[PATCH v2 3/5] irqchip/gic: Convert the GIC driver to ACPI probing
Marc Zyngier
marc.zyngier at arm.com
Sun Sep 13 07:02:21 PDT 2015
Now that we have a basic infrastructure to register irqchips and
call them on discovery of a matching entry in MADT, convert the
GIC driver to this new probing method.
It ends up being a code deletion party, which is a rather good thing.
Signed-off-by: Marc Zyngier <marc.zyngier at arm.com>
---
arch/arm64/include/asm/acpi.h | 1 -
arch/arm64/include/asm/irq.h | 2 --
arch/arm64/kernel/acpi.c | 25 -------------
drivers/irqchip/irq-gic.c | 69 ++++++++++++++++++------------------
drivers/irqchip/irqchip.c | 3 --
include/linux/irqchip/arm-gic-acpi.h | 31 ----------------
6 files changed, 35 insertions(+), 96 deletions(-)
delete mode 100644 include/linux/irqchip/arm-gic-acpi.h
diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h
index 208cec0..6894205 100644
--- a/arch/arm64/include/asm/acpi.h
+++ b/arch/arm64/include/asm/acpi.h
@@ -12,7 +12,6 @@
#ifndef _ASM_ACPI_H
#define _ASM_ACPI_H
-#include <linux/irqchip/arm-gic-acpi.h>
#include <linux/mm.h>
#include <linux/psci.h>
diff --git a/arch/arm64/include/asm/irq.h b/arch/arm64/include/asm/irq.h
index 1a1037a..94c5367 100644
--- a/arch/arm64/include/asm/irq.h
+++ b/arch/arm64/include/asm/irq.h
@@ -1,8 +1,6 @@
#ifndef __ASM_IRQ_H
#define __ASM_IRQ_H
-#include <linux/irqchip/arm-gic-acpi.h>
-
#include <asm-generic/irq.h>
struct pt_regs;
diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c
index 19de753..d6463bb 100644
--- a/arch/arm64/kernel/acpi.c
+++ b/arch/arm64/kernel/acpi.c
@@ -205,28 +205,3 @@ void __init acpi_boot_table_init(void)
disable_acpi();
}
}
-
-void __init acpi_gic_init(void)
-{
- struct acpi_table_header *table;
- acpi_status status;
- acpi_size tbl_size;
- int err;
-
- if (acpi_disabled)
- return;
-
- status = acpi_get_table_with_size(ACPI_SIG_MADT, 0, &table, &tbl_size);
- if (ACPI_FAILURE(status)) {
- const char *msg = acpi_format_exception(status);
-
- pr_err("Failed to get MADT table, %s\n", msg);
- return;
- }
-
- err = gic_v2_acpi_init(table);
- if (err)
- pr_err("Failed to initialize GIC IRQ controller");
-
- early_acpi_os_unmap_memory((char *)table, tbl_size);
-}
diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c
index e6b7ed5..8a0b9c3 100644
--- a/drivers/irqchip/irq-gic.c
+++ b/drivers/irqchip/irq-gic.c
@@ -41,7 +41,6 @@
#include <linux/irqchip.h>
#include <linux/irqchip/chained_irq.h>
#include <linux/irqchip/arm-gic.h>
-#include <linux/irqchip/arm-gic-acpi.h>
#include <asm/cputype.h>
#include <asm/irq.h>
@@ -1177,7 +1176,7 @@ IRQCHIP_DECLARE(msm_qgic2, "qcom,msm-qgic2", gic_of_init);
#endif
#ifdef CONFIG_ACPI
-static phys_addr_t dist_phy_base, cpu_phy_base __initdata;
+static phys_addr_t cpu_phy_base __initdata;
static int __init
gic_acpi_parse_madt_cpu(struct acpi_subtable_header *header,
@@ -1205,60 +1204,56 @@ gic_acpi_parse_madt_cpu(struct acpi_subtable_header *header,
return 0;
}
-static int __init
-gic_acpi_parse_madt_distributor(struct acpi_subtable_header *header,
- const unsigned long end)
+/* The things you have to do to just *count* something... */
+static int __init acpi_dummy_func(struct acpi_subtable_header *header,
+ const unsigned long end)
{
- struct acpi_madt_generic_distributor *dist;
+ return 0;
+}
- dist = (struct acpi_madt_generic_distributor *)header;
+static bool __init acpi_gic_redist_is_present(void)
+{
+ return acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_REDISTRIBUTOR,
+ acpi_dummy_func, 0) > 0;
+}
- if (BAD_MADT_ENTRY(dist, end))
- return -EINVAL;
+static bool __init gic_validate_dist(struct acpi_subtable_header *header,
+ struct acpi_probe_entry *ape)
+{
+ struct acpi_madt_generic_distributor *dist;
+ dist = (struct acpi_madt_generic_distributor *)header;
- dist_phy_base = dist->base_address;
- return 0;
+ return (dist->version == ape->driver_data &&
+ (dist->version != ACPI_MADT_GIC_VERSION_NONE ||
+ !acpi_gic_redist_is_present()));
}
-int __init
-gic_v2_acpi_init(struct acpi_table_header *table)
+#define ACPI_GICV2_DIST_MEM_SIZE (SZ_4K)
+#define ACPI_GIC_CPU_IF_MEM_SIZE (SZ_8K)
+
+static int __init gic_v2_acpi_init(struct acpi_subtable_header *header,
+ const unsigned long end)
{
+ struct acpi_madt_generic_distributor *dist;
void __iomem *cpu_base, *dist_base;
int count;
/* Collect CPU base addresses */
- count = acpi_parse_entries(ACPI_SIG_MADT,
- sizeof(struct acpi_table_madt),
- gic_acpi_parse_madt_cpu, table,
- ACPI_MADT_TYPE_GENERIC_INTERRUPT, 0);
+ count = acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_INTERRUPT,
+ gic_acpi_parse_madt_cpu, 0);
if (count <= 0) {
pr_err("No valid GICC entries exist\n");
return -EINVAL;
}
- /*
- * Find distributor base address. We expect one distributor entry since
- * ACPI 5.1 spec neither support multi-GIC instances nor GIC cascade.
