treewide: remove redundant IS_ERR() before error code check

[linux/fpc-iii.git] / arch / powerpc / sysdev / fsl_rmu.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Freescale MPC85xx/MPC86xx RapidIO RMU support
 *
 * Copyright 2009 Sysgo AG
 * Thomas Moll <thomas.moll@sysgo.com>
 * - fixed maintenance access routines, check for aligned access
 *
 * Copyright 2009 Integrated Device Technology, Inc.
 * Alex Bounine <alexandre.bounine@idt.com>
 * - Added Port-Write message handling
 * - Added Machine Check exception handling
 *
 * Copyright (C) 2007, 2008, 2010, 2011 Freescale Semiconductor, Inc.
 * Zhang Wei <wei.zhang@freescale.com>
 * Lian Minghuan-B31939 <Minghuan.Lian@freescale.com>
 * Liu Gang <Gang.Liu@freescale.com>
 *
 * Copyright 2005 MontaVista Software, Inc.
 * Matt Porter <mporter@kernel.crashing.org>
 */

#include <linux/types.h>
#include <linux/dma-mapping.h>
#include <linux/interrupt.h>
#include <linux/of_irq.h>
#include <linux/of_platform.h>
#include <linux/slab.h>

#include "fsl_rio.h"

#define GET_RMM_HANDLE(mport) \
                (((struct rio_priv *)(mport->priv))->rmm_handle)

/* RapidIO definition irq, which read from OF-tree */
#define IRQ_RIO_PW(m)           (((struct fsl_rio_pw *)(m))->pwirq)
#define IRQ_RIO_BELL(m) (((struct fsl_rio_dbell *)(m))->bellirq)
#define IRQ_RIO_TX(m) (((struct fsl_rmu *)(GET_RMM_HANDLE(m)))->txirq)
#define IRQ_RIO_RX(m) (((struct fsl_rmu *)(GET_RMM_HANDLE(m)))->rxirq)

#define RIO_MIN_TX_RING_SIZE    2
#define RIO_MAX_TX_RING_SIZE    2048
#define RIO_MIN_RX_RING_SIZE    2
#define RIO_MAX_RX_RING_SIZE    2048

#define RIO_IPWMR_SEN           0x00100000
#define RIO_IPWMR_QFIE          0x00000100
#define RIO_IPWMR_EIE           0x00000020
#define RIO_IPWMR_CQ            0x00000002
#define RIO_IPWMR_PWE           0x00000001

#define RIO_IPWSR_QF            0x00100000
#define RIO_IPWSR_TE            0x00000080
#define RIO_IPWSR_QFI           0x00000010
#define RIO_IPWSR_PWD           0x00000008
#define RIO_IPWSR_PWB           0x00000004

#define RIO_EPWISR              0x10010
/* EPWISR Error match value */
#define RIO_EPWISR_PINT1        0x80000000
#define RIO_EPWISR_PINT2        0x40000000
#define RIO_EPWISR_MU           0x00000002
#define RIO_EPWISR_PW           0x00000001

#define IPWSR_CLEAR             0x98
#define OMSR_CLEAR              0x1cb3
#define IMSR_CLEAR              0x491
#define IDSR_CLEAR              0x91
#define ODSR_CLEAR              0x1c00
#define LTLEECSR_ENABLE_ALL     0xFFC000FC
#define RIO_LTLEECSR            0x060c

#define RIO_IM0SR               0x64
#define RIO_IM1SR               0x164
#define RIO_OM0SR               0x4
#define RIO_OM1SR               0x104

#define RIO_DBELL_WIN_SIZE      0x1000

#define RIO_MSG_OMR_MUI         0x00000002
#define RIO_MSG_OSR_TE          0x00000080
#define RIO_MSG_OSR_QOI         0x00000020
#define RIO_MSG_OSR_QFI         0x00000010
#define RIO_MSG_OSR_MUB         0x00000004
#define RIO_MSG_OSR_EOMI        0x00000002
#define RIO_MSG_OSR_QEI         0x00000001

#define RIO_MSG_IMR_MI          0x00000002
#define RIO_MSG_ISR_TE          0x00000080
#define RIO_MSG_ISR_QFI         0x00000010
#define RIO_MSG_ISR_DIQI        0x00000001

#define RIO_MSG_DESC_SIZE       32
#define RIO_MSG_BUFFER_SIZE     4096

#define DOORBELL_DMR_DI         0x00000002
#define DOORBELL_DSR_TE         0x00000080
#define DOORBELL_DSR_QFI        0x00000010
#define DOORBELL_DSR_DIQI       0x00000001

#define DOORBELL_MESSAGE_SIZE   0x08

static DEFINE_SPINLOCK(fsl_rio_doorbell_lock);

struct rio_msg_regs {
        u32 omr;
        u32 osr;
        u32 pad1;
        u32 odqdpar;
        u32 pad2;
        u32 osar;
        u32 odpr;
        u32 odatr;
        u32 odcr;
        u32 pad3;
        u32 odqepar;
        u32 pad4[13];
        u32 imr;
        u32 isr;
        u32 pad5;
        u32 ifqdpar;
        u32 pad6;
        u32 ifqepar;
};

struct rio_dbell_regs {
        u32 odmr;
        u32 odsr;
        u32 pad1[4];
        u32 oddpr;
        u32 oddatr;
        u32 pad2[3];
        u32 odretcr;
        u32 pad3[12];
        u32 dmr;
        u32 dsr;
        u32 pad4;
        u32 dqdpar;
        u32 pad5;
        u32 dqepar;
};

