x86/unwinder: Handle stack overflows more gracefully

[linux/fpc-iii.git] / drivers / bus / mvebu-mbus.c

/*
 * Address map functions for Marvell EBU SoCs (Kirkwood, Armada
 * 370/XP, Dove, Orion5x and MV78xx0)
 *
 * This file is licensed under the terms of the GNU General Public
 * License version 2.  This program is licensed "as is" without any
 * warranty of any kind, whether express or implied.
 *
 * The Marvell EBU SoCs have a configurable physical address space:
 * the physical address at which certain devices (PCIe, NOR, NAND,
 * etc.) sit can be configured. The configuration takes place through
 * two sets of registers:
 *
 * - One to configure the access of the CPU to the devices. Depending
 *   on the families, there are between 8 and 20 configurable windows,
 *   each can be use to create a physical memory window that maps to a
 *   specific device. Devices are identified by a tuple (target,
 *   attribute).
 *
 * - One to configure the access to the CPU to the SDRAM. There are
 *   either 2 (for Dove) or 4 (for other families) windows to map the
 *   SDRAM into the physical address space.
 *
 * This driver:
 *
 * - Reads out the SDRAM address decoding windows at initialization
 *   time, and fills the mvebu_mbus_dram_info structure with these
 *   informations. The exported function mv_mbus_dram_info() allow
 *   device drivers to get those informations related to the SDRAM
 *   address decoding windows. This is because devices also have their
 *   own windows (configured through registers that are part of each
 *   device register space), and therefore the drivers for Marvell
 *   devices have to configure those device -> SDRAM windows to ensure
 *   that DMA works properly.
 *
 * - Provides an API for platform code or device drivers to
 *   dynamically add or remove address decoding windows for the CPU ->
 *   device accesses. This API is mvebu_mbus_add_window_by_id(),
 *   mvebu_mbus_add_window_remap_by_id() and
 *   mvebu_mbus_del_window().
 *
 * - Provides a debugfs interface in /sys/kernel/debug/mvebu-mbus/ to
 *   see the list of CPU -> SDRAM windows and their configuration
 *   (file 'sdram') and the list of CPU -> devices windows and their
 *   configuration (file 'devices').
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/mbus.h>
#include <linux/io.h>
#include <linux/ioport.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/debugfs.h>
#include <linux/log2.h>
#include <linux/memblock.h>
#include <linux/syscore_ops.h>

/*
 * DDR target is the same on all platforms.
 */
#define TARGET_DDR              0

/*
 * CPU Address Decode Windows registers
 */
#define WIN_CTRL_OFF            0x0000
#define   WIN_CTRL_ENABLE       BIT(0)
/* Only on HW I/O coherency capable platforms */
#define   WIN_CTRL_SYNCBARRIER  BIT(1)
#define   WIN_CTRL_TGT_MASK     0xf0
#define   WIN_CTRL_TGT_SHIFT    4
#define   WIN_CTRL_ATTR_MASK    0xff00
#define   WIN_CTRL_ATTR_SHIFT   8
#define   WIN_CTRL_SIZE_MASK    0xffff0000
#define   WIN_CTRL_SIZE_SHIFT   16
#define WIN_BASE_OFF            0x0004
#define   WIN_BASE_LOW          0xffff0000
#define   WIN_BASE_HIGH         0xf
#define WIN_REMAP_LO_OFF        0x0008
#define   WIN_REMAP_LOW         0xffff0000
#define WIN_REMAP_HI_OFF        0x000c

#define UNIT_SYNC_BARRIER_OFF   0x84
#define   UNIT_SYNC_BARRIER_ALL 0xFFFF

#define ATTR_HW_COHERENCY       (0x1 << 4)

#define DDR_BASE_CS_OFF(n)      (0x0000 + ((n) << 3))
#define  DDR_BASE_CS_HIGH_MASK  0xf
#define  DDR_BASE_CS_LOW_MASK   0xff000000
#define DDR_SIZE_CS_OFF(n)      (0x0004 + ((n) << 3))
#define  DDR_SIZE_ENABLED       BIT(0)
#define  DDR_SIZE_CS_MASK       0x1c
#define  DDR_SIZE_CS_SHIFT      2
#define  DDR_SIZE_MASK          0xff000000

#define DOVE_DDR_BASE_CS_OFF(n) ((n) << 4)

