diff options
Diffstat (limited to 'arch/ia64/kernel/salinfo.c')
-rw-r--r-- | arch/ia64/kernel/salinfo.c | 646 |
1 files changed, 646 insertions, 0 deletions
diff --git a/arch/ia64/kernel/salinfo.c b/arch/ia64/kernel/salinfo.c new file mode 100644 index 0000000000..03b632c568 --- /dev/null +++ b/arch/ia64/kernel/salinfo.c @@ -0,0 +1,646 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * salinfo.c + * + * Creates entries in /proc/sal for various system features. + * + * Copyright (c) 2003, 2006 Silicon Graphics, Inc. All rights reserved. + * Copyright (c) 2003 Hewlett-Packard Co + * Bjorn Helgaas <bjorn.helgaas@hp.com> + * + * 10/30/2001 jbarnes@sgi.com copied much of Stephane's palinfo + * code to create this file + * Oct 23 2003 kaos@sgi.com + * Replace IPI with set_cpus_allowed() to read a record from the required cpu. + * Redesign salinfo log processing to separate interrupt and user space + * contexts. + * Cache the record across multi-block reads from user space. + * Support > 64 cpus. + * Delete module_exit and MOD_INC/DEC_COUNT, salinfo cannot be a module. + * + * Jan 28 2004 kaos@sgi.com + * Periodically check for outstanding MCA or INIT records. + * + * Dec 5 2004 kaos@sgi.com + * Standardize which records are cleared automatically. + * + * Aug 18 2005 kaos@sgi.com + * mca.c may not pass a buffer, a NULL buffer just indicates that a new + * record is available in SAL. + * Replace some NR_CPUS by cpus_online, for hotplug cpu. + * + * Jan 5 2006 kaos@sgi.com + * Handle hotplug cpus coming online. + * Handle hotplug cpus going offline while they still have outstanding records. + * Use the cpu_* macros consistently. + * Replace the counting semaphore with a mutex and a test if the cpumask is non-empty. + * Modify the locking to make the test for "work to do" an atomic operation. + */ + +#include <linux/capability.h> +#include <linux/cpu.h> +#include <linux/types.h> +#include <linux/proc_fs.h> +#include <linux/seq_file.h> +#include <linux/module.h> +#include <linux/smp.h> +#include <linux/timer.h> +#include <linux/vmalloc.h> +#include <linux/semaphore.h> + +#include <asm/sal.h> +#include <linux/uaccess.h> + +MODULE_AUTHOR("Jesse Barnes <jbarnes@sgi.com>"); +MODULE_DESCRIPTION("/proc interface to IA-64 SAL features"); +MODULE_LICENSE("GPL"); + +typedef struct { + const char *name; /* name of the proc entry */ + unsigned long feature; /* feature bit */ + struct proc_dir_entry *entry; /* registered entry (removal) */ +} salinfo_entry_t; + +/* + * List {name,feature} pairs for every entry in /proc/sal/<feature> + * that this module exports + */ +static const salinfo_entry_t salinfo_entries[]={ + { "bus_lock", IA64_SAL_PLATFORM_FEATURE_BUS_LOCK, }, + { "irq_redirection", IA64_SAL_PLATFORM_FEATURE_IRQ_REDIR_HINT, }, + { "ipi_redirection", IA64_SAL_PLATFORM_FEATURE_IPI_REDIR_HINT, }, + { "itc_drift", IA64_SAL_PLATFORM_FEATURE_ITC_DRIFT, }, +}; + +#define NR_SALINFO_ENTRIES ARRAY_SIZE(salinfo_entries) + +static char *salinfo_log_name[] = { + "mca", + "init", + "cmc", + "cpe", +}; + +static struct proc_dir_entry *salinfo_proc_entries[ + ARRAY_SIZE(salinfo_entries) + /* /proc/sal/bus_lock */ + ARRAY_SIZE(salinfo_log_name) + /* /proc/sal/{mca,...} */ + (2 * ARRAY_SIZE(salinfo_log_name)) + /* /proc/sal/mca/{event,data} */ + 1]; /* /proc/sal */ + +/* Some records we get ourselves, some are accessed as saved data in buffers + * that are owned by mca.c. + */ +struct salinfo_data_saved { + u8* buffer; + u64 size; + u64 id; + int cpu; +}; + +/* State transitions. Actions are :- + * Write "read <cpunum>" to the data file. + * Write "clear <cpunum>" to the data file. + * Write "oemdata <cpunum> <offset> to the data file. + * Read from the data file. + * Close the data file. + * + * Start state is NO_DATA. + * + * NO_DATA + * write "read <cpunum>" -> NO_DATA or LOG_RECORD. + * write "clear <cpunum>" -> NO_DATA or LOG_RECORD. + * write "oemdata <cpunum> <offset> -> return -EINVAL. + * read data -> return EOF. + * close -> unchanged. Free record areas. + * + * LOG_RECORD + * write "read <cpunum>" -> NO_DATA or LOG_RECORD. + * write "clear <cpunum>" -> NO_DATA or LOG_RECORD. + * write "oemdata <cpunum> <offset> -> format the oem data, goto OEMDATA. + * read data -> return the INIT/MCA/CMC/CPE record. + * close -> unchanged. Keep record areas. + * + * OEMDATA + * write "read <cpunum>" -> NO_DATA or LOG_RECORD. + * write "clear <cpunum>" -> NO_DATA or LOG_RECORD. + * write "oemdata <cpunum> <offset> -> format the oem data, goto OEMDATA. + * read data -> return the formatted oemdata. + * close -> unchanged. Keep record areas. + * + * Closing the data file does not change the state. This allows shell scripts + * to manipulate salinfo data, each shell redirection opens the file, does one + * action then closes it again. The record areas are only freed at close when + * the state is NO_DATA. + */ +enum salinfo_state { + STATE_NO_DATA, + STATE_LOG_RECORD, + STATE_OEMDATA, +}; + +struct salinfo_data { + cpumask_t cpu_event; /* which cpus have outstanding events */ + wait_queue_head_t read_wait; + u8 *log_buffer; + u64 log_size; + u8 *oemdata; /* decoded oem data */ + u64 oemdata_size; + int open; /* single-open to prevent races */ + u8 type; + u8 saved_num; /* using a saved record? */ + enum salinfo_state state :8; /* processing state */ + u8 padding; + int cpu_check; /* next CPU to check */ + struct salinfo_data_saved data_saved[5];/* save last 5 records from mca.c, must be < 255 */ +}; + +static struct salinfo_data salinfo_data[ARRAY_SIZE(salinfo_log_name)]; + +static DEFINE_SPINLOCK(data_lock); +static DEFINE_SPINLOCK(data_saved_lock); + +/** salinfo_platform_oemdata - optional callback to decode oemdata from an error + * record. + * @sect_header: pointer to the start of the section to decode. + * @oemdata: returns vmalloc area containing the decoded output. + * @oemdata_size: returns length of decoded output (strlen). + * + * Description: If user space asks for oem data to be decoded by the kernel + * and/or prom and the platform has set salinfo_platform_oemdata to the address + * of a platform specific routine then call that routine. salinfo_platform_oemdata + * vmalloc's and formats its output area, returning the address of the text + * and its strlen. Returns 0 for success, -ve for error. The callback is + * invoked on the cpu that generated the error record. + */ +int (*salinfo_platform_oemdata)(const u8 *sect_header, u8 **oemdata, u64 *oemdata_size); + +struct salinfo_platform_oemdata_parms { + const u8 *efi_guid; + u8 **oemdata; + u64 *oemdata_size; +}; + +static long +salinfo_platform_oemdata_cpu(void *context) +{ + struct salinfo_platform_oemdata_parms *parms = context; + + return salinfo_platform_oemdata(parms->efi_guid, parms->oemdata, parms->oemdata_size); +} + +static void +shift1_data_saved (struct salinfo_data *data, int shift) +{ + memcpy(data->data_saved+shift, data->data_saved+shift+1, + (ARRAY_SIZE(data->data_saved) - (shift+1)) * sizeof(data->data_saved[0])); + memset(data->data_saved + ARRAY_SIZE(data->data_saved) - 1, 0, + sizeof(data->data_saved[0])); +} + +/* This routine is invoked in interrupt context. Note: mca.c enables + * interrupts before calling this code for CMC/CPE. MCA and INIT events are + * not irq safe, do not call any routines that use spinlocks, they may deadlock. + * MCA and INIT records are recorded, a timer event will look for any + * outstanding events and wake up the user space code. + * + * The buffer passed from mca.c points to the output from ia64_log_get. This is + * a persistent buffer but its contents can change