// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * 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 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 <linux/slab.h>
#include <linux/uaccess.h>
#include <linux/hugetlb.h>
#include <asm/lppaca.h>
#include <asm/hvcall.h>
#include <asm/firmware.h>
#include <asm/rtas.h>
#include <asm/time.h>
#include <asm/prom.h>
#include <asm/vdso_datapage.h>
#include <asm/vio.h>
#include <asm/mmu.h>
#include <asm/machdep.h>
#include <asm/drmem.h>

#include "pseries.h"

/*
 * This isn't a module but we expose that to userspace
 * via /proc so leave the definitions here
 */
#define MODULE_VERS "1.9"
#define MODULE_NAME "lparcfg"

/* #define LPARCFG_DEBUG */

/*
 * Track sum of all purrs across all processors. This is used to further
 * calculate usage values by different applications
 */
static void cpu_get_purr(void *arg)
{
        atomic64_t *sum = arg;

        atomic64_add(mfspr(SPRN_PURR), sum);
}

static unsigned long get_purr(void)
{
        atomic64_t purr = ATOMIC64_INIT(0);

        on_each_cpu(cpu_get_purr, &purr, 1);

        return atomic64_read(&purr);
}

/*
 * Methods used to fetch LPAR data when running on a pSeries platform.
 */

struct hvcall_ppp_data {
        u64     entitlement;
        u64     unallocated_entitlement;
        u16     group_num;
        u16     pool_num;
        u8      capped;
        u8      weight;
        u8      unallocated_weight;
        u16     active_procs_in_pool;
        u16     active_system_procs;
        u16     phys_platform_procs;
        u32     max_proc_cap_avail;
        u32     entitled_proc_cap_avail;
};

/*
 * 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.
 *  R8 (QQQQRRRRRRSSSSSS). if ibm,partition-performance-parameters-level >= 1
 *      XXXX - Physical platform procs allocated to virtualization.
 *          XXXXXX - Max procs capacity % available to the partitions pool.
 *                XXXXXX - Entitled procs capacity % available to the
 *                         partitions pool.
 */
static unsigned int h_get_ppp(struct hvcall_ppp_data *ppp_data)
{
        unsigned long rc;
        unsigned long retbuf[PLPAR_HCALL9_BUFSIZE];

        rc = plpar_hcall9(H_GET_PPP, retbuf);

        ppp_data->entitlement = retbuf[0];
        ppp_data->unallocated_entitlement = retbuf[1];

        ppp_data->group_num = (retbuf[2] >> 2 * 8) & 0xffff;
        ppp_data->pool_num = retbuf[2] & 0xffff;

        ppp_data->capped = (retbuf[3] >> 6 * 8) & 0x01;
        ppp_data->weight = (retbuf[3] >> 5 * 8) & 0xff;
        ppp_data->unallocated_weight = (retbuf[3] >> 4 * 8) & 0xff;
        ppp_data->active_procs_in_pool = (retbuf[3] >> 2 * 8) & 0xffff;
        ppp_data->active_system_procs = retbuf[3] & 0xffff;

        ppp_data->phys_platform_procs = retbuf[4] >> 6 * 8;
        ppp_data->max_proc_cap_avail = (retbuf[4] >> 3 * 8) & 0xffffff;
        ppp_data->entitled_proc_cap_avail = retbuf[4] & 0xffffff;

        return rc;
}

static void show_gpci_data(struct seq_file *m)
{
        struct hv_gpci_request_buffer *buf;
        unsigned int affinity_score;
        long ret;

        buf = kmalloc(sizeof(*buf), GFP_KERNEL);
        if (buf == NULL)
                return;

        /*
         * Show the local LPAR's affinity score.
         *
         * 0xB1 selects the Affinity_Domain_Info_By_Partition subcall.
         * The score is at byte 0xB in the output buffer.
         */
        memset(&buf->params, 0, sizeof(buf->params));
        buf->params.counter_request = cpu_to_be32(0xB1);
        buf->params.starting_index = cpu_to_be32(-1);   /* local LPAR */
        buf->params.counter_info_version_in = 0x5;      /* v5+ for score */
        ret = plpar_hcall_norets(H_GET_PERF_COUNTER_INFO, virt_to_phys(buf),
                                 sizeof(*buf));
        if (ret != H_SUCCESS) {
                pr_debug("hcall failed: H_GET_PERF_COUNTER_INFO: %ld, %x\n",
                         ret, be32_to_cpu(buf->params.detail_rc));
                goto out;
        }
        affinity_score = buf->bytes[0xB];
        seq_printf(m, "partition_affinity_score=%u\n", affinity_score);
out:
        kfree(buf);
}

