sta2x11-fixup.c

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/*
 * arch/x86/pci/sta2x11-fixup.c
 * glue code for lib/swiotlb.c and DMA translation between STA2x11
 * AMBA memory mapping and the X86 memory mapping
 *
 * ST Microelectronics ConneXt (STA2X11/STA2X10)
 *
 * Copyright (c) 2010-2011 Wind River Systems, Inc.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 */

#include <linux/pci.h>
#include <linux/pci_ids.h>
#include <linux/export.h>
#include <linux/list.h>

#define STA2X11_SWIOTLB_SIZE (4*1024*1024)
extern int swiotlb_late_init_with_default_size(size_t default_size);

/*
 * We build a list of bus numbers that are under the ConneXt. The
 * main bridge hosts 4 busses, which are the 4 endpoints, in order.
 */
#define STA2X11_NR_EP       4   /* 0..3 included */
#define STA2X11_NR_FUNCS    8   /* 0..7 included */
#define STA2X11_AMBA_SIZE   (512 << 20)

struct sta2x11_ahb_regs { /* saved during suspend */
    u32 base, pexlbase, pexhbase, crw;
};

struct sta2x11_mapping {
    u32 amba_base;
    int is_suspended;
    struct sta2x11_ahb_regs regs[STA2X11_NR_FUNCS];
};

struct sta2x11_instance {
    struct list_head list;
    int bus0;
    struct sta2x11_mapping map[STA2X11_NR_EP];
};

static LIST_HEAD(sta2x11_instance_list);

/* At probe time, record new instances of this bridge (likely one only) */
static void sta2x11_new_instance(struct pci_dev *pdev)
{
    struct sta2x11_instance *instance;

    instance = kzalloc(sizeof(*instance), GFP_ATOMIC);
    if (!instance)
        return;
    /* This has a subordinate bridge, with 4 more-subordinate ones */
    instance->bus0 = pdev->subordinate->number + 1;

    if (list_empty(&sta2x11_instance_list)) {
        int size = STA2X11_SWIOTLB_SIZE;
        /* First instance: register your own swiotlb area */
        dev_info(&pdev->dev, "Using SWIOTLB (size %i)\n", size);
        if (swiotlb_late_init_with_default_size(size))
            dev_emerg(&pdev->dev, "init swiotlb failed\n");
    }
    list_add(&instance->list, &sta2x11_instance_list);
}
DECLARE_PCI_FIXUP_ENABLE(PCI_VENDOR_ID_STMICRO, 0xcc17, sta2x11_new_instance);

/*
 * Utility functions used in this file from below
 */
static struct sta2x11_instance *sta2x11_pdev_to_instance(struct pci_dev *pdev)
{
    struct sta2x11_instance *instance;
    int ep;

    list_for_each_entry(instance, &sta2x11_instance_list, list) {
        ep = pdev->bus->number - instance->bus0;
        if (ep >= 0 && ep < STA2X11_NR_EP)
            return instance;
    }
    return NULL;
}

static int sta2x11_pdev_to_ep(struct pci_dev *pdev)
{
    struct sta2x11_instance *instance;

    instance = sta2x11_pdev_to_instance(pdev);
    if (!instance)
        return -1;

    return pdev->bus->number - instance->bus0;
}

static struct sta2x11_mapping *sta2x11_pdev_to_mapping(struct pci_dev *pdev)
{
    struct sta2x11_instance *instance;
    int ep;

    instance = sta2x11_pdev_to_instance(pdev);
    if (!instance)
        return NULL;
    ep = sta2x11_pdev_to_ep(pdev);
    return instance->map + ep;
}

