// SPDX-License-Identifier: GPL-2.0
/*
 * qdio queue initialization
 *
 * Copyright IBM Corp. 2008
 * Author(s): Jan Glauber <jang@linux.vnet.ibm.com>
 */
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/export.h>
#include <linux/io.h>

#include <asm/ebcdic.h>
#include <asm/qdio.h>

#include "cio.h"
#include "css.h"
#include "device.h"
#include "ioasm.h"
#include "chsc.h"
#include "qdio.h"
#include "qdio_debug.h"

#define QBUFF_PER_PAGE (PAGE_SIZE / sizeof(struct qdio_buffer))

static struct kmem_cache *qdio_q_cache;

/**
 * qdio_free_buffers() - free qdio buffers
 * @buf: array of pointers to qdio buffers
 * @count: number of qdio buffers to free
 */
void qdio_free_buffers(struct qdio_buffer **buf, unsigned int count)
{
        int pos;

        for (pos = 0; pos < count; pos += QBUFF_PER_PAGE)
                free_page((unsigned long) buf[pos]);
}
EXPORT_SYMBOL_GPL(qdio_free_buffers);

/**
 * qdio_alloc_buffers() - allocate qdio buffers
 * @buf: array of pointers to qdio buffers
 * @count: number of qdio buffers to allocate
 */
int qdio_alloc_buffers(struct qdio_buffer **buf, unsigned int count)
{
        int pos;

        for (pos = 0; pos < count; pos += QBUFF_PER_PAGE) {
                buf[pos] = (void *) get_zeroed_page(GFP_KERNEL);
                if (!buf[pos]) {
                        qdio_free_buffers(buf, count);
                        return -ENOMEM;
                }
        }
        for (pos = 0; pos < count; pos++)
                if (pos % QBUFF_PER_PAGE)
                        buf[pos] = buf[pos - 1] + 1;
        return 0;
}
EXPORT_SYMBOL_GPL(qdio_alloc_buffers);

/**
 * qdio_reset_buffers() - reset qdio buffers
 * @buf: array of pointers to qdio buffers
 * @count: number of qdio buffers that will be zeroed
 */
void qdio_reset_buffers(struct qdio_buffer **buf, unsigned int count)
{
        int pos;

        for (pos = 0; pos < count; pos++)
                memset(buf[pos], 0, sizeof(struct qdio_buffer));
}
EXPORT_SYMBOL_GPL(qdio_reset_buffers);

static void __qdio_free_queues(struct qdio_q **queues, unsigned int count)
{
        struct qdio_q *q;
        unsigned int i;

        for (i = 0; i < count; i++) {
                q = queues[i];
                free_page((unsigned long)q->sl_page);
                kmem_cache_free(qdio_q_cache, q);
        }
}

void qdio_free_queues(struct qdio_irq *irq_ptr)
{
        __qdio_free_queues(irq_ptr->input_qs, irq_ptr->max_input_qs);
        irq_ptr->max_input_qs = 0;

        __qdio_free_queues(irq_ptr->output_qs, irq_ptr->max_output_qs);
        irq_ptr->max_output_qs = 0;
}

static int __qdio_allocate_qs(struct qdio_q **irq_ptr_qs, int nr_queues)
{
        struct qdio_q *q;
        int i;

        for (i = 0; i < nr_queues; i++) {
                q = kmem_cache_zalloc(qdio_q_cache, GFP_KERNEL);
                if (!q) {
                        __qdio_free_queues(irq_ptr_qs, i);
                        return -ENOMEM;
                }

                q->sl_page = (void *)__get_free_page(GFP_KERNEL);
                if (!q->sl_page) {
                        kmem_cache_free(qdio_q_cache, q);
                        __qdio_free_queues(irq_ptr_qs, i);
                        return -ENOMEM;
                }
                q->slib = q->sl_page;
                /* As per architecture: SLIB is 2K bytes long, and SL 1K. */
                q->sl = (struct sl *)(q->slib + 1);

                irq_ptr_qs[i] = q;
        }
        return 0;
}

int qdio_allocate_qs(struct qdio_irq *irq_ptr, int nr_input_qs, int nr_output_qs)
{
        int rc;

        rc = __qdio_allocate_qs(irq_ptr->input_qs, nr_input_qs);
        if (rc)
                return rc;

        rc = __qdio_allocate_qs(irq_ptr->output_qs, nr_output_qs);
        if (rc) {
                __qdio_free_queues(irq_ptr->input_qs, nr_input_qs);
                return rc;
        }

        irq_ptr->max_input_qs = nr_input_qs;
        irq_ptr->max_output_qs = nr_output_qs;
        return 0;
}

static void setup_queues_misc(struct qdio_q *q, struct qdio_irq *irq_ptr,
                              qdio_handler_t *handler, int i)
{
        struct slib *const slib = q->slib;
        void *const sl_page = q->sl_page;
        struct sl *const sl = q->sl;