struct rio_pw_regs {
        u32 pwmr;
        u32 pwsr;
        u32 epwqbar;
        u32 pwqbar;
};


struct rio_tx_desc {
        u32 pad1;
        u32 saddr;
        u32 dport;
        u32 dattr;
        u32 pad2;
        u32 pad3;
        u32 dwcnt;
        u32 pad4;
};

struct rio_msg_tx_ring {
        void *virt;
        dma_addr_t phys;
        void *virt_buffer[RIO_MAX_TX_RING_SIZE];
        dma_addr_t phys_buffer[RIO_MAX_TX_RING_SIZE];
        int tx_slot;
        int size;
        void *dev_id;
};

struct rio_msg_rx_ring {
        void *virt;
        dma_addr_t phys;
        void *virt_buffer[RIO_MAX_RX_RING_SIZE];
        int rx_slot;
        int size;
        void *dev_id;
};

struct fsl_rmu {
        struct rio_msg_regs __iomem *msg_regs;
        struct rio_msg_tx_ring msg_tx_ring;
        struct rio_msg_rx_ring msg_rx_ring;
        int txirq;
        int rxirq;
};

struct rio_dbell_msg {
        u16 pad1;
        u16 tid;
        u16 sid;
        u16 info;
};

/**
 * fsl_rio_tx_handler - MPC85xx outbound message interrupt handler
 * @irq: Linux interrupt number
 * @dev_instance: Pointer to interrupt-specific data
 *
 * Handles outbound message interrupts. Executes a register outbound
 * mailbox event handler and acks the interrupt occurrence.
 */
static irqreturn_t
fsl_rio_tx_handler(int irq, void *dev_instance)
{
        int osr;
        struct rio_mport *port = (struct rio_mport *)dev_instance;
        struct fsl_rmu *rmu = GET_RMM_HANDLE(port);

        osr = in_be32(&rmu->msg_regs->osr);

        if (osr & RIO_MSG_OSR_TE) {
                pr_info("RIO: outbound message transmission error\n");
                out_be32(&rmu->msg_regs->osr, RIO_MSG_OSR_TE);
                goto out;
        }

        if (osr & RIO_MSG_OSR_QOI) {
                pr_info("RIO: outbound message queue overflow\n");
                out_be32(&rmu->msg_regs->osr, RIO_MSG_OSR_QOI);
                goto out;
        }

        if (osr & RIO_MSG_OSR_EOMI) {
                u32 dqp = in_be32(&rmu->msg_regs->odqdpar);
                int slot = (dqp - rmu->msg_tx_ring.phys) >> 5;
                if (port->outb_msg[0].mcback != NULL) {
                        port->outb_msg[0].mcback(port, rmu->msg_tx_ring.dev_id,
                                        -1,
                                        slot);
                }
                /* Ack the end-of-message interrupt */
                out_be32(&rmu->msg_regs->osr, RIO_MSG_OSR_EOMI);
        }

out:
        return IRQ_HANDLED;
}

/**
 * fsl_rio_rx_handler - MPC85xx inbound message interrupt handler
 * @irq: Linux interrupt number
 * @dev_instance: Pointer to interrupt-specific data
 *
 * Handles inbound message interrupts. Executes a registered inbound
 * mailbox event handler and acks the interrupt occurrence.
 */
static irqreturn_t
fsl_rio_rx_handler(int irq, void *dev_instance)
{
        int isr;
        struct rio_mport *port = (struct rio_mport *)dev_instance;
        struct fsl_rmu *rmu = GET_RMM_HANDLE(port);

        isr = in_be32(&rmu->msg_regs->isr);

        if (isr & RIO_MSG_ISR_TE) {
                pr_info("RIO: inbound message reception error\n");
                out_be32((void *)&rmu->msg_regs->isr, RIO_MSG_ISR_TE);
                goto out;
        }

        /* XXX Need to check/dispatch until queue empty */
        if (isr & RIO_MSG_ISR_DIQI) {
                /*
                * Can receive messages for any mailbox/letter to that
                * mailbox destination. So, make the callback with an
                * unknown/invalid mailbox number argument.
                */
                if (port->inb_msg[0].mcback != NULL)
                        port->inb_msg[0].mcback(port, rmu->msg_rx_ring.dev_id,
                                -1,
                                -1);

                /* Ack the queueing interrupt */
                out_be32(&rmu->msg_regs->isr, RIO_MSG_ISR_DIQI);
        }

out:
        return IRQ_HANDLED;
}

/**
 * fsl_rio_dbell_handler - MPC85xx doorbell interrupt handler
 * @irq: Linux interrupt number
 * @dev_instance: Pointer to interrupt-specific data
 *
 * Handles doorbell interrupts. Parses a list of registered
 * doorbell event handlers and executes a matching event handler.
 */
static irqreturn_t
fsl_rio_dbell_handler(int irq, void *dev_instance)
{
        int dsr;
        struct fsl_rio_dbell *fsl_dbell = (struct fsl_rio_dbell *)dev_instance;
        int i;

        dsr = in_be32(&fsl_dbell->dbell_regs->dsr);

        if (dsr & DOORBELL_DSR_TE) {
                pr_info("RIO: doorbell reception error\n");
                out_be32(&fsl_dbell->dbell_regs->dsr, DOORBELL_DSR_TE);
                goto out;
        }

        if (dsr & DOORBELL_DSR_QFI) {
                pr_info("RIO: doorbell queue full\n");
                out_be32(&fsl_dbell->dbell_regs->dsr, DOORBELL_DSR_QFI);
        }

