Subject: [PATCH v4 07/10] irqchip / GICv3 / ACPI: Add GICR support via GICC structures

From: [email-masked] (Hanjun Guo)
Date: Wed, 05 Aug 2015 22:11:22 +0800

On 08/04/2015 09:37 PM, Marc Zyngier wrote:
> On 29/07/15 11:08, Hanjun Guo wrote:
>> On systems supporting GICv3 and above, in MADT GICC structures, the
>> field of GICR Base Address holds the 64-bit physical address of the
>> associated Redistributor if the GIC Redistributors are not in the
>> always-on power domain, so instead of init GICR regions via GIC
>> redistributor structure(s), init it with GICR base address in GICC
>> structures in that case.
>>
>> As GICR base in MADT GICC is another way to indicate the GIC version
>> is 3 or 4, add its support to find out the GIC versions.
>>
>> Signed-off-by: Hanjun Guo <[email-masked]>
>> ---
>>   drivers/irqchip/irq-gic-acpi.c       |  35 ++++++-
>>   drivers/irqchip/irq-gic-v3.c         | 197 +++++++++++++++++++++++++++++++----
>>   include/linux/irqchip/arm-gic-acpi.h |   2 +
>>   3 files changed, 215 insertions(+), 19 deletions(-)
>>
>> diff --git a/drivers/irqchip/irq-gic-acpi.c b/drivers/irqchip/irq-gic-acpi.c
>> index 95454e3..3e5c8f4 100644
>> --- a/drivers/irqchip/irq-gic-acpi.c
>> +++ b/drivers/irqchip/irq-gic-acpi.c
>> @@ -21,6 +21,11 @@ static u8 gic_version __initdata = ACPI_MADT_GIC_VERSION_NONE;
>>
>>   static phys_addr_t dist_phy_base __initdata;
>>
>> +u8 __init acpi_gic_version(void)
>> +{
>> +       return gic_version;
>> +}
>> +
>>   static int __init
>>   acpi_gic_parse_distributor(struct acpi_subtable_header *header,
>>                             const unsigned long end)
>> @@ -38,6 +43,27 @@ acpi_gic_parse_distributor(struct acpi_subtable_header *header,
>>   }
>>
>>   static int __init
>> +gic_acpi_parse_madt_gicc(struct acpi_subtable_header *header,
>> +                        const unsigned long end)
>> +{
>> +       struct acpi_madt_generic_interrupt *gicc;
>> +
>> +       gicc = (struct acpi_madt_generic_interrupt *)header;
>> +
>> +       if (BAD_MADT_GICC_ENTRY(gicc, end))
>> +               return -EINVAL;
>> +
>> +       /*
>> +        * If GICC is enabled but has no valid gicr base address, then it
>> +        * means GICR base is not presented via GICC
>> +        */
>> +       if ((gicc->flags & ACPI_MADT_ENABLED) && !gicc->gicr_base_address)
>> +               return -ENODEV;
>> +
>> +       return 0;
>> +}
>> +
>> +static int __init
>>   match_gic_redist(struct acpi_subtable_header *header, const unsigned long end)
>>   {
>>          return 0;
>> @@ -51,7 +77,14 @@ static bool __init acpi_gic_redist_is_present(void)
>>          count  =  acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_REDISTRIBUTOR,
>>                                          match_gic_redist, 0);
>>
>> -       /* that's true if we have at least one GIC redistributor entry */
>> +       /* has at least one GIC redistributor entry */
>> +       if (count > 0)
>> +               return true;
>> +
>> +       /* else try to find GICR base in GICC entries */
>> +       count = acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_INTERRUPT,
>> +                                     gic_acpi_parse_madt_gicc, 0);
>> +
>>          return count > 0;
>>   }
>>
>> diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c
>> index ebc5604..b72ccbb 100644
>> --- a/drivers/irqchip/irq-gic-v3.c
>> +++ b/drivers/irqchip/irq-gic-v3.c
>> @@ -389,9 +389,8 @@ static void __init gic_dist_init(void)
>>                  writeq_relaxed(affinity, base + GICD_IROUTER + i * 8);
>>   }
>>
>> -static int gic_populate_rdist(void)
>> +static int gic_populate_rdist_with_regions(u64 mpidr)
>>   {
>> -       u64 mpidr = cpu_logical_map(smp_processor_id());
>>          u64 typer;
>>          u32 aff;
>>          int i;
>> @@ -439,6 +438,34 @@ static int gic_populate_rdist(void)
>>                  } while (!(typer & GICR_TYPER_LAST));
>>          }
>>
>> +       return -ENODEV;
>> +}
>> +
>> +#ifdef CONFIG_ACPI
>> +/*
>> + * Populate redist when GIC redistributor address is presented in ACPI
>> + * MADT GICC entries
>> + */
>> +static int gic_populate_rdist_with_gicr_base(u64 mpidr);
>> +#else
>> +static inline int gic_populate_rdist_with_gicr_base(u64 mpidr)
>> +{
>> +       return -ENODEV;
>> +}
>> +#endif
>> +
>> +static int gic_populate_rdist(void)
>> +{
