[RFC part2 PATCH 9/9] ACPI / GIC: Initialize GIC using the information in MADT

Hanjun Guo
2013-12-03T16:41:28Z

In MADT table, there are GIC cpu interface base address and
GIC distributor base address, use them to convert GIC to ACPI.

Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>
---
arch/arm64/kernel/irq.c | 5 ++++
drivers/acpi/plat/arm-core.c | 66 ++++++++++++++++++++++++++++++++++++------
include/linux/acpi.h | 6 ++++
3 files changed, 68 insertions(+), 9 deletions(-)

diff --git a/arch/arm64/kernel/irq.c b/arch/arm64/kernel/irq.c
index 473e5db..a9e68bf 100644
--- a/arch/arm64/kernel/irq.c
+++ b/arch/arm64/kernel/irq.c
@@ -25,6 +25,7 @@
#include <linux/irq.h>
#include <linux/smp.h>
#include <linux/init.h>
+#include <linux/acpi.h>
#include <linux/irqchip.h>
#include <linux/seq_file.h>
#include <linux/ratelimit.h>
@@ -78,6 +79,10 @@ void __init set_handle_irq(void (*handle_irq)(struct pt_regs *))
void __init init_IRQ(void)
{
irqchip_init();
+
+ if (!handle_arch_irq)
+ acpi_gic_init();
+
if (!handle_arch_irq)
panic("No interrupt controller found.");
}
diff --git a/drivers/acpi/plat/arm-core.c b/drivers/acpi/plat/arm-core.c
index 17c99e1..509b847 100644
--- a/drivers/acpi/plat/arm-core.c
+++ b/drivers/acpi/plat/arm-core.c
@@ -29,6 +29,7 @@
#include <linux/module.h>
#include <linux/irq.h>
#include <linux/irqdomain.h>
+#include <linux/irqchip/arm-gic.h>
#include <linux/slab.h>
#include <linux/bootmem.h>
#include <linux/ioport.h>
@@ -211,11 +212,21 @@ acpi_parse_gic(struct acpi_subtable_header *header, const unsigned long end)
return 0;
}

+#ifdef CONFIG_ARM_GIC
+/*
+ * Hard code here, we can not get memory size from MADT (but FDT does),
+ * this size is described in ARMv8 foudation model's User Guide
+ */
+#define GIC_DISTRIBUTOR_MEMORY_SIZE (SZ_8K)
+#define GIC_CPU_INTERFACE_MEMORY_SIZE (SZ_4K)
+
static int __init
acpi_parse_gic_distributor(struct acpi_subtable_header *header,
const unsigned long end)
{
struct acpi_madt_generic_distributor *distributor = NULL;
+ void __iomem *dist_base = NULL;
+ void __iomem *cpu_base = NULL;

distributor = (struct acpi_madt_generic_distributor *)header;

@@ -224,8 +235,43 @@ acpi_parse_gic_distributor(struct acpi_subtable_header *header,

acpi_table_print_madt_entry(header);

+ /* GIC is initialised after page_init(), no need for early_ioremap */
+ dist_base = ioremap(distributor->base_address,
+ GIC_CPU_INTERFACE_MEMORY_SIZE);
+ if (!dist_base) {
+ pr_warn(PREFIX "unable to map gic dist registers\n");
+ return -ENOMEM;
+ }
+
+ /*
+ * acpi_lapic_addr is stored in acpi_parse_madt(),
+ * so we can use it here for GIC init
+ */
+ if (acpi_lapic_addr) {
+ iounmap(dist_base);
+ pr_warn(PREFIX "Invalid GIC cpu interface base address\n");
+ return -EINVAL;
+ }
+
+ cpu_base = ioremap(acpi_lapic_addr, GIC_CPU_INTERFACE_MEMORY_SIZE);
+ if (!cpu_base) {
+ iounmap(dist_base);
+ pr_warn(PREFIX "unable to map gic cpu registers\n");
+ return -ENOMEM;
+ }
+
+ gic_init(distributor->gic_id, -1, dist_base, cpu_base);
+
return 0;
}
+#else
+static int __init
+acpi_parse_gic_distributor(struct acpi_subtable_header *header,
+ const unsigned long end)
+{
+ return -ENODEV;
+}
+#endif /* CONFIG_ARM_GIC */

/*
* Parse GIC cpu interface related entries in MADT
@@ -234,7 +280,7 @@ acpi_parse_gic_distributor(struct acpi_subtable_header *header,
static int __init acpi_parse_madt_gic_entries(void)
{
int count;
-
+
/*
* do a partial walk of MADT to determine how many CPUs
* we have including disabled CPUs
@@ -468,19 +514,21 @@ static void __init acpi_process_madt(void)
* Parse MADT GIC cpu interface entries
*/
error = acpi_parse_madt_gic_entries();
- if (!error) {
- /*
- * Parse MADT GIC distributor entries
- */
- acpi_parse_madt_gic_distributor_entries();
- }
+ if (!error)
+ pr_info("Using ACPI for processor (GIC) configuration information\n");
}

- pr_info("Using ACPI for processor (GIC) configuration information\n");
-
return;
}

+int __init acpi_gic_init(void)
+{
+ /*
+ * Parse MADT GIC distributor entries
+ */
+ return acpi_parse_madt_gic_distributor_entries();
+}
+
/*
* acpi_boot_table_init() and acpi_boot_init()
* called from setup_arch(), always.
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index edd5806..58a4bf4 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -112,6 +112,7 @@ char * __acpi_map_table (unsigned long phys_addr, unsigned long size);
void __acpi_unmap_table(char *map, unsigned long size);
int early_acpi_boot_init(void);
int acpi_boot_init (void);
+int acpi_gic_init(void);
void acpi_boot_table_init (void);
int acpi_mps_check (void);
int acpi_numa_init (void);
@@ -444,6 +445,11 @@ static inline int acpi_boot_init(void)
return 0;
}

+static inline int acpi_gic_init(void)
+{
+ return -ENODEV;
+}
+
static inline void acpi_boot_table_init(void)
{
return;
--
1.7.9.5