        /* queue must be cleared for qdio_establish */
        memset(q, 0, sizeof(*q));
        memset(sl_page, 0, PAGE_SIZE);
        q->sl_page = sl_page;
        q->sl = sl;
        q->slib = slib;
        q->irq_ptr = irq_ptr;
        q->mask = 1 << (31 - i);
        q->nr = i;
        q->handler = handler;
}

static void setup_storage_lists(struct qdio_q *q, struct qdio_irq *irq_ptr,
                                struct qdio_buffer **sbals_array, int i)
{
        struct qdio_q *prev;
        int j;

        DBF_HEX(&q, sizeof(void *));

        /* fill in sbal */
        for (j = 0; j < QDIO_MAX_BUFFERS_PER_Q; j++)
                q->sbal[j] = *sbals_array++;

        /* fill in slib */
        if (i > 0) {
                prev = (q->is_input_q) ? irq_ptr->input_qs[i - 1]
                        : irq_ptr->output_qs[i - 1];
                prev->slib->nsliba = (unsigned long)q->slib;
        }

        q->slib->sla = (unsigned long)q->sl;
        q->slib->slsba = (unsigned long)&q->slsb.val[0];

        /* fill in sl */
        for (j = 0; j < QDIO_MAX_BUFFERS_PER_Q; j++)
                q->sl->element[j].sbal = virt_to_dma64(q->sbal[j]);
}

static void setup_queues(struct qdio_irq *irq_ptr,
                         struct qdio_initialize *qdio_init)
{
        struct qdio_q *q;
        int i;

        for_each_input_queue(irq_ptr, q, i) {
                DBF_EVENT("inq:%1d", i);
                setup_queues_misc(q, irq_ptr, qdio_init->input_handler, i);

                q->is_input_q = 1;

                setup_storage_lists(q, irq_ptr,
                                    qdio_init->input_sbal_addr_array[i], i);
        }

        for_each_output_queue(irq_ptr, q, i) {
                DBF_EVENT("outq:%1d", i);
                setup_queues_misc(q, irq_ptr, qdio_init->output_handler, i);

                q->is_input_q = 0;
                setup_storage_lists(q, irq_ptr,
                                    qdio_init->output_sbal_addr_array[i], i);
        }
}

static void check_and_setup_qebsm(struct qdio_irq *irq_ptr,
                                  unsigned char qdioac, unsigned long token)
{
        if (!(irq_ptr->qib.rflags & QIB_RFLAGS_ENABLE_QEBSM))
                goto no_qebsm;
        if (!(qdioac & AC1_SC_QEBSM_AVAILABLE) ||
            (!(qdioac & AC1_SC_QEBSM_ENABLED)))
                goto no_qebsm;

        irq_ptr->sch_token = token;

        DBF_EVENT("V=V:1");
        DBF_EVENT("%8lx", irq_ptr->sch_token);
        return;

no_qebsm:
        irq_ptr->sch_token = 0;
        irq_ptr->qib.rflags &= ~QIB_RFLAGS_ENABLE_QEBSM;
        DBF_EVENT("noV=V");
}

/*
 * If there is a qdio_irq we use the chsc_page and store the information
 * in the qdio_irq, otherwise we copy it to the specified structure.
 */
int qdio_setup_get_ssqd(struct qdio_irq *irq_ptr,
                        struct subchannel_id *schid,
                        struct qdio_ssqd_desc *data)
{
        struct chsc_ssqd_area *ssqd;
        int rc;

