sas_host_smp.c

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/*
 * Serial Attached SCSI (SAS) Expander discovery and configuration
 *
 * Copyright (C) 2007 James E.J. Bottomley
 *      <[email protected]>
 *
 * 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; version 2 only.
 */
#include <linux/scatterlist.h>
#include <linux/blkdev.h>
#include <linux/slab.h>
#include <linux/export.h>

#include "sas_internal.h"

#include <scsi/scsi_transport.h>
#include <scsi/scsi_transport_sas.h>
#include "../scsi_sas_internal.h"

static void sas_host_smp_discover(struct sas_ha_struct *sas_ha, u8 *resp_data,
                  u8 phy_id)
{
    struct sas_phy *phy;
    struct sas_rphy *rphy;

    if (phy_id >= sas_ha->num_phys) {
        resp_data[2] = SMP_RESP_NO_PHY;
        return;
    }
    resp_data[2] = SMP_RESP_FUNC_ACC;

    phy = sas_ha->sas_phy[phy_id]->phy;
    resp_data[9] = phy_id;
    resp_data[13] = phy->negotiated_linkrate;
    memcpy(resp_data + 16, sas_ha->sas_addr, SAS_ADDR_SIZE);
    memcpy(resp_data + 24, sas_ha->sas_phy[phy_id]->attached_sas_addr,
           SAS_ADDR_SIZE);
    resp_data[40] = (phy->minimum_linkrate << 4) |
        phy->minimum_linkrate_hw;
    resp_data[41] = (phy->maximum_linkrate << 4) |
        phy->maximum_linkrate_hw;

    if (!sas_ha->sas_phy[phy_id]->port ||
        !sas_ha->sas_phy[phy_id]->port->port_dev)
        return;

    rphy = sas_ha->sas_phy[phy_id]->port->port_dev->rphy;
    resp_data[12] = rphy->identify.device_type << 4;
    resp_data[14] = rphy->identify.initiator_port_protocols;
    resp_data[15] = rphy->identify.target_port_protocols;
}

static u8 *to_sas_gpio_gp_bit(unsigned int od, u8 *data, u8 index, u8 count, u8 *bit)
{
    unsigned int reg;
    u8 byte;

    /* gp registers start at index 1 */
    if (index == 0)
        return NULL;

    index--; /* make index 0-based */
    if (od < index * 32)
        return NULL;

    od -= index * 32;
    reg = od >> 5;

    if (reg >= count)
        return NULL;

    od &= (1 << 5) - 1;
    byte = 3 - (od >> 3);
    *bit = od & ((1 << 3) - 1);

    return &data[reg * 4 + byte];
}

int try_test_sas_gpio_gp_bit(unsigned int od, u8 *data, u8 index, u8 count)
{
    u8 *byte;
    u8 bit;

    byte = to_sas_gpio_gp_bit(od, data, index, count, &bit);
    if (!byte)
        return -1;

    return (*byte >> bit) & 1;
}
EXPORT_SYMBOL(try_test_sas_gpio_gp_bit);

static int sas_host_smp_write_gpio(struct sas_ha_struct *sas_ha, u8 *resp_data,
                   u8 reg_type, u8 reg_index, u8 reg_count,
                   u8 *req_data)
{
    struct sas_internal *i = to_sas_internal(sas_ha->core.shost->transportt);
    int written;

    if (i->dft->lldd_write_gpio == NULL) {
        resp_data[2] = SMP_RESP_FUNC_UNK;
        return 0;
    }

    written = i->dft->lldd_write_gpio(sas_ha, reg_type, reg_index,
                      reg_count, req_data);

    if (written < 0) {
        resp_data[2] = SMP_RESP_FUNC_FAILED;
        written = 0;
    } else
        resp_data[2] = SMP_RESP_FUNC_ACC;

    return written;
}

static void sas_report_phy_sata(struct sas_ha_struct *sas_ha, u8 *resp_data,
                u8 phy_id)
{
    struct sas_rphy *rphy;
    struct dev_to_host_fis *fis;
    int i;

    if (phy_id >= sas_ha->num_phys) {
        resp_data[2] = SMP_RESP_NO_PHY;
        return;
    }

