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;
> +#endif
I 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
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