/* Relative to mbusbridge_base */
#define MBUS_BRIDGE_CTRL_OFF    0x0
#define MBUS_BRIDGE_BASE_OFF    0x4

/* Maximum number of windows, for all known platforms */
#define MBUS_WINS_MAX           20

struct mvebu_mbus_state;

struct mvebu_mbus_soc_data {
        unsigned int num_wins;
        bool has_mbus_bridge;
        unsigned int (*win_cfg_offset)(const int win);
        unsigned int (*win_remap_offset)(const int win);
        void (*setup_cpu_target)(struct mvebu_mbus_state *s);
        int (*save_cpu_target)(struct mvebu_mbus_state *s,
                               u32 __iomem *store_addr);
        int (*show_cpu_target)(struct mvebu_mbus_state *s,
                               struct seq_file *seq, void *v);
};

/*
 * Used to store the state of one MBus window accross suspend/resume.
 */
struct mvebu_mbus_win_data {
        u32 ctrl;
        u32 base;
        u32 remap_lo;
        u32 remap_hi;
};

struct mvebu_mbus_state {
        void __iomem *mbuswins_base;
        void __iomem *sdramwins_base;
        void __iomem *mbusbridge_base;
        phys_addr_t sdramwins_phys_base;
        struct dentry *debugfs_root;
        struct dentry *debugfs_sdram;
        struct dentry *debugfs_devs;
        struct resource pcie_mem_aperture;
        struct resource pcie_io_aperture;
        const struct mvebu_mbus_soc_data *soc;
        int hw_io_coherency;

        /* Used during suspend/resume */
        u32 mbus_bridge_ctrl;
        u32 mbus_bridge_base;
        struct mvebu_mbus_win_data wins[MBUS_WINS_MAX];
};

static struct mvebu_mbus_state mbus_state;

/*
 * We provide two variants of the mv_mbus_dram_info() function:
 *
 * - The normal one, where the described DRAM ranges may overlap with
 *   the I/O windows, but for which the DRAM ranges are guaranteed to
 *   have a power of two size. Such ranges are suitable for the DMA
 *   masters that only DMA between the RAM and the device, which is
 *   actually all devices except the crypto engines.
 *
 * - The 'nooverlap' one, where the described DRAM ranges are
 *   guaranteed to not overlap with the I/O windows, but for which the
 *   DRAM ranges will not have power of two sizes. They will only be
 *   aligned on a 64 KB boundary, and have a size multiple of 64
 *   KB. Such ranges are suitable for the DMA masters that DMA between
 *   the crypto SRAM (which is mapped through an I/O window) and a
 *   device. This is the case for the crypto engines.
 */

static struct mbus_dram_target_info mvebu_mbus_dram_info;
static struct mbus_dram_target_info mvebu_mbus_dram_info_nooverlap;

const struct mbus_dram_target_info *mv_mbus_dram_info(void)
{
        return &mvebu_mbus_dram_info;
}
EXPORT_SYMBOL_GPL(mv_mbus_dram_info);

const struct mbus_dram_target_info *mv_mbus_dram_info_nooverlap(void)
{
        return &mvebu_mbus_dram_info_nooverlap;
}
EXPORT_SYMBOL_GPL(mv_mbus_dram_info_nooverlap);

/* Checks whether the given window has remap capability */
static bool mvebu_mbus_window_is_remappable(struct mvebu_mbus_state *mbus,
                                            const int win)
{
        return mbus->soc->win_remap_offset(win) != MVEBU_MBUS_NO_REMAP;
}

/*
 * Functions to manipulate the address decoding windows
 */

static void mvebu_mbus_read_window(struct mvebu_mbus_state *mbus,
                                   int win, int *enabled, u64 *base,
                                   u32 *size, u8 *target, u8 *attr,
                                   u64 *remap)
{
        void __iomem *addr = mbus->mbuswins_base +
                mbus->soc->win_cfg_offset(win);
        u32 basereg = readl(addr + WIN_BASE_OFF);
        u32 ctrlreg = readl(addr + WIN_CTRL_OFF);

        if (!(ctrlreg & WIN_CTRL_ENABLE)) {
                *enabled = 0;
                return;
        }