    resp_data[2] = SMP_RESP_PHY_NO_SATA;

    if (!sas_ha->sas_phy[phy_id]->port)
        return;

    rphy = sas_ha->sas_phy[phy_id]->port->port_dev->rphy;
    fis = (struct dev_to_host_fis *)
        sas_ha->sas_phy[phy_id]->port->port_dev->frame_rcvd;
    if (rphy->identify.target_port_protocols != SAS_PROTOCOL_SATA)
        return;

    resp_data[2] = SMP_RESP_FUNC_ACC;
    resp_data[9] = phy_id;
    memcpy(resp_data + 16, sas_ha->sas_phy[phy_id]->attached_sas_addr,
           SAS_ADDR_SIZE);

    /* check to see if we have a valid d2h fis */
    if (fis->fis_type != 0x34)
        return;

    /* the d2h fis is required by the standard to be in LE format */
    for (i = 0; i < 20; i += 4) {
        u8 *dst = resp_data + 24 + i, *src =
            &sas_ha->sas_phy[phy_id]->port->port_dev->frame_rcvd[i];
        dst[0] = src[3];
        dst[1] = src[2];
        dst[2] = src[1];
        dst[3] = src[0];
    }
}

static void sas_phy_control(struct sas_ha_struct *sas_ha, u8 phy_id,
                u8 phy_op, enum sas_linkrate min,
                enum sas_linkrate max, u8 *resp_data)
{
    struct sas_internal *i =
        to_sas_internal(sas_ha->core.shost->transportt);
    struct sas_phy_linkrates rates;
    struct asd_sas_phy *asd_phy;

    if (phy_id >= sas_ha->num_phys) {
        resp_data[2] = SMP_RESP_NO_PHY;
        return;
    }

    asd_phy = sas_ha->sas_phy[phy_id];
    switch (phy_op) {
    case PHY_FUNC_NOP:
    case PHY_FUNC_LINK_RESET:
    case PHY_FUNC_HARD_RESET:
    case PHY_FUNC_DISABLE:
    case PHY_FUNC_CLEAR_ERROR_LOG:
    case PHY_FUNC_CLEAR_AFFIL:
    case PHY_FUNC_TX_SATA_PS_SIGNAL:
        break;

    default:
        resp_data[2] = SMP_RESP_PHY_UNK_OP;
        return;
    }

    rates.minimum_linkrate = min;
    rates.maximum_linkrate = max;

    /* filter reset requests through libata eh */
    if (phy_op == PHY_FUNC_LINK_RESET && sas_try_ata_reset(asd_phy) == 0) {
        resp_data[2] = SMP_RESP_FUNC_ACC;
        return;
    }

    if (i->dft->lldd_control_phy(asd_phy, phy_op, &rates))
        resp_data[2] = SMP_RESP_FUNC_FAILED;
    else
        resp_data[2] = SMP_RESP_FUNC_ACC;
}

int sas_smp_host_handler(struct Scsi_Host *shost, struct request *req,
             struct request *rsp)
{
    u8 *req_data = NULL, *resp_data = NULL, *buf;
    struct sas_ha_struct *sas_ha = SHOST_TO_SAS_HA(shost);
    int error = -EINVAL;

    /* eight is the minimum size for request and response frames */
    if (blk_rq_bytes(req) < 8 || blk_rq_bytes(rsp) < 8)
        goto out;

    if (bio_offset(req->bio) + blk_rq_bytes(req) > PAGE_SIZE ||
        bio_offset(rsp->bio) + blk_rq_bytes(rsp) > PAGE_SIZE) {
        shost_printk(KERN_ERR, shost,
            "SMP request/response frame crosses page boundary");
        goto out;
    }

    req_data = kzalloc(blk_rq_bytes(req), GFP_KERNEL);

