Thread (30 messages) 30 messages, 8 authors, 2013-12-10

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

From: Rob Herring <hidden>
Date: 2013-12-03 17:09:47
Also in: linux-acpi, lkml

On Tue, Dec 3, 2013 at 10:39 AM, Hanjun Guo [off-list ref] wrote:
quoted hunk ↗ jump to hunk
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 <redacted>
---
 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
Perhaps this should go in the GIC code? This is more of a general
question of where init/probing code goes. For DT, this as been with
the driver code.
+/*
+ * 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)
You have the sizes swapped. The cpu interface has the DIR register at 0x1000.
+
 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;
Initialization here is unnecessary.
quoted hunk ↗ jump to hunk
        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);
Should be GIC_DISTRIBUTOR_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) {
Checking this first would be cleaner.
+               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);
How are gic's with different cpu address per core going to be handled?
+       if (!cpu_base) {
+               iounmap(dist_base);
+               pr_warn(PREFIX "unable to map gic cpu registers\n");
All the printks are a bit verbose for my tastes. I think a single
error print would suffice.
+               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 */
A "if (!IS_ENABLED(CONFIG_ARM_GIC)) return;" in the above function
would eliminate this ifdef.
quoted hunk ↗ jump to hunk
 /*
  * 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;
-
+
Unnecessary whitespace change.
quoted hunk ↗ jump to hunk
        /*
         * 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


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