        *enabled = 1;
        *base = ((u64)basereg & WIN_BASE_HIGH) << 32;
        *base |= (basereg & WIN_BASE_LOW);
        *size = (ctrlreg | ~WIN_CTRL_SIZE_MASK) + 1;

        if (target)
                *target = (ctrlreg & WIN_CTRL_TGT_MASK) >> WIN_CTRL_TGT_SHIFT;

        if (attr)
                *attr = (ctrlreg & WIN_CTRL_ATTR_MASK) >> WIN_CTRL_ATTR_SHIFT;

        if (remap) {
                if (mvebu_mbus_window_is_remappable(mbus, win)) {
                        u32 remap_low, remap_hi;
                        void __iomem *addr_rmp = mbus->mbuswins_base +
                                mbus->soc->win_remap_offset(win);
                        remap_low = readl(addr_rmp + WIN_REMAP_LO_OFF);
                        remap_hi  = readl(addr_rmp + WIN_REMAP_HI_OFF);
                        *remap = ((u64)remap_hi << 32) | remap_low;
                } else
                        *remap = 0;
        }
}

static void mvebu_mbus_disable_window(struct mvebu_mbus_state *mbus,
                                      int win)
{
        void __iomem *addr;

        addr = mbus->mbuswins_base + mbus->soc->win_cfg_offset(win);
        writel(0, addr + WIN_BASE_OFF);
        writel(0, addr + WIN_CTRL_OFF);

        if (mvebu_mbus_window_is_remappable(mbus, win)) {
                addr = mbus->mbuswins_base + mbus->soc->win_remap_offset(win);
                writel(0, addr + WIN_REMAP_LO_OFF);
                writel(0, addr + WIN_REMAP_HI_OFF);
        }
}

/* Checks whether the given window number is available */

static int mvebu_mbus_window_is_free(struct mvebu_mbus_state *mbus,
                                     const int win)
{
        void __iomem *addr = mbus->mbuswins_base +
                mbus->soc->win_cfg_offset(win);
        u32 ctrl = readl(addr + WIN_CTRL_OFF);

        return !(ctrl & WIN_CTRL_ENABLE);
}

/*
 * Checks whether the given (base, base+size) area doesn't overlap an
 * existing region
 */
static int mvebu_mbus_window_conflicts(struct mvebu_mbus_state *mbus,
                                       phys_addr_t base, size_t size,
                                       u8 target, u8 attr)
{
        u64 end = (u64)base + size;
        int win;

        for (win = 0; win < mbus->soc->num_wins; win++) {
                u64 wbase, wend;
                u32 wsize;
                u8 wtarget, wattr;
                int enabled;

                mvebu_mbus_read_window(mbus, win,
                                       &enabled, &wbase, &wsize,
                                       &wtarget, &wattr, NULL);

                if (!enabled)
                        continue;

                wend = wbase + wsize;

                /*
                 * Check if the current window overlaps with the
                 * proposed physical range
                 */
                if ((u64)base < wend && end > wbase)
                        return 0;
        }

        return 1;
}

static int mvebu_mbus_find_window(struct mvebu_mbus_state *mbus,
                                  phys_addr_t base, size_t size)
{
        int win;

        for (win = 0; win < mbus->soc->num_wins; win++) {
                u64 wbase;
                u32 wsize;
                int enabled;

                mvebu_mbus_read_window(mbus, win,
                                       &enabled, &wbase, &wsize,
                                       NULL, NULL, NULL);

                if (!enabled)
                        continue;

                if (base == wbase && size == wsize)
                        return win;
        }

        return -ENODEV;
}

static int mvebu_mbus_setup_window(struct mvebu_mbus_state *mbus,
                                   int win, phys_addr_t base, size_t size,
                                   phys_addr_t remap, u8 target,
                                   u8 attr)
{
        void __iomem *addr = mbus->mbuswins_base +
                mbus->soc->win_cfg_offset(win);
        u32 ctrl, remap_addr;

        if (!is_power_of_2(size)) {
                WARN(true, "Invalid MBus window size: 0x%zx\n", size);
                return -EINVAL;
        }

        if ((base & (phys_addr_t)(size - 1)) != 0) {
                WARN(true, "Invalid MBus base/size: %pa len 0x%zx\n", &base,
                     size);
                return -EINVAL;
        }