        DBF_EVENT("getssqd:%4x", schid->sch_no);
        if (!irq_ptr) {
                ssqd = (struct chsc_ssqd_area *)__get_free_page(GFP_KERNEL);
                if (!ssqd)
                        return -ENOMEM;
        } else {
                ssqd = (struct chsc_ssqd_area *)irq_ptr->chsc_page;
        }

        rc = chsc_ssqd(*schid, ssqd);
        if (rc)
                goto out;

        if (!(ssqd->qdio_ssqd.flags & CHSC_FLAG_QDIO_CAPABILITY) ||
            !(ssqd->qdio_ssqd.flags & CHSC_FLAG_VALIDITY) ||
            (ssqd->qdio_ssqd.sch != schid->sch_no))
                rc = -EINVAL;

        if (!rc)
                memcpy(data, &ssqd->qdio_ssqd, sizeof(*data));

out:
        if (!irq_ptr)
                free_page((unsigned long)ssqd);

        return rc;
}

void qdio_setup_ssqd_info(struct qdio_irq *irq_ptr)
{
        unsigned char qdioac;
        int rc;

        rc = qdio_setup_get_ssqd(irq_ptr, &irq_ptr->schid, &irq_ptr->ssqd_desc);
        if (rc) {
                DBF_ERROR("%4x ssqd ERR", irq_ptr->schid.sch_no);
                DBF_ERROR("rc:%x", rc);
                /* all flags set, worst case */
                qdioac = AC1_SIGA_INPUT_NEEDED | AC1_SIGA_OUTPUT_NEEDED |
                         AC1_SIGA_SYNC_NEEDED;
        } else
                qdioac = irq_ptr->ssqd_desc.qdioac1;

        check_and_setup_qebsm(irq_ptr, qdioac, irq_ptr->ssqd_desc.sch_token);
        irq_ptr->qdioac1 = qdioac;
        DBF_EVENT("ac 1:%2x 2:%4x", qdioac, irq_ptr->ssqd_desc.qdioac2);
        DBF_EVENT("3:%4x qib:%4x", irq_ptr->ssqd_desc.qdioac3, irq_ptr->qib.ac);
}

static void qdio_fill_qdr_desc(struct qdesfmt0 *desc, struct qdio_q *queue)
{
        desc->sliba = virt_to_dma64(queue->slib);
        desc->sla = virt_to_dma64(queue->sl);
        desc->slsba = virt_to_dma64(&queue->slsb);

        desc->akey = PAGE_DEFAULT_KEY >> 4;
        desc->bkey = PAGE_DEFAULT_KEY >> 4;
        desc->ckey = PAGE_DEFAULT_KEY >> 4;
        desc->dkey = PAGE_DEFAULT_KEY >> 4;
}

static void setup_qdr(struct qdio_irq *irq_ptr,
                      struct qdio_initialize *qdio_init)
{
        struct qdesfmt0 *desc = &irq_ptr->qdr->qdf0[0];
        int i;

        memset(irq_ptr->qdr, 0, sizeof(struct qdr));

        irq_ptr->qdr->qfmt = qdio_init->q_format;
        irq_ptr->qdr->ac = qdio_init->qdr_ac;
        irq_ptr->qdr->iqdcnt = qdio_init->no_input_qs;
        irq_ptr->qdr->oqdcnt = qdio_init->no_output_qs;
        irq_ptr->qdr->iqdsz = sizeof(struct qdesfmt0) / 4; /* size in words */
        irq_ptr->qdr->oqdsz = sizeof(struct qdesfmt0) / 4;
        irq_ptr->qdr->qiba = virt_to_dma64(&irq_ptr->qib);
        irq_ptr->qdr->qkey = PAGE_DEFAULT_KEY >> 4;

        for (i = 0; i < qdio_init->no_input_qs; i++)
                qdio_fill_qdr_desc(desc++, irq_ptr->input_qs[i]);

        for (i = 0; i < qdio_init->no_output_qs; i++)
                qdio_fill_qdr_desc(desc++, irq_ptr->output_qs[i]);
}

static void setup_qib(struct qdio_irq *irq_ptr,
                      struct qdio_initialize *init_data)
{
        memset(&irq_ptr->qib, 0, sizeof(irq_ptr->qib));

        irq_ptr->qib.qfmt = init_data->q_format;
        irq_ptr->qib.pfmt = init_data->qib_param_field_format;

        irq_ptr->qib.rflags = init_data->qib_rflags;
        if (css_general_characteristics.qebsm)
                irq_ptr->qib.rflags |= QIB_RFLAGS_ENABLE_QEBSM;

