// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  linux/drivers/net/ethernet/ibm/ehea/ehea_qmr.c
 *
 *  eHEA ethernet device driver for IBM eServer System p
 *
 *  (C) Copyright IBM Corp. 2006
 *
 *  Authors:
 *       Christoph Raisch <raisch@de.ibm.com>
 *       Jan-Bernd Themann <themann@de.ibm.com>
 *       Thomas Klein <tklein@de.ibm.com>
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/mm.h>
#include <linux/slab.h>
#include "ehea.h"
#include "ehea_phyp.h"
#include "ehea_qmr.h"

static struct ehea_bmap *ehea_bmap;

static void *hw_qpageit_get_inc(struct hw_queue *queue)
{
        void *retvalue = hw_qeit_get(queue);

        queue->current_q_offset += queue->pagesize;
        if (queue->current_q_offset > queue->queue_length) {
                queue->current_q_offset -= queue->pagesize;
                retvalue = NULL;
        } else if (((u64) retvalue) & (EHEA_PAGESIZE-1)) {
                pr_err("not on pageboundary\n");
                retvalue = NULL;
        }
        return retvalue;
}

static int hw_queue_ctor(struct hw_queue *queue, const u32 nr_of_pages,
                          const u32 pagesize, const u32 qe_size)
{
        int pages_per_kpage = PAGE_SIZE / pagesize;
        int i, k;

        if ((pagesize > PAGE_SIZE) || (!pages_per_kpage)) {
                pr_err("pagesize conflict! kernel pagesize=%d, ehea pagesize=%d\n",
                       (int)PAGE_SIZE, (int)pagesize);
                return -EINVAL;
        }

        queue->queue_length = nr_of_pages * pagesize;
        queue->queue_pages = kmalloc_array(nr_of_pages, sizeof(void *),
                                           GFP_KERNEL);
        if (!queue->queue_pages)
                return -ENOMEM;

        /*
         * allocate pages for queue:
         * outer loop allocates whole kernel pages (page aligned) and
         * inner loop divides a kernel page into smaller hea queue pages
         */
        i = 0;
        while (i < nr_of_pages) {
                u8 *kpage = (u8 *)get_zeroed_page(GFP_KERNEL);
                if (!kpage)
                        goto out_nomem;
                for (k = 0; k < pages_per_kpage && i < nr_of_pages; k++) {
                        (queue->queue_pages)[i] = (struct ehea_page *)kpage;
                        kpage += pagesize;
                        i++;
                }
        }

        queue->current_q_offset = 0;
        queue->qe_size = qe_size;
        queue->pagesize = pagesize;
        queue->toggle_state = 1;

        return 0;
out_nomem:
        for (i = 0; i < nr_of_pages; i += pages_per_kpage) {
                if (!(queue->queue_pages)[i])
                        break;
                free_page((unsigned long)(queue->queue_pages)[i]);
        }
        return -ENOMEM;
}

static void hw_queue_dtor(struct hw_queue *queue)
{
        int pages_per_kpage;
        int i, nr_pages;

        if (!queue || !queue->queue_pages)
                return;

        pages_per_kpage = PAGE_SIZE / queue->pagesize;

        nr_pages = queue->queue_length / queue->pagesize;

        for (i = 0; i < nr_pages; i += pages_per_kpage)
                free_page((unsigned long)(queue->queue_pages)[i]);

        kfree(queue->queue_pages);
}

struct ehea_cq *ehea_create_cq(struct ehea_adapter *adapter,
                               int nr_of_cqe, u64 eq_handle, u32 cq_token)
{
        struct ehea_cq *cq;
        u64 hret, rpage;
        u32 counter;
        int ret;
        void *vpage;

        cq = kzalloc_obj(*cq);
        if (!cq)
                goto out_nomem;

        cq->attr.max_nr_of_cqes = nr_of_cqe;
        cq->attr.cq_token = cq_token;
        cq->attr.eq_handle = eq_handle;

        cq->adapter = adapter;

        hret = ehea_h_alloc_resource_cq(adapter->handle, &cq->attr,
                                        &cq->fw_handle, &cq->epas);
        if (hret != H_SUCCESS) {
                pr_err("alloc_resource_cq failed\n");
                goto out_freemem;
        }