        ctrl = ((size - 1) & WIN_CTRL_SIZE_MASK) |
                (attr << WIN_CTRL_ATTR_SHIFT)    |
                (target << WIN_CTRL_TGT_SHIFT)   |
                WIN_CTRL_ENABLE;
        if (mbus->hw_io_coherency)
                ctrl |= WIN_CTRL_SYNCBARRIER;

        writel(base & WIN_BASE_LOW, addr + WIN_BASE_OFF);
        writel(ctrl, addr + WIN_CTRL_OFF);

        if (mvebu_mbus_window_is_remappable(mbus, win)) {
                void __iomem *addr_rmp = mbus->mbuswins_base +
                        mbus->soc->win_remap_offset(win);

                if (remap == MVEBU_MBUS_NO_REMAP)
                        remap_addr = base;
                else
                        remap_addr = remap;
                writel(remap_addr & WIN_REMAP_LOW, addr_rmp + WIN_REMAP_LO_OFF);
                writel(0, addr_rmp + WIN_REMAP_HI_OFF);
        }

        return 0;
}

static int mvebu_mbus_alloc_window(struct mvebu_mbus_state *mbus,
                                   phys_addr_t base, size_t size,
                                   phys_addr_t remap, u8 target,
                                   u8 attr)
{
        int win;

        if (remap == MVEBU_MBUS_NO_REMAP) {
                for (win = 0; win < mbus->soc->num_wins; win++) {
                        if (mvebu_mbus_window_is_remappable(mbus, win))
                                continue;

                        if (mvebu_mbus_window_is_free(mbus, win))
                                return mvebu_mbus_setup_window(mbus, win, base,
                                                               size, remap,
                                                               target, attr);
                }
        }

        for (win = 0; win < mbus->soc->num_wins; win++) {
                /* Skip window if need remap but is not supported */
                if ((remap != MVEBU_MBUS_NO_REMAP) &&
                    !mvebu_mbus_window_is_remappable(mbus, win))
                        continue;

                if (mvebu_mbus_window_is_free(mbus, win))
                        return mvebu_mbus_setup_window(mbus, win, base, size,
                                                       remap, target, attr);
        }

        return -ENOMEM;
}

/*
 * Debugfs debugging
 */

/* Common function used for Dove, Kirkwood, Armada 370/XP and Orion 5x */
static int mvebu_sdram_debug_show_orion(struct mvebu_mbus_state *mbus,
                                        struct seq_file *seq, void *v)
{
        int i;

        for (i = 0; i < 4; i++) {
                u32 basereg = readl(mbus->sdramwins_base + DDR_BASE_CS_OFF(i));
                u32 sizereg = readl(mbus->sdramwins_base + DDR_SIZE_CS_OFF(i));
                u64 base;
                u32 size;

                if (!(sizereg & DDR_SIZE_ENABLED)) {
                        seq_printf(seq, "[%d] disabled\n", i);
                        continue;
                }

                base = ((u64)basereg & DDR_BASE_CS_HIGH_MASK) << 32;
                base |= basereg & DDR_BASE_CS_LOW_MASK;
                size = (sizereg | ~DDR_SIZE_MASK);

                seq_printf(seq, "[%d] %016llx - %016llx : cs%d\n",
                           i, (unsigned long long)base,
                           (unsigned long long)base + size + 1,
                           (sizereg & DDR_SIZE_CS_MASK) >> DDR_SIZE_CS_SHIFT);
        }

        return 0;
}

/* Special function for Dove */
static int mvebu_sdram_debug_show_dove(struct mvebu_mbus_state *mbus,
                                       struct seq_file *seq, void *v)
{
        int i;

        for (i = 0; i < 2; i++) {
                u32 map = readl(mbus->sdramwins_base + DOVE_DDR_BASE_CS_OFF(i));
                u64 base;
                u32 size;

                if (!(map & 1)) {
                        seq_printf(seq, "[%d] disabled\n", i);
                        continue;
                }

                base = map & 0xff800000;
                size = 0x100000 << (((map & 0x000f0000) >> 16) - 4);

                seq_printf(seq, "[%d] %016llx - %016llx : cs%d\n",
                           i, (unsigned long long)base,
                           (unsigned long long)base + size, i);
        }

        return 0;
}

static int mvebu_sdram_debug_show(struct seq_file *seq, void *v)
{
        struct mvebu_mbus_state *mbus = &mbus_state;
        return mbus->soc->show_cpu_target(mbus, seq, v);
}

