From f0b99f70e92dcdc4fecf5cf7ce2f6857ddd82c65 Mon Sep 17 00:00:00 2001 From: Yongji Xie Date: Tue, 13 Sep 2016 17:00:31 +0800 Subject: [PATCH] PCI: Ignore requested alignment for PROBE_ONLY and fixed resources Users may request additional alignment of PCI resources, e.g., to align BARs on page boundaries so they can be shared with guests via VFIO. This of course may require reallocation if firmware has already assigned the BARs with smaller alignments. If the platform has requested PCI_PROBE_ONLY, we should never change any PCI BARs, so we can't provide any additional alignment. Also, if a BAR is marked as IORESOURCE_PCI_FIXED, e.g., for PCI Enhanced Allocation or if the firmware depends on the current BAR value, we can't change the alignment. In these cases, log a message and ignore the user's alignment requests. [bhelgaas: changelog, use goto to simplify PCI_PROBE_ONLY check] Signed-off-by: Yongji Xie Signed-off-by: Bjorn Helgaas --- drivers/pci/pci.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index aab9d5115a5f..ed9447aee863 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -4959,6 +4959,13 @@ static resource_size_t pci_specified_resource_alignment(struct pci_dev *dev) spin_lock(&resource_alignment_lock); p = resource_alignment_param; + if (!*p) + goto out; + if (pci_has_flag(PCI_PROBE_ONLY)) { + pr_info_once("PCI: Ignoring requested alignments (PCI_PROBE_ONLY)\n"); + goto out; + } + while (*p) { count = 0; if (sscanf(p, "%d%n", &align_order, &count) == 1 && @@ -5023,6 +5030,7 @@ static resource_size_t pci_specified_resource_alignment(struct pci_dev *dev) } p++; } +out: spin_unlock(&resource_alignment_lock); return align; } @@ -5063,6 +5071,12 @@ 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, "Ignoring requested alignment for BAR%d: %pR\n", + i, r); + continue; + } + size = resource_size(r); if (size < align) { size = align;