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arm64: kernel: implement ACPI parking protocol

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The SBBR and ACPI specifications allow ACPI based systems that do not
implement PSCI (eg systems with no EL3) to boot through the ACPI parking
protocol specification[1].

This patch implements the ACPI parking protocol CPU operations, and adds
code that eases parsing the parking protocol data structures to the
ARM64 SMP initializion carried out at the same time as cpus enumeration.

To wake-up the CPUs from the parked state, this patch implements a
wakeup IPI for ARM64 (ie arch_send_wakeup_ipi_mask()) that mirrors the
ARM one, so that a specific IPI is sent for wake-up purpose in order
to distinguish it from other IPI sources.

Given the current ACPI MADT parsing API, the patch implements a glue
layer that helps passing MADT GICC data structure from SMP initialization
code to the parking protocol implementation somewhat overriding the CPU
operations interfaces. This to avoid creating a completely trasparent
DT/ACPI CPU operations layer that would require creating opaque
structure handling for CPUs data (DT represents CPU through DT nodes, ACPI
through static MADT table entries), which seems overkill given that ACPI
on ARM64 mandates only two booting protocols (PSCI and parking protocol),
so there is no need for further protocol additions.

Based on the original work by Mark Salter <msalter@redhat.com>

[1] https://acpica.org/sites/acpica/files/MP%20Startup%20for%20ARM%20platforms.docx

Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Tested-by: Loc Ho <lho@apm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Hanjun Guo <hanjun.guo@linaro.org>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Al Stone <ahs3@redhat.com>
[catalin.marinas@arm.com: Added WARN_ONCE(!acpi_parking_protocol_valid() on the IPI]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
This commit is contained in:
Lorenzo Pieralisi
2016-01-26 11:10:38 +00:00
committed by Catalin Marinas
parent 068a17a580
commit 5e89c55e4e
8 changed files with 242 additions and 6 deletions
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9
arch/arm64/include/asm/smp.h
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@@ -64,6 +64,15 @@ extern void secondary_entry(void);
extern void arch_send_call_function_single_ipi(int cpu);
extern void arch_send_call_function_ipi_mask(const struct cpumask *mask);
#ifdef CONFIG_ARM64_ACPI_PARKING_PROTOCOL
extern void arch_send_wakeup_ipi_mask(const struct cpumask *mask);
#else
static inline void arch_send_wakeup_ipi_mask(const struct cpumask *mask)
{
BUILD_BUG();
}
#endif
extern int __cpu_disable(void);
extern void __cpu_die(unsigned int cpu);