menu "Boot options"
+config ARM64_ACPI_PARKING_PROTOCOL
+ bool "Enable support for the ARM64 ACPI parking protocol"
+ depends on ACPI
+ help
+ Enable support for the ARM64 ACPI parking protocol. If disabled
+ the kernel will not allow booting through the ARM64 ACPI parking
+ protocol even if the corresponding data is present in the ACPI
+ MADT table.
+
config CMDLINE
string "Default kernel command string"
default ""
static inline void acpi_init_cpus(void) { }
#endif /* CONFIG_ACPI */
+#ifdef CONFIG_ARM64_ACPI_PARKING_PROTOCOL
+bool acpi_parking_protocol_valid(int cpu);
+void __init
+acpi_set_mailbox_entry(int cpu, struct acpi_madt_generic_interrupt *processor);
+#else
+static inline bool acpi_parking_protocol_valid(int cpu) { return false; }
+static inline void
+acpi_set_mailbox_entry(int cpu, struct acpi_madt_generic_interrupt *processor)
+{}
+#endif
+
static inline const char *acpi_get_enable_method(int cpu)
{
- return acpi_psci_present() ? "psci" : NULL;
+ if (acpi_psci_present())
+ return "psci";
+
+ if (acpi_parking_protocol_valid(cpu))
+ return "parking-protocol";
+
+ return NULL;
}
#ifdef CONFIG_ACPI_APEI
#include <linux/threads.h>
#include <asm/irq.h>
-#define NR_IPI 5
+#define NR_IPI 6
typedef struct {
unsigned int __softirq_pending;
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);
arm64-obj-$(CONFIG_PCI) += pci.o
arm64-obj-$(CONFIG_ARMV8_DEPRECATED) += armv8_deprecated.o
arm64-obj-$(CONFIG_ACPI) += acpi.o
+arm64-obj-$(CONFIG_ARM64_ACPI_PARKING_PROTOCOL) += acpi_parking_protocol.o
arm64-obj-$(CONFIG_PARAVIRT) += paravirt.o
obj-y += $(arm64-obj-y) vdso/
--- /dev/null
+/*
+ * ARM64 ACPI Parking Protocol implementation
+ *
+ * Authors: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
+ * Mark Salter <msalter@redhat.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <linux/acpi.h>
+#include <linux/types.h>
+
+#include <asm/cpu_ops.h>
+
+struct cpu_mailbox_entry {
+ phys_addr_t mailbox_addr;
+ u8 version;
+ u8 gic_cpu_id;
+};
+
+static struct cpu_mailbox_entry cpu_mailbox_entries[NR_CPUS];
+
+void __init acpi_set_mailbox_entry(int cpu,
+ struct acpi_madt_generic_interrupt *p)
+{
+ struct cpu_mailbox_entry *cpu_entry = &cpu_mailbox_entries[cpu];
+
+ cpu_entry->mailbox_addr = p->parked_address;
+ cpu_entry->version = p->parking_version;
+ cpu_entry->gic_cpu_id = p->cpu_interface_number;
+}
+
+bool acpi_parking_protocol_valid(int cpu)
+{
+ struct cpu_mailbox_entry *cpu_entry = &cpu_mailbox_entries[cpu];
+
+ return cpu_entry->mailbox_addr && cpu_entry->version;
+}
+
+static int acpi_parking_protocol_cpu_init(unsigned int cpu)
+{
+ pr_debug("%s: ACPI parked addr=%llx\n", __func__,
+ cpu_mailbox_entries[cpu].mailbox_addr);
+
+ return 0;
+}
+
+static int acpi_parking_protocol_cpu_prepare(unsigned int cpu)
+{
+ return 0;
+}
+
+struct parking_protocol_mailbox {
+ __le32 cpu_id;
+ __le32 reserved;
+ __le64 entry_point;
+};
+
+static int acpi_parking_protocol_cpu_boot(unsigned int cpu)
+{
+ struct cpu_mailbox_entry *cpu_entry = &cpu_mailbox_entries[cpu];
+ struct parking_protocol_mailbox __iomem *mailbox;
+ __le32 cpu_id;
+
+ /*
+ * Map mailbox memory with attribute device nGnRE (ie ioremap -
+ * this deviates from the parking protocol specifications since
+ * the mailboxes are required to be mapped nGnRnE; the attribute
+ * discrepancy is harmless insofar as the protocol specification
+ * is concerned).
+ * If the mailbox is mistakenly allocated in the linear mapping
+ * by FW ioremap will fail since the mapping will be prevented
+ * by the kernel (it clashes with the linear mapping attributes
+ * specifications).