        ret = hw_queue_ctor(&cq->hw_queue, cq->attr.nr_pages,
                            EHEA_PAGESIZE, sizeof(struct ehea_cqe));
        if (ret)
                goto out_freeres;

        for (counter = 0; counter < cq->attr.nr_pages; counter++) {
                vpage = hw_qpageit_get_inc(&cq->hw_queue);
                if (!vpage) {
                        pr_err("hw_qpageit_get_inc failed\n");
                        goto out_kill_hwq;
                }

                rpage = __pa(vpage);
                hret = ehea_h_register_rpage(adapter->handle,
                                             0, EHEA_CQ_REGISTER_ORIG,
                                             cq->fw_handle, rpage, 1);
                if (hret < H_SUCCESS) {
                        pr_err("register_rpage_cq failed ehea_cq=%p hret=%llx counter=%i act_pages=%i\n",
                               cq, hret, counter, cq->attr.nr_pages);
                        goto out_kill_hwq;
                }

                if (counter == (cq->attr.nr_pages - 1)) {
                        vpage = hw_qpageit_get_inc(&cq->hw_queue);

                        if ((hret != H_SUCCESS) || (vpage)) {
                                pr_err("registration of pages not complete hret=%llx\n",
                                       hret);
                                goto out_kill_hwq;
                        }
                } else {
                        if (hret != H_PAGE_REGISTERED) {
                                pr_err("CQ: registration of page failed hret=%llx\n",
                                       hret);
                                goto out_kill_hwq;
                        }
                }
        }

        hw_qeit_reset(&cq->hw_queue);
        ehea_reset_cq_ep(cq);
        ehea_reset_cq_n1(cq);

        return cq;

out_kill_hwq:
        hw_queue_dtor(&cq->hw_queue);

out_freeres:
        ehea_h_free_resource(adapter->handle, cq->fw_handle, FORCE_FREE);

out_freemem:
        kfree(cq);

out_nomem:
        return NULL;
}

static u64 ehea_destroy_cq_res(struct ehea_cq *cq, u64 force)
{
        u64 hret;
        u64 adapter_handle = cq->adapter->handle;

        /* deregister all previous registered pages */
        hret = ehea_h_free_resource(adapter_handle, cq->fw_handle, force);
        if (hret != H_SUCCESS)
                return hret;

        hw_queue_dtor(&cq->hw_queue);
        kfree(cq);

        return hret;
}

int ehea_destroy_cq(struct ehea_cq *cq)
{
        u64 hret, aer, aerr;
        if (!cq)
                return 0;

        hcp_epas_dtor(&cq->epas);
        hret = ehea_destroy_cq_res(cq, NORMAL_FREE);
        if (hret == H_R_STATE) {
                ehea_error_data(cq->adapter, cq->fw_handle, &aer, &aerr);
                hret = ehea_destroy_cq_res(cq, FORCE_FREE);
        }

        if (hret != H_SUCCESS) {
                pr_err("destroy CQ failed\n");
                return -EIO;
        }

        return 0;
}

struct ehea_eq *ehea_create_eq(struct ehea_adapter *adapter,
                               const enum ehea_eq_type type,
                               const u32 max_nr_of_eqes, const u8 eqe_gen)
{
        int ret, i;
        u64 hret, rpage;
        void *vpage;
        struct ehea_eq *eq;

        eq = kzalloc_obj(*eq);
        if (!eq)
                return NULL;

        eq->adapter = adapter;
        eq->attr.type = type;
        eq->attr.max_nr_of_eqes = max_nr_of_eqes;
        eq->attr.eqe_gen = eqe_gen;
        spin_lock_init(&eq->spinlock);

        hret = ehea_h_alloc_resource_eq(adapter->handle,
                                        &eq->attr, &eq->fw_handle);
        if (hret != H_SUCCESS) {
                pr_err("alloc_resource_eq failed\n");
                goto out_freemem;
        }

        ret = hw_queue_ctor(&eq->hw_queue, eq->attr.nr_pages,
                            EHEA_PAGESIZE, sizeof(struct ehea_eqe));
        if (ret) {
                pr_err("can't allocate eq pages\n");
                goto out_freeres;
        }