static int mvebu_sdram_debug_open(struct inode *inode, struct file *file)
{
        return single_open(file, mvebu_sdram_debug_show, inode->i_private);
}

static const struct file_operations mvebu_sdram_debug_fops = {
        .open = mvebu_sdram_debug_open,
        .read = seq_read,
        .llseek = seq_lseek,
        .release = single_release,
};

static int mvebu_devs_debug_show(struct seq_file *seq, void *v)
{
        struct mvebu_mbus_state *mbus = &mbus_state;
        int win;

        for (win = 0; win < mbus->soc->num_wins; win++) {
                u64 wbase, wremap;
                u32 wsize;
                u8 wtarget, wattr;
                int enabled;

                mvebu_mbus_read_window(mbus, win,
                                       &enabled, &wbase, &wsize,
                                       &wtarget, &wattr, &wremap);

                if (!enabled) {
                        seq_printf(seq, "[%02d] disabled\n", win);
                        continue;
                }

                seq_printf(seq, "[%02d] %016llx - %016llx : %04x:%04x",
                           win, (unsigned long long)wbase,
                           (unsigned long long)(wbase + wsize), wtarget, wattr);

                if (!is_power_of_2(wsize) ||
                    ((wbase & (u64)(wsize - 1)) != 0))
                        seq_puts(seq, " (Invalid base/size!!)");

                if (mvebu_mbus_window_is_remappable(mbus, win)) {
                        seq_printf(seq, " (remap %016llx)\n",
                                   (unsigned long long)wremap);
                } else
                        seq_printf(seq, "\n");
        }

        return 0;
}

static int mvebu_devs_debug_open(struct inode *inode, struct file *file)
{
        return single_open(file, mvebu_devs_debug_show, inode->i_private);
}

static const struct file_operations mvebu_devs_debug_fops = {
        .open = mvebu_devs_debug_open,
        .read = seq_read,
        .llseek = seq_lseek,
        .release = single_release,
};

/*
 * SoC-specific functions and definitions
 */

static unsigned int generic_mbus_win_cfg_offset(int win)
{
        return win << 4;
}

static unsigned int armada_370_xp_mbus_win_cfg_offset(int win)
{
        /* The register layout is a bit annoying and the below code
         * tries to cope with it.
         * - At offset 0x0, there are the registers for the first 8
         *   windows, with 4 registers of 32 bits per window (ctrl,
         *   base, remap low, remap high)
         * - Then at offset 0x80, there is a hole of 0x10 bytes for
         *   the internal registers base address and internal units
         *   sync barrier register.
         * - Then at offset 0x90, there the registers for 12
         *   windows, with only 2 registers of 32 bits per window
         *   (ctrl, base).
         */
        if (win < 8)
                return win << 4;
        else
                return 0x90 + ((win - 8) << 3);
}

static unsigned int mv78xx0_mbus_win_cfg_offset(int win)
{
        if (win < 8)
                return win << 4;
        else
                return 0x900 + ((win - 8) << 4);
}

static unsigned int generic_mbus_win_remap_2_offset(int win)
{
        if (win < 2)
                return generic_mbus_win_cfg_offset(win);
        else
                return MVEBU_MBUS_NO_REMAP;
}

static unsigned int generic_mbus_win_remap_4_offset(int win)
{
        if (win < 4)
                return generic_mbus_win_cfg_offset(win);
        else
                return MVEBU_MBUS_NO_REMAP;
}

static unsigned int generic_mbus_win_remap_8_offset(int win)
{
        if (win < 8)
                return generic_mbus_win_cfg_offset(win);
        else
                return MVEBU_MBUS_NO_REMAP;
}

static unsigned int armada_xp_mbus_win_remap_offset(int win)
{
        if (win < 8)
                return generic_mbus_win_cfg_offset(win);
        else if (win == 13)
                return 0xF0 - WIN_REMAP_LO_OFF;
        else
                return MVEBU_MBUS_NO_REMAP;
}

/*
 * Use the memblock information to find the MBus bridge hole in the
 * physical address space.
 */
static void __init
mvebu_mbus_find_bridge_hole(uint64_t *start, uint64_t *end)
{
        struct memblock_region *r;
        uint64_t s = 0;

        for_each_memblock(memory, r) {
                /*
                 * This part of the memory is above 4 GB, so we don't
                 * care for the MBus bridge hole.
                 */
                if (r->base >= 0x100000000ULL)
                        continue;

