[PATCH v3 1/7] PCI: Ignore enforced alignment when kernel uses existing firmware setup

[Yongji Xie]

PCI resources allocator will use firmware setup and not try to
reassign resource when PCI_PROBE_ONLY or IORESOURCE_PCI_FIXED
is set.

The enforced alignment in pci_reassigndev_resource_alignment()
should be ignored in this case. Otherwise, some PCI devices'
resources would be released here and not re-allocated.

Signed-off-by: Yongji Xie <xyjxie@xxxxxxxxxxxxxxxxxx>
---
 drivers/pci/pci.c |   12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index c8b4dbd..be8f72c 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -4760,6 +4760,13 @@ static resource_size_t pci_specified_resource_alignment(struct pci_dev *dev)
 
 	spin_lock(&resource_alignment_lock);
 	p = resource_alignment_param;
+	if (pci_has_flag(PCI_PROBE_ONLY)) {
+		if (*p)
+			printk_once(KERN_INFO "PCI: Ignore resource_alignment parameter: %s with PCI_PROBE_ONLY set\n",
+						p);
+		spin_unlock(&resource_alignment_lock);
+		return 0;
+	}
 	while (*p) {
 		count = 0;
 		if (sscanf(p, "%d%n", &align_order, &count) == 1 &&
@@ -4837,6 +4844,11 @@ void pci_reassigndev_resource_alignment(struct pci_dev *dev)
 		r = &dev->resource[i];
 		if (!(r->flags & IORESOURCE_MEM))
 			continue;
+		if (r->flags & IORESOURCE_PCI_FIXED) {
+			dev_info(&dev->dev, "No alignment for fixed BAR%d: %pR\n",
+				i, r);
+			continue;
+		}
 		size = resource_size(r);
 		if (size < align) {
 			size = align;
-- 
1.7.9.5