From 2c3c1048746a4622d8c89a29670120dc8fab93c4 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 20:49:45 +0200 Subject: Adding upstream version 6.1.76. Signed-off-by: Daniel Baumann --- arch/powerpc/platforms/pseries/cmm.c | 663 +++++++++++++++++++++++++++++++++++ 1 file changed, 663 insertions(+) create mode 100644 arch/powerpc/platforms/pseries/cmm.c (limited to 'arch/powerpc/platforms/pseries/cmm.c') diff --git a/arch/powerpc/platforms/pseries/cmm.c b/arch/powerpc/platforms/pseries/cmm.c new file mode 100644 index 000000000..5f4037c1d --- /dev/null +++ b/arch/powerpc/platforms/pseries/cmm.c @@ -0,0 +1,663 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Collaborative memory management interface. + * + * Copyright (C) 2008 IBM Corporation + * Author(s): Brian King (brking@linux.vnet.ibm.com), + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "pseries.h" + +#define CMM_DRIVER_VERSION "1.0.0" +#define CMM_DEFAULT_DELAY 1 +#define CMM_HOTPLUG_DELAY 5 +#define CMM_DEBUG 0 +#define CMM_DISABLE 0 +#define CMM_OOM_KB 1024 +#define CMM_MIN_MEM_MB 256 +#define KB2PAGES(_p) ((_p)>>(PAGE_SHIFT-10)) +#define PAGES2KB(_p) ((_p)<<(PAGE_SHIFT-10)) + +#define CMM_MEM_HOTPLUG_PRI 1 + +static unsigned int delay = CMM_DEFAULT_DELAY; +static unsigned int hotplug_delay = CMM_HOTPLUG_DELAY; +static unsigned int oom_kb = CMM_OOM_KB; +static unsigned int cmm_debug = CMM_DEBUG; +static unsigned int cmm_disabled = CMM_DISABLE; +static unsigned long min_mem_mb = CMM_MIN_MEM_MB; +static bool __read_mostly simulate; +static unsigned long simulate_loan_target_kb; +static struct device cmm_dev; + +MODULE_AUTHOR("Brian King "); +MODULE_DESCRIPTION("IBM System p Collaborative Memory Manager"); +MODULE_LICENSE("GPL"); +MODULE_VERSION(CMM_DRIVER_VERSION); + +module_param_named(delay, delay, uint, 0644); +MODULE_PARM_DESC(delay, "Delay (in seconds) between polls to query hypervisor paging requests. " + "[Default=" __stringify(CMM_DEFAULT_DELAY) "]"); +module_param_named(hotplug_delay, hotplug_delay, uint, 0644); +MODULE_PARM_DESC(hotplug_delay, "Delay (in seconds) after memory hotplug remove " + "before loaning resumes. " + "[Default=" __stringify(CMM_HOTPLUG_DELAY) "]"); +module_param_named(oom_kb, oom_kb, uint, 0644); +MODULE_PARM_DESC(oom_kb, "Amount of memory in kb to free on OOM. " + "[Default=" __stringify(CMM_OOM_KB) "]"); +module_param_named(min_mem_mb, min_mem_mb, ulong, 0644); +MODULE_PARM_DESC(min_mem_mb, "Minimum amount of memory (in MB) to not balloon. " + "[Default=" __stringify(CMM_MIN_MEM_MB) "]"); +module_param_named(debug, cmm_debug, uint, 0644); +MODULE_PARM_DESC(debug, "Enable module debugging logging. Set to 1 to enable. " + "[Default=" __stringify(CMM_DEBUG) "]"); +module_param_named(simulate, simulate, bool, 0444); +MODULE_PARM_DESC(simulate, "Enable simulation mode (no communication with hw)."); + +#define cmm_dbg(...) if (cmm_debug) { printk(KERN_INFO "cmm: "__VA_ARGS__); } + +static atomic_long_t loaned_pages; +static unsigned long loaned_pages_target; +static unsigned long oom_freed_pages; + +static DEFINE_MUTEX(hotplug_mutex); +static int hotplug_occurred; /* protected by the hotplug mutex */ + +static struct task_struct *cmm_thread_ptr; +static struct balloon_dev_info b_dev_info; + +static long plpar_page_set_loaned(struct page *page) +{ + const unsigned long vpa = page_to_phys(page); + unsigned long