Messages in this thread | | | Date | Thu, 04 Sep 2014 12:10:28 +0200 | From | Tomasz Nowicki <> | Subject | Re: [PATCH v3 13/17] ARM64 / ACPI: Add GICv2 specific ACPI boot support |
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On 03.09.2014 20:42, Arnd Bergmann wrote: > On Monday 01 September 2014 22:57:51 Hanjun Guo wrote: >> + /* Collect CPU base addresses */ >> + count = acpi_parse_entries(sizeof(struct acpi_table_madt), >> + gic_acpi_parse_madt_cpu, table, >> + ACPI_MADT_TYPE_GENERIC_INTERRUPT, >> + ACPI_MAX_GIC_CPU_INTERFACE_ENTRIES); >> + if (count < 0) { >> + pr_err("Error during GICC entries parsing\n"); >> + return -EFAULT; >> + } else if (!count) { >> + /* No GICC entries provided, use address from MADT header */ >> + struct acpi_table_madt *madt = (struct acpi_table_madt *)table; >> + >> + if (!madt->address) >> + return -EFAULT; >> + >> + cpu_phy_base = (u64)madt->address; >> + } > > After I read through ACPI-5.1 section 5.2.12.14, I wonder if this is the > best way to treat a missing ACPI_MADT_TYPE_GENERIC_INTERRUPT table. > > Do we expect to see those in practice? It seems like using the x86 local > APIC address as a fallback for the GIC address is not something we > should do unless we absolutely have to support a system that doesn't > have the GIC table.
No, we do not expect and hopefully there will be no such :)
But, we are trying to be as much as possible inline with 5.1 spec, 5.2.12.14 says: [...] If provided here (CPU physical base address), the "Local Interrupt Controller Address" field in the MADT must be ignored by the OSPM. [...]
Regards, Tomasz
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