/*
 * PowerPC64 LPAR Configuration Information Driver
 *
 * Dave Engebretsen engebret@us.ibm.com
 *    Copyright (c) 2003 Dave Engebretsen
 * Will Schmidt willschm@us.ibm.com
 *    SPLPAR updates, Copyright (c) 2003 Will Schmidt IBM Corporation.
 *    seq_file updates, Copyright (c) 2004 Will Schmidt IBM Corporation.
 * Nathan Lynch nathanl@austin.ibm.com
 *    Added lparcfg_write, Copyright (C) 2004 Nathan Lynch IBM Corporation.
 *
 *      This program is free software; you can redistribute it and/or
 *      modify it under the terms of the GNU General Public License
 *      as published by the Free Software Foundation; either version
 *      2 of the License, or (at your option) any later version.
 *
 * This driver creates a proc file at /proc/ppc64/lparcfg which contains
 * keyword - value pairs that specify the configuration of the partition.
 */

#include <linux/module.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/proc_fs.h>
#include <linux/init.h>
#include <linux/seq_file.h>
#include <asm/uaccess.h>
#include <asm/iseries/hv_lp_config.h>
#include <asm/lppaca.h>
#include <asm/hvcall.h>
#include <asm/firmware.h>
#include <asm/rtas.h>
#include <asm/system.h>
#include <asm/time.h>
#include <asm/prom.h>
#include <asm/vdso_datapage.h>

#define MODULE_VERS "1.7"
#define MODULE_NAME "lparcfg"

/* #define LPARCFG_DEBUG */

static struct proc_dir_entry *proc_ppc64_lparcfg;
#define LPARCFG_BUFF_SIZE 4096

/*
 * Track sum of all purrs across all processors. This is used to further
 * calculate usage values by different applications
 */
static unsigned long get_purr(void)
{
        unsigned long sum_purr = 0;
        int cpu;

        for_each_possible_cpu(cpu) {
                if (firmware_has_feature(FW_FEATURE_ISERIES))
                        sum_purr += lppaca[cpu].emulated_time_base;
                else {
                        struct cpu_usage *cu;

                        cu = &per_cpu(cpu_usage_array, cpu);
                        sum_purr += cu->current_tb;
                }
        }
        return sum_purr;
}

#ifdef CONFIG_PPC_ISERIES

/*
 * Methods used to fetch LPAR data when running on an iSeries platform.
 */
static int iseries_lparcfg_data(struct seq_file *m, void *v)
{
        unsigned long pool_id;
        int shared, entitled_capacity, max_entitled_capacity;
        int processors, max_processors;
        unsigned long purr = get_purr();

        shared = (int)(local_paca->lppaca_ptr->shared_proc);

        seq_printf(m, "system_active_processors=%d\n",
                   (int)HvLpConfig_getSystemPhysicalProcessors());

        seq_printf(m, "system_potential_processors=%d\n",
                   (int)HvLpConfig_getSystemPhysicalProcessors());

        processors = (int)HvLpConfig_getPhysicalProcessors();
        seq_printf(m, "partition_active_processors=%d\n", processors);

        max_processors = (int)HvLpConfig_getMaxPhysicalProcessors();
        seq_printf(m, "partition_potential_processors=%d\n", max_processors);

        if (shared) {
                entitled_capacity = HvLpConfig_getSharedProcUnits();
                max_entitled_capacity = HvLpConfig_getMaxSharedProcUnits();
        } else {
                entitled_capacity = processors * 100;
                max_entitled_capacity = max_processors * 100;
        }
        seq_printf(m, "partition_entitled_capacity=%d\n", entitled_capacity);

        seq_printf(m, "partition_max_entitled_capacity=%d\n",
                   max_entitled_capacity);

        if (shared) {
                pool_id = HvLpConfig_getSharedPoolIndex();
                seq_printf(m, "pool=%d\n", (int)pool_id);
                seq_printf(m, "pool_capacity=%d\n",
                           (int)(HvLpConfig_getNumProcsInSharedPool(pool_id) *
                                 100));
                seq_printf(m, "purr=%ld\n", purr);
        }

        seq_printf(m, "shared_processor_mode=%d\n", shared);

        return 0;
}

#else                           /* CONFIG_PPC_ISERIES */

static int iseries_lparcfg_data(struct seq_file *m, void *v)
{
        return 0;
}

