On Fri, Jun 19, 2015 at 09:46:06AM +0100, Hanjun Guo wrote:
[...]
+static int __init +match_gic_redist(struct acpi_subtable_header *header, const unsigned long end) +{
- return 0;
+} +static bool __init acpi_gic_redist_is_present(void) +{
- int count;
- /* scan MADT table to find if we have redistributor entries */
- count = acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_REDISTRIBUTOR,
match_gic_redist, 0);- /* has at least one GIC redistributor entry */
- if (count > 0)
return true;- else
return false;+}
return count > 0;
What about systems where the redistributor data is in the GICC subtable ? Do you treat them as GIC V2 :) ?
On a side note, having to define an empty function like match_gic_redist is horrible.
I wonder whether it is not better to refactor map_madt_entry(), create a MADT subtable iterator out of it and make that code generic, instead of being forced to add these useless MADT handlers just to count entries, it is not the first I noticed.
+static int __init acpi_gic_version_init(void) +{
- int count;
- void __iomem *dist_base;
- u32 reg;
- count = acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_DISTRIBUTOR,
acpi_gic_parse_distributor, 0);- if (count <= 0) {
pr_err("No valid GIC distributor entry exists\n");return -ENODEV;- }
- if (gic_version >= ACPI_MADT_GIC_VERSION_RESERVED) {
pr_err("Invalid GIC version %d in MADT\n", gic_version);return -EINVAL;- }
- /*
* when the GIC version is 0, we fallback to hardware discovery.* this is also needed to keep compatiable with ACPI 5.1,* which has no gic_version field in distributor structure and* reserved as 0.** For hardware discovery, the offset for GICv1/2 and GICv3/4 to* get the GIC version is different (0xFE8 for GICv1/2 and 0xFFE8* for GICv3/4), so we need to handle it separately.
*/- if (gic_version == ACPI_MADT_GIC_VERSION_NONE) {
/* it's GICv3/v4 if redistributor is present */if (acpi_gic_redist_is_present()) {
See above, IIUC you might have systems with GIC v3 where this call would fail, and we do not want to fall back to GIC v2.
Lorenzo
dist_base = ioremap(dist_phy_base,ACPI_GICV3_DIST_MEM_SIZE);if (!dist_base)return -ENOMEM;reg = readl_relaxed(dist_base + GICD_PIDR2) &GIC_PIDR2_ARCH_MASK;if (reg == GIC_PIDR2_ARCH_GICv3)gic_version = ACPI_MADT_GIC_VERSION_V3;elsegic_version = ACPI_MADT_GIC_VERSION_V4;iounmap(dist_base);} else {gic_version = ACPI_MADT_GIC_VERSION_V2;}
- }
- return 0;
+} diff --git a/include/linux/irqchip/arm-gic-acpi.h b/include/linux/irqchip/arm-gic-acpi.h index de3419e..13bc676 100644 --- a/include/linux/irqchip/arm-gic-acpi.h +++ b/include/linux/irqchip/arm-gic-acpi.h @@ -19,6 +19,7 @@ */ #define ACPI_GICV2_DIST_MEM_SIZE (SZ_4K) #define ACPI_GIC_CPU_IF_MEM_SIZE (SZ_8K) +#define ACPI_GICV3_DIST_MEM_SIZE (SZ_64K) struct acpi_table_header; -- 1.9.1