Re: [PATCH v4 09/10] PCI: ACPI: Bind GIC MSI frame to PCI host bridge

[Hanjun Guo <hanjun.guo@linaro.org>]

On 08/04/2015 10:04 PM, Marc Zyngier wrote:
> On 29/07/15 11:08, Hanjun Guo wrote:
>> From: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
>>
>> This patch introduces pci_host_bridge_acpi_msi_domain(), which queries
>> a GIC MSI irq-domain token and use it to retrieve an irq_domain with
>> DOMAIN_BUS_PCI_MSI bus type, and bind it to PCI host-bridge.
>>
>> Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
>> Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>
>> ---
>>   drivers/pci/pci-acpi.c   | 18 ++++++++++++++++++
>>   drivers/pci/probe.c      |  3 +++
>>   include/linux/pci-acpi.h |  4 ++++
>>   3 files changed, 25 insertions(+)
>>
>> diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
>> index 314a625..5f11653 100644
>> --- a/drivers/pci/pci-acpi.c
>> +++ b/drivers/pci/pci-acpi.c
>> @@ -9,6 +9,7 @@
>>
>>   #include <linux/delay.h>
>>   #include <linux/init.h>
>> +#include <linux/irqdomain.h>
>>   #include <linux/pci.h>
>>   #include <linux/pci_hotplug.h>
>>   #include <linux/module.h>
>> @@ -16,6 +17,7 @@
>>   #include <linux/pci-acpi.h>
>>   #include <linux/pm_runtime.h>
>>   #include <linux/pm_qos.h>
>> +#include <acpi/acpi_gic.h>
>>   #include "pci.h"
>>
>>   /*
>> @@ -681,6 +683,22 @@ static bool pci_acpi_bus_match(struct device *dev)
>>   	return dev_is_pci(dev);
>>   }
>>
>> +#ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN
>> +struct irq_domain *pci_host_bridge_acpi_msi_domain(struct pci_bus *bus)
>> +{
>> +	struct irq_domain *d = NULL;
>> +	void *token = acpi_gic_get_msi_token(&bus->dev);
>
> Do you see why I positively *hate* having hardware details in generic
> layers? They propagate everywhere...
>
>> +
>> +	if (token)
>> +		d = irq_find_matching_host(token, DOMAIN_BUS_PCI_MSI);
>> +
>> +	if (!d)
>> +		pr_debug("Fail to find domain for MSI\n");
>> +
>> +	return d;
>> +}
>> +#endif /*CONFIG_GENERIC_MSI_IRQ_DOMAIN*/
>> +
>>   static struct acpi_bus_type acpi_pci_bus = {
>>   	.name = "PCI",
>>   	.match = pci_acpi_bus_match,
>> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
>> index a7afeac..8c1204c 100644
>> --- a/drivers/pci/probe.c
>> +++ b/drivers/pci/probe.c
>> @@ -12,6 +12,7 @@
>>   #include <linux/module.h>
>>   #include <linux/cpumask.h>
>>   #include <linux/pci-aspm.h>
>> +#include <linux/pci-acpi.h>
>>   #include <asm-generic/pci-bridge.h>
>>   #include "pci.h"
>>
>> @@ -670,6 +671,8 @@ static struct irq_domain *pci_host_bridge_msi_domain(struct pci_bus *bus)
>>   	 * should be called from here.
>>   	 */
>>   	d = pci_host_bridge_of_msi_domain(bus);
>> +	if (!d)
>> +		d = pci_host_bridge_acpi_msi_domain(bus);
>>
>>   	return d;
>>   }
>> diff --git a/include/linux/pci-acpi.h b/include/linux/pci-acpi.h
>> index a965efa..766d045 100644
>> --- a/include/linux/pci-acpi.h
>> +++ b/include/linux/pci-acpi.h
>> @@ -77,6 +77,8 @@ static inline void acpiphp_remove_slots(struct pci_bus *bus) { }
>>   static inline void acpiphp_check_host_bridge(struct acpi_device *adev) { }
>>   #endif
>>
>> +struct irq_domain *pci_host_bridge_acpi_msi_domain(struct pci_bus *bus);
>> +
>>   extern const u8 pci_acpi_dsm_uuid[];
>>   #define DEVICE_LABEL_DSM	0x07
>>   #define RESET_DELAY_DSM		0x08
>> @@ -85,6 +87,8 @@ extern const u8 pci_acpi_dsm_uuid[];
>>   #else	/* CONFIG_ACPI */
>>   static inline void acpi_pci_add_bus(struct pci_bus *bus) { }
>>   static inline void acpi_pci_remove_bus(struct pci_bus *bus) { }
>> +static inline struct irq_domain *
>> +pci_host_bridge_acpi_msi_domain(struct pci_bus *bus) { return NULL; }
>>   #endif	/* CONFIG_ACPI */
>>
>>   #ifdef CONFIG_ACPI_APEI
>>
>
> Once you solve the HW abstraction issue, this will be OK.

Sure, I will sync with Suravee to fix that.

Thanks for you comments!
Hanjun