On 21.01.2016 19:22, Lorenzo Pieralisi wrote:
Hi Tomasz, On Wed, Jan 13, 2016 at 02:20:59PM +0100, Tomasz Nowicki wrote: [...]@@ -4796,14 +4797,34 @@ void pci_bus_assign_domain_nr(struct pci_bus *bus, struct device *parent) * API and update the use_dt_domains value to keep track of method we * are using to assign domain numbers (use_dt_domains = 0). * + * IF ACPI, we expect non-DT method (use_dt_domains == -1) + * and call _SEG method for corresponding host bridge device. + * If _SEG method does not exist, following ACPI spec (6.5.6) + * all PCI buses belong to domain 0. + * * All other combinations imply we have a platform that is trying - * to mix domain numbers obtained from DT and pci_get_new_domain_nr(), - * which is a recipe for domain mishandling and it is prevented by - * invalidating the domain value (domain = -1) and printing a - * corresponding error. + * to mix domain numbers obtained from DT, ACPI and + * pci_get_new_domain_nr(), which is a recipe for domain mishandling and + * it is prevented by invalidating the domain value (domain = -1) and + * printing a corresponding error. */ + if (domain >= 0 && use_dt_domains) { use_dt_domains = 1; +#ifdef CONFIG_ACPI + } else if (!acpi_disabled && use_dt_domains == -1) { + struct acpi_device *acpi_dev = to_acpi_device(parent); + unsigned long long segment = 0; + acpi_status status; + + status = acpi_evaluate_integer(acpi_dev->handle, + METHOD_NAME__SEG, NULL, + &segment); + if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) + dev_err(&acpi_dev->dev, "can't evaluate _SEG\n"); + + domain = segment; +#endifI think you can reshuffle a bit the code to make it easier to follow. How about this ? (on top of mainline, I just compiled it do not take it verbatim): -- >8 -- diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index d1a7105..467a316 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -7,6 +7,7 @@ * Copyright 1997 -- 2000 Martin Mares <mj@xxxxxx> */ +#include <linux/acpi.h> #include <linux/kernel.h> #include <linux/delay.h> #include <linux/init.h> @@ -4769,7 +4770,27 @@ int pci_get_new_domain_nr(void) } #ifdef CONFIG_PCI_DOMAINS_GENERIC -void pci_bus_assign_domain_nr(struct pci_bus *bus, struct device *parent) +/* Feel free to add this to drivers/acpi as a helper */ +#ifdef CONFIG_ACPI +int pci_bus_acpi_domain_nr(struct device *parent) +{ + struct acpi_device *acpi_dev = to_acpi_device(parent); + unsigned long long segment = 0; + acpi_status status; + + status = acpi_evaluate_integer(acpi_dev->handle, + METHOD_NAME__SEG, NULL, + &segment); + if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) + dev_err(&acpi_dev->dev, "can't evaluate _SEG\n"); + + return segment; +} +#else +int pci_bus_acpi_domain_nr(struct device *parent) { return -1; } +#endif + +int pci_bus_of_domain_nr(struct device *parent) { static int use_dt_domains = -1; int domain = of_get_pci_domain_nr(parent->of_node); @@ -4811,7 +4832,13 @@ void pci_bus_assign_domain_nr(struct pci_bus *bus, struct device *parent) domain = -1; } - bus->domain_nr = domain; + return domain; +} + +void pci_bus_assign_domain_nr(struct pci_bus *bus, struct device *parent) +{ + bus->domain_nr = acpi_disabled ? pci_bus_of_domain_nr(parent) : + pci_bus_acpi_domain_nr(parent); } #endif #endif
It looks nice, I will integrate your patch. Thanks! Tomasz -- 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
