| Message ID | 20190423082730.370-7-vidyas@nvidia.com (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Headers | show |
| Series | Add Tegra194 PCIe support | expand |
On Tue, Apr 23, 2019 at 01:57:20PM +0530, Vidya Sagar wrote: > Add extended configuration space capability search API using struct dw_pcie * > pointer > > Signed-off-by: Vidya Sagar <vidyas@nvidia.com> > Acked-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com> > --- > Changes from [v3]: > * None > > Changes from [v2]: > * None > > Changes from [v1]: > * This is a new patch in v2 series > > drivers/pci/controller/dwc/pcie-designware.c | 41 ++++++++++++++++++++ > drivers/pci/controller/dwc/pcie-designware.h | 1 + > 2 files changed, 42 insertions(+) > > diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c > index 6a98135244d6..ecf5fe8842f6 100644 > --- a/drivers/pci/controller/dwc/pcie-designware.c > +++ b/drivers/pci/controller/dwc/pcie-designware.c > @@ -53,6 +53,47 @@ u8 dw_pcie_find_capability(struct dw_pcie *pci, u8 cap) > return __dw_pcie_find_next_cap(pci, next_cap_ptr, cap); > } > Please make sure there's a comment here about why pci_find_ext_capability() can't be used (a comment covering both this and pci_find_capability() is fine, if the reason is the same). > +static int dw_pcie_find_next_ext_capability(struct dw_pcie *pci, int start, > + int cap) > +{ > + u32 header; > + int ttl; > + int pos = PCI_CFG_SPACE_SIZE; > + > + /* minimum 8 bytes per capability */ > + ttl = (PCI_CFG_SPACE_EXP_SIZE - PCI_CFG_SPACE_SIZE) / 8; > + > + if (start) > + pos = start; > + > + header = dw_pcie_readl_dbi(pci, pos); > + /* > + * If we have no capabilities, this is indicated by cap ID, > + * cap version and next pointer all being 0. > + */ > + if (header == 0) > + return 0; > + > + while (ttl-- > 0) { > + if (PCI_EXT_CAP_ID(header) == cap && pos != start) > + return pos; > + > + pos = PCI_EXT_CAP_NEXT(header); > + if (pos < PCI_CFG_SPACE_SIZE) > + break; > + > + header = dw_pcie_readl_dbi(pci, pos); > + } > + > + return 0; > +} > + > +int dw_pcie_find_ext_capability(struct dw_pcie *pci, int cap) > +{ > + return dw_pcie_find_next_ext_capability(pci, 0, cap); > +} > +EXPORT_SYMBOL_GPL(dw_pcie_find_ext_capability); > + > int dw_pcie_read(void __iomem *addr, int size, u32 *val) > { > if (!IS_ALIGNED((uintptr_t)addr, size)) { > diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h > index 35160b4ce929..67307842e003 100644 > --- a/drivers/pci/controller/dwc/pcie-designware.h > +++ b/drivers/pci/controller/dwc/pcie-designware.h > @@ -249,6 +249,7 @@ struct dw_pcie { > container_of((endpoint), struct dw_pcie, ep) > > u8 dw_pcie_find_capability(struct dw_pcie *pci, u8 cap); > +int dw_pcie_find_ext_capability(struct dw_pcie *pci, int cap); > > int dw_pcie_read(void __iomem *addr, int size, u32 *val); > int dw_pcie_write(void __iomem *addr, int size, u32 val); > -- > 2.17.1 >
On 4/24/2019 2:05 AM, Bjorn Helgaas wrote: > On Tue, Apr 23, 2019 at 01:57:20PM +0530, Vidya Sagar wrote: >> Add extended configuration space capability search API using struct dw_pcie * >> pointer >> >> Signed-off-by: Vidya Sagar <vidyas@nvidia.com> >> Acked-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com> >> --- >> Changes from [v3]: >> * None >> >> Changes from [v2]: >> * None >> >> Changes from [v1]: >> * This is a new patch in v2 series >> >> drivers/pci/controller/dwc/pcie-designware.c | 41 ++++++++++++++++++++ >> drivers/pci/controller/dwc/pcie-designware.h | 1 + >> 2 files changed, 42 insertions(+) >> >> diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c >> index 6a98135244d6..ecf5fe8842f6 100644 >> --- a/drivers/pci/controller/dwc/pcie-designware.c >> +++ b/drivers/pci/controller/dwc/pcie-designware.c >> @@ -53,6 +53,47 @@ u8 dw_pcie_find_capability(struct dw_pcie *pci, u8 cap) >> return __dw_pcie_find_next_cap(pci, next_cap_ptr, cap); >> } >> > > Please make sure there's a comment here about why > pci_find_ext_capability() can't