static unsigned 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];

        return rc;
}

/*
 * parse_ppp_data
 * Parse out the data returned from h_get_ppp and h_pic
 */
static void parse_ppp_data(struct seq_file *m)
{
        struct hvcall_ppp_data ppp_data;
        struct device_node *root;
        const __be32 *perf_level;
        int rc;

        rc = h_get_ppp(&ppp_data);
        if (rc)
                return;

        seq_printf(m, "partition_entitled_capacity=%lld\n",
                   ppp_data.entitlement);
        seq_printf(m, "group=%d\n", ppp_data.group_num);
        seq_printf(m, "system_active_processors=%d\n",
                   ppp_data.active_system_procs);

        /* pool related entries are appropriate for shared configs */
        if (lppaca_shared_proc(get_lppaca())) {
                unsigned long pool_idle_time, pool_procs;

                seq_printf(m, "pool=%d\n", ppp_data.pool_num);

                /* report pool_capacity in percentage */
                seq_printf(m, "pool_capacity=%d\n",
                           ppp_data.active_procs_in_pool * 100);

                h_pic(&pool_idle_time, &pool_procs);
                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=%d\n",
                   ppp_data.unallocated_weight);
        seq_printf(m, "capacity_weight=%d\n", ppp_data.weight);
        seq_printf(m, "capped=%d\n", ppp_data.capped);
        seq_printf(m, "unallocated_capacity=%lld\n",
                   ppp_data.unallocated_entitlement);

        /* The last bits of information returned from h_get_ppp are only
         * valid if the ibm,partition-performance-parameters-level
         * property is >= 1.
         */
        root = of_find_node_by_path("/");
        if (root) {
                perf_level = of_get_property(root,
                                "ibm,partition-performance-parameters-level",
                                             NULL);
                if (perf_level && (be32_to_cpup(perf_level) >= 1)) {
                        seq_printf(m,
                            "physical_procs_allocated_to_virtualization=%d\n",
                                   ppp_data.phys_platform_procs);
                        seq_printf(m, "max_proc_capacity_available=%d\n",
                                   ppp_data.max_proc_cap_avail);
                        seq_printf(m, "entitled_proc_capacity_available=%d\n",
                                   ppp_data.entitled_proc_cap_avail);
                }

                of_node_put(root);
        }
}

/**
 * parse_mpp_data
 * Parse out data returned from h_get_mpp
 */
static void parse_mpp_data(struct seq_file *m)
{
        struct hvcall_mpp_data mpp_data;
        int rc;

        rc = h_get_mpp(&mpp_data);
        if (rc)
                return;

        seq_printf(m, "entitled_memory=%ld\n", mpp_data.entitled_mem);

        if (mpp_data.mapped_mem != -1)
                seq_printf(m, "mapped_entitled_memory=%ld\n",
                           mpp_data.mapped_mem);

        seq_printf(m, "entitled_memory_group_number=%d\n", mpp_data.group_num);
        seq_printf(m, "entitled_memory_pool_number=%d\n", mpp_data.pool_num);

        seq_printf(m, "entitled_memory_weight=%d\n", mpp_data.mem_weight);
        seq_printf(m, "unallocated_entitled_memory_weight=%d\n",
                   mpp_data.unallocated_mem_weight);
        seq_printf(m, "unallocated_io_mapping_entitlement=%ld\n",
                   mpp_data.unallocated_entitlement);

        if (mpp_data.pool_size != -1)
                seq_printf(m, "entitled_memory_pool_size=%ld bytes\n",
                           mpp_data.pool_size);

        seq_printf(m, "entitled_memory_loan_request=%ld\n",
                   mpp_data.loan_request);

        seq_printf(m, "backing_memory=%ld bytes\n", mpp_data.backing_mem);
}

/**
 * parse_mpp_x_data
 * Parse out data returned from h_get_mpp_x
 */
static void parse_mpp_x_data(struct seq_file *m)
{
        struct hvcall_mpp_x_data mpp_x_data;

        if (!firmware_has_feature(FW_FEATURE_XCMO))
                return;
        if (h_get_mpp_x(&mpp_x_data))
                return;

        seq_printf(m, "coalesced_bytes=%ld\n", mpp_x_data.coalesced_bytes);

        if (mpp_x_data.pool_coalesced_bytes)
                seq_printf(m, "pool_coalesced_bytes=%ld\n",
                           mpp_x_data.pool_coalesced_bytes);
        if (mpp_x_data.pool_purr_cycles)
                seq_printf(m, "coalesce_pool_purr=%ld\n", mpp_x_data.pool_purr_cycles);
        if (mpp_x_data.pool_spurr_cycles)
                seq_printf(m, "coalesce_pool_spurr=%ld\n", mpp_x_data.pool_spurr_cycles);
}

