On Tue, Jan 26, 2016 at 11:10:38AM +0000, Lorenzo Pieralisi wrote: > 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@xxxxxxxxxx> > > [1] https://acpica.org/sites/acpica/files/MP%20Startup%20for%20ARM%20platforms.docx > > Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx> > Cc: Will Deacon <will.deacon@xxxxxxx> > Cc: Hanjun Guo <hanjun.guo@xxxxxxxxxx> > Cc: Loc Ho <lho@xxxxxxx> > Cc: Sudeep Holla <sudeep.holla@xxxxxxx> > Cc: Catalin Marinas <catalin.marinas@xxxxxxx> > Cc: Mark Rutland <mark.rutland@xxxxxxx> > Cc: Mark Salter <msalter@xxxxxxxxxx> > Cc: Al Stone <ahs3@xxxxxxxxxx> Applied, with a minor addition just to warn people from not using it in other configurations (#ifdef still needed otherwise the acpi_parking_protocol_valid symbol is not available; but I prefer uglier code than people starting to use this IPI in their firmware): --- a/arch/arm64/kernel/smp.c +++ b/arch/arm64/kernel/smp.c @@ -767,6 +767,12 @@ 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: Thanks. -- Catalin -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