        for (i = 0; i < eq->attr.nr_pages; i++) {
                vpage = hw_qpageit_get_inc(&eq->hw_queue);
                if (!vpage) {
                        pr_err("hw_qpageit_get_inc failed\n");
                        hret = H_RESOURCE;
                        goto out_kill_hwq;
                }

                rpage = __pa(vpage);

                hret = ehea_h_register_rpage(adapter->handle, 0,
                                             EHEA_EQ_REGISTER_ORIG,
                                             eq->fw_handle, rpage, 1);

                if (i == (eq->attr.nr_pages - 1)) {
                        /* last page */
                        vpage = hw_qpageit_get_inc(&eq->hw_queue);
                        if ((hret != H_SUCCESS) || (vpage))
                                goto out_kill_hwq;

                } else {
                        if (hret != H_PAGE_REGISTERED)
                                goto out_kill_hwq;

                }
        }

        hw_qeit_reset(&eq->hw_queue);
        return eq;

out_kill_hwq:
        hw_queue_dtor(&eq->hw_queue);

out_freeres:
        ehea_h_free_resource(adapter->handle, eq->fw_handle, FORCE_FREE);

out_freemem:
        kfree(eq);
        return NULL;
}

struct ehea_eqe *ehea_poll_eq(struct ehea_eq *eq)
{
        struct ehea_eqe *eqe;
        unsigned long flags;

        spin_lock_irqsave(&eq->spinlock, flags);
        eqe = hw_eqit_eq_get_inc_valid(&eq->hw_queue);
        spin_unlock_irqrestore(&eq->spinlock, flags);

        return eqe;
}

static u64 ehea_destroy_eq_res(struct ehea_eq *eq, u64 force)
{
        u64 hret;
        unsigned long flags;

        spin_lock_irqsave(&eq->spinlock, flags);

        hret = ehea_h_free_resource(eq->adapter->handle, eq->fw_handle, force);
        spin_unlock_irqrestore(&eq->spinlock, flags);

        if (hret != H_SUCCESS)
                return hret;

        hw_queue_dtor(&eq->hw_queue);
        kfree(eq);

        return hret;
}

int ehea_destroy_eq(struct ehea_eq *eq)
{
        u64 hret, aer, aerr;
        if (!eq)
                return 0;

        hcp_epas_dtor(&eq->epas);

        hret = ehea_destroy_eq_res(eq, NORMAL_FREE);
        if (hret == H_R_STATE) {
                ehea_error_data(eq->adapter, eq->fw_handle, &aer, &aerr);
                hret = ehea_destroy_eq_res(eq, FORCE_FREE);
        }

        if (hret != H_SUCCESS) {
                pr_err("destroy EQ failed\n");
                return -EIO;
        }

        return 0;
}

/* allocates memory for a queue and registers pages in phyp */
static int ehea_qp_alloc_register(struct ehea_qp *qp, struct hw_queue *hw_queue,
                           int nr_pages, int wqe_size, int act_nr_sges,
                           struct ehea_adapter *adapter, int h_call_q_selector)
{
        u64 hret, rpage;
        int ret, cnt;
        void *vpage;

        ret = hw_queue_ctor(hw_queue, nr_pages, EHEA_PAGESIZE, wqe_size);
        if (ret)
                return ret;

        for (cnt = 0; cnt < nr_pages; cnt++) {
                vpage = hw_qpageit_get_inc(hw_queue);
                if (!vpage) {
                        pr_err("hw_qpageit_get_inc failed\n");
                        goto out_kill_hwq;
                }
                rpage = __pa(vpage);
                hret = ehea_h_register_rpage(adapter->handle,
                                             0, h_call_q_selector,
                                             qp->fw_handle, rpage, 1);
                if (hret < H_SUCCESS) {
                        pr_err("register_rpage_qp failed\n");
                        goto out_kill_hwq;
                }
        }
        hw_qeit_reset(hw_queue);
        return 0;

out_kill_hwq:
        hw_queue_dtor(hw_queue);
        return -EIO;
}

static inline u32 map_wqe_size(u8 wqe_enc_size)
{
        return 128 << wqe_enc_size;
}