>> +       u64 mpidr = cpu_logical_map(smp_processor_id());
>> +
>> +       if (gic_data.nr_redist_regions) {
>> +               if (!gic_populate_rdist_with_regions(mpidr))
>> +                       return 0;
>> +       } else {
>> +               if (!gic_populate_rdist_with_gicr_base(mpidr))
>> +                       return 0;
>> +       }
>> +
>>          /* We couldn't even deal with ourselves... */
>>          WARN(true, "CPU%d: mpidr %llx has no re-distributor!\n",
>>               smp_processor_id(), (unsigned long long)mpidr);
>> @@ -900,6 +927,16 @@ IRQCHIP_DECLARE(gic_v3, "arm,gic-v3", gic_of_init);
>>   #endif
>>
>>   #ifdef CONFIG_ACPI
>> +
>> +struct acpi_gicc_redist {
>> +       struct list_head list;
>> +       u64 mpidr;
>> +       phys_addr_t phys_base;
>> +       void __iomem *redist_base;
>> +};
>> +
>> +static LIST_HEAD(redist_list);
>> +
>>   static struct redist_region *redist_regs __initdata;
>>   static u32 nr_redist_regions __initdata;
>>   static phys_addr_t dist_phys_base __initdata;
>> @@ -932,6 +969,17 @@ gic_acpi_register_redist(u64 phys_base, u64 size)
>>          return 0;
>>   }
>>
>> +static void __init
>> +gic_acpi_release_redist_regions(void)
>> +{
>> +       int i;
>> +
>> +       for (i = 0; i < nr_redist_regions; i++)
>> +               if (redist_regs[i].redist_base)
>> +                       iounmap(redist_regs[i].redist_base);
>> +       kfree(redist_regs);
>> +}
>> +
>>   static int __init
>>   gic_acpi_parse_madt_redist(struct acpi_subtable_header *header,
>>                          const unsigned long end)
>> @@ -989,9 +1037,130 @@ static int gic_acpi_gsi_desc_populate(struct acpi_gsi_descriptor *data,
>>   }
>>
>>   static int __init
>> +gic_acpi_add_gicc_redist(phys_addr_t phys_base, u64 mpidr)
>> +{
>> +       struct acpi_gicc_redist *redist;
>> +
>> +       redist = kzalloc(sizeof(*redist), GFP_KERNEL);
>> +       if (!redist)
>> +               return -ENOMEM;
>> +
>> +       redist->mpidr = mpidr;
>> +       redist->phys_base = phys_base;
>> +
>> +       if (acpi_gic_version() == ACPI_MADT_GIC_VERSION_V3)
>> +               /* RD_base + SGI_base */
>> +               redist->redist_base = ioremap(phys_base, 2 * SZ_64K);
>> +       else
>> +               /*
>> +                * RD_base + SGI_base + VLPI_base,
>> +                * we don't map reserved page as it's buggy to access it
>> +                */
>> +               redist->redist_base = ioremap(phys_base, 3 * SZ_64K);
>> +
>> +       if (!redist->redist_base) {
>> +               kfree(redist);
>> +               return -ENOMEM;
>> +       }
>> +
>> +       list_add(&redist->list, &redist_list);
>> +       return 0;
>> +}
>> +
>> +static void __init
>> +gic_acpi_release_gicc_redist(void)
>> +{
>> +       struct acpi_gicc_redist *redist, *t;
>> +
>> +       list_for_each_entry_safe(redist, t, &redist_list, list) {
>> +               list_del(&redist->list);
>> +               iounmap(redist->redist_base);
>> +               kfree(redist);
>> +       }
>> +}
>> +
>> +static int __init
>> +gic_acpi_parse_madt_gicc(struct acpi_subtable_header *header,
>> +                        const unsigned long end)
>> +{
>> +       struct acpi_madt_generic_interrupt *gicc;
>> +
>> +       gicc = (struct acpi_madt_generic_interrupt *)header;
>> +
>> +       if (BAD_MADT_GICC_ENTRY(gicc, end))
>> +               return -EINVAL;
>> +
>> +       /*
>> +        * just quietly ingore the disabled CPU(s) and continue
>> +        * to find the enabled one(s), if we return error here,
>> +        * the scanning will be stopped.
>> +        */
>> +       if (!(gicc->flags & ACPI_MADT_ENABLED))
>> +               return 0;
>> +
>> +       return gic_acpi_add_gicc_redist(gicc->gicr_base_address,
>> +                                       gicc->arm_mpidr);
>> +}
>> +
>> +static int gic_populate_rdist_with_gicr_base(u64 mpidr)
>> +{
>> +       struct acpi_gicc_redist *redist;
>> +       void __iomem *ptr;
>> +       u32 reg;
>> +
>> +       list_for_each_entry(redist, &redist_list, list) {
>> +               if (redist->mpidr != mpidr)
>> +                       continue;
>> +
>> +               ptr = redist->redist_base;
>> +               reg = readl_relaxed(ptr + GICR_PIDR2) & GIC_PIDR2_ARCH_MASK;
>> +               if (reg != GIC_PIDR2_ARCH_GICv3 && reg != GIC_PIDR2_ARCH_GICv4) {