between the interrupt and + * when user space processes the record. Save the record id to identify + * changes. If the buffer is NULL then just update the bitmap. + */ +void +salinfo_log_wakeup(int type, u8 *buffer, u64 size, int irqsafe) +{ + struct salinfo_data *data = salinfo_data + type; + struct salinfo_data_saved *data_saved; + unsigned long flags = 0; + int i; + int saved_size = ARRAY_SIZE(data->data_saved); + + BUG_ON(type >= ARRAY_SIZE(salinfo_log_name)); + + if (irqsafe) + spin_lock_irqsave(&data_saved_lock, flags); + if (buffer) { + for (i = 0, data_saved = data->data_saved; i < saved_size; ++i, ++data_saved) { + if (!data_saved->buffer) + break; + } + if (i == saved_size) { + if (!data->saved_num) { + shift1_data_saved(data, 0); + data_saved = data->data_saved + saved_size - 1; + } else + data_saved = NULL; + } + if (data_saved) { + data_saved->cpu = smp_processor_id(); + data_saved->id = ((sal_log_record_header_t *)buffer)->id; + data_saved->size = size; + data_saved->buffer = buffer; + } + } + cpumask_set_cpu(smp_processor_id(), &data->cpu_event); + if (irqsafe) { + wake_up_interruptible(&data->read_wait); + spin_unlock_irqrestore(&data_saved_lock, flags); + } +} + +/* Check for outstanding MCA/INIT records every minute (arbitrary) */ +#define SALINFO_TIMER_DELAY (60*HZ) +static struct timer_list salinfo_timer; +extern void ia64_mlogbuf_dump(void); + +static void +salinfo_timeout_check(struct salinfo_data *data) +{ + if (!data->open) + return; + if (!cpumask_empty(&data->cpu_event)) + wake_up_interruptible(&data->read_wait); +} + +static void +salinfo_timeout(struct timer_list *unused) +{ + ia64_mlogbuf_dump(); + salinfo_timeout_check(salinfo_data + SAL_INFO_TYPE_MCA); + salinfo_timeout_check(salinfo_data + SAL_INFO_TYPE_INIT); + salinfo_timer.expires = jiffies + SALINFO_TIMER_DELAY; + add_timer(&salinfo_timer); +} + +static int +salinfo_event_open(struct inode *inode, struct file *file) +{ + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + return 0; +} + +static ssize_t +salinfo_event_read(struct file *file, char __user *buffer, size_t count, loff_t *ppos) +{ + struct salinfo_data *data = pde_data(file_inode(file)); + char cmd[32]; + size_t size; + int i, n, cpu = -1; + +retry: + if (cpumask_empty(&data->cpu_event)) { + if (file->f_flags & O_NONBLOCK) + return -EAGAIN; + if (wait_event_interruptible(data->read_wait, + !cpumask_empty(&data->cpu_event))) + return -EINTR; + } + + n = data->cpu_check; + for (i = 0; i < nr_cpu_ids; i++) { + if (cpumask_test_cpu(n, &data->cpu_event)) { + if (!cpu_online(n)) { + cpumask_clear_cpu(n, &data->cpu_event); + continue; + } + cpu = n; + break; + } + if (++n == nr_cpu_ids) + n = 0; + } + + if (cpu == -1) + goto retry; + + ia64_mlogbuf_dump(); + + /* for next read, start checking at next CPU */ + data->cpu_check = cpu; + if (++data->cpu_check == nr_cpu_ids) + data->cpu_check = 0; + + snprintf(cmd, sizeof(cmd), "read %d\n", cpu); + + size = strlen(cmd); + if (size > count) + size = count; + if (copy_to_user(buffer, cmd, size)) + return -EFAULT; + + return size; +} + +static const struct proc_ops salinfo_event_proc_ops = { + .proc_open = salinfo_event_open, + .proc_read = salinfo_event_read, + .proc_lseek = noop_llseek, +}; + +static int +salinfo_log_open(struct inode *inode, struct file *file) +{ + struct salinfo_data *data = pde_data(inode); + + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + spin_lock(&data_lock); + if (data->open) { + spin_unlock(&data_lock); + return -EBUSY; + } + data->open = 1; + spin_unlock(&data_lock); + + if (data->state == STATE_NO_DATA && + !