    /* make sure frame can always be built ... we copy
     * back only the requested length */
    resp_data = kzalloc(max(blk_rq_bytes(rsp), 128U), GFP_KERNEL);

    if (!req_data || !resp_data) {
        error = -ENOMEM;
        goto out;
    }

    local_irq_disable();
    buf = kmap_atomic(bio_page(req->bio));
    memcpy(req_data, buf, blk_rq_bytes(req));
    kunmap_atomic(buf - bio_offset(req->bio));
    local_irq_enable();

    if (req_data[0] != SMP_REQUEST)
        goto out;

    /* always succeeds ... even if we can't process the request
     * the result is in the response frame */
    error = 0;

    /* set up default don't know response */
    resp_data[0] = SMP_RESPONSE;
    resp_data[1] = req_data[1];
    resp_data[2] = SMP_RESP_FUNC_UNK;

    switch (req_data[1]) {
    case SMP_REPORT_GENERAL:
        req->resid_len -= 8;
        rsp->resid_len -= 32;
        resp_data[2] = SMP_RESP_FUNC_ACC;
        resp_data[9] = sas_ha->num_phys;
        break;

    case SMP_REPORT_MANUF_INFO:
        req->resid_len -= 8;
        rsp->resid_len -= 64;
        resp_data[2] = SMP_RESP_FUNC_ACC;
        memcpy(resp_data + 12, shost->hostt->name,
               SAS_EXPANDER_VENDOR_ID_LEN);
        memcpy(resp_data + 20, "libsas virt phy",
               SAS_EXPANDER_PRODUCT_ID_LEN);
        break;

    case SMP_READ_GPIO_REG:
        /* FIXME: need GPIO support in the transport class */
        break;

    case SMP_DISCOVER:
        req->resid_len -= 16;
        if ((int)req->resid_len < 0) {
            req->resid_len = 0;
            error = -EINVAL;
            goto out;
        }
        rsp->resid_len -= 56;
        sas_host_smp_discover(sas_ha, resp_data, req_data[9]);
        break;

    case SMP_REPORT_PHY_ERR_LOG:
        /* FIXME: could implement this with additional
         * libsas callbacks providing the HW supports it */
        break;

    case SMP_REPORT_PHY_SATA:
        req->resid_len -= 16;
        if ((int)req->resid_len < 0) {
            req->resid_len = 0;
            error = -EINVAL;
            goto out;
        }
        rsp->resid_len -= 60;
        sas_report_phy_sata(sas_ha, resp_data, req_data[9]);
        break;

    case SMP_REPORT_ROUTE_INFO:
        /* Can't implement; hosts have no routes */
        break;

    case SMP_WRITE_GPIO_REG: {
        /* SFF-8485 v0.7 */
        const int base_frame_size = 11;
        int to_write = req_data[4];

        if (blk_rq_bytes(req) < base_frame_size + to_write * 4 ||
            req->resid_len < base_frame_size + to_write * 4) {
            resp_data[2] = SMP_RESP_INV_FRM_LEN;
            break;
        }

        to_write = sas_host_smp_write_gpio(sas_ha, resp_data, req_data[2],
                           req_data[3], to_write, &req_data[8]);
        req->resid_len -= base_frame_size + to_write * 4;
        rsp->resid_len -= 8;
        break;
    }

    case SMP_CONF_ROUTE_INFO:
        /* Can't implement; hosts have no routes */
        break;

    case SMP_PHY_CONTROL:
        req->resid_len -= 44;
        if ((int)req->resid_len < 0) {
            req->resid_len = 0;
            error = -EINVAL;
            goto out;
        }
        rsp->resid_len -= 8;
        sas_phy_control(sas_ha, req_data[9], req_data[10],
                req_data[32] >> 4, req_data[33] >> 4,
                resp_data);
        break;

    case SMP_PHY_TEST_FUNCTION:
        /* FIXME: should this be implemented? */
        break;

    default:
        /* probably a 2.0 function */
        break;
    }

    local_irq_disable();
    buf = kmap_atomic(bio_page(rsp->bio));
    memcpy(buf, resp_data, blk_rq_bytes(rsp));
    flush_kernel_dcache_page(bio_page(rsp->bio));
    kunmap_atomic(buf - bio_offset(rsp->bio));
    local_irq_enable();

 out:
    kfree(req_data);
    kfree(resp_data);
    return error;
}