                /*
                 * The MBus bridge hole is at the end of the RAM under
                 * the 4 GB limit.
                 */
                if (r->base + r->size > s)
                        s = r->base + r->size;
        }

        *start = s;
        *end = 0x100000000ULL;
}

/*
 * This function fills in the mvebu_mbus_dram_info_nooverlap data
 * structure, by looking at the mvebu_mbus_dram_info data, and
 * removing the parts of it that overlap with I/O windows.
 */
static void __init
mvebu_mbus_setup_cpu_target_nooverlap(struct mvebu_mbus_state *mbus)
{
        uint64_t mbus_bridge_base, mbus_bridge_end;
        int cs_nooverlap = 0;
        int i;

        mvebu_mbus_find_bridge_hole(&mbus_bridge_base, &mbus_bridge_end);

        for (i = 0; i < mvebu_mbus_dram_info.num_cs; i++) {
                struct mbus_dram_window *w;
                u64 base, size, end;

                w = &mvebu_mbus_dram_info.cs[i];
                base = w->base;
                size = w->size;
                end = base + size;

                /*
                 * The CS is fully enclosed inside the MBus bridge
                 * area, so ignore it.
                 */
                if (base >= mbus_bridge_base && end <= mbus_bridge_end)
                        continue;

                /*
                 * Beginning of CS overlaps with end of MBus, raise CS
                 * base address, and shrink its size.
                 */
                if (base >= mbus_bridge_base && end > mbus_bridge_end) {
                        size -= mbus_bridge_end - base;
                        base = mbus_bridge_end;
                }

                /*
                 * End of CS overlaps with beginning of MBus, shrink
                 * CS size.
                 */
                if (base < mbus_bridge_base && end > mbus_bridge_base)
                        size -= end - mbus_bridge_base;

                w = &mvebu_mbus_dram_info_nooverlap.cs[cs_nooverlap++];
                w->cs_index = i;
                w->mbus_attr = 0xf & ~(1 << i);
                if (mbus->hw_io_coherency)
                        w->mbus_attr |= ATTR_HW_COHERENCY;
                w->base = base;
                w->size = size;
        }

        mvebu_mbus_dram_info_nooverlap.mbus_dram_target_id = TARGET_DDR;
        mvebu_mbus_dram_info_nooverlap.num_cs = cs_nooverlap;
}

static void __init
mvebu_mbus_default_setup_cpu_target(struct mvebu_mbus_state *mbus)
{
        int i;
        int cs;

        mvebu_mbus_dram_info.mbus_dram_target_id = TARGET_DDR;

        for (i = 0, cs = 0; i < 4; i++) {
                u32 base = readl(mbus->sdramwins_base + DDR_BASE_CS_OFF(i));
                u32 size = readl(mbus->sdramwins_base + DDR_SIZE_CS_OFF(i));

                /*
                 * We only take care of entries for which the chip
                 * select is enabled, and that don't have high base
                 * address bits set (devices can only access the first
                 * 32 bits of the memory).
                 */
                if ((size & DDR_SIZE_ENABLED) &&
                    !(base & DDR_BASE_CS_HIGH_MASK)) {
                        struct mbus_dram_window *w;

                        w = &mvebu_mbus_dram_info.cs[cs++];
                        w->cs_index = i;
                        w->mbus_attr = 0xf & ~(1 << i);
                        if (mbus->hw_io_coherency)
                                w->mbus_attr |= ATTR_HW_COHERENCY;
                        w->base = base & DDR_BASE_CS_LOW_MASK;
                        w->size = (u64)(size | ~DDR_SIZE_MASK) + 1;
                }
        }
        mvebu_mbus_dram_info.num_cs = cs;
}

static int
mvebu_mbus_default_save_cpu_target(struct mvebu_mbus_state *mbus,
                                   u32 __iomem *store_addr)
{
        int i;

        for (i = 0; i < 4; i++) {
                u32 base = readl(mbus->sdramwins_base + DDR_BASE_CS_OFF(i));
                u32 size = readl(mbus->sdramwins_base + DDR_SIZE_CS_OFF(i));

                writel(mbus->sdramwins_phys_base + DDR_BASE_CS_OFF(i),
                       store_addr++);
                writel(base, store_addr++);
                writel(mbus->sdramwins_phys_base + DDR_SIZE_CS_OFF(i),
                       store_addr++);
                writel(size, store_addr++);
        }

