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

From: Marc Zyngier
Date: Thu Aug 06 2015 - 12:42:59 EST


On 05/08/15 15:11, Hanjun Guo wrote:
> 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 <hanjun.guo@xxxxxxxxxx>
>>> ---
>>> 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 ?

This is exactly what I wrote.

Thanks,

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