| Message ID | 20181013004919.3202-1-changbin.du@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
| Series | PCI: make pci_size() return real size | expand |
Hi Bjorn. Have you checked this little improvment? The idea here is that this is not a hotspot, so readbility matters than trick. Thanks! On Sat, Oct 13, 2018 at 08:49:19AM +0800, changbin.du@gmail.com wrote: > From: Du Changbin <changbin.du@gmail.com> > > Currently, the pci_size() function actually return 'size-1'. > Make it return real size to avoid confusing. > > Signed-off-by: Du Changbin <changbin.du@gmail.com> > --- > drivers/pci/probe.c | 8 ++++---- > 1 file changed, 4 insertions(+), 4 deletions(-) > > diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c > index 201f9e5ff55c..8ff2b1413865 100644 > --- a/drivers/pci/probe.c > +++ b/drivers/pci/probe.c > @@ -121,13 +121,13 @@ static u64 pci_size(u64 base, u64 maxbase, u64 mask) > * Get the lowest of them to find the decode size, and from that > * the extent. > */ > - size = (size & ~(size-1)) - 1; > + size = size & ~(size-1); > > /* > * base == maxbase can be valid only if the BAR has already been > * programmed with all 1s. > */ > - if (base == maxbase && ((base | size) & mask) != mask) > + if (base == maxbase && ((base | (size - 1)) & mask) != mask) > return 0; > > return size; > @@ -278,7 +278,7 @@ int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type, > /* Above 32-bit boundary; try to reallocate */ > res->flags |= IORESOURCE_UNSET; > res->start = 0; > - res->end = sz64; > + res->end = sz64 - 1; > pci_info(dev, "reg 0x%x: can't handle BAR above 4GB (bus address %#010llx)\n", > pos, (unsigned long long)l64); > goto out; > @@ -286,7 +286,7 @@ int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type, > } > > region.start = l64; > - region.end = l64 + sz64; > + region.end = l64 + sz64 - 1; > > pcibios_bus_to_resource(dev->bus, res, ®ion); > pcibios_resource_to_bus(dev->bus, &inverted_region, res); > -- > 2.17.1 >
On Sat, Oct 13, 2018 at 08:49:19AM +0800, changbin.du@gmail.com wrote: > From: Du Changbin <changbin.du@gmail.com> > > Currently, the pci_size() function actually return 'size-1'. > Make it return real size to avoid confusing. > > Signed-off-by: Du Changbin <changbin.du@gmail.com> Applied to pci/enumeration for v5.1, thanks! I think it's good to have the "end = start + size - 1" idiom made more obvious to help avoid off-by-one errors. > --- > drivers/pci/probe.c | 8 ++++---- > 1 file changed, 4 insertions(+), 4 deletions(-) > > diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c > index 201f9e5ff55c..8ff2b1413865 100644 > --- a/drivers/pci/probe.c > +++ b/drivers/pci/probe.c > @@ -121,13 +121,13 @@ static u64 pci_size(u64 base, u64 maxbase, u64 mask) > * Get the lowest of them to find the decode size, and from that > * the extent. > */ > - size = (size & ~(size-1)) - 1; > + size = size & ~(size-1); > > /* > * base == maxbase can be valid only if the BAR has already been > * programmed with all 1s. > */ > - if (base == maxbase && ((base | size) & mask) != mask) > + if (base == maxbase && ((base | (size - 1)) & mask) != mask) > return 0; > > return size; > @@ -278,7 +278,7 @@ int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type, > /* Above 32-bit boundary; try to reallocate */ > res->flags |= IORESOURCE_UNSET; > res->start = 0; > - res->end = sz64; > + res->end = sz64 - 1; > pci_info(dev, "reg 0x%x: can't handle BAR above 4GB (bus address %#010llx)\n", > pos, (unsigned long long)l64); > goto out; > @@ -286,7 +286,7 @@ int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type, > } > > region.start = l64; > - region.end = l64 + sz64; > + region.end = l64 + sz64 - 1; > > pcibios_bus_to_resource(dev->bus, res, ®ion); > pcibios_resource_to_bus(dev->bus, &inverted_region, res); > -- > 2.17.1 >
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 201f9e5ff55c..8ff2b1413865 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -121,13 +121,13 @@ static u64 pci_size(u64 base, u64 maxbase, u64 mask) * Get the lowest of them to find the decode size, and from that * the extent. */ - size = (size & ~(size-1)) - 1; + size = size & ~(size-1); /* * base == maxbase can be valid only if the BAR has already been * programmed with all 1s. */ - if (base == maxbase && ((base | size) & mask) != mask) + if (base == maxbase && ((base | (size - 1)) & mask) != mask) return 0; return size; @@ -278,7 +278,7 @@ int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type, /* Above 32-bit boundary; try to reallocate */ res->flags |= IORESOURCE_UNSET; res->start = 0; - res->end = sz64; + res->end = sz64 - 1; pci_info(dev, "reg 0x%x: can't handle BAR above 4GB (bus address %#010llx)\n", pos, (unsigned long long)l64); goto out; @@ -286,7 +286,7 @@ int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type, } region.start = l64; - region.end = l64 + sz64; + region.end = l64 + sz64 - 1; pcibios_bus_to_resource(dev->bus, res, ®ion); pcibios_resource_to_bus(dev->bus, &inverted_region, res);