#endif                          /* CONFIG_PPC_ISERIES */

#ifdef CONFIG_PPC_PSERIES
/*
 * Methods used to fetch LPAR data when running on a pSeries platform.
 */
static void log_plpar_hcall_return(unsigned long rc, char *tag)
{
        switch(rc) {
        case 0:
                return;
        case H_HARDWARE:
                printk(KERN_INFO "plpar-hcall (%s) "
                                "Hardware fault\n", tag);
                return;
        case H_FUNCTION:
                printk(KERN_INFO "plpar-hcall (%s) "
                                "Function not allowed\n", tag);
                return;
        case H_AUTHORITY:
                printk(KERN_INFO "plpar-hcall (%s) "
                                "Not authorized to this function\n", tag);
                return;
        case H_PARAMETER:
                printk(KERN_INFO "plpar-hcall (%s) "
                                "Bad parameter(s)\n",tag);
                return;
        default:
                printk(KERN_INFO "plpar-hcall (%s) "
                                "Unexpected rc(0x%lx)\n", tag, rc);
        }
}

/*
 * H_GET_PPP hcall returns info in 4 parms.
 *  entitled_capacity,unallocated_capacity,
 *  aggregation, resource_capability).
 *
 *  R4 = Entitled Processor Capacity Percentage.
 *  R5 = Unallocated Processor Capacity Percentage.
 *  R6 (AABBCCDDEEFFGGHH).
 *      XXXX - reserved (0)
 *          XXXX - reserved (0)
 *              XXXX - Group Number
 *                  XXXX - Pool Number.
 *  R7 (IIJJKKLLMMNNOOPP).
 *      XX - reserved. (0)
 *        XX - bit 0-6 reserved (0).   bit 7 is Capped indicator.
 *          XX - variable processor Capacity Weight
 *            XX - Unallocated Variable Processor Capacity Weight.
 *              XXXX - Active processors in Physical Processor Pool.
 *                  XXXX  - Processors active on platform.
 */
static unsigned int h_get_ppp(unsigned long *entitled,
                              unsigned long *unallocated,
                              unsigned long *aggregation,
                              unsigned long *resource)
{
        unsigned long rc;
        unsigned long retbuf[PLPAR_HCALL_BUFSIZE];

        rc = plpar_hcall(H_GET_PPP, retbuf);

        *entitled = retbuf[0];
        *unallocated = retbuf[1];
        *aggregation = retbuf[2];
        *resource = retbuf[3];

        log_plpar_hcall_return(rc, "H_GET_PPP");

        return rc;
}

static void h_pic(unsigned long *pool_idle_time, unsigned long *num_procs)
{
        unsigned long rc;
        unsigned long retbuf[PLPAR_HCALL_BUFSIZE];

        rc = plpar_hcall(H_PIC, retbuf);

        *pool_idle_time = retbuf[0];
        *num_procs = retbuf[1];

        if (rc != H_AUTHORITY)
                log_plpar_hcall_return(rc, "H_PIC");
}

#define SPLPAR_CHARACTERISTICS_TOKEN 20
#define SPLPAR_MAXLENGTH 1026*(sizeof(char))

/*
 * parse_system_parameter_string()
 * Retrieve the potential_processors, max_entitled_capacity and friends
 * through the get-system-parameter rtas call.  Replace keyword strings as
 * necessary.
 */
static void parse_system_parameter_string(struct seq_file *m)
{
        int call_status;

        unsigned char *local_buffer = kmalloc(SPLPAR_MAXLENGTH, GFP_KERNEL);
        if (!local_buffer) {
                printk(KERN_ERR "%s %s kmalloc failure at line %d \n",
                       __FILE__, __FUNCTION__, __LINE__);
                return;
        }

        spin_lock(&rtas_data_buf_lock);
        memset(rtas_data_buf, 0, SPLPAR_MAXLENGTH);
        call_status = rtas_call(rtas_token("ibm,get-system-parameter"), 3, 1,
                                NULL,
                                SPLPAR_CHARACTERISTICS_TOKEN,
                                __pa(rtas_data_buf),
                                RTAS_DATA_BUF_SIZE);
        memcpy(local_buffer, rtas_data_buf, SPLPAR_MAXLENGTH);
        spin_unlock(&rtas_data_buf_lock);

