// SPDX-License-Identifier: GPL-2.0
/*
 * PCI I/O adapter configuration related functions.
 *
 * Copyright IBM Corp. 2016
 */
#define pr_fmt(fmt) "sclp_cmd: " fmt

#include <linux/completion.h>
#include <linux/export.h>
#include <linux/mutex.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/err.h>

#include <asm/sclp.h>

#include "sclp.h"

#define SCLP_CMDW_CONFIGURE_PCI                 0x001a0001
#define SCLP_CMDW_DECONFIGURE_PCI               0x001b0001

#define SCLP_ATYPE_PCI                          2

static DEFINE_MUTEX(sclp_pci_mutex);
static struct sclp_register sclp_pci_event = {
        .send_mask = EVTYP_ERRNOTIFY_MASK,
};

struct pci_cfg_sccb {
        struct sccb_header header;
        u8 atype;               /* adapter type */
        u8 reserved1;
        u16 reserved2;
        u32 aid;                /* adapter identifier */
} __packed;

static int do_pci_configure(sclp_cmdw_t cmd, u32 fid)
{
        struct pci_cfg_sccb *sccb;
        int rc;

        if (!SCLP_HAS_PCI_RECONFIG)
                return -EOPNOTSUPP;

        sccb = (struct pci_cfg_sccb *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
        if (!sccb)
                return -ENOMEM;

        sccb->header.length = PAGE_SIZE;
        sccb->atype = SCLP_ATYPE_PCI;
        sccb->aid = fid;
        rc = sclp_sync_request(cmd, sccb);
        if (rc)
                goto out;
        switch (sccb->header.response_code) {
        case 0x0020:
        case 0x0120:
                break;
        default:
                pr_warn("configure PCI I/O adapter failed: cmd=0x%08x  response=0x%04x\n",
                        cmd, sccb->header.response_code);
                rc = -EIO;
                break;
        }
out:
        free_page((unsigned long) sccb);
        return rc;
}

int sclp_pci_configure(u32 fid)
{
        return do_pci_configure(SCLP_CMDW_CONFIGURE_PCI, fid);
}
EXPORT_SYMBOL(sclp_pci_configure);

int sclp_pci_deconfigure(u32 fid)
{
        return do_pci_configure(SCLP_CMDW_DECONFIGURE_PCI, fid);
}
EXPORT_SYMBOL(sclp_pci_deconfigure);

static void sclp_pci_callback(struct sclp_req *req, void *data)
{
        struct completion *completion = data;

        complete(completion);
}

static int sclp_pci_check_report(struct zpci_report_error_header *report)
{
        if (report->version != 1)
                return -EINVAL;

        switch (report->action) {
        case SCLP_ERRNOTIFY_AQ_RESET:
        case SCLP_ERRNOTIFY_AQ_REPAIR:
        case SCLP_ERRNOTIFY_AQ_INFO_LOG:
        case SCLP_ERRNOTIFY_AQ_OPTICS_DATA:
        case SCLP_ERRNOTIFY_AQ_NVME_SMART_LOG:
                break;
        default:
                return -EINVAL;
        }

        if (report->length > (PAGE_SIZE - sizeof(struct err_notify_sccb)))
                return -EINVAL;

        return 0;
}

int sclp_pci_report(struct zpci_report_error_header *report, u32 fh, u32 fid)
{
        DECLARE_COMPLETION_ONSTACK(completion);
        struct err_notify_sccb *sccb;
        struct sclp_req req;
        int ret;

        ret = sclp_pci_check_report(report);
        if (ret)
                return ret;

        mutex_lock(&sclp_pci_mutex);
        ret = sclp_register(&sclp_pci_event);
        if (ret)
                goto out_unlock;

        if (!(sclp_pci_event.sclp_receive_mask & EVTYP_ERRNOTIFY_MASK)) {
                ret = -EOPNOTSUPP;
                goto out_unregister;
        }

        sccb = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
        if (!sccb) {
                ret = -ENOMEM;
                goto out_unregister;
        }

        memset(&req, 0, sizeof(req));
        req.callback_data = &completion;
        req.callback = sclp_pci_callback;
        req.command = SCLP_CMDW_WRITE_EVENT_DATA;
        req.status = SCLP_REQ_FILLED;
        req.sccb = sccb;

        sccb->evbuf.header.length = sizeof(sccb->evbuf) + report->length;
        sccb->evbuf.header.type = EVTYP_ERRNOTIFY;
        sccb->header.length = sizeof(sccb->header) + sccb->evbuf.header.length;

        sccb->evbuf.action = report->action;
        sccb->evbuf.atype = SCLP_ATYPE_PCI;
        sccb->evbuf.fh = fh;
        sccb->evbuf.fid = fid;

        memcpy(sccb->evbuf.data, report->data, report->length);

        ret = sclp_add_request(&req);
        if (ret)
                goto out_free_req;

        wait_for_completion(&completion);
        if (req.status != SCLP_REQ_DONE) {
                pr_warn("request failed (status=0x%02x)\n",
                        req.status);
                ret = -EIO;
                goto out_free_req;
        }

        if (sccb->header.response_code != 0x0020) {
                pr_warn("request failed with response code 0x%x\n",
                        sccb->header.response_code);
                ret = -EIO;
        }

out_free_req:
        free_page((unsigned long) sccb);
out_unregister:
        sclp_unregister(&sclp_pci_event);
out_unlock:
        mutex_unlock(&sclp_pci_mutex);
        return ret;
}