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5e89c55e4e
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>
121 lines
2.9 KiB
C
121 lines
2.9 KiB
C
/*
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* CPU kernel entry/exit control
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*
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* Copyright (C) 2013 ARM Ltd.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <linux/acpi.h>
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#include <linux/errno.h>
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#include <linux/of.h>
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#include <linux/string.h>
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#include <asm/acpi.h>
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#include <asm/cpu_ops.h>
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#include <asm/smp_plat.h>
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extern const struct cpu_operations smp_spin_table_ops;
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extern const struct cpu_operations acpi_parking_protocol_ops;
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extern const struct cpu_operations cpu_psci_ops;
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const struct cpu_operations *cpu_ops[NR_CPUS];
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static const struct cpu_operations *dt_supported_cpu_ops[] __initconst = {
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&smp_spin_table_ops,
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&cpu_psci_ops,
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NULL,
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};
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static const struct cpu_operations *acpi_supported_cpu_ops[] __initconst = {
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#ifdef CONFIG_ARM64_ACPI_PARKING_PROTOCOL
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&acpi_parking_protocol_ops,
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#endif
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&cpu_psci_ops,
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NULL,
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};
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static const struct cpu_operations * __init cpu_get_ops(const char *name)
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{
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const struct cpu_operations **ops;
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ops = acpi_disabled ? dt_supported_cpu_ops : acpi_supported_cpu_ops;
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while (*ops) {
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if (!strcmp(name, (*ops)->name))
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return *ops;
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ops++;
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}
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return NULL;
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}
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static const char *__init cpu_read_enable_method(int cpu)
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{
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const char *enable_method;
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if (acpi_disabled) {
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struct device_node *dn = of_get_cpu_node(cpu, NULL);
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if (!dn) {
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if (!cpu)
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pr_err("Failed to find device node for boot cpu\n");
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return NULL;
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}
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enable_method = of_get_property(dn, "enable-method", NULL);
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if (!enable_method) {
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/*
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* The boot CPU may not have an enable method (e.g.
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* when spin-table is used for secondaries).
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* Don't warn spuriously.
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*/
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if (cpu != 0)
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pr_err("%s: missing enable-method property\n",
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dn->full_name);
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}
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} else {
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enable_method = acpi_get_enable_method(cpu);
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if (!enable_method) {
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/*
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* In ACPI systems the boot CPU does not require
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* checking the enable method since for some
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* boot protocol (ie parking protocol) it need not
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* be initialized. Don't warn spuriously.
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*/
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if (cpu != 0)
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pr_err("Unsupported ACPI enable-method\n");
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}
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}
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return enable_method;
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}
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/*
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* Read a cpu's enable method and record it in cpu_ops.
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*/
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int __init cpu_read_ops(int cpu)
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{
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const char *enable_method = cpu_read_enable_method(cpu);
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if (!enable_method)
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return -ENODEV;
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cpu_ops[cpu] = cpu_get_ops(enable_method);
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if (!cpu_ops[cpu]) {
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pr_warn("Unsupported enable-method: %s\n", enable_method);
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return -EOPNOTSUPP;
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}
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return 0;
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}
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