struct ehea_qp *ehea_create_qp(struct ehea_adapter *adapter,
                               u32 pd, struct ehea_qp_init_attr *init_attr)
{
        int ret;
        u64 hret;
        struct ehea_qp *qp;
        u32 wqe_size_in_bytes_sq, wqe_size_in_bytes_rq1;
        u32 wqe_size_in_bytes_rq2, wqe_size_in_bytes_rq3;


        qp = kzalloc_obj(*qp);
        if (!qp)
                return NULL;

        qp->adapter = adapter;

        hret = ehea_h_alloc_resource_qp(adapter->handle, init_attr, pd,
                                        &qp->fw_handle, &qp->epas);
        if (hret != H_SUCCESS) {
                pr_err("ehea_h_alloc_resource_qp failed\n");
                goto out_freemem;
        }

        wqe_size_in_bytes_sq = map_wqe_size(init_attr->act_wqe_size_enc_sq);
        wqe_size_in_bytes_rq1 = map_wqe_size(init_attr->act_wqe_size_enc_rq1);
        wqe_size_in_bytes_rq2 = map_wqe_size(init_attr->act_wqe_size_enc_rq2);
        wqe_size_in_bytes_rq3 = map_wqe_size(init_attr->act_wqe_size_enc_rq3);

        ret = ehea_qp_alloc_register(qp, &qp->hw_squeue, init_attr->nr_sq_pages,
                                     wqe_size_in_bytes_sq,
                                     init_attr->act_wqe_size_enc_sq, adapter,
                                     0);
        if (ret) {
                pr_err("can't register for sq ret=%x\n", ret);
                goto out_freeres;
        }

        ret = ehea_qp_alloc_register(qp, &qp->hw_rqueue1,
                                     init_attr->nr_rq1_pages,
                                     wqe_size_in_bytes_rq1,
                                     init_attr->act_wqe_size_enc_rq1,
                                     adapter, 1);
        if (ret) {
                pr_err("can't register for rq1 ret=%x\n", ret);
                goto out_kill_hwsq;
        }

        if (init_attr->rq_count > 1) {
                ret = ehea_qp_alloc_register(qp, &qp->hw_rqueue2,
                                             init_attr->nr_rq2_pages,
                                             wqe_size_in_bytes_rq2,
                                             init_attr->act_wqe_size_enc_rq2,
                                             adapter, 2);
                if (ret) {
                        pr_err("can't register for rq2 ret=%x\n", ret);
                        goto out_kill_hwr1q;
                }
        }

        if (init_attr->rq_count > 2) {
                ret = ehea_qp_alloc_register(qp, &qp->hw_rqueue3,
                                             init_attr->nr_rq3_pages,
                                             wqe_size_in_bytes_rq3,
                                             init_attr->act_wqe_size_enc_rq3,
                                             adapter, 3);
                if (ret) {
                        pr_err("can't register for rq3 ret=%x\n", ret);
                        goto out_kill_hwr2q;
                }
        }

        qp->init_attr = *init_attr;

        return qp;

out_kill_hwr2q:
        hw_queue_dtor(&qp->hw_rqueue2);

out_kill_hwr1q:
        hw_queue_dtor(&qp->hw_rqueue1);

out_kill_hwsq:
        hw_queue_dtor(&qp->hw_squeue);

out_freeres:
        ehea_h_disable_and_get_hea(adapter->handle, qp->fw_handle);
        ehea_h_free_resource(adapter->handle, qp->fw_handle, FORCE_FREE);

out_freemem:
        kfree(qp);
        return NULL;
}

static u64 ehea_destroy_qp_res(struct ehea_qp *qp, u64 force)
{
        u64 hret;
        struct ehea_qp_init_attr *qp_attr = &qp->init_attr;


        ehea_h_disable_and_get_hea(qp->adapter->handle, qp->fw_handle);
        hret = ehea_h_free_resource(qp->adapter->handle, qp->fw_handle, force);
        if (hret != H_SUCCESS)
                return hret;

        hw_queue_dtor(&qp->hw_squeue);
        hw_queue_dtor(&qp->hw_rqueue1);

