PCI: make pci_size() return real size
PATCH 1/1 PCI: make pci_size() return real size
From: Du Changbin <[email protected]>
Currently, the pci_size() function actually return 'size-1'. Make it return real size to avoid confusing.
Signed-off-by Du Changbin <[email protected]>
--- drivers/pci/probe.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
drivers/pci/probe.c +4 -4
@@ -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);
Signature · 1 line
2.17.1
Hi Bjorn. Have you checked this little improvment? The idea here is that this is not a hotspot, so readbility matters than trick. Thanks!
Quoted 51 lines · On Sat, Oct 13, 2018 at 08:49:19AM +0800, [email protected] wrote:
From: Du Changbin <[email protected]>
Currently, the
pci_size()function actually return 'size-1'. Make it return real size to avoid confusing.Signed-off-by Du Changbin <[email protected]>--- drivers/pci/probe.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)drivers/pci/probe.c +4
-4@@ -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);Signature · 1 line
2.17.1
Signature · 2 lines
Thanks, Du Changbin
Bjorn Helgaas
AppliedQuoted 6 lines · On Sat, Oct 13, 2018 at 08:49:19AM +0800, [email protected] wrote:
From: Du Changbin <[email protected]>
Currently, the
pci_size()function actually return 'size-1'. Make it return real size to avoid confusing.Signed-off-by Du Changbin <[email protected]>
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.
Quoted 45 lines
--- drivers/pci/probe.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)drivers/pci/probe.c +4
-4@@ -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);Signature · 1 line
2.17.1