+ */
+ mailbox = ioremap(cpu_entry->mailbox_addr, sizeof(*mailbox));
+ if (!mailbox)
+ return -EIO;
+
+ cpu_id = readl_relaxed(&mailbox->cpu_id);
+ /*
+ * Check if firmware has set-up the mailbox entry properly
+ * before kickstarting the respective cpu.
+ */
+ if (cpu_id != ~0U) {
+ iounmap(mailbox);
+ return -ENXIO;
+ }
+
+ /*
+ * We write the entry point and cpu id as LE regardless of the
+ * native endianness of the kernel. Therefore, any boot-loaders
+ * that read this address need to convert this address to the
+ * Boot-Loader's endianness before jumping.
+ */
+ writeq_relaxed(__pa(secondary_entry), &mailbox->entry_point);
+ writel_relaxed(cpu_entry->gic_cpu_id, &mailbox->cpu_id);
+
+ arch_send_wakeup_ipi_mask(cpumask_of(cpu));
+
+ iounmap(mailbox);
+
+ return 0;
+}
+
+static void acpi_parking_protocol_cpu_postboot(void)
+{
+ int cpu = smp_processor_id();
+ struct cpu_mailbox_entry *cpu_entry = &cpu_mailbox_entries[cpu];
+ struct parking_protocol_mailbox __iomem *mailbox;
+ __le64 entry_point;
+
+ /*
+ * Map mailbox memory with attribute device nGnRE (ie ioremap -
+ * this deviates from the parking protocol specifications since
+ * the mailboxes are required to be mapped nGnRnE; the attribute
+ * discrepancy is harmless insofar as the protocol specification
+ * is concerned).
+ * If the mailbox is mistakenly allocated in the linear mapping
+ * by FW ioremap will fail since the mapping will be prevented
+ * by the kernel (it clashes with the linear mapping attributes
+ * specifications).
+ */
+ mailbox = ioremap(cpu_entry->mailbox_addr, sizeof(*mailbox));
+ if (!mailbox)
+ return;
+
+ entry_point = readl_relaxed(&mailbox->entry_point);
+ /*
+ * Check if firmware has cleared the entry_point as expected
+ * by the protocol specification.
+ */
+ WARN_ON(entry_point);
+
+ iounmap(mailbox);
+}
+
+const struct cpu_operations acpi_parking_protocol_ops = {
+ .name = "parking-protocol",
+ .cpu_init = acpi_parking_protocol_cpu_init,
+ .cpu_prepare = acpi_parking_protocol_cpu_prepare,
+ .cpu_boot = acpi_parking_protocol_cpu_boot,
+ .cpu_postboot = acpi_parking_protocol_cpu_postboot
+};
#include <asm/smp_plat.h>
extern const struct cpu_operations smp_spin_table_ops;
+extern const struct cpu_operations acpi_parking_protocol_ops;
extern const struct cpu_operations cpu_psci_ops;
const struct cpu_operations *cpu_ops[NR_CPUS];
-static const struct cpu_operations *supported_cpu_ops[] __initconst = {
+static const struct cpu_operations *dt_supported_cpu_ops[] __initconst = {
&smp_spin_table_ops,
&cpu_psci_ops,
NULL,
};
+static const struct cpu_operations *acpi_supported_cpu_ops[] __initconst = {
+#ifdef CONFIG_ARM64_ACPI_PARKING_PROTOCOL
+ &acpi_parking_protocol_ops,
+#endif
+ &cpu_psci_ops,
+ NULL,
+};
+
static const struct cpu_operations * __init cpu_get_ops(const char *name)
{
- const struct cpu_operations **ops = supported_cpu_ops;
+ const struct cpu_operations **ops;
+
+ ops = acpi_disabled ? dt_supported_cpu_ops : acpi_supported_cpu_ops;
while (*ops) {
if (!strcmp(name, (*ops)->name))
}
} else {
enable_method = acpi_get_enable_method(cpu);
- if (!enable_method)
- pr_err("Unsupported ACPI enable-method\n");
+ if (!enable_method) {
+ /*
+ * In ACPI systems the boot CPU does not require
+ * checking the enable method since for some
+ * boot protocol (ie parking protocol) it need not
+ * be initialized. Don't warn spuriously.
+ */
+ if (cpu != 0)
+ pr_err("Unsupported ACPI enable-method\n");
+ }
}
return enable_method;
IPI_CPU_STOP,
IPI_TIMER,
IPI_IRQ_WORK,
+ IPI_WAKEUP
};
/*
/* 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++;
}
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)
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)
{
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;