        if (call_status != 0) {
                printk(KERN_INFO
                       "%s %s Error calling get-system-parameter (0x%x)\n",
                       __FILE__, __FUNCTION__, call_status);
        } else {
                int splpar_strlen;
                int idx, w_idx;
                char *workbuffer = kzalloc(SPLPAR_MAXLENGTH, GFP_KERNEL);
                if (!workbuffer) {
                        printk(KERN_ERR "%s %s kmalloc failure at line %d \n",
                               __FILE__, __FUNCTION__, __LINE__);
                        kfree(local_buffer);
                        return;
                }
#ifdef LPARCFG_DEBUG
                printk(KERN_INFO "success calling get-system-parameter \n");
#endif
                splpar_strlen = local_buffer[0] * 256 + local_buffer[1];
                local_buffer += 2;      /* step over strlen value */

                w_idx = 0;
                idx = 0;
                while ((*local_buffer) && (idx < splpar_strlen)) {
                        workbuffer[w_idx++] = local_buffer[idx++];
                        if ((local_buffer[idx] == ',')
                            || (local_buffer[idx] == '\0')) {
                                workbuffer[w_idx] = '\0';
                                if (w_idx) {
                                        /* avoid the empty string */
                                        seq_printf(m, "%s\n", workbuffer);
                                }
                                memset(workbuffer, 0, SPLPAR_MAXLENGTH);
                                idx++;  /* skip the comma */
                                w_idx = 0;
                        } else if (local_buffer[idx] == '=') {
                                /* code here to replace workbuffer contents
                                   with different keyword strings */
                                if (0 == strcmp(workbuffer, "MaxEntCap")) {
                                        strcpy(workbuffer,
                                               "partition_max_entitled_capacity");
                                        w_idx = strlen(workbuffer);
                                }
                                if (0 == strcmp(workbuffer, "MaxPlatProcs")) {
                                        strcpy(workbuffer,
                                               "system_potential_processors");
                                        w_idx = strlen(workbuffer);
                                }
                        }
                }
                kfree(workbuffer);
                local_buffer -= 2;      /* back up over strlen value */
        }
        kfree(local_buffer);
}

/* Return the number of processors in the system.
 * This function reads through the device tree and counts
 * the virtual processors, this does not include threads.
 */
static int lparcfg_count_active_processors(void)
{
        struct device_node *cpus_dn = NULL;
        int count = 0;

        while ((cpus_dn = of_find_node_by_type(cpus_dn, "cpu"))) {
#ifdef LPARCFG_DEBUG
                printk(KERN_ERR "cpus_dn %p \n", cpus_dn);
#endif
                count++;
        }
        return count;
}

static int pseries_lparcfg_data(struct seq_file *m, void *v)
{
        int partition_potential_processors;
        int partition_active_processors;
        struct device_node *rtas_node;
        const int *lrdrp = NULL;

        rtas_node = of_find_node_by_path("/rtas");
        if (rtas_node)
                lrdrp = of_get_property(rtas_node, "ibm,lrdr-capacity", NULL);

        if (lrdrp == NULL) {
                partition_potential_processors = vdso_data->processorCount;
        } else {
                partition_potential_processors = *(lrdrp + 4);
        }
        of_node_put(rtas_node);

        partition_active_processors = lparcfg_count_active_processors();

        if (firmware_has_feature(FW_FEATURE_SPLPAR)) {
                unsigned long h_entitled, h_unallocated;
                unsigned long h_aggregation, h_resource;
                unsigned long pool_idle_time, pool_procs;
                unsigned long purr;

                h_get_ppp(&h_entitled, &h_unallocated, &h_aggregation,
                          &h_resource);

                seq_printf(m, "R4=0x%lx\n", h_entitled);
                seq_printf(m, "R5=0x%lx\n", h_unallocated);
                seq_printf(m, "R6=0x%lx\n", h_aggregation);
                seq_printf(m, "R7=0x%lx\n", h_resource);

                purr = get_purr();

                /* this call handles the ibm,get-system-parameter contents */
                parse_system_parameter_string(m);

                seq_printf(m, "partition_entitled_capacity=%ld\n", h_entitled);

                seq_printf(m, "group=%ld\n", (h_aggregation >> 2 * 8) & 0xffff);

                seq_printf(m, "system_active_processors=%ld\n",
                           (h_resource >> 0 * 8) & 0xffff);

                /* pool related entries are apropriate for shared configs */
                if (lppaca[0].shared_proc) {

                        h_pic(&pool_idle_time, &pool_procs);