        if (qp_attr->rq_count > 1)
                hw_queue_dtor(&qp->hw_rqueue2);
        if (qp_attr->rq_count > 2)
                hw_queue_dtor(&qp->hw_rqueue3);
        kfree(qp);

        return hret;
}

int ehea_destroy_qp(struct ehea_qp *qp)
{
        u64 hret, aer, aerr;
        if (!qp)
                return 0;

        hcp_epas_dtor(&qp->epas);

        hret = ehea_destroy_qp_res(qp, NORMAL_FREE);
        if (hret == H_R_STATE) {
                ehea_error_data(qp->adapter, qp->fw_handle, &aer, &aerr);
                hret = ehea_destroy_qp_res(qp, FORCE_FREE);
        }

        if (hret != H_SUCCESS) {
                pr_err("destroy QP failed\n");
                return -EIO;
        }

        return 0;
}

static inline int ehea_calc_index(unsigned long i, unsigned long s)
{
        return (i >> s) & EHEA_INDEX_MASK;
}

static inline int ehea_init_top_bmap(struct ehea_top_bmap *ehea_top_bmap,
                                     int dir)
{
        if (!ehea_top_bmap->dir[dir]) {
                ehea_top_bmap->dir[dir] =
                        kzalloc_obj(struct ehea_dir_bmap);
                if (!ehea_top_bmap->dir[dir])
                        return -ENOMEM;
        }
        return 0;
}

static inline int ehea_init_bmap(struct ehea_bmap *ehea_bmap, int top, int dir)
{
        if (!ehea_bmap->top[top]) {
                ehea_bmap->top[top] =
                        kzalloc_obj(struct ehea_top_bmap);
                if (!ehea_bmap->top[top])
                        return -ENOMEM;
        }
        return ehea_init_top_bmap(ehea_bmap->top[top], dir);
}

static DEFINE_MUTEX(ehea_busmap_mutex);
static unsigned long ehea_mr_len;

#define EHEA_BUSMAP_ADD_SECT 1
#define EHEA_BUSMAP_REM_SECT 0

static void ehea_rebuild_busmap(void)
{
        u64 vaddr = EHEA_BUSMAP_START;
        int top, dir, idx;

        for (top = 0; top < EHEA_MAP_ENTRIES; top++) {
                struct ehea_top_bmap *ehea_top;
                int valid_dir_entries = 0;

                if (!ehea_bmap->top[top])
                        continue;
                ehea_top = ehea_bmap->top[top];
                for (dir = 0; dir < EHEA_MAP_ENTRIES; dir++) {
                        struct ehea_dir_bmap *ehea_dir;
                        int valid_entries = 0;

                        if (!ehea_top->dir[dir])
                                continue;
                        valid_dir_entries++;
                        ehea_dir = ehea_top->dir[dir];
                        for (idx = 0; idx < EHEA_MAP_ENTRIES; idx++) {
                                if (!ehea_dir->ent[idx])
                                        continue;
                                valid_entries++;
                                ehea_dir->ent[idx] = vaddr;
                                vaddr += EHEA_SECTSIZE;
                        }
                        if (!valid_entries) {
                                ehea_top->dir[dir] = NULL;
                                kfree(ehea_dir);
                        }
                }
                if (!valid_dir_entries) {
                        ehea_bmap->top[top] = NULL;
                        kfree(ehea_top);
                }
        }
}

static int ehea_update_busmap(unsigned long pfn, unsigned long nr_pages, int add)
{
        unsigned long i, start_section, end_section;

        if (!nr_pages)
                return 0;

        if (!ehea_bmap) {
                ehea_bmap = kzalloc_obj(struct ehea_bmap);
                if (!ehea_bmap)
                        return -ENOMEM;
        }

        start_section = (pfn * PAGE_SIZE) / EHEA_SECTSIZE;
        end_section = start_section + ((nr_pages * PAGE_SIZE) / EHEA_SECTSIZE);
        /* Mark entries as valid or invalid only; address is assigned later */
        for (i = start_section; i < end_section; i++) {
                u64 flag;
                int top = ehea_calc_index(i, EHEA_TOP_INDEX_SHIFT);
                int dir = ehea_calc_index(i, EHEA_DIR_INDEX_SHIFT);
                int idx = i & EHEA_INDEX_MASK;

