Hi Lorenzo Thanks for reviewing > -----Original Message----- > From: Lorenzo Pieralisi [mailto:lorenzo.pieralisi@xxxxxxx] > Sent: 22 November 2016 15:57 > To: liudongdong (C) > Cc: helgaas@xxxxxxxxxx; arnd@xxxxxxxx; rafael@xxxxxxxxxx; > tn@xxxxxxxxxxxx; Wangzhou (B); pratyush.anand@xxxxxxxxx; linux- > pci@xxxxxxxxxxxxxxx; linux-acpi@xxxxxxxxxxxxxxx; linux- > kernel@xxxxxxxxxxxxxxx; jcm@xxxxxxxxxx; Gabriele Paoloni; Chenxin > (Charles); hanjun.guo@xxxxxxxxxx; Linuxarm > Subject: Re: [PATCH V6 1/2] PCI/ACPI: Provide acpi_get_rc_resources() > for ARM64 platform > > On Tue, Nov 22, 2016 at 08:08:48PM +0800, Dongdong Liu wrote: > > The acpi_get_rc_resources() is used to get the RC register address > that can > > not be described in MCFG. It takes the _HID&segment to look for and > returns > > the RC address resource. Use PNP0C02 devices to describe such RC > address > > resource. Use _UID to match segment to tell which root bus the > PNP0C02 > > resource belong to. > > Here (ie interpreting the _UID as a segment identifier) is where we > start interpreting the specs instead of relying on them, if you want to > go ahead with this feel free but I do not like this attitude at all. Obviously there are no specs to specify the segment id of a quirk. Looking at the ACPI specs it seems to me that the _UID is no worse than other device identification objects... Maybe we can use the _SUN as an alternative solution? > > > Signed-off-by: Dongdong Liu <liudongdong3@xxxxxxxxxx> > > Signed-off-by: Tomasz Nowicki <tn@xxxxxxxxxxxx> > > --- > > drivers/pci/pci-acpi.c | 69 > ++++++++++++++++++++++++++++++++++++++++++++++++++ > > drivers/pci/pci.h | 4 +++ > > 2 files changed, 73 insertions(+) > > > > diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c > > index d966d47..76fd6f4 100644 > > --- a/drivers/pci/pci-acpi.c > > +++ b/drivers/pci/pci-acpi.c > > @@ -29,6 +29,75 @@ > > 0x91, 0x17, 0xea, 0x4d, 0x19, 0xc3, 0x43, 0x4d > > }; > > > > +#ifdef CONFIG_ARM64 > > CONFIG_PCI_ECAM_QUIRKS (that you will introduce earlier in your > series). > > The way you did it seems to imply that on ARM64 to get RC address we > need to (and are allowed to) use this function (and related, *Linux > specific*, ACPI bindings) and that's a generic way of getting config > space. It is not and it must not be and I consider it a bit of a > stretch > to have it in generic code but I can live with that as long as it comes > with its own config option that describes that this stuff is > non-compliant code used by non-compliant platform drivers. Yes probably better to have #ifdef CONFIG_PCI_ECAM_QUIRKS Thanks Gab > > Thanks, > Lorenzo > > > +static struct resource *acpi_get_rc_addr(struct acpi_device *adev) > > +{ > > + struct resource_entry *entry; > > + struct list_head list; > > + unsigned long flags; > > + int ret; > > + struct resource *res; > > + > > + INIT_LIST_HEAD(&list); > > + flags = IORESOURCE_MEM; > > + ret = acpi_dev_get_resources(adev, &list, > > + acpi_dev_filter_resource_type_cb, > > + (void *) flags); > > + if (ret <= 0) > > + return NULL; > > + > > + entry = list_first_entry(&list, struct resource_entry, node); > > + res = entry->res; > > + acpi_dev_free_resource_list(&list); > > + return res; > > +} > > + > > +static acpi_status acpi_match_rc(acpi_handle handle, u32 lvl, void > *context, > > + void **retval) > > +{ > > + u16 *segment = context; > > + unsigned long long uid; > > + acpi_status status; > > + > > + status = acpi_evaluate_integer(handle, "_UID", NULL, &uid); > > + if (ACPI_FAILURE(status) || uid != *segment) > > + return AE_CTRL_DEPTH; > > + > > + *(acpi_handle *)retval = handle; > > + return AE_CTRL_TERMINATE; > > +} > > + > > +/** > > + * acpi_get_rc_resources() - get the RC address resource. > > + * @hid: HID to search for. > > + * @segment: PCI Segment number. > > + * > > + * Get the RC address resource that can not be described in MCFG. It > takes > > + * the _HID&segment to look for and returns the RC address resource. > Use > > + * _CRS of PNP0C02 devices to describe such RC address resource. Use > _UID > > + * to match segment to tell which root bus the PNP0C02 resource > belong to. > > + * > > + * Return: RC address resource. > > + */ > > +struct resource *acpi_get_rc_resources(const char *hid, u16 segment) > > +{ > > + struct acpi_device *adev; > > + acpi_status status; > > + acpi_handle handle; > > + int ret; > > + > > + status = acpi_get_devices(hid, acpi_match_rc, &segment, &handle); > > + if (ACPI_FAILURE(status)) > > + return -ENODEV; > > + > > + ret = acpi_bus_get_device(handle, &adev); > > + if (ret) > > + return ret; > > + > > + return acpi_get_rc_addr(adev); > > +} > > +#endif > > + > > phys_addr_t acpi_pci_root_get_mcfg_addr(acpi_handle handle) > > { > > acpi_status status = AE_NOT_EXIST; > > diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h > > index 4518562..bf1dbfe 100644 > > --- a/drivers/pci/pci.h > > +++ b/drivers/pci/pci.h > > @@ -356,4 +356,8 @@ static inline int pci_dev_specific_reset(struct > pci_dev *dev, int probe) > > } > > #endif > > > > +#if defined(CONFIG_ARM64) && defined(CONFIG_ACPI) > > +struct resource *acpi_get_rc_resources(const char *hid, u16 > segment); > > +#endif > > + > > #endif /* DRIVERS_PCI_H */ > > -- > > 1.9.1 > > -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