                        seq_printf(m, "pool=%ld\n",
                                   (h_aggregation >> 0 * 8) & 0xffff);

                        /* report pool_capacity in percentage */
                        seq_printf(m, "pool_capacity=%ld\n",
                                   ((h_resource >> 2 * 8) & 0xffff) * 100);

                        seq_printf(m, "pool_idle_time=%ld\n", pool_idle_time);

                        seq_printf(m, "pool_num_procs=%ld\n", pool_procs);
                }

                seq_printf(m, "unallocated_capacity_weight=%ld\n",
                           (h_resource >> 4 * 8) & 0xFF);

                seq_printf(m, "capacity_weight=%ld\n",
                           (h_resource >> 5 * 8) & 0xFF);

                seq_printf(m, "capped=%ld\n", (h_resource >> 6 * 8) & 0x01);

                seq_printf(m, "unallocated_capacity=%ld\n", h_unallocated);

                seq_printf(m, "purr=%ld\n", purr);

        } else {                /* non SPLPAR case */

                seq_printf(m, "system_active_processors=%d\n",
                           partition_potential_processors);

                seq_printf(m, "system_potential_processors=%d\n",
                           partition_potential_processors);

                seq_printf(m, "partition_max_entitled_capacity=%d\n",
                           partition_potential_processors * 100);

                seq_printf(m, "partition_entitled_capacity=%d\n",
                           partition_active_processors * 100);
        }

        seq_printf(m, "partition_active_processors=%d\n",
                   partition_active_processors);

        seq_printf(m, "partition_potential_processors=%d\n",
                   partition_potential_processors);

        seq_printf(m, "shared_processor_mode=%d\n", lppaca[0].shared_proc);

        return 0;
}

/*
 * Interface for changing system parameters (variable capacity weight
 * and entitled capacity).  Format of input is "param_name=value";
 * anything after value is ignored.  Valid parameters at this time are
 * "partition_entitled_capacity" and "capacity_weight".  We use
 * H_SET_PPP to alter parameters.
 *
 * This function should be invoked only on systems with
 * FW_FEATURE_SPLPAR.
 */
static ssize_t lparcfg_write(struct file *file, const char __user * buf,
                             size_t count, loff_t * off)
{
        char *kbuf;
        char *tmp;
        u64 new_entitled, *new_entitled_ptr = &new_entitled;
        u8 new_weight, *new_weight_ptr = &new_weight;

        unsigned long current_entitled; /* parameters for h_get_ppp */
        unsigned long dummy;
        unsigned long resource;
        u8 current_weight;

        ssize_t retval = -ENOMEM;

        if (!firmware_has_feature(FW_FEATURE_SPLPAR) ||
                        firmware_has_feature(FW_FEATURE_ISERIES))
                return -EINVAL;

        kbuf = kmalloc(count, GFP_KERNEL);
        if (!kbuf)
                goto out;

        retval = -EFAULT;
        if (copy_from_user(kbuf, buf, count))
                goto out;

        retval = -EINVAL;
        kbuf[count - 1] = '\0';
        tmp = strchr(kbuf, '=');
        if (!tmp)
                goto out;

        *tmp++ = '\0';

        if (!strcmp(kbuf, "partition_entitled_capacity")) {
                char *endp;
                *new_entitled_ptr = (u64) simple_strtoul(tmp, &endp, 10);
                if (endp == tmp)
                        goto out;
                new_weight_ptr = &current_weight;
        } else if (!strcmp(kbuf, "capacity_weight")) {
                char *endp;
                *new_weight_ptr = (u8) simple_strtoul(tmp, &endp, 10);
                if (endp == tmp)
                        goto out;
                new_entitled_ptr = &current_entitled;
        } else
                goto out;