#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__, __func__, __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);
        local_buffer[SPLPAR_MAXLENGTH - 1] = '\0';
        spin_unlock(&rtas_data_buf_lock);

        if (call_status != 0) {
                printk(KERN_INFO
                       "%s %s Error calling get-system-parameter (0x%x)\n",
                       __FILE__, __func__, 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__, __func__, __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;
        int count = 0;

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

static void pseries_cmo_data(struct seq_file *m)
{
        int cpu;
        unsigned long cmo_faults = 0;
        unsigned long cmo_fault_time = 0;

        seq_printf(m, "cmo_enabled=%d\n", firmware_has_feature(FW_FEATURE_CMO));

        if (!firmware_has_feature(FW_FEATURE_CMO))
                return;

        for_each_possible_cpu(cpu) {
                cmo_faults += be64_to_cpu(lppaca_of(cpu).cmo_faults);
                cmo_fault_time += be64_to_cpu(lppaca_of(cpu).cmo_fault_time);
        }

        seq_printf(m, "cmo_faults=%lu\n", cmo_faults);
        seq_printf(m, "cmo_fault_time_usec=%lu\n",
                   cmo_fault_time / tb_ticks_per_usec);
        seq_printf(m, "cmo_primary_psp=%d\n", cmo_get_primary_psp());
        seq_printf(m, "cmo_secondary_psp=%d\n", cmo_get_secondary_psp());
        seq_printf(m, "cmo_page_size=%lu\n", cmo_get_page_size());
}

static void splpar_dispatch_data(struct seq_file *m)
{
        int cpu;
        unsigned long dispatches = 0;
        unsigned long dispatch_dispersions = 0;

        for_each_possible_cpu(cpu) {
                dispatches += be32_to_cpu(lppaca_of(cpu).yield_count);
                dispatch_dispersions +=
                        be32_to_cpu(lppaca_of(cpu).dispersion_count);
        }

        seq_printf(m, "dispatches=%lu\n", dispatches);
        seq_printf(m, "dispatch_dispersions=%lu\n", dispatch_dispersions);
}

static void parse_em_data(struct seq_file *m)
{
        unsigned long retbuf[PLPAR_HCALL_BUFSIZE];

        if (firmware_has_feature(FW_FEATURE_LPAR) &&
            plpar_hcall(H_GET_EM_PARMS, retbuf) == H_SUCCESS)
                seq_printf(m, "power_mode_data=%016lx\n", retbuf[0]);
}

static void maxmem_data(struct seq_file *m)
{
        unsigned long maxmem = 0;

        maxmem += (unsigned long)drmem_info->n_lmbs * drmem_info->lmb_size;
        maxmem += hugetlb_total_pages() * PAGE_SIZE;

        seq_printf(m, "MaxMem=%lu\n", maxmem);
}

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 __be32 *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 = be32_to_cpup(lrdrp + 4);
        }
        of_node_put(rtas_node);

        partition_active_processors = lparcfg_count_active_processors();

        if (firmware_has_feature(FW_FEATURE_SPLPAR)) {
                /* this call handles the ibm,get-system-parameter contents */
                parse_system_parameter_string(m);
                parse_ppp_data(m);
                parse_mpp_data(m);
                parse_mpp_x_data(m);
                pseries_cmo_data(m);
                splpar_dispatch_data(m);

                seq_printf(m, "purr=%ld\n", get_purr());
                seq_printf(m, "tbr=%ld\n", mftb());
        } 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);
        }

        show_gpci_data(m);

        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_shared_proc(get_lppaca()));

#ifdef CONFIG_PPC_BOOK3S_64
        seq_printf(m, "slb_size=%d\n", mmu_slb_size);
#endif
        parse_em_data(m);
        maxmem_data(m);

        seq_printf(m, "security_flavor=%u\n", pseries_security_flavor);

        return 0;
}

static ssize_t update_ppp(u64 *entitlement, u8 *weight)
{
        struct hvcall_ppp_data ppp_data;
        u8 new_weight;
        u64 new_entitled;
        ssize_t retval;

