arm64: kernel: implement ACPI parking protocol
authorLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Tue, 26 Jan 2016 11:10:38 +0000 (11:10 +0000)
committerAlex Shi <alex.shi@linaro.org>
Mon, 14 Nov 2016 06:39:14 +0000 (14:39 +0800)
commit762f201f0a4445cec9cd8130dde538d946aedee1
tree5dc84e4a7078144d5373abd00247bbf0cdf9b2b6
parenta146f6b94592514d9ee2e11377eb71b804cc941d
arm64: kernel: implement ACPI parking protocol

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>
(cherry picked from commit 5e89c55e4ed81d7abb1ce8828db35fa389dc0e90)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Conflicts:
have probes/ now in arch/arm64/kernel/Makefile
arch/arm64/Kconfig
arch/arm64/include/asm/acpi.h
arch/arm64/include/asm/hardirq.h
arch/arm64/include/asm/smp.h
arch/arm64/kernel/Makefile
arch/arm64/kernel/acpi_parking_protocol.c [new file with mode: 0644]
arch/arm64/kernel/cpu_ops.c
arch/arm64/kernel/smp.c