        /* XXX Need to check/dispatch until queue empty */
        if (dsr & DOORBELL_DSR_DIQI) {
                struct rio_dbell_msg *dmsg =
                        fsl_dbell->dbell_ring.virt +
                        (in_be32(&fsl_dbell->dbell_regs->dqdpar) & 0xfff);
                struct rio_dbell *dbell;
                int found = 0;

                pr_debug
                        ("RIO: processing doorbell,"
                        " sid %2.2x tid %2.2x info %4.4x\n",
                        dmsg->sid, dmsg->tid, dmsg->info);

                for (i = 0; i < MAX_PORT_NUM; i++) {
                        if (fsl_dbell->mport[i]) {
                                list_for_each_entry(dbell,
                                        &fsl_dbell->mport[i]->dbells, node) {
                                        if ((dbell->res->start
                                                <= dmsg->info)
                                                && (dbell->res->end
                                                >= dmsg->info)) {
                                                found = 1;
                                                break;
                                        }
                                }
                                if (found && dbell->dinb) {
                                        dbell->dinb(fsl_dbell->mport[i],
                                                dbell->dev_id, dmsg->sid,
                                                dmsg->tid,
                                                dmsg->info);
                                        break;
                                }
                        }
                }

                if (!found) {
                        pr_debug
                                ("RIO: spurious doorbell,"
                                " sid %2.2x tid %2.2x info %4.4x\n",
                                dmsg->sid, dmsg->tid,
                                dmsg->info);
                }
                setbits32(&fsl_dbell->dbell_regs->dmr, DOORBELL_DMR_DI);
                out_be32(&fsl_dbell->dbell_regs->dsr, DOORBELL_DSR_DIQI);
        }

out:
        return IRQ_HANDLED;
}

void msg_unit_error_handler(void)
{

        /*XXX: Error recovery is not implemented, we just clear errors */
        out_be32((u32 *)(rio_regs_win + RIO_LTLEDCSR), 0);

        out_be32((u32 *)(rmu_regs_win + RIO_IM0SR), IMSR_CLEAR);
        out_be32((u32 *)(rmu_regs_win + RIO_IM1SR), IMSR_CLEAR);
        out_be32((u32 *)(rmu_regs_win + RIO_OM0SR), OMSR_CLEAR);
        out_be32((u32 *)(rmu_regs_win + RIO_OM1SR), OMSR_CLEAR);

        out_be32(&dbell->dbell_regs->odsr, ODSR_CLEAR);
        out_be32(&dbell->dbell_regs->dsr, IDSR_CLEAR);

        out_be32(&pw->pw_regs->pwsr, IPWSR_CLEAR);
}

/**
 * fsl_rio_port_write_handler - MPC85xx port write interrupt handler
 * @irq: Linux interrupt number
 * @dev_instance: Pointer to interrupt-specific data
 *
 * Handles port write interrupts. Parses a list of registered
 * port write event handlers and executes a matching event handler.
 */
static irqreturn_t
fsl_rio_port_write_handler(int irq, void *dev_instance)
{
        u32 ipwmr, ipwsr;
        struct fsl_rio_pw *pw = (struct fsl_rio_pw *)dev_instance;
        u32 epwisr, tmp;

        epwisr = in_be32(rio_regs_win + RIO_EPWISR);
        if (!(epwisr & RIO_EPWISR_PW))
                goto pw_done;

        ipwmr = in_be32(&pw->pw_regs->pwmr);
        ipwsr = in_be32(&pw->pw_regs->pwsr);

#ifdef DEBUG_PW
        pr_debug("PW Int->IPWMR: 0x%08x IPWSR: 0x%08x (", ipwmr, ipwsr);
        if (ipwsr & RIO_IPWSR_QF)
                pr_debug(" QF");
        if (ipwsr & RIO_IPWSR_TE)
                pr_debug(" TE");
        if (ipwsr & RIO_IPWSR_QFI)
                pr_debug(" QFI");
        if (ipwsr & RIO_IPWSR_PWD)
                pr_debug(" PWD");
        if (ipwsr & RIO_IPWSR_PWB)
                pr_debug(" PWB");
        pr_debug(" )\n");
#endif
        /* Schedule deferred processing if PW was received */
        if (ipwsr & RIO_IPWSR_QFI) {
                /* Save PW message (if there is room in FIFO),
                 * otherwise discard it.
                 */
                if (kfifo_avail(&pw->pw_fifo) >= RIO_PW_MSG_SIZE) {
                        pw->port_write_msg.msg_count++;
                        kfifo_in(&pw->pw_fifo, pw->port_write_msg.virt,
                                 RIO_PW_MSG_SIZE);
                } else {
                        pw->port_write_msg.discard_count++;
                        pr_debug("RIO: ISR Discarded Port-Write Msg(s) (%d)\n",
                                 pw->port_write_msg.discard_count);
                }
                /* Clear interrupt and issue Clear Queue command. This allows
                 * another port-write to be received.
                 */
                out_be32(&pw->pw_regs->pwsr,    RIO_IPWSR_QFI);
                out_be32(&pw->pw_regs->pwmr, ipwmr | RIO_IPWMR_CQ);