        /* We've written 16 words to the store address */
        return 16;
}

static void __init
mvebu_mbus_dove_setup_cpu_target(struct mvebu_mbus_state *mbus)
{
        int i;
        int cs;

        mvebu_mbus_dram_info.mbus_dram_target_id = TARGET_DDR;

        for (i = 0, cs = 0; i < 2; i++) {
                u32 map = readl(mbus->sdramwins_base + DOVE_DDR_BASE_CS_OFF(i));

                /*
                 * Chip select enabled?
                 */
                if (map & 1) {
                        struct mbus_dram_window *w;

                        w = &mvebu_mbus_dram_info.cs[cs++];
                        w->cs_index = i;
                        w->mbus_attr = 0; /* CS address decoding done inside */
                                          /* the DDR controller, no need to  */
                                          /* provide attributes */
                        w->base = map & 0xff800000;
                        w->size = 0x100000 << (((map & 0x000f0000) >> 16) - 4);
                }
        }

        mvebu_mbus_dram_info.num_cs = cs;
}

static int
mvebu_mbus_dove_save_cpu_target(struct mvebu_mbus_state *mbus,
                                u32 __iomem *store_addr)
{
        int i;

        for (i = 0; i < 2; i++) {
                u32 map = readl(mbus->sdramwins_base + DOVE_DDR_BASE_CS_OFF(i));

                writel(mbus->sdramwins_phys_base + DOVE_DDR_BASE_CS_OFF(i),
                       store_addr++);
                writel(map, store_addr++);
        }

        /* We've written 4 words to the store address */
        return 4;
}

int mvebu_mbus_save_cpu_target(u32 __iomem *store_addr)
{
        return mbus_state.soc->save_cpu_target(&mbus_state, store_addr);
}

static const struct mvebu_mbus_soc_data armada_370_mbus_data = {
        .num_wins            = 20,
        .has_mbus_bridge     = true,
        .win_cfg_offset      = armada_370_xp_mbus_win_cfg_offset,
        .win_remap_offset    = generic_mbus_win_remap_8_offset,
        .setup_cpu_target    = mvebu_mbus_default_setup_cpu_target,
        .show_cpu_target     = mvebu_sdram_debug_show_orion,
        .save_cpu_target     = mvebu_mbus_default_save_cpu_target,
};

static const struct mvebu_mbus_soc_data armada_xp_mbus_data = {
        .num_wins            = 20,
        .has_mbus_bridge     = true,
        .win_cfg_offset      = armada_370_xp_mbus_win_cfg_offset,
        .win_remap_offset    = armada_xp_mbus_win_remap_offset,
        .setup_cpu_target    = mvebu_mbus_default_setup_cpu_target,
        .show_cpu_target     = mvebu_sdram_debug_show_orion,
        .save_cpu_target     = mvebu_mbus_default_save_cpu_target,
};

static const struct mvebu_mbus_soc_data kirkwood_mbus_data = {
        .num_wins            = 8,
        .win_cfg_offset      = generic_mbus_win_cfg_offset,
        .save_cpu_target     = mvebu_mbus_default_save_cpu_target,
        .win_remap_offset    = generic_mbus_win_remap_4_offset,
        .setup_cpu_target    = mvebu_mbus_default_setup_cpu_target,
        .show_cpu_target     = mvebu_sdram_debug_show_orion,
};

static const struct mvebu_mbus_soc_data dove_mbus_data = {
        .num_wins            = 8,
        .win_cfg_offset      = generic_mbus_win_cfg_offset,
        .save_cpu_target     = mvebu_mbus_dove_save_cpu_target,
        .win_remap_offset    = generic_mbus_win_remap_4_offset,
        .setup_cpu_target    = mvebu_mbus_dove_setup_cpu_target,
        .show_cpu_target     = mvebu_sdram_debug_show_dove,
};

