[PATCH 3/3] MIPS: Loongson64: Implement PM suspend for LEFI firmware

From: Jiaxun Yang
Date: Tue May 07 2024 - 11:22:57 EST


Implement PM suspend for LEFI firmware.
Entering STR (Suspend to RAM) is as simple as save our context
then go to a firmware vector.
Wake is a little bit treaky as we need to setup some CP0 status
first, which can be done with smp_slave_setup.

Signed-off-by: Jiaxun Yang <jiaxun.yang@xxxxxxxxxxx>
---
arch/mips/loongson64/Makefile | 2 +-
arch/mips/loongson64/pm.c | 88 +++++++++---------------------------------
arch/mips/loongson64/sleeper.S | 17 ++++++++
3 files changed, 36 insertions(+), 71 deletions(-)

diff --git a/arch/mips/loongson64/Makefile b/arch/mips/loongson64/Makefile
index e806280bbb85..cbba30dfddf5 100644
--- a/arch/mips/loongson64/Makefile
+++ b/arch/mips/loongson64/Makefile
@@ -8,7 +8,7 @@ obj-$(CONFIG_MACH_LOONGSON64) += cop2-ex.o dma.o \
obj-$(CONFIG_SMP) += smp.o
obj-$(CONFIG_NUMA) += numa.o
obj-$(CONFIG_RS780_HPET) += hpet.o
-obj-$(CONFIG_SUSPEND) += pm.o
+obj-$(CONFIG_SUSPEND) += pm.o sleeper.o
obj-$(CONFIG_PCI_QUIRKS) += vbios_quirk.o
obj-$(CONFIG_CPU_LOONGSON3_CPUCFG_EMULATION) += cpucfg-emul.o
obj-$(CONFIG_SYSFS) += boardinfo.o
diff --git a/arch/mips/loongson64/pm.c b/arch/mips/loongson64/pm.c
index 7c8556f09781..5f0604af8f13 100644
--- a/arch/mips/loongson64/pm.c
+++ b/arch/mips/loongson64/pm.c
@@ -6,98 +6,46 @@
* Author: Wu Zhangjin <wuzhangjin@xxxxxxxxx>
*/
#include <linux/suspend.h>
-#include <linux/interrupt.h>
#include <linux/pm.h>

-#include <asm/i8259.h>
#include <asm/mipsregs.h>

#include <loongson.h>

-static unsigned int __maybe_unused cached_master_mask; /* i8259A */
-static unsigned int __maybe_unused cached_slave_mask;
-static unsigned int __maybe_unused cached_bonito_irq_mask; /* bonito */
+asmlinkage void loongson_lefi_sleep(unsigned long sleep_addr);

-void arch_suspend_disable_irqs(void)
+static int lefi_pm_enter(suspend_state_t state)
{
- /* disable all mips events */
- local_irq_disable();
-
-#ifdef CONFIG_I8259
- /* disable all events of i8259A */
- cached_slave_mask = inb(PIC_SLAVE_IMR);
- cached_master_mask = inb(PIC_MASTER_IMR);
-
- outb(0xff, PIC_SLAVE_IMR);
- inb(PIC_SLAVE_IMR);
- outb(0xff, PIC_MASTER_IMR);
- inb(PIC_MASTER_IMR);
-#endif
- /* disable all events of bonito */
- cached_bonito_irq_mask = LOONGSON_INTEN;
- LOONGSON_INTENCLR = 0xffff;
- (void)LOONGSON_INTENCLR;
-}
-
-void arch_suspend_enable_irqs(void)
-{
- /* enable all mips events */
- local_irq_enable();
-#ifdef CONFIG_I8259
- /* only enable the cached events of i8259A */
- outb(cached_slave_mask, PIC_SLAVE_IMR);
- outb(cached_master_mask, PIC_MASTER_IMR);
-#endif
- /* enable all cached events of bonito */
- LOONGSON_INTENSET = cached_bonito_irq_mask;
- (void)LOONGSON_INTENSET;
-}
-
-/*
- * Setup the board-specific events for waking up loongson from wait mode
- */
-void __weak setup_wakeup_events(void)
-{
-}
-
-void __weak mach_suspend(void)
-{
-}
-
-void __weak mach_resume(void)
-{
-}
-
-static int loongson_pm_enter(suspend_state_t state)
-{
- mach_suspend();
-
- mach_resume();
-
- return 0;
+ switch (state) {
+ case PM_SUSPEND_MEM:
+ pm_set_suspend_via_firmware();
+ loongson_lefi_sleep(loongson_sysconf.suspend_addr);
+ pm_set_resume_via_firmware();
+ return 0;
+ default:
+ return -EINVAL;
+ }
}

-static int loongson_pm_valid_state(suspend_state_t state)
+static int lefi_pm_valid_state(suspend_state_t state)
{
switch (state) {
- case PM_SUSPEND_ON:
- case PM_SUSPEND_STANDBY:
case PM_SUSPEND_MEM:
- return 1;
-
+ return !!loongson_sysconf.suspend_addr;
default:
return 0;
}
}

-static const struct platform_suspend_ops loongson_pm_ops = {
- .valid = loongson_pm_valid_state,
- .enter = loongson_pm_enter,
+static const struct platform_suspend_ops lefi_pm_ops = {
+ .valid = lefi_pm_valid_state,
+ .enter = lefi_pm_enter,
};

static int __init loongson_pm_init(void)
{
- suspend_set_ops(&loongson_pm_ops);
+ if (loongson_sysconf.fw_interface == LOONGSON_LEFI)
+ suspend_set_ops(&lefi_pm_ops);

return 0;
}
diff --git a/arch/mips/loongson64/sleeper.S b/arch/mips/loongson64/sleeper.S
new file mode 100644
index 000000000000..04874b9bf430
--- /dev/null
+++ b/arch/mips/loongson64/sleeper.S
@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2024, Jiaxun Yang <jiaxun.yang@xxxxxxxxxxx>
+ * Loongson EFI firmware sleeper routine
+ */
+
+#include <asm/asm.h>
+#include <asm/pm.h>
+
+#include <kernel-entry-init.h>
+
+LEAF(loongson_lefi_sleep)
+ SUSPEND_SAVE
+ jalr a0
+ smp_slave_setup
+ RESUME_RESTORE_REGS_RETURN
+END(loongson_lefi_sleep)

--
2.34.1