| Message ID | 1467283993-3185-5-git-send-email-xyjxie@linux.vnet.ibm.com |
|---|---|
| State | Superseded |
| Headers | show |
On Thu, Jun 30, 2016 at 06:53:10PM +0800, Yongji Xie wrote: >When using resource_alignment kernel parameter, the current >implement reassigns the alignment by changing resources' size >which can potentially break some drivers. For example, the driver >uses the size to locate some register whose length is related >to the size. > >This patch adds a new option "noresize" for the parameter to >solve this problem. > >Signed-off-by: Yongji Xie <xyjxie@linux.vnet.ibm.com> Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com> >--- > Documentation/kernel-parameters.txt | 5 ++++- > drivers/pci/pci.c | 35 +++++++++++++++++++++++++---------- > 2 files changed, 29 insertions(+), 11 deletions(-) > >diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt >index 82b42c9..c4802f5 100644 >--- a/Documentation/kernel-parameters.txt >+++ b/Documentation/kernel-parameters.txt >@@ -2997,13 +2997,16 @@ 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 6241cfc..1d80a94 100644 >--- a/drivers/pci/pci.c >+++ b/drivers/pci/pci.c >@@ -4748,11 +4748,13 @@ static DEFINE_SPINLOCK(resource_alignment_lock); > /** > * pci_specified_resource_alignment - get resource alignment specified by user. > * @dev: the PCI device to get >+ * @resize: whether or not to change resources' size when reassigning alignment > * > * 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; >@@ -4787,6 +4789,11 @@ 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) && >@@ -4819,6 +4826,7 @@ void pci_reassigndev_resource_alignment(struct pci_dev *dev) > { > int i; > struct resource *r; >+ bool resize = true; > resource_size_t align, size; > > /* We should never try to reassign VF's alignment */ >@@ -4826,7 +4834,7 @@ void pci_reassigndev_resource_alignment(struct pci_dev *dev) > return; > > /* 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; > >@@ -4848,15 +4856,22 @@ void pci_reassigndev_resource_alignment(struct pci_dev *dev) > 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 { >+ r->flags &= ~IORESOURCE_SIZEALIGN; >+ r->flags |= IORESOURCE_STARTALIGN | IORESOURCE_UNSET; f->flags |= (IORESOURCE_STARTALIGN | IORESOURCE_UNSET); Yongji, one quick question - when IORESOURCE_UNSET is cleared? If it's not cleared, is there any unexpected side effects? Thanks. >+ r->start = max(align, size); >+ 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 Thanks, Gavin -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi Gavin, On 2016/7/1 10:25, Gavin Shan wrote: > On Thu, Jun 30, 2016 at 06:53:10PM +0800, Yongji Xie wrote: >> When using resource_alignment kernel parameter, the current >> implement reassigns the alignment by changing resources' size >> which can potentially break some drivers. For example, the driver >> uses the size to locate some register whose length is related >> to the size. >> >> This patch adds a new option "noresize" for the parameter to >> solve this problem. >> >> Signed-off-by: Yongji Xie <xyjxie@linux.vnet.ibm.com> > Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com> > >> --- >> Documentation/kernel-parameters.txt | 5 ++++- >> drivers/pci/pci.c | 35 +++++++++++++++++++++++++---------- >> 2 files changed, 29 insertions(+), 11 deletions(-) >> >> diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt >> index 82b42c9..c4802f5 100644 >> --- a/Documentation/kernel-parameters.txt >> +++ b/Documentation/kernel-parameters.txt >> @@ -2997,13 +2997,16 @@ 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 6241cfc..1d80a94 100644 >> --- a/drivers/pci/pci.c >> +++ b/drivers/pci/pci.c >> @@ -4748,11 +4748,13 @@ static DEFINE_SPINLOCK(resource_alignment_lock); >> /** >> * pci_specified_resource_alignment - get resource alignment specified by user. >> * @dev: the PCI device to get >> + * @resize: whether or not to change resources' size when reassigning alignment >> * >> * 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; >> @@ -4787,6 +4789,11 @@ 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) && >> @@ -4819,6 +4826,7 @@ void pci_reassigndev_resource_alignment(struct pci_dev *dev) >> { >> int i; >> struct resource *r; >> + bool resize = true; >> resource_size_t align, size; >> >> /* We should never try to reassign VF's alignment */ >> @@ -4826,7 +4834,7 @@ void pci_reassigndev_resource_alignment(struct pci_dev *dev) >> return; >> >> /* 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; >> >> @@ -4848,15 +4856,22 @@ void pci_reassigndev_resource_alignment(struct pci_dev *dev) >> 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 { >> + r->flags &= ~IORESOURCE_SIZEALIGN; >> + r->flags |= IORESOURCE_STARTALIGN | IORESOURCE_UNSET; > f->flags |= (IORESOURCE_STARTALIGN | IORESOURCE_UNSET); > > Yongji, one quick question - when IORESOURCE_UNSET is cleared? If it's not > cleared, is there any unexpected side effects? Thanks. PCI core will clear this flag in pci_assign_resource() when the BAR has been assigned properly. If it's not cleared, the driver will fail in binding the device because pci_enable_resources() will check this flag. Thanks, Yongji -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 82b42c9..c4802f5 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -2997,13 +2997,16 @@ 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 6241cfc..1d80a94 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -4748,11 +4748,13 @@ static DEFINE_SPINLOCK(resource_alignment_lock); /** * pci_specified_resource_alignment - get resource alignment specified by user. * @dev: the PCI device to get + * @resize: whether or not to change resources' size when reassigning alignment * * 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; @@ -4787,6 +4789,11 @@ 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) && @@ -4819,6 +4826,7 @@ void pci_reassigndev_resource_alignment(struct pci_dev *dev) { int i; struct resource *r; + bool resize = true; resource_size_t align, size; /* We should never try to reassign VF's alignment */ @@ -4826,7 +4834,7 @@ void pci_reassigndev_resource_alignment(struct pci_dev *dev) return; /* 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; @@ -4848,15 +4856,22 @@ void pci_reassigndev_resource_alignment(struct pci_dev *dev) 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 { + r->flags &= ~IORESOURCE_SIZEALIGN; + r->flags |= IORESOURCE_STARTALIGN | IORESOURCE_UNSET; + r->start = max(align, size); + 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
When using resource_alignment kernel parameter, the current implement reassigns the alignment by changing resources' size which can potentially break some drivers. For example, the driver uses the size to locate some register whose length is related to the size. This patch adds a new option "noresize" for the parameter to solve this problem. Signed-off-by: Yongji Xie <xyjxie@linux.vnet.ibm.com> --- Documentation/kernel-parameters.txt | 5 ++++- drivers/pci/pci.c | 35 +++++++++++++++++++++++++---------- 2 files changed, 29 insertions(+), 11 deletions(-)