spider-pci.c

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/*
 * IO workarounds for PCI on Celleb/Cell platform
 *
 * (C) Copyright 2006-2007 TOSHIBA CORPORATION
 *
 * 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; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#undef DEBUG

#include <linux/kernel.h>
#include <linux/of_platform.h>
#include <linux/slab.h>
#include <linux/io.h>

#include <asm/ppc-pci.h>
#include <asm/pci-bridge.h>
#include <asm/io-workarounds.h>

#define SPIDER_PCI_DISABLE_PREFETCH

struct spiderpci_iowa_private {
    void __iomem *regs;
};

static void spiderpci_io_flush(struct iowa_bus *bus)
{
    struct spiderpci_iowa_private *priv;
    u32 val;

    priv = bus->private;
    val = in_be32(priv->regs + SPIDER_PCI_DUMMY_READ);
    iosync();
}

#define SPIDER_PCI_MMIO_READ(name, ret)                 \
static ret spiderpci_##name(const PCI_IO_ADDR addr)         \
{                                   \
    ret val = __do_##name(addr);                    \
    spiderpci_io_flush(iowa_mem_find_bus(addr));            \
    return val;                         \
}

#define SPIDER_PCI_MMIO_READ_STR(name)                  \
static void spiderpci_##name(const PCI_IO_ADDR addr, void *buf,     \
                 unsigned long count)           \
{                                   \
    __do_##name(addr, buf, count);                  \
    spiderpci_io_flush(iowa_mem_find_bus(addr));            \
}

SPIDER_PCI_MMIO_READ(readb, u8)
SPIDER_PCI_MMIO_READ(readw, u16)
SPIDER_PCI_MMIO_READ(readl, u32)
SPIDER_PCI_MMIO_READ(readq, u64)
SPIDER_PCI_MMIO_READ(readw_be, u16)
SPIDER_PCI_MMIO_READ(readl_be, u32)
SPIDER_PCI_MMIO_READ(readq_be, u64)
SPIDER_PCI_MMIO_READ_STR(readsb)
SPIDER_PCI_MMIO_READ_STR(readsw)
SPIDER_PCI_MMIO_READ_STR(readsl)

static void spiderpci_memcpy_fromio(void *dest, const PCI_IO_ADDR src,
                    unsigned long n)
{
    __do_memcpy_fromio(dest, src, n);
    spiderpci_io_flush(iowa_mem_find_bus(src));
}

static int __init spiderpci_pci_setup_chip(struct pci_controller *phb,
                       void __iomem *regs)
{
    void *dummy_page_va;
    dma_addr_t dummy_page_da;

#ifdef SPIDER_PCI_DISABLE_PREFETCH
    u32 val = in_be32(regs + SPIDER_PCI_VCI_CNTL_STAT);
    pr_debug("SPIDER_IOWA:PVCI_Control_Status was 0x%08x\n", val);
    out_be32(regs + SPIDER_PCI_VCI_CNTL_STAT, val | 0x8);
#endif /* SPIDER_PCI_DISABLE_PREFETCH */

    /* setup dummy read */
    /*
     * On CellBlade, we can't know that which XDR memory is used by
     * kmalloc() to allocate dummy_page_va.
     * In order to imporve the performance, the XDR which is used to
     * allocate dummy_page_va is the nearest the spider-pci.
     * We have to select the CBE which is the nearest the spider-pci
     * to allocate memory from the best XDR, but I don't know that
     * how to do.
     *
     * Celleb does not have this problem, because it has only one XDR.
     */
    dummy_page_va = kmalloc(PAGE_SIZE, GFP_KERNEL);
    if (!dummy_page_va) {
        pr_err("SPIDERPCI-IOWA:Alloc dummy_page_va failed.\n");
        return -1;
    }

    dummy_page_da = dma_map_single(phb->parent, dummy_page_va,
                       PAGE_SIZE, DMA_FROM_DEVICE);
    if (dma_mapping_error(phb->parent, dummy_page_da)) {
        pr_err("SPIDER-IOWA:Map dummy page filed.\n");
        kfree(dummy_page_va);
        return -1;
    }

    out_be32(regs + SPIDER_PCI_DUMMY_READ_BASE, dummy_page_da);

    return 0;
}

int __init spiderpci_iowa_init(struct iowa_bus *bus, void *data)
{
    void __iomem *regs = NULL;
    struct spiderpci_iowa_private *priv;
    struct device_node *np = bus->phb->dn;
    struct resource r;
    unsigned long offset = (unsigned long)data;

    pr_debug("SPIDERPCI-IOWA:Bus initialize for spider(%s)\n",
         np->full_name);

    priv = kzalloc(sizeof(struct spiderpci_iowa_private), GFP_KERNEL);
    if (!priv) {
        pr_err("SPIDERPCI-IOWA:"
               "Can't allocate struct spiderpci_iowa_private");
        return -1;
    }

    if (of_address_to_resource(np, 0, &r)) {
        pr_err("SPIDERPCI-IOWA:Can't get resource.\n");
        goto error;
    }

    regs = ioremap(r.start + offset, SPIDER_PCI_REG_SIZE);
    if (!regs) {
        pr_err("SPIDERPCI-IOWA:ioremap failed.\n");
        goto error;
    }
    priv->regs = regs;
    bus->private = priv;

    if (spiderpci_pci_setup_chip(bus->phb, regs))
        goto error;

    return 0;

error:
    kfree(priv);
    bus->private = NULL;

    if (regs)
        iounmap(regs);

    return -1;
}

struct ppc_pci_io spiderpci_ops = {
    .readb = spiderpci_readb,
    .readw = spiderpci_readw,
    .readl = spiderpci_readl,
    .readq = spiderpci_readq,
    .readw_be = spiderpci_readw_be,
    .readl_be = spiderpci_readl_be,
    .readq_be = spiderpci_readq_be,
    .readsb = spiderpci_readsb,
    .readsw = spiderpci_readsw,
    .readsl = spiderpci_readsl,
    .memcpy_fromio = spiderpci_memcpy_fromio,
};