                schedule_work(&pw->pw_work);
        }

        if ((ipwmr & RIO_IPWMR_EIE) && (ipwsr & RIO_IPWSR_TE)) {
                pw->port_write_msg.err_count++;
                pr_debug("RIO: Port-Write Transaction Err (%d)\n",
                         pw->port_write_msg.err_count);
                /* Clear Transaction Error: port-write controller should be
                 * disabled when clearing this error
                 */
                out_be32(&pw->pw_regs->pwmr, ipwmr & ~RIO_IPWMR_PWE);
                out_be32(&pw->pw_regs->pwsr,    RIO_IPWSR_TE);
                out_be32(&pw->pw_regs->pwmr, ipwmr);
        }

        if (ipwsr & RIO_IPWSR_PWD) {
                pw->port_write_msg.discard_count++;
                pr_debug("RIO: Port Discarded Port-Write Msg(s) (%d)\n",
                         pw->port_write_msg.discard_count);
                out_be32(&pw->pw_regs->pwsr, RIO_IPWSR_PWD);
        }

pw_done:
        if (epwisr & RIO_EPWISR_PINT1) {
                tmp = in_be32(rio_regs_win + RIO_LTLEDCSR);
                pr_debug("RIO_LTLEDCSR = 0x%x\n", tmp);
                fsl_rio_port_error_handler(0);
        }

        if (epwisr & RIO_EPWISR_PINT2) {
                tmp = in_be32(rio_regs_win + RIO_LTLEDCSR);
                pr_debug("RIO_LTLEDCSR = 0x%x\n", tmp);
                fsl_rio_port_error_handler(1);
        }

        if (epwisr & RIO_EPWISR_MU) {
                tmp = in_be32(rio_regs_win + RIO_LTLEDCSR);
                pr_debug("RIO_LTLEDCSR = 0x%x\n", tmp);
                msg_unit_error_handler();
        }

        return IRQ_HANDLED;
}

static void fsl_pw_dpc(struct work_struct *work)
{
        struct fsl_rio_pw *pw = container_of(work, struct fsl_rio_pw, pw_work);
        union rio_pw_msg msg_buffer;
        int i;

        /*
         * Process port-write messages
         */
        while (kfifo_out_spinlocked(&pw->pw_fifo, (unsigned char *)&msg_buffer,
                         RIO_PW_MSG_SIZE, &pw->pw_fifo_lock)) {
#ifdef DEBUG_PW
                {
                u32 i;
                pr_debug("%s : Port-Write Message:", __func__);
                for (i = 0; i < RIO_PW_MSG_SIZE/sizeof(u32); i++) {
                        if ((i%4) == 0)
                                pr_debug("\n0x%02x: 0x%08x", i*4,
                                         msg_buffer.raw[i]);
                        else
                                pr_debug(" 0x%08x", msg_buffer.raw[i]);
                }
                pr_debug("\n");
                }
#endif
                /* Pass the port-write message to RIO core for processing */
                for (i = 0; i < MAX_PORT_NUM; i++) {
                        if (pw->mport[i])
                                rio_inb_pwrite_handler(pw->mport[i],
                                                       &msg_buffer);
                }
        }
}

/**
 * fsl_rio_pw_enable - enable/disable port-write interface init
 * @mport: Master port implementing the port write unit
 * @enable:    1=enable; 0=disable port-write message handling
 */
int fsl_rio_pw_enable(struct rio_mport *mport, int enable)
{
        u32 rval;

        rval = in_be32(&pw->pw_regs->pwmr);

        if (enable)
                rval |= RIO_IPWMR_PWE;
        else
                rval &= ~RIO_IPWMR_PWE;

        out_be32(&pw->pw_regs->pwmr, rval);

        return 0;
}

/**
 * fsl_rio_port_write_init - MPC85xx port write interface init
 * @mport: Master port implementing the port write unit
 *
 * Initializes port write unit hardware and DMA buffer
 * ring. Called from fsl_rio_setup(). Returns %0 on success
 * or %-ENOMEM on failure.
 */

int fsl_rio_port_write_init(struct fsl_rio_pw *pw)
{
        int rc = 0;

        /* Following configurations require a disabled port write controller */
        out_be32(&pw->pw_regs->pwmr,
                 in_be32(&pw->pw_regs->pwmr) & ~RIO_IPWMR_PWE);

        /* Initialize port write */
        pw->port_write_msg.virt = dma_alloc_coherent(pw->dev,
                                        RIO_PW_MSG_SIZE,
                                        &pw->port_write_msg.phys, GFP_KERNEL);
        if (!pw->port_write_msg.virt) {
                pr_err("RIO: unable allocate port write queue\n");
                return -ENOMEM;
        }

        pw->port_write_msg.err_count = 0;
        pw->port_write_msg.discard_count = 0;

        /* Point dequeue/enqueue pointers at first entry */
        out_be32(&pw->pw_regs->epwqbar, 0);
        out_be32(&pw->pw_regs->pwqbar, (u32) pw->port_write_msg.phys);

        pr_debug("EIPWQBAR: 0x%08x IPWQBAR: 0x%08x\n",
                 in_be32(&pw->pw_regs->epwqbar),
                 in_be32(&pw->pw_regs->pwqbar));

        /* Clear interrupt status IPWSR */
        out_be32(&pw->pw_regs->pwsr,
                 (RIO_IPWSR_TE | RIO_IPWSR_QFI | RIO_IPWSR_PWD));