(data->log_buffer = vmalloc(ia64_sal_get_state_info_size(data->type)))) { + data->open = 0; + return -ENOMEM; + } + + return 0; +} + +static int +salinfo_log_release(struct inode *inode, struct file *file) +{ + struct salinfo_data *data = pde_data(inode); + + if (data->state == STATE_NO_DATA) { + vfree(data->log_buffer); + vfree(data->oemdata); + data->log_buffer = NULL; + data->oemdata = NULL; + } + spin_lock(&data_lock); + data->open = 0; + spin_unlock(&data_lock); + return 0; +} + +static long +salinfo_log_read_cpu(void *context) +{ + struct salinfo_data *data = context; + sal_log_record_header_t *rh; + data->log_size = ia64_sal_get_state_info(data->type, (u64 *) data->log_buffer); + rh = (sal_log_record_header_t *)(data->log_buffer); + /* Clear corrected errors as they are read from SAL */ + if (rh->severity == sal_log_severity_corrected) + ia64_sal_clear_state_info(data->type); + return 0; +} + +static void +salinfo_log_new_read(int cpu, struct salinfo_data *data) +{ + struct salinfo_data_saved *data_saved; + unsigned long flags; + int i; + int saved_size = ARRAY_SIZE(data->data_saved); + + data->saved_num = 0; + spin_lock_irqsave(&data_saved_lock, flags); +retry: + for (i = 0, data_saved = data->data_saved; i < saved_size; ++i, ++data_saved) { + if (data_saved->buffer && data_saved->cpu == cpu) { + sal_log_record_header_t *rh = (sal_log_record_header_t *)(data_saved->buffer); + data->log_size = data_saved->size; + memcpy(data->log_buffer, rh, data->log_size); + barrier(); /* id check must not be moved */ + if (rh->id == data_saved->id) { + data->saved_num = i+1; + break; + } + /* saved record changed by mca.c since interrupt, discard it */ + shift1_data_saved(data, i); + goto retry; + } + } + spin_unlock_irqrestore(&data_saved_lock, flags); + + if (!data->saved_num) + work_on_cpu_safe(cpu, salinfo_log_read_cpu, data); + if (!data->log_size) { + data->state = STATE_NO_DATA; + cpumask_clear_cpu(cpu, &data->cpu_event); + } else { + data->state = STATE_LOG_RECORD; + } +} + +static ssize_t +salinfo_log_read(struct file *file, char __user *buffer, size_t count, loff_t *ppos) +{ + struct salinfo_data *data = pde_data(file_inode(file)); + u8 *buf; + u64 bufsize; + + if (data->state == STATE_LOG_RECORD) { + buf = data->log_buffer; + bufsize = data->log_size; + } else if (data->state == STATE_OEMDATA) { + buf = data->oemdata; + bufsize = data->oemdata_size; + } else { + buf = NULL; + bufsize = 0; + } + return simple_read_from_buffer(buffer, count, ppos, buf, bufsize); +} + +static long +salinfo_log_clear_cpu(void *context) +{ + struct salinfo_data *data = context; + + ia64_sal_clear_state_info(data->type); + return 0; +} + +static int +salinfo_log_clear(struct salinfo_data *data, int cpu) +{ + sal_log_record_header_t *rh; + unsigned long flags; + spin_lock_irqsave(&data_saved_lock, flags); + data->state = STATE_NO_DATA; + if (!cpumask_test_cpu(cpu, &data->cpu_event)) { + spin_unlock_irqrestore(&data_saved_lock, flags); + return 0; + } + cpumask_clear_cpu(cpu, &data->cpu_event); + if (data->saved_num) { + shift1_data_saved(data, data->saved_num - 1); + data->saved_num = 0; + } + spin_unlock_irqrestore(&data_saved_lock, flags); + rh = (sal_log_record_header_t *)(data->log_buffer); + /* Corrected errors have already been cleared from SAL */ + if (rh->severity != sal_log_severity_corrected) + work_on_cpu_safe(cpu, salinfo_log_clear_cpu, data); + /* clearing a record may make a new record visible */ + salinfo_log_new_read(cpu, data); + if (data->state == STATE_LOG_RECORD) { + spin_lock_irqsave(&data_saved_lock, flags); + cpumask_set_cpu(cpu, &data->cpu_event); + wake_up_interruptible(&data->read_wait); + spin_unlock_irqrestore(&data_saved_lock, flags); + } + return 0; +} + +static ssize_t +salinfo_log_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos) +{ + struct salinfo_data *data = pde_data(file_inode(file)); + char cmd[32]; + size_t size; + u32 offset; + int cpu; + + size = sizeof(cmd); + if (count < size) + size = count; + if (copy_from_user(cmd, buffer, size)) + return -EFAULT; + + if (sscanf(cmd, "read %d", &cpu) == 1) { + salinfo_log_new_read(cpu, data); + } else if (sscanf(cmd, "clear %d", &cpu) == 1) { + int ret; + if ((ret = salinfo_log_clear(data, cpu))) + count = ret; + } else if (sscanf(cmd, "oemdata %d %d", &cpu, &offset) == 2) { + if (data->state != STATE_LOG_RECORD && data->state != STATE_OEMDATA) + return -EINVAL; + if (offset > data->log_size - sizeof(efi_guid_t)) + return -EINVAL; + data->state = STATE_OEMDATA; + if (salinfo_platform_oemdata) { + struct salinfo_platform_oemdata_parms parms = { + .efi_guid = data->log_buffer + offset, + .oemdata = &data->oemdata, + .oemdata_size = &data->oemdata_size + }; + count = work_on_cpu_safe(cpu, salinfo_platform_oemdata_cpu, + &parms); + } else + data->oemdata_size = 0; + } else + return -EINVAL; + + return count; +} + +static const struct proc_ops salinfo_data_proc_ops = { + .proc_open = salinfo_log_open, + .proc_release = salinfo_log_release, + .proc_read = salinfo_log_read, + .proc_write = salinfo_log_write, + .proc_lseek = default_llseek, +}; + +static int salinfo_cpu_online(unsigned int cpu) +{ + unsigned int i, end = ARRAY_SIZE(salinfo_data); + struct salinfo_data *data; + + spin_lock_irq(&data_saved_lock); + for (i = 0, data = salinfo_data; i < end; ++i, ++data) { + cpumask_set_cpu(cpu, &data->cpu_event); + wake_up_interruptible(&data->read_wait); + } + spin_unlock_irq(&data_saved_lock); + return 0; +} + +static int salinfo_cpu_pre_down(unsigned int cpu) +{ + unsigned int i, end = ARRAY_SIZE(salinfo_data); + struct salinfo_data *data; + + spin_lock_irq(&data_saved_lock); + for (i = 0, data = salinfo_data; i < end; ++i, ++data) { + struct salinfo_data_saved *data_saved; + int j = ARRAY_SIZE(data->data_saved) - 1; + + for (data_saved = data->data_saved + j; j >= 0; + --j, --data_saved) { + if (data_saved->buffer && data_saved->cpu == cpu) + shift1_data_saved(data, j); + } + cpumask_clear_cpu(cpu, &data->cpu_event); + } + spin_unlock_irq(&data_saved_lock); + return 0; +} + +/* + * 'data' contains an integer that corresponds to the feature we're + * testing + */ +static int __maybe_unused proc_salinfo_show(struct seq_file *m, void *v) +{ + unsigned long data = (unsigned long)v; + seq_puts(m, (sal_platform_features & data) ? "1\n" : "0\n"); + return 0; +} + +static int __init +salinfo_init(void) +{ + struct proc_dir_entry *salinfo_dir; /* /proc/sal dir entry */ + struct proc_dir_entry **sdir = salinfo_proc_entries; /* keeps track of every entry */ + struct proc_dir_entry *dir, *entry; + struct salinfo_data *data; + int i; + + salinfo_dir = proc_mkdir("sal", NULL); + if (!salinfo_dir) + return 0; + + for (i=0; i < NR_SALINFO_ENTRIES; i++) { + /* pass the feature bit in question as misc data */ + *sdir++ = proc_create_single_data(salinfo_entries[i].name, 0, + salinfo_dir, proc_salinfo_show, + (void *)salinfo_entries[i].feature); + } + + for (i = 0; i < ARRAY_SIZE(salinfo_log_name); i++) { + data = salinfo_data + i; + data->type = i; + init_waitqueue_head(&data->read_wait); + dir = proc_mkdir(salinfo_log_name[i], salinfo_dir); + if (!dir) + continue; + + entry = proc_create_data("event", S_IRUSR, dir, + &salinfo_event_proc_ops, data); + if (!entry) + continue; + *sdir++ = entry; + + entry = proc_create_data("data", S_IRUSR | S_IWUSR, dir, + &salinfo_data_proc_ops, data); + if (!entry) + continue; + *sdir++ = entry; + + *sdir++ = dir; + } + + *sdir++ = salinfo_dir; + + timer_setup(&salinfo_timer, salinfo_timeout, 0); + salinfo_timer.expires = jiffies + SALINFO_TIMER_DELAY; + add_timer(&salinfo_timer); + + i = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "ia64/salinfo:online", + salinfo_cpu_online, salinfo_cpu_pre_down); + WARN_ON(i < 0); + return 0; +} + +module_init(salinfo_init); |