/* This is exported, as some devices need to access the MFD registers */
struct sta2x11_instance *sta2x11_get_instance(struct pci_dev *pdev)
{
    return sta2x11_pdev_to_instance(pdev);
}
EXPORT_SYMBOL(sta2x11_get_instance);


static dma_addr_t p2a(dma_addr_t p, struct pci_dev *pdev)
{
    struct sta2x11_mapping *map;
    dma_addr_t a;

    map = sta2x11_pdev_to_mapping(pdev);
    a = p + map->amba_base;
    return a;
}

static dma_addr_t a2p(dma_addr_t a, struct pci_dev *pdev)
{
    struct sta2x11_mapping *map;
    dma_addr_t p;

    map = sta2x11_pdev_to_mapping(pdev);
    p = a - map->amba_base;
    return p;
}

static void *sta2x11_swiotlb_alloc_coherent(struct device *dev,
                        size_t size,
                        dma_addr_t *dma_handle,
                        gfp_t flags,
                        struct dma_attrs *attrs)
{
    void *vaddr;

    vaddr = dma_generic_alloc_coherent(dev, size, dma_handle, flags, attrs);
    if (!vaddr)
        vaddr = swiotlb_alloc_coherent(dev, size, dma_handle, flags);
    *dma_handle = p2a(*dma_handle, to_pci_dev(dev));
    return vaddr;
}

/* We have our own dma_ops: the same as swiotlb but from alloc (above) */
static struct dma_map_ops sta2x11_dma_ops = {
    .alloc = sta2x11_swiotlb_alloc_coherent,
    .free = swiotlb_free_coherent,
    .map_page = swiotlb_map_page,
    .unmap_page = swiotlb_unmap_page,
    .map_sg = swiotlb_map_sg_attrs,
    .unmap_sg = swiotlb_unmap_sg_attrs,
    .sync_single_for_cpu = swiotlb_sync_single_for_cpu,
    .sync_single_for_device = swiotlb_sync_single_for_device,
    .sync_sg_for_cpu = swiotlb_sync_sg_for_cpu,
    .sync_sg_for_device = swiotlb_sync_sg_for_device,
    .mapping_error = swiotlb_dma_mapping_error,
    .dma_supported = NULL, /* FIXME: we should use this instead! */
};

/* At setup time, we use our own ops if the device is a ConneXt one */
static void sta2x11_setup_pdev(struct pci_dev *pdev)
{
    struct sta2x11_instance *instance = sta2x11_pdev_to_instance(pdev);

    if (!instance) /* either a sta2x11 bridge or another ST device */
        return;
    pci_set_consistent_dma_mask(pdev, STA2X11_AMBA_SIZE - 1);
    pci_set_dma_mask(pdev, STA2X11_AMBA_SIZE - 1);
    pdev->dev.archdata.dma_ops = &sta2x11_dma_ops;

    /* We must enable all devices as master, for audio DMA to work */
    pci_set_master(pdev);
}
DECLARE_PCI_FIXUP_ENABLE(PCI_VENDOR_ID_STMICRO, PCI_ANY_ID, sta2x11_setup_pdev);

/*
 * The following three functions are exported (used in swiotlb: FIXME)
 */
bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)
{
    struct sta2x11_mapping *map;

    if (dev->archdata.dma_ops != &sta2x11_dma_ops) {
        if (!dev->dma_mask)
            return false;
        return addr + size - 1 <= *dev->dma_mask;
    }

    map = sta2x11_pdev_to_mapping(to_pci_dev(dev));

    if (!map || (addr < map->amba_base))
        return false;
    if (addr + size >= map->amba_base + STA2X11_AMBA_SIZE) {
        return false;
    }

    return true;
}

dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
{
    if (dev->archdata.dma_ops != &sta2x11_dma_ops)
        return paddr;
    return p2a(paddr, to_pci_dev(dev));
}

phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr)
{
    if (dev->archdata.dma_ops != &sta2x11_dma_ops)
        return daddr;
    return a2p(daddr, to_pci_dev(dev));
}


/*
 * At boot we must set up the mappings for the pcie-to-amba bridge.
 * It involves device access, and the same happens at suspend/resume time
 */