        /* Configure port write controller for snooping enable all reporting,
           clear queue full */
        out_be32(&pw->pw_regs->pwmr,
                 RIO_IPWMR_SEN | RIO_IPWMR_QFIE | RIO_IPWMR_EIE | RIO_IPWMR_CQ);


        /* Hook up port-write handler */
        rc = request_irq(IRQ_RIO_PW(pw), fsl_rio_port_write_handler,
                        IRQF_SHARED, "port-write", (void *)pw);
        if (rc < 0) {
                pr_err("MPC85xx RIO: unable to request inbound doorbell irq");
                goto err_out;
        }
        /* Enable Error Interrupt */
        out_be32((u32 *)(rio_regs_win + RIO_LTLEECSR), LTLEECSR_ENABLE_ALL);

        INIT_WORK(&pw->pw_work, fsl_pw_dpc);
        spin_lock_init(&pw->pw_fifo_lock);
        if (kfifo_alloc(&pw->pw_fifo, RIO_PW_MSG_SIZE * 32, GFP_KERNEL)) {
                pr_err("FIFO allocation failed\n");
                rc = -ENOMEM;
                goto err_out_irq;
        }

        pr_debug("IPWMR: 0x%08x IPWSR: 0x%08x\n",
                 in_be32(&pw->pw_regs->pwmr),
                 in_be32(&pw->pw_regs->pwsr));

        return rc;

err_out_irq:
        free_irq(IRQ_RIO_PW(pw), (void *)pw);
err_out:
        dma_free_coherent(pw->dev, RIO_PW_MSG_SIZE,
                pw->port_write_msg.virt,
                pw->port_write_msg.phys);
        return rc;
}

/**
 * fsl_rio_doorbell_send - Send a MPC85xx doorbell message
 * @mport: RapidIO master port info
 * @index: ID of RapidIO interface
 * @destid: Destination ID of target device
 * @data: 16-bit info field of RapidIO doorbell message
 *
 * Sends a MPC85xx doorbell message. Returns %0 on success or
 * %-EINVAL on failure.
 */
int fsl_rio_doorbell_send(struct rio_mport *mport,
                                int index, u16 destid, u16 data)
{
        unsigned long flags;

        pr_debug("fsl_doorbell_send: index %d destid %4.4x data %4.4x\n",
                 index, destid, data);

        spin_lock_irqsave(&fsl_rio_doorbell_lock, flags);

        /* In the serial version silicons, such as MPC8548, MPC8641,
         * below operations is must be.
         */
        out_be32(&dbell->dbell_regs->odmr, 0x00000000);
        out_be32(&dbell->dbell_regs->odretcr, 0x00000004);
        out_be32(&dbell->dbell_regs->oddpr, destid << 16);
        out_be32(&dbell->dbell_regs->oddatr, (index << 20) | data);
        out_be32(&dbell->dbell_regs->odmr, 0x00000001);

        spin_unlock_irqrestore(&fsl_rio_doorbell_lock, flags);

        return 0;
}

/**
 * fsl_add_outb_message - Add message to the MPC85xx outbound message queue
 * @mport: Master port with outbound message queue
 * @rdev: Target of outbound message
 * @mbox: Outbound mailbox
 * @buffer: Message to add to outbound queue
 * @len: Length of message
 *
 * Adds the @buffer message to the MPC85xx outbound message queue. Returns
 * %0 on success or %-EINVAL on failure.
 */
int
fsl_add_outb_message(struct rio_mport *mport, struct rio_dev *rdev, int mbox,
                        void *buffer, size_t len)
{
        struct fsl_rmu *rmu = GET_RMM_HANDLE(mport);
        u32 omr;
        struct rio_tx_desc *desc = (struct rio_tx_desc *)rmu->msg_tx_ring.virt
                                        + rmu->msg_tx_ring.tx_slot;
        int ret = 0;

        pr_debug("RIO: fsl_add_outb_message(): destid %4.4x mbox %d buffer " \
                 "%p len %8.8zx\n", rdev->destid, mbox, buffer, len);
        if ((len < 8) || (len > RIO_MAX_MSG_SIZE)) {
                ret = -EINVAL;
                goto out;
        }

        /* Copy and clear rest of buffer */
        memcpy(rmu->msg_tx_ring.virt_buffer[rmu->msg_tx_ring.tx_slot], buffer,
                        len);
        if (len < (RIO_MAX_MSG_SIZE - 4))
                memset(rmu->msg_tx_ring.virt_buffer[rmu->msg_tx_ring.tx_slot]
                                + len, 0, RIO_MAX_MSG_SIZE - len);

        /* Set mbox field for message, and set destid */
        desc->dport = (rdev->destid << 16) | (mbox & 0x3);

        /* Enable EOMI interrupt and priority */
        desc->dattr = 0x28000000 | ((mport->index) << 20);

        /* Set transfer size aligned to next power of 2 (in double words) */
        desc->dwcnt = is_power_of_2(len) ? len : 1 << get_bitmask_order(len);

        /* Set snooping and source buffer address */
        desc->saddr = 0x00000004
                | rmu->msg_tx_ring.phys_buffer[rmu->msg_tx_ring.tx_slot];

        /* Increment enqueue pointer */
        omr = in_be32(&rmu->msg_regs->omr);
        out_be32(&rmu->msg_regs->omr, omr | RIO_MSG_OMR_MUI);