>> +                       pr_warn("No redistributor present @%p\n", ptr);
>> +                       return -ENODEV;
>> +               }
>> +
>> +               gic_data_rdist_rd_base() = ptr;
>> +               gic_data_rdist()->phys_base = redist->phys_base;
>> +               pr_info("CPU%d: found redistributor %llx phys base:%pa\n",
>> +                       smp_processor_id(),
>> +                       (unsigned long long)mpidr,
>> +                       &gic_data_rdist()->phys_base);
>> +               return 0;
>> +       }
>> +
>> +       return -ENODEV;
>> +}
>> +
>> +static int __init collect_gicr_base(struct acpi_table_header *table)
>> +{
>> +       int count;
>> +
>> +       /* Collect redistributor base addresses in GICR entries */
>> +       count = acpi_parse_entries(ACPI_SIG_MADT,
>> +                       sizeof(struct acpi_table_madt),
>> +                       gic_acpi_parse_madt_redist, table,
>> +                       ACPI_MADT_TYPE_GENERIC_REDISTRIBUTOR, 0);
>> +       if (count > 0)
>> +               return 0;
>> +
>> +       pr_info("No valid GICR entries exist, try GICC entries\n");
>> +
>> +       /* Collect redistributor base addresses in GICC entries */
>> +       count = acpi_parse_entries(ACPI_SIG_MADT,
>> +                       sizeof(struct acpi_table_madt),
>> +                       gic_acpi_parse_madt_gicc, table,
>> +                       ACPI_MADT_TYPE_GENERIC_INTERRUPT, 0);
>> +       if (count > 0 && !list_empty(&redist_list))
>> +               return 0;
>> +
>> +       pr_info("No valid GICC entries exist for GICR base\n");
>> +       return -ENODEV;
>> +}
>> +
>> +static int __init
>>   gic_acpi_init(struct acpi_table_header *table)
>>   {
>> -       int count, i, err = 0;
>> +       int count, err = 0;
>>          void __iomem *dist_base;
>>
>>          /* Get distributor base address */
>> @@ -1020,30 +1189,22 @@ gic_acpi_init(struct acpi_table_header *table)
>>          }
>>
>>          /* Collect redistributor base addresses */
>> -       count = acpi_parse_entries(ACPI_SIG_MADT,
>> -                       sizeof(struct acpi_table_madt),
>> -                       gic_acpi_parse_madt_redist, table,
>> -                       ACPI_MADT_TYPE_GENERIC_REDISTRIBUTOR, 0);
>> -       if (count <= 0) {
>> -               pr_info("No valid GICR entries exist\n");
>> -               err = -EINVAL;
>> -               goto out_redist_unmap;
>> -       }
>> +       if (collect_gicr_base(table))
>> +               goto out_release_redist;
>>
>>          err = gic_init_bases(dist_base, redist_regs, nr_redist_regions, 0,
>>                               (void *)ACPI_IRQ_MODEL_GIC);
>>          if (err)
>> -               goto out_redist_unmap;
>> +               goto out_release_redist;
>>
>>          acpi_set_irq_model(ACPI_IRQ_MODEL_GIC, ACPI_IRQ_MODEL_GIC,
>>                             gic_acpi_gsi_desc_populate);
>>          return 0;
>>
>> -out_redist_unmap:
>> -       for (i = 0; i < nr_redist_regions; i++)
>> -               if (redist_regs[i].redist_base)
>> -                       iounmap(redist_regs[i].redist_base);
>> -       kfree(redist_regs);
>> +out_release_redist:
>> +       gic_acpi_release_redist_regions();
>> +       if (!list_empty(&redist_list))
>> +               gic_acpi_release_gicc_redist();
>>   out_dist_unmap:
>>          iounmap(dist_base);
>>          return err;
>> diff --git a/include/linux/irqchip/arm-gic-acpi.h b/include/linux/irqchip/arm-gic-acpi.h
>> index 56cd82c..0d43f515 100644
>> --- a/include/linux/irqchip/arm-gic-acpi.h
>> +++ b/include/linux/irqchip/arm-gic-acpi.h
>> @@ -21,5 +21,7 @@
>>   #define ACPI_GIC_CPU_IF_MEM_SIZE       (SZ_8K)
>>   #define ACPI_GICV3_DIST_MEM_SIZE       (SZ_64K)
>>
>> +u8 acpi_gic_version(void);
>> +
>>   #endif /* CONFIG_ACPI */
>>   #endif /* ARM_GIC_ACPI_H_ */
>> --
>> 1.9.1
>>
>
> This looks absolutely horrid. Why don't you simply populate one region
> per redistributor, add a flag to struct redist_region so we know not to
> check for GICR_TYPER_LAST but to move on to the next region instead?

There is no regions in GICC structures, and only have the GICR base
address for each CPU, I think we can't figure out which GICR bases
are belonging to a GICR region.

So do you mean populate each GICR base as a region, and use the
existing infrastructure ?

Thanks
Hanjun