cmo_page_sz = cmo_get_page_size(); + long rc = 0; + int i; + + if (unlikely(simulate)) + return 0; + + for (i = 0; !rc && i < PAGE_SIZE; i += cmo_page_sz) + rc = plpar_hcall_norets(H_PAGE_INIT, H_PAGE_SET_LOANED, vpa + i, 0); + + for (i -= cmo_page_sz; rc && i != 0; i -= cmo_page_sz) + plpar_hcall_norets(H_PAGE_INIT, H_PAGE_SET_ACTIVE, + vpa + i - cmo_page_sz, 0); + + return rc; +} + +static long plpar_page_set_active(struct page *page) +{ + const unsigned long vpa = page_to_phys(page); + unsigned long cmo_page_sz = cmo_get_page_size(); + long rc = 0; + int i; + + if (unlikely(simulate)) + return 0; + + for (i = 0; !rc && i < PAGE_SIZE; i += cmo_page_sz) + rc = plpar_hcall_norets(H_PAGE_INIT, H_PAGE_SET_ACTIVE, vpa + i, 0); + + for (i -= cmo_page_sz; rc && i != 0; i -= cmo_page_sz) + plpar_hcall_norets(H_PAGE_INIT, H_PAGE_SET_LOANED, + vpa + i - cmo_page_sz, 0); + + return rc; +} + +/** + * cmm_alloc_pages - Allocate pages and mark them as loaned + * @nr: number of pages to allocate + * + * Return value: + * number of pages requested to be allocated which were not + **/ +static long cmm_alloc_pages(long nr) +{ + struct page *page; + long rc; + + cmm_dbg("Begin request for %ld pages\n", nr); + + while (nr) { + /* Exit if a hotplug operation is in progress or occurred */ + if (mutex_trylock(&hotplug_mutex)) { + if (hotplug_occurred) { + mutex_unlock(&hotplug_mutex); + break; + } + mutex_unlock(&hotplug_mutex); + } else { + break; + } + + page = balloon_page_alloc(); + if (!page) + break; + rc = plpar_page_set_loaned(page); + if (rc) { + pr_err("%s: Can not set page to loaned. rc=%ld\n", __func__, rc); + __free_page(page); + break; + } + + balloon_page_enqueue(&b_dev_info, page); + atomic_long_inc(&loaned_pages); + adjust_managed_page_count(page, -1); + nr--; + } + + cmm_dbg("End request with %ld pages unfulfilled\n", nr); + return nr; +} + +/** + * cmm_free_pages - Free pages and mark them as active + * @nr: number of pages to free + * + * Return value: + * number of pages requested to be freed which were not + **/ +static long cmm_free_pages(long nr) +{ + struct page *page; + + cmm_dbg("Begin free of %ld pages.\n", nr); + while (nr) { + page = balloon_page_dequeue(&b_dev_info); + if (!page) + break; + plpar_page_set_active(page); + adjust_managed_page_count(page, 1); + __free_page(page); + atomic_long_dec(&loaned_pages); + nr--; + } + cmm_dbg("End request with %ld pages unfulfilled\n", nr); + return nr; +} + +/** + * cmm_oom_notify - OOM notifier + * @self: notifier block struct + * @dummy: not used + * @parm: returned - number of pages freed + * + * Return value: + * NOTIFY_OK + **/ +static int cmm_oom_notify(struct notifier_block *self, + unsigned long dummy, void *parm) +{ + unsigned long *freed = parm; + long nr = KB2PAGES(oom_kb); + + cmm_dbg("OOM processing started\n"); + nr = cmm_free_pages(nr); + loaned_pages_target = atomic_long_read(&loaned_pages); + *freed += KB2PAGES(oom_kb) - nr; + oom_freed_pages += KB2PAGES(oom_kb) - nr; + cmm_dbg("OOM processing complete\n"); + return NOTIFY_OK; +} + +/** + * cmm_get_mpp - Read memory performance parameters + * + * Makes hcall to query the current page loan request from the hypervisor. + * + * Return value: + * nothing + **/ +static void cmm_get_mpp(void) +{ + const long __loaned_pages = atomic_long_read(&loaned_pages); + const long total_pages = totalram_pages() + __loaned_pages; + int rc; + struct hvcall_mpp_data mpp_data; + signed long active_pages_target, page_loan_request, target; + signed long min_mem_pages = (min_mem_mb * 1024 * 1024) / PAGE_SIZE; + + if (likely(!simulate)) { + rc = h_get_mpp(&mpp_data); + if (rc != H_SUCCESS) + return; + page_loan_request = div_s64((s64)mpp_data.loan_request, + PAGE_SIZE); + target = page_loan_request + __loaned_pages; + } else { + target = KB2PAGES(simulate_loan_target_kb); + page_loan_request = target - __loaned_pages; + } + + if (target < 0 || total_pages < min_mem_pages) + target = 0; + + if (target > oom_freed_pages) + target -= oom_freed_pages; + else + target = 0; + + active_pages_target = total_pages - target; + + if (min_mem_pages > active_pages_target) + target = total_pages - min_mem_pages; + + if (target < 0) + target = 0; + + loaned_pages_target = target; + + cmm_dbg("delta = %ld, loaned = %lu, target = %lu, oom = %lu, totalram = %lu\n", + page_loan_request, __loaned_pages, loaned_pages_target, + oom_freed_pages, totalram_pages()); +} + +static struct notifier_block cmm_oom_nb = { + .notifier_call = cmm_oom_notify +}; + +/** + * cmm_thread - CMM task thread + * @dummy: not used + * + * Return value: + * 0 + **/ +static int cmm_thread(void *dummy) +{ + unsigned long timeleft; + long __loaned_pages; + + while (1) { + timeleft = msleep_interruptible(delay * 1000); + + if (kthread_should_stop() || timeleft) + break; + + if (mutex_trylock(&hotplug_mutex)) { + if (hotplug_occurred) { + hotplug_occurred = 0; + mutex_unlock(&hotplug_mutex); + cmm_dbg("Hotplug operation has occurred, " + "loaning activity suspended " + "for %d seconds.\n", + hotplug_delay); + timeleft = msleep_interruptible(hotplug_delay * + 1000); + if (kthread_should_stop() || timeleft) + break; + continue; + } + mutex_unlock(&hotplug_mutex); + } else { + cmm_dbg("Hotplug operation in progress, activity " + "suspended\n"); + continue; + } + + cmm_get_mpp(); + + __loaned_pages = atomic_long_read(&loaned_pages); + if (loaned_pages_target > __loaned_pages) { + if (cmm_alloc_pages(loaned_pages_target - __loaned_pages)) + loaned_pages_target = __loaned_pages; + } else if (loaned_pages_target < __loaned_pages) + cmm_free_pages(__loaned_pages - loaned_pages_target); + } + return 0; +} + +#define CMM_SHOW(name, format, args...) \ + static ssize_t show_##name(struct device *dev, \ + struct device_attribute *attr, \ + char *buf) \ + { \ + return sprintf(buf, format, ##args); \ + } \ + static DEVICE_ATTR(name, 0444, show_##name, NULL) + +CMM_SHOW(loaned_kb, "%lu\n", PAGES2KB(atomic_long_read(&loaned_pages))); +CMM_SHOW(loaned_target_kb, "%lu\n", PAGES2KB(loaned_pages_target)); + +static ssize_t show_oom_pages(struct device *dev, + struct device_attribute *attr, char *buf) +{ + return sprintf(buf, "%lu\n", PAGES2KB(oom_freed_pages)); +} + +static ssize_t store_oom_pages(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + unsigned long val = simple_strtoul (buf, NULL, 10); + + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + if (val != 0) + return -EBADMSG; + + oom_freed_pages = 0; + return count; +} + +static DEVICE_ATTR(oom_freed_kb, 0644, + show_oom_pages, store_oom_pages); + +static struct device_attribute *cmm_attrs[] = { + &dev_attr_loaned_kb, + &dev_attr_loaned_target_kb, + &dev_attr_oom_freed_kb, +}; + +static DEVICE_ULONG_ATTR(simulate_loan_target_kb, 