        /* Go to next descriptor */
        if (++rmu->msg_tx_ring.tx_slot == rmu->msg_tx_ring.size)
                rmu->msg_tx_ring.tx_slot = 0;

out:
        return ret;
}

/**
 * fsl_open_outb_mbox - Initialize MPC85xx outbound mailbox
 * @mport: Master port implementing the outbound message unit
 * @dev_id: Device specific pointer to pass on event
 * @mbox: Mailbox to open
 * @entries: Number of entries in the outbound mailbox ring
 *
 * Initializes buffer ring, request the outbound message interrupt,
 * and enables the outbound message unit. Returns %0 on success and
 * %-EINVAL or %-ENOMEM on failure.
 */
int
fsl_open_outb_mbox(struct rio_mport *mport, void *dev_id, int mbox, int entries)
{
        int i, j, rc = 0;
        struct rio_priv *priv = mport->priv;
        struct fsl_rmu *rmu = GET_RMM_HANDLE(mport);

        if ((entries < RIO_MIN_TX_RING_SIZE) ||
                (entries > RIO_MAX_TX_RING_SIZE) || (!is_power_of_2(entries))) {
                rc = -EINVAL;
                goto out;
        }

        /* Initialize shadow copy ring */
        rmu->msg_tx_ring.dev_id = dev_id;
        rmu->msg_tx_ring.size = entries;

        for (i = 0; i < rmu->msg_tx_ring.size; i++) {
                rmu->msg_tx_ring.virt_buffer[i] =
                        dma_alloc_coherent(priv->dev, RIO_MSG_BUFFER_SIZE,
                                &rmu->msg_tx_ring.phys_buffer[i], GFP_KERNEL);
                if (!rmu->msg_tx_ring.virt_buffer[i]) {
                        rc = -ENOMEM;
                        for (j = 0; j < rmu->msg_tx_ring.size; j++)
                                if (rmu->msg_tx_ring.virt_buffer[j])
                                        dma_free_coherent(priv->dev,
                                                        RIO_MSG_BUFFER_SIZE,
                                                        rmu->msg_tx_ring.
                                                        virt_buffer[j],
                                                        rmu->msg_tx_ring.
                                                        phys_buffer[j]);
                        goto out;
                }
        }

        /* Initialize outbound message descriptor ring */
        rmu->msg_tx_ring.virt = dma_alloc_coherent(priv->dev,
                                                   rmu->msg_tx_ring.size * RIO_MSG_DESC_SIZE,
                                                   &rmu->msg_tx_ring.phys,
                                                   GFP_KERNEL);
        if (!rmu->msg_tx_ring.virt) {
                rc = -ENOMEM;
                goto out_dma;
        }
        rmu->msg_tx_ring.tx_slot = 0;

        /* Point dequeue/enqueue pointers at first entry in ring */
        out_be32(&rmu->msg_regs->odqdpar, rmu->msg_tx_ring.phys);
        out_be32(&rmu->msg_regs->odqepar, rmu->msg_tx_ring.phys);

        /* Configure for snooping */
        out_be32(&rmu->msg_regs->osar, 0x00000004);

        /* Clear interrupt status */
        out_be32(&rmu->msg_regs->osr, 0x000000b3);

        /* Hook up outbound message handler */
        rc = request_irq(IRQ_RIO_TX(mport), fsl_rio_tx_handler, 0,
                         "msg_tx", (void *)mport);
        if (rc < 0)
                goto out_irq;

        /*
         * Configure outbound message unit
         *      Snooping
         *      Interrupts (all enabled, except QEIE)
         *      Chaining mode
         *      Disable
         */
        out_be32(&rmu->msg_regs->omr, 0x00100220);

        /* Set number of entries */
        out_be32(&rmu->msg_regs->omr,
                 in_be32(&rmu->msg_regs->omr) |
                 ((get_bitmask_order(entries) - 2) << 12));

        /* Now enable the unit */
        out_be32(&rmu->msg_regs->omr, in_be32(&rmu->msg_regs->omr) | 0x1);

out:
        return rc;

out_irq:
        dma_free_coherent(priv->dev,
                rmu->msg_tx_ring.size * RIO_MSG_DESC_SIZE,
                rmu->msg_tx_ring.virt, rmu->msg_tx_ring.phys);

out_dma:
        for (i = 0; i < rmu->msg_tx_ring.size; i++)
                dma_free_coherent(priv->dev, RIO_MSG_BUFFER_SIZE,
                rmu->msg_tx_ring.virt_buffer[i],
                rmu->msg_tx_ring.phys_buffer[i]);

        return rc;
}

/**
 * fsl_close_outb_mbox - Shut down MPC85xx outbound mailbox
 * @mport: Master port implementing the outbound message unit
 * @mbox: Mailbox to close
 *
 * Disables the outbound message unit, free all buffers, and
 * frees the outbound message interrupt.
 */
void fsl_close_outb_mbox(struct rio_mport *mport, int mbox)
{
        struct rio_priv *priv = mport->priv;
        struct fsl_rmu *rmu = GET_RMM_HANDLE(mport);

        /* Disable inbound message unit */
        out_be32(&rmu->msg_regs->omr, 0);

        /* Free ring */
        dma_free_coherent(priv->dev,
        rmu->msg_tx_ring.size * RIO_MSG_DESC_SIZE,
        rmu->msg_tx_ring.virt, rmu->msg_tx_ring.phys);