                if (add) {
                        int ret = ehea_init_bmap(ehea_bmap, top, dir);
                        if (ret)
                                return ret;
                        flag = 1; /* valid */
                        ehea_mr_len += EHEA_SECTSIZE;
                } else {
                        if (!ehea_bmap->top[top])
                                continue;
                        if (!ehea_bmap->top[top]->dir[dir])
                                continue;
                        flag = 0; /* invalid */
                        ehea_mr_len -= EHEA_SECTSIZE;
                }

                ehea_bmap->top[top]->dir[dir]->ent[idx] = flag;
        }
        ehea_rebuild_busmap(); /* Assign contiguous addresses for mr */
        return 0;
}

int ehea_add_sect_bmap(unsigned long pfn, unsigned long nr_pages)
{
        int ret;

        mutex_lock(&ehea_busmap_mutex);
        ret = ehea_update_busmap(pfn, nr_pages, EHEA_BUSMAP_ADD_SECT);
        mutex_unlock(&ehea_busmap_mutex);
        return ret;
}

int ehea_rem_sect_bmap(unsigned long pfn, unsigned long nr_pages)
{
        int ret;

        mutex_lock(&ehea_busmap_mutex);
        ret = ehea_update_busmap(pfn, nr_pages, EHEA_BUSMAP_REM_SECT);
        mutex_unlock(&ehea_busmap_mutex);
        return ret;
}

static int ehea_is_hugepage(unsigned long pfn)
{
        if (pfn & EHEA_HUGEPAGE_PFN_MASK)
                return 0;

        if (page_shift(pfn_to_page(pfn)) != EHEA_HUGEPAGESHIFT)
                return 0;

        return 1;
}

static int ehea_create_busmap_callback(unsigned long initial_pfn,
                                       unsigned long total_nr_pages, void *arg)
{
        int ret;
        unsigned long pfn, start_pfn, end_pfn, nr_pages;

        if ((total_nr_pages * PAGE_SIZE) < EHEA_HUGEPAGE_SIZE)
                return ehea_update_busmap(initial_pfn, total_nr_pages,
                                          EHEA_BUSMAP_ADD_SECT);

        /* Given chunk is >= 16GB -> check for hugepages */
        start_pfn = initial_pfn;
        end_pfn = initial_pfn + total_nr_pages;
        pfn = start_pfn;

        while (pfn < end_pfn) {
                if (ehea_is_hugepage(pfn)) {
                        /* Add mem found in front of the hugepage */
                        nr_pages = pfn - start_pfn;
                        ret = ehea_update_busmap(start_pfn, nr_pages,
                                                 EHEA_BUSMAP_ADD_SECT);
                        if (ret)
                                return ret;

                        /* Skip the hugepage */
                        pfn += (EHEA_HUGEPAGE_SIZE / PAGE_SIZE);
                        start_pfn = pfn;
                } else
                        pfn += (EHEA_SECTSIZE / PAGE_SIZE);
        }

        /* Add mem found behind the hugepage(s)  */
        nr_pages = pfn - start_pfn;
        return ehea_update_busmap(start_pfn, nr_pages, EHEA_BUSMAP_ADD_SECT);
}

int ehea_create_busmap(void)
{
        int ret;

        mutex_lock(&ehea_busmap_mutex);
        ehea_mr_len = 0;
        ret = walk_system_ram_range(0, 1ULL << MAX_PHYSMEM_BITS, NULL,
                                   ehea_create_busmap_callback);
        mutex_unlock(&ehea_busmap_mutex);
        return ret;
}

void ehea_destroy_busmap(void)
{
        int top, dir;
        mutex_lock(&ehea_busmap_mutex);
        if (!ehea_bmap)
                goto out_destroy;

        for (top = 0; top < EHEA_MAP_ENTRIES; top++) {
                if (!ehea_bmap->top[top])
                        continue;

                for (dir = 0; dir < EHEA_MAP_ENTRIES; dir++) {
                        if (!ehea_bmap->top[top]->dir[dir])
                                continue;