        /* Get our current parameters */
        retval = h_get_ppp(&ppp_data);
        if (retval)
                return retval;

        if (entitlement) {
                new_weight = ppp_data.weight;
                new_entitled = *entitlement;
        } else if (weight) {
                new_weight = *weight;
                new_entitled = ppp_data.entitlement;
        } else
                return -EINVAL;

        pr_debug("%s: current_entitled = %llu, current_weight = %u\n",
                 __func__, ppp_data.entitlement, ppp_data.weight);

        pr_debug("%s: new_entitled = %llu, new_weight = %u\n",
                 __func__, new_entitled, new_weight);

        retval = plpar_hcall_norets(H_SET_PPP, new_entitled, new_weight);
        return retval;
}

/**
 * update_mpp
 *
 * Update the memory entitlement and weight for the partition.  Caller must
 * specify either a new entitlement or weight, not both, to be updated
 * since the h_set_mpp call takes both entitlement and weight as parameters.
 */
static ssize_t update_mpp(u64 *entitlement, u8 *weight)
{
        struct hvcall_mpp_data mpp_data;
        u64 new_entitled;
        u8 new_weight;
        ssize_t rc;

        if (entitlement) {
                /* Check with vio to ensure the new memory entitlement
                 * can be handled.
                 */
                rc = vio_cmo_entitlement_update(*entitlement);
                if (rc)
                        return rc;
        }

        rc = h_get_mpp(&mpp_data);
        if (rc)
                return rc;

        if (entitlement) {
                new_weight = mpp_data.mem_weight;
                new_entitled = *entitlement;
        } else if (weight) {
                new_weight = *weight;
                new_entitled = mpp_data.entitled_mem;
        } else
                return -EINVAL;

        pr_debug("%s: current_entitled = %lu, current_weight = %u\n",
                 __func__, mpp_data.entitled_mem, mpp_data.mem_weight);

        pr_debug("%s: new_entitled = %llu, new_weight = %u\n",
                 __func__, new_entitled, new_weight);

        rc = plpar_hcall_norets(H_SET_MPP, new_entitled, new_weight);
        return rc;
}

/*
 * 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[64];
        char *tmp;
        u64 new_entitled, *new_entitled_ptr = &new_entitled;
        u8 new_weight, *new_weight_ptr = &new_weight;
        ssize_t retval;

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

        if (count > sizeof(kbuf))
                return -EINVAL;

        if (copy_from_user(kbuf, buf, count))
                return -EFAULT;

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

        *tmp++ = '\0';

        if (!strcmp(kbuf, "partition_entitled_capacity")) {
                char *endp;
                *new_entitled_ptr = (u64) simple_strtoul(tmp, &endp, 10);
                if (endp == tmp)
                        return -EINVAL;

                retval = update_ppp(new_entitled_ptr, NULL);
        } else if (!strcmp(kbuf, "capacity_weight")) {
                char *endp;
                *new_weight_ptr = (u8) simple_strtoul(tmp, &endp, 10);
                if (endp == tmp)
                        return -EINVAL;

                retval = update_ppp(NULL, new_weight_ptr);
        } else if (!strcmp(kbuf, "entitled_memory")) {
                char *endp;
                *new_entitled_ptr = (u64) simple_strtoul(tmp, &endp, 10);
                if (endp == tmp)
                        return -EINVAL;

                retval = update_mpp(new_entitled_ptr, NULL);
        } else if (!strcmp(kbuf, "entitled_memory_weight")) {
                char *endp;
                *new_weight_ptr = (u8) simple_strtoul(tmp, &endp, 10);
                if (endp == tmp)
                        return -EINVAL;

                retval = update_mpp(NULL, new_weight_ptr);
        } else
                return -EINVAL;

        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;
        }

        return retval;
}

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 __be32 *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;
                tmp = of_get_property(rootdn, "system-id", NULL);
                if (tmp)
                        system_id = tmp;
                lp_index_ptr = of_get_property(rootdn, "ibm,partition-no",
                                        NULL);
                if (lp_index_ptr)
                        lp_index = be32_to_cpup(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);

        return pseries_lparcfg_data(m, v);
}

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

static const struct proc_ops lparcfg_proc_ops = {
        .proc_read      = seq_read,
        .proc_write     = lparcfg_write,
        .proc_open      = lparcfg_open,
        .proc_release   = single_release,
        .proc_lseek     = seq_lseek,
};

static int __init lparcfg_init(void)
{
        umode_t mode = 0444;

        /* Allow writing if we have FW_FEATURE_SPLPAR */
        if (firmware_has_feature(FW_FEATURE_SPLPAR))
                mode |= 0200;

        if (!proc_create("powerpc/lparcfg", mode, NULL, &lparcfg_proc_ops)) {
                printk(KERN_ERR "Failed to create powerpc/lparcfg\n");
                return -EIO;
        }
        return 0;
}
machine_device_initcall(pseries, lparcfg_init);