Re: [PATCH V5 5/7] irqchip, gicv3, its: Probe ITS in the ACPI way.

Marc Zyngier
2016-06-04T11:55:47Z

On Tue, 31 May 2016 13:19:42 +0200
Tomasz Nowicki <tn@semihalf.com> wrote:

> ITS is prepared for being initialized different than DT,
> therefore we can initialize it in ACPI way. We collect register base
> address from MADT table and pass mandatory info to firmware-agnostic
> ITS init call.
>
> Note that we are using here IORT lib to register ITS domain which
> then can be found and used on to build another PCI MSI domain
> in hierarchical stack domain.
>
> Signed-off-by: Tomasz Nowicki <tn@semihalf.com>
> ---
> drivers/irqchip/Kconfig | 1 +
> drivers/irqchip/irq-gic-v3-its.c | 60 ++++++++++++++++++++++++++++++++++++++++
> 2 files changed, 61 insertions(+)
>
> diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
> index fa33c50..c6e652f 100644
> --- a/drivers/irqchip/Kconfig
> +++ b/drivers/irqchip/Kconfig
> @@ -32,6 +32,7 @@ config ARM_GIC_V3
> config ARM_GIC_V3_ITS
> bool
> select PCI_MSI_IRQ_DOMAIN
> + select IORT_TABLE if ACPI
>
> config ARM_NVIC
> bool
> diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
> index 6a97ee5..c8f36a5 100644
> --- a/drivers/irqchip/irq-gic-v3-its.c
> +++ b/drivers/irqchip/irq-gic-v3-its.c
> @@ -15,10 +15,13 @@
> * along with this program. If not, see <http://www.gnu.org/licenses/>.
> */
>
> +#include <linux/acpi.h>
> #include <linux/bitmap.h>
> #include <linux/cpu.h>
> #include <linux/delay.h>
> #include <linux/interrupt.h>
> +#include <linux/irqdomain.h>
> +#include <linux/iort.h>
> #include <linux/log2.h>
> #include <linux/mm.h>
> #include <linux/msi.h>
> @@ -1312,6 +1315,11 @@ static int its_irq_gic_domain_alloc(struct irq_domain *domain,
> fwspec.param[0] = GIC_IRQ_TYPE_LPI;
> fwspec.param[1] = hwirq;
> fwspec.param[2] = IRQ_TYPE_EDGE_RISING;
> + } else if (is_fwnode_irqchip(domain->parent->fwnode)) {
> + fwspec.fwnode = domain->parent->fwnode;
> + fwspec.param_count = 2;
> + fwspec.param[0] = hwirq;
> + fwspec.param[1] = IRQ_TYPE_EDGE_RISING;
> } else {
> return -EINVAL;
> }
> @@ -1645,6 +1653,56 @@ static int __init its_of_probe(struct device_node *node)
> return 0;
> }
>
> +#ifdef CONFIG_ACPI
> +
> +#define ACPI_GICV3_ITS_MEM_SIZE (2 * SZ_64K)

SZ_128k?

> +
> +static int __init gic_acpi_parse_madt_its(struct acpi_subtable_header *header,
> + const unsigned long end)
> +{
> + struct acpi_madt_generic_translator *its_entry;
> + struct fwnode_handle *dom_handle;
> + struct resource res;
> + int err;
> +
> + its_entry = (struct acpi_madt_generic_translator *)header;
> + res.start = its_entry->base_address;
> + res.end = its_entry->base_address + ACPI_GICV3_ITS_MEM_SIZE - 1;
> +
> + dom_handle = irq_domain_alloc_fwnode((void *)its_entry->base_address);
> + if (!dom_handle) {
> + pr_err("ITS@%pa: Unable to allocate GICv3 ITS domain token\n",
> + &res.start);
> + return -ENOMEM;
> + }
> +
> + err = iort_register_domain_token(its_entry->translation_id, dom_handle);
> + if (err) {
> + pr_err("ITS@%pa: Unable to register GICv3 ITS domain token (ITS ID %d) to IORT\n",
> + &res.start, its_entry->translation_id);
> + goto dom_err;
> + }
> +
> + err = its_probe_one(&res, dom_handle);
> + if (!err)
> + return 0;
> +
> + iort_deregister_domain_token(its_entry->translation_id);
> +dom_err:
> + irq_domain_free_fwnode(dom_handle);
> + return err;
> +}
> +
> +void __init its_acpi_probe(void)

Should be static.

> +{
> + if (acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_TRANSLATOR,
> + gic_acpi_parse_madt_its, 0) <= 0)
> + pr_info("No valid GIC ITS entries exist\n");

We already have a message further down, no need to shout twice.

> +}
> +#else
> +static inline void __init its_acpi_probe(struct irq_domain *parent_domain) { }

Drop the inline, the compiler can figure out that by itself.

> +#endif
> +
> int __init its_init(struct fwnode_handle *handle, struct rdists *rdists,
> struct irq_domain *parent_domain)
> {
> @@ -1654,6 +1712,8 @@ int __init its_init(struct fwnode_handle *handle, struct rdists *rdists,
> of_node = to_of_node(handle);
> if (of_node)
> its_of_probe(of_node);
> + else
> + its_acpi_probe();
>
> if (list_empty(&its_nodes)) {
> pr_warn("ITS: No ITS available, not enabling LPIs\n");

Thanks,

M.
--
Jazz is not dead. It just smells funny.