diff options
Diffstat (limited to 'arch/powerpc/platforms/pseries/suspend.c')
| -rw-r--r-- | arch/powerpc/platforms/pseries/suspend.c | 242 |
1 files changed, 242 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/pseries/suspend.c b/arch/powerpc/platforms/pseries/suspend.c new file mode 100644 index 000000000..64b36a93c --- /dev/null +++ b/arch/powerpc/platforms/pseries/suspend.c @@ -0,0 +1,242 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2010 Brian King IBM Corporation + */ + +#include <linux/cpu.h> +#include <linux/delay.h> +#include <linux/suspend.h> +#include <linux/stat.h> +#include <asm/firmware.h> +#include <asm/hvcall.h> +#include <asm/machdep.h> +#include <asm/mmu.h> +#include <asm/rtas.h> +#include <asm/topology.h> + +static u64 stream_id; +static struct device suspend_dev; +static DECLARE_COMPLETION(suspend_work); +static struct rtas_suspend_me_data suspend_data; +static atomic_t suspending; + +/** + * pseries_suspend_begin - First phase of hibernation + * + * Check to ensure we are in a valid state to hibernate + * + * Return value: + * 0 on success / other on failure + **/ +static int pseries_suspend_begin(suspend_state_t state) +{ + long vasi_state, rc; + unsigned long retbuf[PLPAR_HCALL_BUFSIZE]; + + /* Make sure the state is valid */ + rc = plpar_hcall(H_VASI_STATE, retbuf, stream_id); + + vasi_state = retbuf[0]; + + if (rc) { + pr_err("pseries_suspend_begin: vasi_state returned %ld\n",rc); + return rc; + } else if (vasi_state == H_VASI_ENABLED) { + return -EAGAIN; + } else if (vasi_state != H_VASI_SUSPENDING) { + pr_err("pseries_suspend_begin: vasi_state returned state %ld\n", + vasi_state); + return -EIO; + } + + return 0; +} + +/** + * pseries_suspend_cpu - Suspend a single CPU + * + * Makes the H_JOIN call to suspend the CPU + * + **/ +static int pseries_suspend_cpu(void) +{ + if (atomic_read(&suspending)) + return rtas_suspend_cpu(&suspend_data); + return 0; +} + +/** + * pseries_suspend_enable_irqs + * + * Post suspend configuration updates + * + **/ +static void pseries_suspend_enable_irqs(void) +{ + /* + * Update configuration which can be modified based on device tree + * changes during resume. + */ + post_mobility_fixup(); +} + +/** + * pseries_suspend_enter - Final phase of hibernation + * + * Return value: + * 0 on success / other on failure + **/ +static int pseries_suspend_enter(suspend_state_t state) +{ + int rc = rtas_suspend_last_cpu(&suspend_data); + + atomic_set(&suspending, 0); + atomic_set(&suspend_data.done, 1); + return rc; +} + +/** + * pseries_prepare_late - Prepare to suspend all other CPUs + * + * Return value: + * 0 on success / other on failure + **/ +static int pseries_prepare_late(void) +{ + atomic_set(&suspending, 1); + atomic_set(&suspend_data.working, 0); + atomic_set(&suspend_data.done, 0); + atomic_set(&suspend_data.error, 0); + suspend_data.complete = &suspend_work; + reinit_completion(&suspend_work); + return 0; +} + +/** + * store_hibernate - Initiate partition hibernation + * @dev: subsys root device + * @attr: device attribute struct + * @buf: buffer + * @count: buffer size + * + * Write the stream ID received from the HMC to this file + * to trigger hibernating the partition + * + * Return value: + * number of bytes printed to buffer / other on failure + **/ +static ssize_t store_hibernate(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + int rc; + + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + stream_id = simple_strtoul(buf, NULL, 16); + + do { + rc = pseries_suspend_begin(PM_SUSPEND_MEM); + if (rc == -EAGAIN) + ssleep(1); + } while (rc == -EAGAIN); + + if (!rc) + rc = pm_suspend(PM_SUSPEND_MEM); + + stream_id = 0; + + if (!rc) + rc = count; + + return rc; +} + +#define USER_DT_UPDATE 0 +#define KERN_DT_UPDATE 1 + +/** + * show_hibernate - Report device tree update responsibilty + * @dev: subsys root device + * @attr: device attribute struct + * @buf: buffer + * + * Report whether a device tree update is performed by the kernel after a + * resume, or if drmgr must coordinate the update from user space. + * + * Return value: + * 0 if drmgr is to initiate update, and 1 otherwise + **/ +static ssize_t show_hibernate(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + return sprintf(buf, "%d\n", KERN_DT_UPDATE); +} + +static DEVICE_ATTR(hibernate, 0644, show_hibernate, store_hibernate); + +static struct bus_type suspend_subsys = { + .name = "power", + .dev_name = "power", +}; + +static const struct platform_suspend_ops pseries_suspend_ops = { + .valid = suspend_valid_only_mem, + .prepare_late = pseries_prepare_late, + .enter = pseries_suspend_enter, +}; + +/** + * pseries_suspend_sysfs_register - Register with sysfs + * + * Return value: + * 0 on success / other on failure + **/ +static int pseries_suspend_sysfs_register(struct device *dev) +{ + int rc; + + if ((rc = subsys_system_register(&suspend_subsys, NULL))) + return rc; + + dev->id = 0; + dev->bus = &suspend_subsys; + + if ((rc = device_create_file(suspend_subsys.dev_root, &dev_attr_hibernate))) + goto subsys_unregister; + + return 0; + +subsys_unregister: + bus_unregister(&suspend_subsys); + return rc; +} + +/** + * pseries_suspend_init - initcall for pSeries suspend + * + * Return value: + * 0 on success / other on failure + **/ +static int __init pseries_suspend_init(void) +{ + int rc; + + if (!firmware_has_feature(FW_FEATURE_LPAR)) + return 0; + + suspend_data.token = rtas_token("ibm,suspend-me"); + if (suspend_data.token == RTAS_UNKNOWN_SERVICE) + return 0; + + if ((rc = pseries_suspend_sysfs_register(&suspend_dev))) + return rc; + + ppc_md.suspend_disable_cpu = pseries_suspend_cpu; + ppc_md.suspend_enable_irqs = pseries_suspend_enable_irqs; + suspend_set_ops(&pseries_suspend_ops); + return 0; +} +machine_device_initcall(pseries, pseries_suspend_init); |