0644, + simulate_loan_target_kb); + +static struct bus_type cmm_subsys = { + .name = "cmm", + .dev_name = "cmm", +}; + +static void cmm_release_device(struct device *dev) +{ +} + +/** + * cmm_sysfs_register - Register with sysfs + * + * Return value: + * 0 on success / other on failure + **/ +static int cmm_sysfs_register(struct device *dev) +{ + int i, rc; + + if ((rc = subsys_system_register(&cmm_subsys, NULL))) + return rc; + + dev->id = 0; + dev->bus = &cmm_subsys; + dev->release = cmm_release_device; + + if ((rc = device_register(dev))) + goto subsys_unregister; + + for (i = 0; i < ARRAY_SIZE(cmm_attrs); i++) { + if ((rc = device_create_file(dev, cmm_attrs[i]))) + goto fail; + } + + if (!simulate) + return 0; + rc = device_create_file(dev, &dev_attr_simulate_loan_target_kb.attr); + if (rc) + goto fail; + return 0; + +fail: + while (--i >= 0) + device_remove_file(dev, cmm_attrs[i]); + device_unregister(dev); +subsys_unregister: + bus_unregister(&cmm_subsys); + return rc; +} + +/** + * cmm_unregister_sysfs - Unregister from sysfs + * + **/ +static void cmm_unregister_sysfs(struct device *dev) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(cmm_attrs); i++) + device_remove_file(dev, cmm_attrs[i]); + device_unregister(dev); + bus_unregister(&cmm_subsys); +} + +/** + * cmm_reboot_notifier - Make sure pages are not still marked as "loaned" + * + **/ +static int cmm_reboot_notifier(struct notifier_block *nb, + unsigned long action, void *unused) +{ + if (action == SYS_RESTART) { + if (cmm_thread_ptr) + kthread_stop(cmm_thread_ptr); + cmm_thread_ptr = NULL; + cmm_free_pages(atomic_long_read(&loaned_pages)); + } + return NOTIFY_DONE; +} + +static struct notifier_block cmm_reboot_nb = { + .notifier_call = cmm_reboot_notifier, +}; + +/** + * cmm_memory_cb - Handle memory hotplug notifier calls + * @self: notifier block struct + * @action: action to take + * @arg: struct memory_notify data for handler + * + * Return value: + * NOTIFY_OK or notifier error based on subfunction return value + * + **/ +static int cmm_memory_cb(struct notifier_block *self, + unsigned long action, void *arg) +{ + switch (action) { + case MEM_GOING_OFFLINE: + mutex_lock(&hotplug_mutex); + hotplug_occurred = 1; + break; + case MEM_OFFLINE: + case MEM_CANCEL_OFFLINE: + mutex_unlock(&hotplug_mutex); + cmm_dbg("Memory offline operation complete.\n"); + break; + case MEM_GOING_ONLINE: + case MEM_ONLINE: + case MEM_CANCEL_ONLINE: + break; + } + + return NOTIFY_OK; +} + +static struct notifier_block cmm_mem_nb = { + .notifier_call = cmm_memory_cb, + .priority = CMM_MEM_HOTPLUG_PRI +}; + +#ifdef CONFIG_BALLOON_COMPACTION +static int cmm_migratepage(struct balloon_dev_info *b_dev_info, + struct page *newpage, struct page *page, + enum migrate_mode mode) +{ + unsigned long flags; + + /* + * loan/"inflate" the newpage first. + * + * We might race against the cmm_thread who might discover after our + * loan request that another page is to be unloaned. However, once + * the cmm_thread runs again later, this error will automatically + * be corrected. + */ + if (plpar_page_set_loaned(newpage)) { + /* Unlikely, but possible. Tell the caller not to retry now. */ + pr_err_ratelimited("%s: Cannot set page to loaned.", __func__); + return -EBUSY; + } + + /* balloon page list reference */ + get_page(newpage); + + /* + * When we migrate a page to a