        /* Get our current parameters */
        retval = h_get_ppp(&current_entitled, &dummy, &dummy, &resource);
        if (retval) {
                retval = -EIO;
                goto out;
        }

        current_weight = (resource >> 5 * 8) & 0xFF;

        pr_debug("%s: current_entitled = %lu, current_weight = %u\n",
                 __FUNCTION__, current_entitled, current_weight);

        pr_debug("%s: new_entitled = %lu, new_weight = %u\n",
                 __FUNCTION__, *new_entitled_ptr, *new_weight_ptr);

        retval = plpar_hcall_norets(H_SET_PPP, *new_entitled_ptr,
                                    *new_weight_ptr);

        if (retval == H_SUCCESS || retval == H_CONSTRAINED) {
                retval = count;
        } else if (retval == H_BUSY) {
                retval = -EBUSY;
        } else if (retval == H_HARDWARE) {
                retval = -EIO;
        } else if (retval == H_PARAMETER) {
                retval = -EINVAL;
        } else {
                printk(KERN_WARNING "%s: received unknown hv return code %ld",
                       __FUNCTION__, retval);
                retval = -EIO;
        }

out:
        kfree(kbuf);
        return retval;
}

#else                           /* CONFIG_PPC_PSERIES */

static int pseries_lparcfg_data(struct seq_file *m, void *v)
{
        return 0;
}

static ssize_t lparcfg_write(struct file *file, const char __user * buf,
                             size_t count, loff_t * off)
{
        return -EINVAL;
}

#endif                          /* CONFIG_PPC_PSERIES */

static int lparcfg_data(struct seq_file *m, void *v)
{
        struct device_node *rootdn;
        const char *model = "";
        const char *system_id = "";
        const char *tmp;
        const unsigned int *lp_index_ptr;
        unsigned int lp_index = 0;

        seq_printf(m, "%s %s \n", MODULE_NAME, MODULE_VERS);

        rootdn = of_find_node_by_path("/");
        if (rootdn) {
                tmp = of_get_property(rootdn, "model", NULL);
                if (tmp) {
                        model = tmp;
                        /* Skip "IBM," - see platforms/iseries/dt.c */
                        if (firmware_has_feature(FW_FEATURE_ISERIES))
                                model += 4;
                }
                tmp = of_get_property(rootdn, "system-id", NULL);
                if (tmp) {
                        system_id = tmp;
                        /* Skip "IBM," - see platforms/iseries/dt.c */
                        if (firmware_has_feature(FW_FEATURE_ISERIES))
                                system_id += 4;
                }
                lp_index_ptr = of_get_property(rootdn, "ibm,partition-no",
                                        NULL);
                if (lp_index_ptr)
                        lp_index = *lp_index_ptr;
                of_node_put(rootdn);
        }
        seq_printf(m, "serial_number=%s\n", system_id);
        seq_printf(m, "system_type=%s\n", model);
        seq_printf(m, "partition_id=%d\n", (int)lp_index);

        if (firmware_has_feature(FW_FEATURE_ISERIES))
                return iseries_lparcfg_data(m, v);
        return pseries_lparcfg_data(m, v);
}

static int lparcfg_open(struct inode *inode, struct file *file)
{
        return single_open(file, lparcfg_data, NULL);
}

const struct file_operations lparcfg_fops = {
        .owner          = THIS_MODULE,
        .read           = seq_read,
        .write          = lparcfg_write,
        .open           = lparcfg_open,
        .release        = single_release,
};

int __init lparcfg_init(void)
{
        struct proc_dir_entry *ent;
        mode_t mode = S_IRUSR | S_IRGRP | S_IROTH;

        /* Allow writing if we have FW_FEATURE_SPLPAR */
        if (firmware_has_feature(FW_FEATURE_SPLPAR) &&
                        !firmware_has_feature(FW_FEATURE_ISERIES))
                mode |= S_IWUSR;

        ent = create_proc_entry("ppc64/lparcfg", mode, NULL);
        if (ent) {
                ent->proc_fops = &lparcfg_fops;
                ent->data = kmalloc(LPARCFG_BUFF_SIZE, GFP_KERNEL);
                if (!ent->data) {
                        printk(KERN_ERR
                               "Failed to allocate buffer for lparcfg\n");
                        remove_proc_entry("lparcfg", ent->parent);
                        return -ENOMEM;
                }
        } else {
                printk(KERN_ERR "Failed to create ppc64/lparcfg\n");
                return -EIO;
        }

        proc_ppc64_lparcfg = ent;
        return 0;
}

void __exit lparcfg_cleanup(void)
{
        if (proc_ppc64_lparcfg) {
                kfree(proc_ppc64_lparcfg->data);
                remove_proc_entry("lparcfg", proc_ppc64_lparcfg->parent);
        }
}

module_init(lparcfg_init);
module_exit(lparcfg_cleanup);
MODULE_DESCRIPTION("Interface for LPAR configuration data");
MODULE_AUTHOR("Dave Engebretsen");
MODULE_LICENSE("GPL");