        /* Free interrupt */
        free_irq(IRQ_RIO_TX(mport), (void *)mport);
}

/**
 * fsl_open_inb_mbox - Initialize MPC85xx inbound mailbox
 * @mport: Master port implementing the inbound message unit
 * @dev_id: Device specific pointer to pass on event
 * @mbox: Mailbox to open
 * @entries: Number of entries in the inbound mailbox ring
 *
 * Initializes buffer ring, request the inbound message interrupt,
 * and enables the inbound message unit. Returns %0 on success
 * and %-EINVAL or %-ENOMEM on failure.
 */
int
fsl_open_inb_mbox(struct rio_mport *mport, void *dev_id, int mbox, int entries)
{
        int i, rc = 0;
        struct rio_priv *priv = mport->priv;
        struct fsl_rmu *rmu = GET_RMM_HANDLE(mport);

        if ((entries < RIO_MIN_RX_RING_SIZE) ||
                (entries > RIO_MAX_RX_RING_SIZE) || (!is_power_of_2(entries))) {
                rc = -EINVAL;
                goto out;
        }

        /* Initialize client buffer ring */
        rmu->msg_rx_ring.dev_id = dev_id;
        rmu->msg_rx_ring.size = entries;
        rmu->msg_rx_ring.rx_slot = 0;
        for (i = 0; i < rmu->msg_rx_ring.size; i++)
                rmu->msg_rx_ring.virt_buffer[i] = NULL;

        /* Initialize inbound message ring */
        rmu->msg_rx_ring.virt = dma_alloc_coherent(priv->dev,
                                rmu->msg_rx_ring.size * RIO_MAX_MSG_SIZE,
                                &rmu->msg_rx_ring.phys, GFP_KERNEL);
        if (!rmu->msg_rx_ring.virt) {
                rc = -ENOMEM;
                goto out;
        }

        /* Point dequeue/enqueue pointers at first entry in ring */
        out_be32(&rmu->msg_regs->ifqdpar, (u32) rmu->msg_rx_ring.phys);
        out_be32(&rmu->msg_regs->ifqepar, (u32) rmu->msg_rx_ring.phys);

        /* Clear interrupt status */
        out_be32(&rmu->msg_regs->isr, 0x00000091);

        /* Hook up inbound message handler */
        rc = request_irq(IRQ_RIO_RX(mport), fsl_rio_rx_handler, 0,
                         "msg_rx", (void *)mport);
        if (rc < 0) {
                dma_free_coherent(priv->dev,
                        rmu->msg_rx_ring.size * RIO_MAX_MSG_SIZE,
                        rmu->msg_rx_ring.virt, rmu->msg_rx_ring.phys);
                goto out;
        }

        /*
         * Configure inbound message unit:
         *      Snooping
         *      4KB max message size
         *      Unmask all interrupt sources
         *      Disable
         */
        out_be32(&rmu->msg_regs->imr, 0x001b0060);

        /* Set number of queue entries */
        setbits32(&rmu->msg_regs->imr, (get_bitmask_order(entries) - 2) << 12);

        /* Now enable the unit */
        setbits32(&rmu->msg_regs->imr, 0x1);

out:
        return rc;
}

/**
 * fsl_close_inb_mbox - Shut down MPC85xx inbound mailbox
 * @mport: Master port implementing the inbound message unit
 * @mbox: Mailbox to close
 *
 * Disables the inbound message unit, free all buffers, and
 * frees the inbound message interrupt.
 */
void fsl_close_inb_mbox(struct rio_mport *mport, int mbox)
{
        struct rio_priv *priv = mport->priv;
        struct fsl_rmu *rmu = GET_RMM_HANDLE(mport);

        /* Disable inbound message unit */
        out_be32(&rmu->msg_regs->imr, 0);

        /* Free ring */
        dma_free_coherent(priv->dev, rmu->msg_rx_ring.size * RIO_MAX_MSG_SIZE,
        rmu->msg_rx_ring.virt, rmu->msg_rx_ring.phys);

        /* Free interrupt */
        free_irq(IRQ_RIO_RX(mport), (void *)mport);
}

/**
 * fsl_add_inb_buffer - Add buffer to the MPC85xx inbound message queue
 * @mport: Master port implementing the inbound message unit
 * @mbox: Inbound mailbox number
 * @buf: Buffer to add to inbound queue
 *
 * Adds the @buf buffer to the MPC85xx inbound message queue. Returns
 * %0 on success or %-EINVAL on failure.
 */
int fsl_add_inb_buffer(struct rio_mport *mport, int mbox, void *buf)
{
        int rc = 0;
        struct fsl_rmu *rmu = GET_RMM_HANDLE(mport);

        pr_debug("RIO: fsl_add_inb_buffer(), msg_rx_ring.rx_slot %d\n",
                 rmu->msg_rx_ring.rx_slot);

        if (rmu->msg_rx_ring.virt_buffer[rmu->msg_rx_ring.rx_slot]) {
                printk(KERN_ERR
                        "RIO: error adding inbound buffer %d, buffer exists\n",
                        rmu->msg_rx_ring.rx_slot);
                rc = -EINVAL;
                goto out;
        }

        rmu->msg_rx_ring.virt_buffer[rmu->msg_rx_ring.rx_slot] = buf;
        if (++rmu->msg_rx_ring.rx_slot == rmu->msg_rx_ring.size)
                rmu->msg_rx_ring.rx_slot = 0;

out:
        return rc;
}

/**
 * fsl_get_inb_message - Fetch inbound message from the MPC85xx message unit
 * @mport: Master port implementing the inbound message unit
 * @mbox: Inbound mailbox number
 *
 * Gets the next available inbound message from the inbound message queue.
 * A pointer to the message is returned on success or NULL on failure.
 */
void *fsl_get_inb_message(struct rio_mport *mport, int mbox)
{
        struct fsl_rmu *rmu = GET_RMM_HANDLE(mport);
        u32 phys_buf;
        void *virt_buf;
        void *buf = NULL;
        int buf_idx;

        phys_buf = in_be32(&rmu->msg_regs->ifqdpar);