- */
- count = acpi_parse_entries(ACPI_SIG_MADT,
- sizeof(struct acpi_table_madt),
- gic_acpi_parse_madt_distributor, table,
- ACPI_MADT_TYPE_GENERIC_DISTRIBUTOR, 0);
- if (count <= 0) {
- pr_err("No valid GICD entries exist\n");
- return -EINVAL;
- } else if (count > 1) {
- pr_err("More than one GICD entry detected\n");
- return -EINVAL;
- }
-
cpu_base = ioremap(cpu_phy_base, ACPI_GIC_CPU_IF_MEM_SIZE);
if (!cpu_base) {
pr_err("Unable to map GICC registers\n");
return -ENOMEM;
}
- dist_base = ioremap(dist_phy_base, ACPI_GICV2_DIST_MEM_SIZE);
+ dist = (struct acpi_madt_generic_distributor *)header;
+ dist_base = ioremap(dist->base_address, ACPI_GICV2_DIST_MEM_SIZE);
if (!dist_base) {
pr_err("Unable to map GICD registers\n");
iounmap(cpu_base);
@@ -1284,4 +1279,10 @@ gic_v2_acpi_init(struct acpi_table_header *table)
acpi_irq_model = ACPI_IRQ_MODEL_GIC;
return 0;
}
+IRQCHIP_ACPI_DECLARE(gic_v2, ACPI_MADT_TYPE_GENERIC_DISTRIBUTOR,
+ gic_validate_dist, ACPI_MADT_GIC_VERSION_V2,
+ gic_v2_acpi_init);
+IRQCHIP_ACPI_DECLARE(gic_v2_maybe, ACPI_MADT_TYPE_GENERIC_DISTRIBUTOR,
+ gic_validate_dist, ACPI_MADT_GIC_VERSION_NONE,
+ gic_v2_acpi_init);
#endif
diff --git a/drivers/irqchip/irqchip.c b/drivers/irqchip/irqchip.c
index 1ee773e..2b35e68 100644
--- a/drivers/irqchip/irqchip.c
+++ b/drivers/irqchip/irqchip.c
@@ -27,8 +27,5 @@ extern struct of_device_id __irqchip_of_table[];
void __init irqchip_init(void)
{
of_irq_init(__irqchip_of_table);
-#if defined(CONFIG_ARM64) && defined(CONFIG_ACPI)
- acpi_gic_init(); /* Temporary hack */
-#endif
acpi_probe_device_table(irqchip);
}
diff --git a/include/linux/irqchip/arm-gic-acpi.h b/include/linux/irqchip/arm-gic-acpi.h
deleted file mode 100644
index de3419e..0000000
--- a/include/linux/irqchip/arm-gic-acpi.h
+++ /dev/null
@@ -1,31 +0,0 @@
-/*
- * Copyright (C) 2014, Linaro Ltd.
- * Author: Tomasz Nowicki <tomasz.nowicki at linaro.org>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- */
-
-#ifndef ARM_GIC_ACPI_H_
-#define ARM_GIC_ACPI_H_
-
-#ifdef CONFIG_ACPI
-
-/*
- * Hard code here, we can not get memory size from MADT (but FDT does),
- * Actually no need to do that, because this size can be inferred
- * from GIC spec.
- */
-#define ACPI_GICV2_DIST_MEM_SIZE (SZ_4K)
-#define ACPI_GIC_CPU_IF_MEM_SIZE (SZ_8K)
-
-struct acpi_table_header;
-
-int gic_v2_acpi_init(struct acpi_table_header *table);
-void acpi_gic_init(void);
-#else
-static inline void acpi_gic_init(void) { }
-#endif
-
-#endif /* ARM_GIC_ACPI_H_ */
--
2.1.4
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