When using resource_alignment kernel parameter, the current
implement reassigns the alignment by changing resources' size
which can potentially break some drivers.
So this patch adds a new option "noresize" for the parameter
to solve this problem.
Signed-off-by: Yongji Xie <xyjxie@xxxxxxxxxxxxxxxxxx>
---
Documentation/kernel-parameters.txt | 5 ++++-
drivers/pci/pci.c | 36 +++++++++++++++++++++++++----------
2 files changed, 30 insertions(+), 11 deletions(-)
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 9a53c92..d8b29ab 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -2912,13 +2912,16 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
window. The default value is 64 megabytes.
resource_alignment=
Format:
- [<order of align>@][<domain>:]<bus>:<slot>.<func>[; ...]
+ [<order of align>@][<domain>:]<bus>:<slot>.<func>
+ [:noresize][; ...]
Specifies alignment and device to reassign
aligned memory resources.
If <order of align> is not specified,
PAGE_SIZE is used as alignment.
PCI-PCI bridge can be specified, if resource
windows need to be expanded.
+ noresize: Don't change the resources' sizes when
+ reassigning alignment.
ecrc= Enable/disable PCIe ECRC (transaction layer
end-to-end CRC checking).
bios: Use BIOS/firmware settings. This is the
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 602eb42..760cce5 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -4598,7 +4598,8 @@ static DEFINE_SPINLOCK(resource_alignment_lock);
* RETURNS: Resource alignment if it is specified.
* Zero if it is not specified.
*/
-static resource_size_t pci_specified_resource_alignment(struct pci_dev *dev)
+static resource_size_t pci_specified_resource_alignment(struct pci_dev *dev,
+ bool *resize)
{
int seg, bus, slot, func, align_order, count;
resource_size_t align = 0;
@@ -4626,6 +4627,11 @@ static resource_size_t pci_specified_resource_alignment(struct pci_dev *dev)
}
}
p += count;
+ if (!strncmp(p, ":noresize", 9)) {
+ *resize = false;
+ p += 9;
+ } else
+ *resize = true;
if (seg == pci_domain_nr(dev->bus) &&
bus == dev->bus->number &&
slot == PCI_SLOT(dev->devfn) &&
@@ -4658,11 +4664,12 @@ void pci_reassigndev_resource_alignment(struct pci_dev *dev)
{
int i;
struct resource *r;
+ bool resize;
resource_size_t align, size;
u16 command;
/* check if specified PCI is target device to reassign */
- align = pci_specified_resource_alignment(dev);
+ align = pci_specified_resource_alignment(dev, &resize);
if (!align)
return;
@@ -4684,15 +4691,24 @@ void pci_reassigndev_resource_alignment(struct pci_dev *dev)
if (!(r->flags & IORESOURCE_MEM))
continue;
size = resource_size(r);
- if (size < align) {
- size = align;
- dev_info(&dev->dev,
- "Rounding up size of resource #%d to %#llx.\n",
- i, (unsigned long long)size);
+ if (resize) {
+ if (size < align) {
+ size = align;
+ dev_info(&dev->dev,
+ "Rounding up size of resource #%d to %#llx.\n",
+ i, (unsigned long long)size);
+ }
+ r->flags |= IORESOURCE_UNSET;
+ r->end = size - 1;
+ r->start = 0;
+ } else {
+ if (size > align)
+ align = size;
+ r->flags &= ~IORESOURCE_SIZEALIGN;
+ r->flags |= IORESOURCE_STARTALIGN | IORESOURCE_UNSET;
+ r->start = align;
+ r->end = r->start + size - 1;
}
- r->flags |= IORESOURCE_UNSET;
- r->end = size - 1;
- r->start = 0;
}
/* Need to disable bridge's resource window,
* to enable the kernel to reassign new resource
--
1.7.9.5
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