        /* If no more messages, then bail out */
        if (phys_buf == in_be32(&rmu->msg_regs->ifqepar))
                goto out2;

        virt_buf = rmu->msg_rx_ring.virt + (phys_buf
                                                - rmu->msg_rx_ring.phys);
        buf_idx = (phys_buf - rmu->msg_rx_ring.phys) / RIO_MAX_MSG_SIZE;
        buf = rmu->msg_rx_ring.virt_buffer[buf_idx];

        if (!buf) {
                printk(KERN_ERR
                        "RIO: inbound message copy failed, no buffers\n");
                goto out1;
        }

        /* Copy max message size, caller is expected to allocate that big */
        memcpy(buf, virt_buf, RIO_MAX_MSG_SIZE);

        /* Clear the available buffer */
        rmu->msg_rx_ring.virt_buffer[buf_idx] = NULL;

out1:
        setbits32(&rmu->msg_regs->imr, RIO_MSG_IMR_MI);

out2:
        return buf;
}

/**
 * fsl_rio_doorbell_init - MPC85xx doorbell interface init
 * @mport: Master port implementing the inbound doorbell unit
 *
 * Initializes doorbell unit hardware and inbound DMA buffer
 * ring. Called from fsl_rio_setup(). Returns %0 on success
 * or %-ENOMEM on failure.
 */
int fsl_rio_doorbell_init(struct fsl_rio_dbell *dbell)
{
        int rc = 0;

        /* Initialize inbound doorbells */
        dbell->dbell_ring.virt = dma_alloc_coherent(dbell->dev, 512 *
                DOORBELL_MESSAGE_SIZE, &dbell->dbell_ring.phys, GFP_KERNEL);
        if (!dbell->dbell_ring.virt) {
                printk(KERN_ERR "RIO: unable allocate inbound doorbell ring\n");
                rc = -ENOMEM;
                goto out;
        }

        /* Point dequeue/enqueue pointers at first entry in ring */
        out_be32(&dbell->dbell_regs->dqdpar, (u32) dbell->dbell_ring.phys);
        out_be32(&dbell->dbell_regs->dqepar, (u32) dbell->dbell_ring.phys);

        /* Clear interrupt status */
        out_be32(&dbell->dbell_regs->dsr, 0x00000091);

        /* Hook up doorbell handler */
        rc = request_irq(IRQ_RIO_BELL(dbell), fsl_rio_dbell_handler, 0,
                         "dbell_rx", (void *)dbell);
        if (rc < 0) {
                dma_free_coherent(dbell->dev, 512 * DOORBELL_MESSAGE_SIZE,
                         dbell->dbell_ring.virt, dbell->dbell_ring.phys);
                printk(KERN_ERR
                        "MPC85xx RIO: unable to request inbound doorbell irq");
                goto out;
        }

        /* Configure doorbells for snooping, 512 entries, and enable */
        out_be32(&dbell->dbell_regs->dmr, 0x00108161);

out:
        return rc;
}

int fsl_rio_setup_rmu(struct rio_mport *mport, struct device_node *node)
{
        struct rio_priv *priv;
        struct fsl_rmu *rmu;
        u64 msg_start;
        const u32 *msg_addr;
        int mlen;
        int aw;

        if (!mport || !mport->priv)
                return -EINVAL;

        priv = mport->priv;

        if (!node) {
                dev_warn(priv->dev, "Can't get %pOF property 'fsl,rmu'\n",
                        priv->dev->of_node);
                return -EINVAL;
        }

        rmu = kzalloc(sizeof(struct fsl_rmu), GFP_KERNEL);
        if (!rmu)
                return -ENOMEM;

        aw = of_n_addr_cells(node);
        msg_addr = of_get_property(node, "reg", &mlen);
        if (!msg_addr) {
                pr_err("%pOF: unable to find 'reg' property of message-unit\n",
                        node);
                kfree(rmu);
                return -ENOMEM;
        }
        msg_start = of_read_number(msg_addr, aw);

        rmu->msg_regs = (struct rio_msg_regs *)
                        (rmu_regs_win + (u32)msg_start);

        rmu->txirq = irq_of_parse_and_map(node, 0);
        rmu->rxirq = irq_of_parse_and_map(node, 1);
        printk(KERN_INFO "%pOF: txirq: %d, rxirq %d\n",
                node, rmu->txirq, rmu->rxirq);

        priv->rmm_handle = rmu;

        rio_init_dbell_res(&mport->riores[RIO_DOORBELL_RESOURCE], 0, 0xffff);
        rio_init_mbox_res(&mport->riores[RIO_INB_MBOX_RESOURCE], 0, 0);
        rio_init_mbox_res(&mport->riores[RIO_OUTB_MBOX_RESOURCE], 0, 0);

        return 0;
}