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authorLorenzo Pieralisi <lorenzo.pieralisi@arm.com>2016-01-26 11:10:38 +0000
committerCatalin Marinas <catalin.marinas@arm.com>2016-02-16 15:12:32 +0000
commit5e89c55e4ed81d7abb1ce8828db35fa389dc0e90 (patch)
treecfd0cd4f288fd346ce3b17cbf6c53d128bdfe132 /arch/arm64/kernel/smp.c
parent068a17a5805dfbca4bbf03e664ca6b19709cc7a8 (diff)
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>
Diffstat (limited to 'arch/arm64/kernel/smp.c')
-rw-r--r--arch/arm64/kernel/smp.c28
1 files changed, 28 insertions, 0 deletions
diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
index 68e7f79630d4..24cb4f800033 100644
--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c
@@ -70,6 +70,7 @@ enum ipi_msg_type {
IPI_CPU_STOP,
IPI_TIMER,
IPI_IRQ_WORK,
+ IPI_WAKEUP
};
/*
@@ -443,6 +444,17 @@ 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;
+ /*
+ * Set-up the ACPI parking protocol cpu entries
+ * while initializing the cpu_logical_map to
+ * avoid parsing MADT entries multiple times for
+ * nothing (ie a valid cpu_logical_map entry should
+ * contain a valid parking protocol data set to
+ * initialize the cpu if the parking protocol is
+ * the only available enable method).
+ */
+ acpi_set_mailbox_entry(cpu_count, processor);
+
cpu_count++;
}
@@ -625,6 +637,7 @@ static const char *ipi_types[NR_IPI] __tracepoint_string = {
S(IPI_CPU_STOP, "CPU stop interrupts"),
S(IPI_TIMER, "Timer broadcast interrupts"),
S(IPI_IRQ_WORK, "IRQ work interrupts"),
+ S(IPI_WAKEUP, "CPU wake-up interrupts"),
};
static void smp_cross_call(const struct cpumask *target, unsigned int ipinr)
@@ -668,6 +681,13 @@ void arch_send_call_function_single_ipi(int cpu)
smp_cross_call(cpumask_of(cpu), IPI_CALL_FUNC);
}
+#ifdef CONFIG_ARM64_ACPI_PARKING_PROTOCOL
+void arch_send_wakeup_ipi_mask(const struct cpumask *mask)
+{
+ smp_cross_call(mask, IPI_WAKEUP);
+}
+#endif
+
#ifdef CONFIG_IRQ_WORK
void arch_irq_work_raise(void)
{
@@ -745,6 +765,14 @@ void handle_IPI(int ipinr, struct pt_regs *regs)
break;
#endif
+#ifdef CONFIG_ARM64_ACPI_PARKING_PROTOCOL
+ case IPI_WAKEUP:
+ WARN_ONCE(!acpi_parking_protocol_valid(cpu),
+ "CPU%u: Wake-up IPI outside the ACPI parking protocol\n",
+ cpu);
+ break;
+#endif
+
default:
pr_crit("CPU%u: Unknown IPI message 0x%x\n", cpu, ipinr);
break;