From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lorenzo Pieralisi Subject: Re: [PATCH v2 1/4] acpi/irq: implement getter for GSI irqdomain Date: Fri, 24 May 2019 11:00:05 +0100 Message-ID: <20190524100005.GB16829@redmoon> References: <20190429131208.3620-1-ard.biesheuvel@linaro.org> <20190429131208.3620-2-ard.biesheuvel@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <20190429131208.3620-2-ard.biesheuvel@linaro.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Ard Biesheuvel Cc: Graeme Gregory , linux-acpi@vger.kernel.org, Marc Zyngier , Linus Walleij , "Rafael J. Wysocki" , linux-gpio@vger.kernel.org, Masahisa Kojima , Mika Westerberg , linux-arm-kernel@lists.infradead.org, Len Brown List-Id: linux-gpio@vger.kernel.org On Mon, Apr 29, 2019 at 03:12:05PM +0200, Ard Biesheuvel wrote: > ACPI permits arbitrary producer->consumer interrupt links to be > described in AML, which means a topology such as the following > is perfectly legal: > > Device (EXIU) { > Name (_HID, "SCX0008") > Name (_UID, Zero) > Name (_CRS, ResourceTemplate () { > ... > }) > } > > Device (GPIO) { > Name (_HID, "SCX0007") > Name (_UID, Zero) > Name (_CRS, ResourceTemplate () { > Memory32Fixed (ReadWrite, SYNQUACER_GPIO_BASE, SYNQUACER_GPIO_SIZE) > Interrupt (ResourceConsumer, Edge, ActiveHigh, ExclusiveAndWake, 0, "\\_SB.EXIU") { > 7, > } > }) > ... > } > > The EXIU in this example is the external interrupt unit as can be found > on Socionext SynQuacer based platforms, which converts a block of 32 SPIs > from arbitrary polarity/trigger into level-high, with a separate set > of config/mask/unmask/clear controls. > > The existing DT based driver in drivers/irqchip/irq-sni-exiu.c models > this as a hierarchical domain stacked on top of the GIC's irqdomain. > Since the GIC is modeled as a DT node as well, obtaining a reference > to this irqdomain is easily done by going through the parent link. > > On ACPI systems, however, the GIC is not modeled as an object in the > namespace, and so device objects cannot refer to it directly. So in > order to obtain the irqdomain reference when driving the EXIU in ACPI > mode, we need a helper that returns the default domain for unqualified > interrupts. > > This is essentially what the ACPI GSI domain provides, so add a helper > that returns a reference to this domain. Or we directly export a function in: drivers/acpi/irq.c that creates a hierarchical domain with the default GSI domain as a parent, instead of exporting a function to get that domain from drivers, this should cut a bit of boilerplate and keep the default GSI domain handling in ACPI core. IIUC, the concept is a bit identical to what we did for MBIgen except that there IORT sets-up the device->msi_domain pointer and therefore the MBIgen driver does not have to do anything. Lorenzo > Signed-off-by: Ard Biesheuvel > --- > drivers/acpi/irq.c | 14 ++++++++++---- > include/linux/acpi.h | 1 + > 2 files changed, 11 insertions(+), 4 deletions(-) > > diff --git a/drivers/acpi/irq.c b/drivers/acpi/irq.c > index c3b2222e2129..d47bbd54d4aa 100644 > --- a/drivers/acpi/irq.c > +++ b/drivers/acpi/irq.c > @@ -17,6 +17,14 @@ enum acpi_irq_model_id acpi_irq_model; > > static struct fwnode_handle *acpi_gsi_domain_id; > > +/** > + * acpi_get_gsi_irqdomain - Retrieve the irqdomain that owns the GSI space. > + */ > +struct irq_domain *acpi_get_gsi_irqdomain(void) > +{ > + return irq_find_matching_fwnode(acpi_gsi_domain_id, DOMAIN_BUS_ANY); > +} > + > /** > * acpi_gsi_to_irq() - Retrieve the linux irq number for a given GSI > * @gsi: GSI IRQ number to map > @@ -29,8 +37,7 @@ static struct fwnode_handle *acpi_gsi_domain_id; > */ > int acpi_gsi_to_irq(u32 gsi, unsigned int *irq) > { > - struct irq_domain *d = irq_find_matching_fwnode(acpi_gsi_domain_id, > - DOMAIN_BUS_ANY); > + struct irq_domain *d = acpi_get_gsi_irqdomain(); > > *irq = irq_find_mapping(d, gsi); > /* > @@ -76,8 +83,7 @@ EXPORT_SYMBOL_GPL(acpi_register_gsi); > */ > void acpi_unregister_gsi(u32 gsi) > { > - struct irq_domain *d = irq_find_matching_fwnode(acpi_gsi_domain_id, > - DOMAIN_BUS_ANY); > + struct irq_domain *d = acpi_get_gsi_irqdomain(); > int irq = irq_find_mapping(d, gsi); > > irq_dispose_mapping(irq); > diff --git a/include/linux/acpi.h b/include/linux/acpi.h > index d5dcebd7aad3..1016027dd626 100644 > --- a/include/linux/acpi.h > +++ b/include/linux/acpi.h > @@ -316,6 +316,7 @@ static inline bool acpi_sci_irq_valid(void) > extern int sbf_port; > extern unsigned long acpi_realmode_flags; > > +struct irq_domain *acpi_get_gsi_irqdomain(void); > int acpi_register_gsi (struct device *dev, u32 gsi, int triggering, int polarity); > int acpi_gsi_to_irq (u32 gsi, unsigned int *irq); > int acpi_isa_irq_to_gsi (unsigned isa_irq, u32 *gsi); > -- > 2.20.1 >