                        kfree(ehea_bmap->top[top]->dir[dir]);
                }

                kfree(ehea_bmap->top[top]);
        }

        kfree(ehea_bmap);
        ehea_bmap = NULL;
out_destroy:
        mutex_unlock(&ehea_busmap_mutex);
}

u64 ehea_map_vaddr(void *caddr)
{
        int top, dir, idx;
        unsigned long index, offset;

        if (!ehea_bmap)
                return EHEA_INVAL_ADDR;

        index = __pa(caddr) >> SECTION_SIZE_BITS;
        top = (index >> EHEA_TOP_INDEX_SHIFT) & EHEA_INDEX_MASK;
        if (!ehea_bmap->top[top])
                return EHEA_INVAL_ADDR;

        dir = (index >> EHEA_DIR_INDEX_SHIFT) & EHEA_INDEX_MASK;
        if (!ehea_bmap->top[top]->dir[dir])
                return EHEA_INVAL_ADDR;

        idx = index & EHEA_INDEX_MASK;
        if (!ehea_bmap->top[top]->dir[dir]->ent[idx])
                return EHEA_INVAL_ADDR;

        offset = (unsigned long)caddr & (EHEA_SECTSIZE - 1);
        return ehea_bmap->top[top]->dir[dir]->ent[idx] | offset;
}

static inline void *ehea_calc_sectbase(int top, int dir, int idx)
{
        unsigned long ret = idx;
        ret |= dir << EHEA_DIR_INDEX_SHIFT;
        ret |= top << EHEA_TOP_INDEX_SHIFT;
        return __va(ret << SECTION_SIZE_BITS);
}

static u64 ehea_reg_mr_section(int top, int dir, int idx, u64 *pt,
                               struct ehea_adapter *adapter,
                               struct ehea_mr *mr)
{
        void *pg;
        u64 j, m, hret;
        unsigned long k = 0;
        u64 pt_abs = __pa(pt);

        void *sectbase = ehea_calc_sectbase(top, dir, idx);

        for (j = 0; j < (EHEA_PAGES_PER_SECTION / EHEA_MAX_RPAGE); j++) {

                for (m = 0; m < EHEA_MAX_RPAGE; m++) {
                        pg = sectbase + ((k++) * EHEA_PAGESIZE);
                        pt[m] = __pa(pg);
                }
                hret = ehea_h_register_rpage_mr(adapter->handle, mr->handle, 0,
                                                0, pt_abs, EHEA_MAX_RPAGE);

                if ((hret != H_SUCCESS) &&
                    (hret != H_PAGE_REGISTERED)) {
                        ehea_h_free_resource(adapter->handle, mr->handle,
                                             FORCE_FREE);
                        pr_err("register_rpage_mr failed\n");
                        return hret;
                }
        }
        return hret;
}

static u64 ehea_reg_mr_sections(int top, int dir, u64 *pt,
                                struct ehea_adapter *adapter,
                                struct ehea_mr *mr)
{
        u64 hret = H_SUCCESS;
        int idx;

        for (idx = 0; idx < EHEA_MAP_ENTRIES; idx++) {
                if (!ehea_bmap->top[top]->dir[dir]->ent[idx])
                        continue;

                hret = ehea_reg_mr_section(top, dir, idx, pt, adapter, mr);
                if ((hret != H_SUCCESS) && (hret != H_PAGE_REGISTERED))
                        return hret;
        }
        return hret;
}

static u64 ehea_reg_mr_dir_sections(int top, u64 *pt,
                                    struct ehea_adapter *adapter,
                                    struct ehea_mr *mr)
{
        u64 hret = H_SUCCESS;
        int dir;

        for (dir = 0; dir < EHEA_MAP_ENTRIES; dir++) {
                if (!ehea_bmap->top[top]->dir[dir])
                        continue;

                hret = ehea_reg_mr_sections(top, dir, pt, adapter, mr);
                if ((hret != H_SUCCESS) && (hret != H_PAGE_REGISTERED))
                        return hret;
        }
        return hret;
}

int ehea_reg_kernel_mr(struct ehea_adapter *adapter, struct ehea_mr *mr)
{
        int ret;
        u64 *pt;
        u64 hret;
        u32 acc_ctrl = EHEA_MR_ACC_CTRL;

        unsigned long top;

        pt = (void *)get_zeroed_page(GFP_KERNEL);
        if (!pt) {
                pr_err("no mem\n");
                ret = -ENOMEM;
                goto out;
        }