#define AHB_MAPB        0xCA4
#define AHB_CRW(i)      (AHB_MAPB + 0  + (i) * 0x10)
#define AHB_CRW_SZMASK          0xfffffc00UL
#define AHB_CRW_ENABLE          (1 << 0)
#define AHB_CRW_WTYPE_MEM       (2 << 1)
#define AHB_CRW_ROE         (1UL << 3)  /* Relax Order Ena */
#define AHB_CRW_NSE         (1UL << 4)  /* No Snoop Enable */
#define AHB_BASE(i)     (AHB_MAPB + 4  + (i) * 0x10)
#define AHB_PEXLBASE(i)     (AHB_MAPB + 8  + (i) * 0x10)
#define AHB_PEXHBASE(i)     (AHB_MAPB + 12 + (i) * 0x10)

/* At probe time, enable mapping for each endpoint, using the pdev */
static void sta2x11_map_ep(struct pci_dev *pdev)
{
    struct sta2x11_mapping *map = sta2x11_pdev_to_mapping(pdev);
    int i;

    if (!map)
        return;
    pci_read_config_dword(pdev, AHB_BASE(0), &map->amba_base);

    /* Configure AHB mapping */
    pci_write_config_dword(pdev, AHB_PEXLBASE(0), 0);
    pci_write_config_dword(pdev, AHB_PEXHBASE(0), 0);
    pci_write_config_dword(pdev, AHB_CRW(0), STA2X11_AMBA_SIZE |
                   AHB_CRW_WTYPE_MEM | AHB_CRW_ENABLE);

    /* Disable all the other windows */
    for (i = 1; i < STA2X11_NR_FUNCS; i++)
        pci_write_config_dword(pdev, AHB_CRW(i), 0);

    dev_info(&pdev->dev,
         "sta2x11: Map EP %i: AMBA address %#8x-%#8x\n",
         sta2x11_pdev_to_ep(pdev),  map->amba_base,
         map->amba_base + STA2X11_AMBA_SIZE - 1);
}
DECLARE_PCI_FIXUP_ENABLE(PCI_VENDOR_ID_STMICRO, PCI_ANY_ID, sta2x11_map_ep);

#ifdef CONFIG_PM /* Some register values must be saved and restored */

static void suspend_mapping(struct pci_dev *pdev)
{
    struct sta2x11_mapping *map = sta2x11_pdev_to_mapping(pdev);
    int i;

    if (!map)
        return;

    if (map->is_suspended)
        return;
    map->is_suspended = 1;

    /* Save all window configs */
    for (i = 0; i < STA2X11_NR_FUNCS; i++) {
        struct sta2x11_ahb_regs *regs = map->regs + i;

        pci_read_config_dword(pdev, AHB_BASE(i), &regs->base);
        pci_read_config_dword(pdev, AHB_PEXLBASE(i), &regs->pexlbase);
        pci_read_config_dword(pdev, AHB_PEXHBASE(i), &regs->pexhbase);
        pci_read_config_dword(pdev, AHB_CRW(i), &regs->crw);
    }
}
DECLARE_PCI_FIXUP_SUSPEND(PCI_VENDOR_ID_STMICRO, PCI_ANY_ID, suspend_mapping);

static void resume_mapping(struct pci_dev *pdev)
{
    struct sta2x11_mapping *map = sta2x11_pdev_to_mapping(pdev);
    int i;

    if (!map)
        return;


    if (!map->is_suspended)
        goto out;
    map->is_suspended = 0;

    /* Restore all window configs */
    for (i = 0; i < STA2X11_NR_FUNCS; i++) {
        struct sta2x11_ahb_regs *regs = map->regs + i;

        pci_write_config_dword(pdev, AHB_BASE(i), regs->base);
        pci_write_config_dword(pdev, AHB_PEXLBASE(i), regs->pexlbase);
        pci_write_config_dword(pdev, AHB_PEXHBASE(i), regs->pexhbase);
        pci_write_config_dword(pdev, AHB_CRW(i), regs->crw);
    }
out:
    pci_set_master(pdev); /* Like at boot, enable master on all devices */
}
DECLARE_PCI_FIXUP_RESUME(PCI_VENDOR_ID_STMICRO, PCI_ANY_ID, resume_mapping);

#endif /* CONFIG_PM */