arm64: add function to get a cpu's MADT GICC table

BugLink: https://bugs.launchpad.net/bugs/1689661
Currently the ACPI parking protocol code needs to parse each CPU's MADT
GICC table to extract the mailbox address and so on. Each time we parse
a GICC table, we call back to the parking protocol code to parse it.

This has been fine so far, but we're about to have more code that needs
to extract data from the GICC tables, and adding a callback for each
user is going to get unwieldy.

Instead, this patch ensures that we stash a copy of each CPU's GICC
table at boot time, such that anything needing to parse it can later
request it. This will allow for other parsers of GICC, and for
simplification to the ACPI parking protocol code. Note that we must
store a copy, rather than a pointer, since the core ACPI code
temporarily maps/unmaps tables while iterating over them.

Since we parse the MADT before we know how many CPUs we have (and hence
before we setup the percpu areas), we must use an NR_CPUS sized array.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Tested-by: Jeremy Linton <jeremy.linton@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
(cherry picked from commit e0013aed489e7ebbba59d7ada2ff5551ac4b61c6)
Signed-off-by: dann frazier <dann.frazier@canonical.com>
Acked-by: Seth Forshee <seth.forshee@canonical.com>
Acked-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>

diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h
index c1976c0adca73025ec4526fc40be077101f8ef62..0e99978da3f05013d145132950ad204a92e3e4b0 100644 (file)
--- a/arch/arm64/include/asm/acpi.h
+++ b/arch/arm64/include/asm/acpi.h
@@ -85,6 +85,8 @@ static inline bool acpi_has_cpu_in_madt(void)
        return true;
 }
 
+struct acpi_madt_generic_interrupt *acpi_cpu_get_madt_gicc(int cpu);
+
 static inline void arch_fix_phys_package_id(int num, u32 slot) { }
 void __init acpi_init_cpus(void);
 

diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
index cb87234cfcf2d2b8ba75f9e83dadf78c927a3e86..840e83ae3ce2423a8ef9a44e947d67ac197f7608 100644 (file)
--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c
@@ -516,6 +516,13 @@ static bool bootcpu_valid __initdata;
 static unsigned int cpu_count = 1;
 
 #ifdef CONFIG_ACPI
+static struct acpi_madt_generic_interrupt cpu_madt_gicc[NR_CPUS];
+
+struct acpi_madt_generic_interrupt *acpi_cpu_get_madt_gicc(int cpu)
+{
+       return &cpu_madt_gicc[cpu];
+}
+
 /*
  * acpi_map_gic_cpu_interface - parse processor MADT entry
  *
@@ -550,6 +557,7 @@ acpi_map_gic_cpu_interface(struct acpi_madt_generic_interrupt *processor)
                        return;
                }
                bootcpu_valid = true;
+               cpu_madt_gicc[0] = *processor;
                early_map_cpu_to_node(0, acpi_numa_get_nid(0, hwid));
                return;
        }
@@ -560,6 +568,8 @@ acpi_map_gic_cpu_interface(struct acpi_madt_generic_interrupt *processor)
        /* map the logical cpu id to cpu MPIDR */
        cpu_logical_map(cpu_count) = hwid;
 
+       cpu_madt_gicc[cpu_count] = *processor;
+
        /*
         * Set-up the ACPI parking protocol cpu entries
         * while initializing the cpu_logical_map to