        if (init_data->no_input_qs)
                irq_ptr->qib.isliba =
                        (unsigned long)(irq_ptr->input_qs[0]->slib);
        if (init_data->no_output_qs)
                irq_ptr->qib.osliba =
                        (unsigned long)(irq_ptr->output_qs[0]->slib);
        memcpy(irq_ptr->qib.ebcnam, dev_name(&irq_ptr->cdev->dev), 8);
        ASCEBC(irq_ptr->qib.ebcnam, 8);

        if (init_data->qib_param_field)
                memcpy(irq_ptr->qib.parm, init_data->qib_param_field,
                       sizeof(irq_ptr->qib.parm));
}

void qdio_setup_irq(struct qdio_irq *irq_ptr, struct qdio_initialize *init_data)
{
        struct ccw_device *cdev = irq_ptr->cdev;

        irq_ptr->qdioac1 = 0;
        memset(&irq_ptr->ssqd_desc, 0, sizeof(irq_ptr->ssqd_desc));
        memset(&irq_ptr->perf_stat, 0, sizeof(irq_ptr->perf_stat));

        irq_ptr->debugfs_dev = NULL;
        irq_ptr->sch_token = irq_ptr->perf_stat_enabled = 0;
        irq_ptr->state = QDIO_IRQ_STATE_INACTIVE;
        irq_ptr->error_handler = init_data->input_handler;

        irq_ptr->int_parm = init_data->int_parm;
        irq_ptr->nr_input_qs = init_data->no_input_qs;
        irq_ptr->nr_output_qs = init_data->no_output_qs;
        ccw_device_get_schid(cdev, &irq_ptr->schid);
        setup_queues(irq_ptr, init_data);

        irq_ptr->irq_poll = init_data->irq_poll;
        set_bit(QDIO_IRQ_DISABLED, &irq_ptr->poll_state);

        setup_qib(irq_ptr, init_data);

        /* fill input and output descriptors */
        setup_qdr(irq_ptr, init_data);

        /* qdr, qib, sls, slsbs, slibs, sbales are filled now */

        /* set our IRQ handler */
        spin_lock_irq(get_ccwdev_lock(cdev));
        irq_ptr->orig_handler = cdev->handler;
        cdev->handler = qdio_int_handler;
        spin_unlock_irq(get_ccwdev_lock(cdev));
}

void qdio_shutdown_irq(struct qdio_irq *irq)
{
        struct ccw_device *cdev = irq->cdev;

        /* restore IRQ handler */
        spin_lock_irq(get_ccwdev_lock(cdev));
        cdev->handler = irq->orig_handler;
        cdev->private->intparm = 0;
        spin_unlock_irq(get_ccwdev_lock(cdev));
}

void qdio_print_subchannel_info(struct qdio_irq *irq_ptr)
{
        dev_info(&irq_ptr->cdev->dev,
                 "qdio: %s on SC %x using AI:%d QEBSM:%d PRI:%d TDD:%d SIGA:%s%s%s\n",
                 (irq_ptr->qib.qfmt == QDIO_QETH_QFMT) ? "OSA" :
                        ((irq_ptr->qib.qfmt == QDIO_ZFCP_QFMT) ? "ZFCP" : "HS"),
                 irq_ptr->schid.sch_no,
                 is_thinint_irq(irq_ptr),
                 (irq_ptr->sch_token) ? 1 : 0,
                 pci_out_supported(irq_ptr) ? 1 : 0,
                 css_general_characteristics.aif_tdd,
                 qdio_need_siga_in(irq_ptr) ? "R" : " ",
                 qdio_need_siga_out(irq_ptr) ? "W" : " ",
                 qdio_need_siga_sync(irq_ptr) ? "S" : " ");
}

int __init qdio_setup_init(void)
{
        qdio_q_cache = kmem_cache_create("qdio_q", sizeof(struct qdio_q),
                                         256, 0, NULL);
        if (!qdio_q_cache)
                return -ENOMEM;

        /* Check for OSA/FCP thin interrupts (bit 67). */
        DBF_EVENT("thinint:%1d",
                  (css_general_characteristics.aif_qdio) ? 1 : 0);

        /* Check for QEBSM support in general (bit 58). */
        DBF_EVENT("cssQEBSM:%1d", css_general_characteristics.qebsm);

        return 0;
}

void qdio_setup_exit(void)
{
        kmem_cache_destroy(qdio_q_cache);
}