different zone, we have to fixup the + * count of both involved zones as we adjusted the managed page count + * when inflating. + */ + if (page_zone(page) != page_zone(newpage)) { + adjust_managed_page_count(page, 1); + adjust_managed_page_count(newpage, -1); + } + + spin_lock_irqsave(&b_dev_info->pages_lock, flags); + balloon_page_insert(b_dev_info, newpage); + balloon_page_delete(page); + b_dev_info->isolated_pages--; + spin_unlock_irqrestore(&b_dev_info->pages_lock, flags); + + /* + * activate/"deflate" the old page. We ignore any errors just like the + * other callers. + */ + plpar_page_set_active(page); + + /* balloon page list reference */ + put_page(page); + + return MIGRATEPAGE_SUCCESS; +} + +static void cmm_balloon_compaction_init(void) +{ + balloon_devinfo_init(&b_dev_info); + b_dev_info.migratepage = cmm_migratepage; +} +#else /* CONFIG_BALLOON_COMPACTION */ +static void cmm_balloon_compaction_init(void) +{ +} +#endif /* CONFIG_BALLOON_COMPACTION */ + +/** + * cmm_init - Module initialization + * + * Return value: + * 0 on success / other on failure + **/ +static int cmm_init(void) +{ + int rc; + + if (!firmware_has_feature(FW_FEATURE_CMO) && !simulate) + return -EOPNOTSUPP; + + cmm_balloon_compaction_init(); + + rc = register_oom_notifier(&cmm_oom_nb); + if (rc < 0) + goto out_balloon_compaction; + + if ((rc = register_reboot_notifier(&cmm_reboot_nb))) + goto out_oom_notifier; + + if ((rc = cmm_sysfs_register(&cmm_dev))) + goto out_reboot_notifier; + + rc = register_memory_notifier(&cmm_mem_nb); + if (rc) + goto out_unregister_notifier; + + if (cmm_disabled) + return 0; + + cmm_thread_ptr = kthread_run(cmm_thread, NULL, "cmmthread"); + if (IS_ERR(cmm_thread_ptr)) { + rc = PTR_ERR(cmm_thread_ptr); + goto out_unregister_notifier; + } + + return 0; +out_unregister_notifier: + unregister_memory_notifier(&cmm_mem_nb); + cmm_unregister_sysfs(&cmm_dev); +out_reboot_notifier: + unregister_reboot_notifier(&cmm_reboot_nb); +out_oom_notifier: + unregister_oom_notifier(&cmm_oom_nb); +out_balloon_compaction: + return rc; +} + +/** + * cmm_exit - Module exit + * + * Return value: + * nothing + **/ +static void cmm_exit(void) +{ + if (cmm_thread_ptr) + kthread_stop(cmm_thread_ptr); + unregister_oom_notifier(&cmm_oom_nb); + unregister_reboot_notifier(&cmm_reboot_nb); + unregister_memory_notifier(&cmm_mem_nb); + cmm_free_pages(atomic_long_read(&loaned_pages)); + cmm_unregister_sysfs(&cmm_dev); +} + +/** + * cmm_set_disable - Disable/Enable CMM + * + * Return value: + * 0 on success / other on failure + **/ +static int cmm_set_disable(const char *val, const struct kernel_param *kp) +{ + int disable = simple_strtoul(val, NULL, 10); + + if (disable != 0 && disable != 1) + return -EINVAL; + + if (disable && !cmm_disabled) { + if (cmm_thread_ptr) + kthread_stop(cmm_thread_ptr); + cmm_thread_ptr = NULL; + cmm_free_pages(atomic_long_read(&loaned_pages)); + } else if (!disable && cmm_disabled) { + cmm_thread_ptr = kthread_run(cmm_thread, NULL, "cmmthread"); + if (IS_ERR(cmm_thread_ptr)) + return PTR_ERR(cmm_thread_ptr); + } + + cmm_disabled = disable; + return 0; +} + +module_param_call(disable, cmm_set_disable, param_get_uint, + &cmm_disabled, 0644); +MODULE_PARM_DESC(disable, "Disable CMM. Set to 1 to disable. " + "[Default=" __stringify(CMM_DISABLE) "]"); + +module_init(cmm_init); +module_exit(cmm_exit); -- cgit v1.2.3