be used (a comment covering both this > and pci_find_capability() is fine, if the reason is the same). Reason is same that standard pci_find_ext_capability() uses 'struct pci_dev *dev' pointer and can only be used post enumeration whereas APIs being added here use 'struct dw_pcie *pci' and can be used before link up also. I'll add a comment in the other patch where I'm moving these APIs from pcie-designware-ep.c file to pcie-designware.c file. > >> +static int dw_pcie_find_next_ext_capability(struct dw_pcie *pci, int start, >> + int cap) >> +{ >> + u32 header; >> + int ttl; >> + int pos = PCI_CFG_SPACE_SIZE; >> + >> + /* minimum 8 bytes per capability */ >> + ttl = (PCI_CFG_SPACE_EXP_SIZE - PCI_CFG_SPACE_SIZE) / 8; >> + >> + if (start) >> + pos = start; >> + >> + header = dw_pcie_readl_dbi(pci, pos); >> + /* >> + * If we have no capabilities, this is indicated by cap ID, >> + * cap version and next pointer all being 0. >> + */ >> + if (header == 0) >> + return 0; >> + >> + while (ttl-- > 0) { >> + if (PCI_EXT_CAP_ID(header) == cap && pos != start) >> + return pos; >> + >> + pos = PCI_EXT_CAP_NEXT(header); >> + if (pos < PCI_CFG_SPACE_SIZE) >> + break; >> + >> + header = dw_pcie_readl_dbi(pci, pos); >> + } >> + >> + return 0; >> +} >> + >> +int dw_pcie_find_ext_capability(struct dw_pcie *pci, int cap) >> +{ >> + return dw_pcie_find_next_ext_capability(pci, 0, cap); >> +} >> +EXPORT_SYMBOL_GPL(dw_pcie_find_ext_capability); >> + >> int dw_pcie_read(void __iomem *addr, int size, u32 *val) >> { >> if (!IS_ALIGNED((uintptr_t)addr, size)) { >> diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h >> index 35160b4ce929..67307842e003 100644 >> --- a/drivers/pci/controller/dwc/pcie-designware.h >> +++ b/drivers/pci/controller/dwc/pcie-designware.h >> @@ -249,6 +249,7 @@ struct dw_pcie { >> container_of((endpoint), struct dw_pcie, ep) >> >> u8 dw_pcie_find_capability(struct dw_pcie *pci, u8 cap); >> +int dw_pcie_find_ext_capability(struct dw_pcie *pci, int cap); >> >> int dw_pcie_read(void __iomem *addr, int size, u32 *val); >> int dw_pcie_write(void __iomem *addr, int size, u32 val); >> -- >> 2.17.1 >>
diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c index 6a98135244d6..ecf5fe8842f6 100644 --- a/drivers/pci/controller/dwc/pcie-designware.c +++ b/drivers/pci/controller/dwc/pcie-designware.c @@ -53,6 +53,47 @@ u8 dw_pcie_find_capability(struct dw_pcie *pci, u8 cap) return __dw_pcie_find_next_cap(pci, next_cap_ptr, cap); } +static int dw_pcie_find_next_ext_capability(struct dw_pcie *pci, int start, + int cap) +{ + u32 header; + int ttl; + int pos = PCI_CFG_SPACE_SIZE; + + /* minimum 8 bytes per capability */ + ttl = (PCI_CFG_SPACE_EXP_SIZE - PCI_CFG_SPACE_SIZE) / 8; + + if (start) + pos = start; + + header = dw_pcie_readl_dbi(pci, pos); + /* + * If we have no capabilities, this is indicated by cap ID, + * cap version and next pointer all being 0. + */ + if (header == 0) + return 0; + + while (ttl-- > 0) { + if (PCI_EXT_CAP_ID(header) == cap && pos != start) + return pos; + + pos = PCI_EXT_CAP_NEXT(header); + if (pos < PCI_CFG_SPACE_SIZE) + break; + + header = dw_pcie_readl_dbi(pci, pos); + } + + return 0; +} + +int dw_pcie_find_ext_capability(struct dw_pcie *pci, int cap) +{ + return dw_pcie_find_next_ext_capability(pci, 0, cap); +} +EXPORT_SYMBOL_GPL(dw_pcie_find_ext_capability); + int dw_pcie_read(void __iomem *addr, int size, u32 *val) { if (!IS_ALIGNED((uintptr_t)addr, size)) { diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h index 35160b4ce929..67307842e003 100644 --- a/drivers/pci/controller/dwc/pcie-designware.h +++ b/drivers/pci/controller/dwc/pcie-designware.h @@ -249,6 +249,7 @@ struct dw_pcie { container_of((endpoint), struct dw_pcie, ep) u8 dw_pcie_find_capability(struct dw_pcie *pci, u8 cap); +int dw_pcie_find_ext_capability(struct dw_pcie *pci, int cap); int dw_pcie_read(void __iomem *addr, int size, u32 *val); int dw_pcie_write(void __iomem *addr, int size, u32 val);