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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