {
+	uint16_t command_mask = 0xffff;
    struct resource *res;
    struct bus *bus;
    u8 line;

for (res = dev->resource_list; res; res = res->next)
-		pci_set_resource(dev, res);
+		pci_set_resource(dev, res, &command_mask);
+	/* If there are unassigned resources, we might
+	   have to disable others of the same type. */
+	dev->command &= command_mask;

for (bus = dev->link_list; bus; bus = bus->next) {
    	if (bus->children)