        hret = ehea_h_alloc_resource_mr(adapter->handle, EHEA_BUSMAP_START,
                                        ehea_mr_len, acc_ctrl, adapter->pd,
                                        &mr->handle, &mr->lkey);

        if (hret != H_SUCCESS) {
                pr_err("alloc_resource_mr failed\n");
                ret = -EIO;
                goto out;
        }

        if (!ehea_bmap) {
                ehea_h_free_resource(adapter->handle, mr->handle, FORCE_FREE);
                pr_err("no busmap available\n");
                ret = -EIO;
                goto out;
        }

        for (top = 0; top < EHEA_MAP_ENTRIES; top++) {
                if (!ehea_bmap->top[top])
                        continue;

                hret = ehea_reg_mr_dir_sections(top, pt, adapter, mr);
                if((hret != H_PAGE_REGISTERED) && (hret != H_SUCCESS))
                        break;
        }

        if (hret != H_SUCCESS) {
                ehea_h_free_resource(adapter->handle, mr->handle, FORCE_FREE);
                pr_err("registering mr failed\n");
                ret = -EIO;
                goto out;
        }

        mr->vaddr = EHEA_BUSMAP_START;
        mr->adapter = adapter;
        ret = 0;
out:
        free_page((unsigned long)pt);
        return ret;
}

int ehea_rem_mr(struct ehea_mr *mr)
{
        u64 hret;

        if (!mr || !mr->adapter)
                return -EINVAL;

        hret = ehea_h_free_resource(mr->adapter->handle, mr->handle,
                                    FORCE_FREE);
        if (hret != H_SUCCESS) {
                pr_err("destroy MR failed\n");
                return -EIO;
        }

        return 0;
}

int ehea_gen_smr(struct ehea_adapter *adapter, struct ehea_mr *old_mr,
                 struct ehea_mr *shared_mr)
{
        u64 hret;

        hret = ehea_h_register_smr(adapter->handle, old_mr->handle,
                                   old_mr->vaddr, EHEA_MR_ACC_CTRL,
                                   adapter->pd, shared_mr);
        if (hret != H_SUCCESS)
                return -EIO;

        shared_mr->adapter = adapter;

        return 0;
}

static void print_error_data(u64 *data)
{
        int length;
        u64 type = EHEA_BMASK_GET(ERROR_DATA_TYPE, data[2]);
        u64 resource = data[1];

        length = EHEA_BMASK_GET(ERROR_DATA_LENGTH, data[0]);

        if (length > EHEA_PAGESIZE)
                length = EHEA_PAGESIZE;

        if (type == EHEA_AER_RESTYPE_QP)
                pr_err("QP (resource=%llX) state: AER=0x%llX, AERR=0x%llX, port=%llX\n",
                       resource, data[6], data[12], data[22]);
        else if (type == EHEA_AER_RESTYPE_CQ)
                pr_err("CQ (resource=%llX) state: AER=0x%llX\n",
                       resource, data[6]);
        else if (type == EHEA_AER_RESTYPE_EQ)
                pr_err("EQ (resource=%llX) state: AER=0x%llX\n",
                       resource, data[6]);

        ehea_dump(data, length, "error data");
}

u64 ehea_error_data(struct ehea_adapter *adapter, u64 res_handle,
                    u64 *aer, u64 *aerr)
{
        unsigned long ret;
        u64 *rblock;
        u64 type = 0;

        rblock = (void *)get_zeroed_page(GFP_KERNEL);
        if (!rblock) {
                pr_err("Cannot allocate rblock memory\n");
                goto out;
        }

        ret = ehea_h_error_data(adapter->handle, res_handle, rblock);

        if (ret == H_SUCCESS) {
                type = EHEA_BMASK_GET(ERROR_DATA_TYPE, rblock[2]);
                *aer = rblock[6];
                *aerr = rblock[12];
                print_error_data(rblock);
        } else if (ret == H_R_STATE) {
                pr_err("No error data available: %llX\n", res_handle);
        } else
                pr_err("Error data could not be fetched: %llX\n", res_handle);

        free_page((unsigned long)rblock);
out:
        return type;
}