/*
 * Some variants of Orion5x have 4 remappable windows, some other have
 * only two of them.
 */
static const struct mvebu_mbus_soc_data orion5x_4win_mbus_data = {
        .num_wins            = 8,
        .win_cfg_offset      = generic_mbus_win_cfg_offset,
        .save_cpu_target     = mvebu_mbus_default_save_cpu_target,
        .win_remap_offset    = generic_mbus_win_remap_4_offset,
        .setup_cpu_target    = mvebu_mbus_default_setup_cpu_target,
        .show_cpu_target     = mvebu_sdram_debug_show_orion,
};

static const struct mvebu_mbus_soc_data orion5x_2win_mbus_data = {
        .num_wins            = 8,
        .win_cfg_offset      = generic_mbus_win_cfg_offset,
        .save_cpu_target     = mvebu_mbus_default_save_cpu_target,
        .win_remap_offset    = generic_mbus_win_remap_2_offset,
        .setup_cpu_target    = mvebu_mbus_default_setup_cpu_target,
        .show_cpu_target     = mvebu_sdram_debug_show_orion,
};

static const struct mvebu_mbus_soc_data mv78xx0_mbus_data = {
        .num_wins            = 14,
        .win_cfg_offset      = mv78xx0_mbus_win_cfg_offset,
        .save_cpu_target     = mvebu_mbus_default_save_cpu_target,
        .win_remap_offset    = generic_mbus_win_remap_8_offset,
        .setup_cpu_target    = mvebu_mbus_default_setup_cpu_target,
        .show_cpu_target     = mvebu_sdram_debug_show_orion,
};

static const struct of_device_id of_mvebu_mbus_ids[] = {
        { .compatible = "marvell,armada370-mbus",
          .data = &armada_370_mbus_data, },
        { .compatible = "marvell,armada375-mbus",
          .data = &armada_xp_mbus_data, },
        { .compatible = "marvell,armada380-mbus",
          .data = &armada_xp_mbus_data, },
        { .compatible = "marvell,armadaxp-mbus",
          .data = &armada_xp_mbus_data, },
        { .compatible = "marvell,kirkwood-mbus",
          .data = &kirkwood_mbus_data, },
        { .compatible = "marvell,dove-mbus",
          .data = &dove_mbus_data, },
        { .compatible = "marvell,orion5x-88f5281-mbus",
          .data = &orion5x_4win_mbus_data, },
        { .compatible = "marvell,orion5x-88f5182-mbus",
          .data = &orion5x_2win_mbus_data, },
        { .compatible = "marvell,orion5x-88f5181-mbus",
          .data = &orion5x_2win_mbus_data, },
        { .compatible = "marvell,orion5x-88f6183-mbus",
          .data = &orion5x_4win_mbus_data, },
        { .compatible = "marvell,mv78xx0-mbus",
          .data = &mv78xx0_mbus_data, },
        { },
};

/*
 * Public API of the driver
 */
int mvebu_mbus_add_window_remap_by_id(unsigned int target,
                                      unsigned int attribute,
                                      phys_addr_t base, size_t size,
                                      phys_addr_t remap)
{
        struct mvebu_mbus_state *s = &mbus_state;

        if (!mvebu_mbus_window_conflicts(s, base, size, target, attribute)) {
                pr_err("cannot add window '%x:%x', conflicts with another window\n",
                       target, attribute);
                return -EINVAL;
        }

        return mvebu_mbus_alloc_window(s, base, size, remap, target, attribute);
}

int mvebu_mbus_add_window_by_id(unsigned int target, unsigned int attribute,
                                phys_addr_t base, size_t size)
{
        return mvebu_mbus_add_window_remap_by_id(target, attribute, base,
                                                 size, MVEBU_MBUS_NO_REMAP);
}

int mvebu_mbus_del_window(phys_addr_t base, size_t size)
{
        int win;

        win = mvebu_mbus_find_window(&mbus_state, base, size);
        if (win < 0)
                return win;

        mvebu_mbus_disable_window(&mbus_state, win);
        return 0;
}

void mvebu_mbus_get_pcie_mem_aperture(struct resource *res)
{
        if (!res)
                return;
        *res = mbus_state.pcie_mem_aperture;
}

void mvebu_mbus_get_pcie_io_aperture(struct resource *res)
{
        if (!res)
                return;
        *res = mbus_state.pcie_io_aperture;
}

int mvebu_mbus_get_dram_win_info(phys_addr_t phyaddr, u8 *target, u8 *attr)
{
        const struct mbus_dram_target_info *dram;
        int i;

        /* Get dram info */
        dram = mv_mbus_dram_info();
        if (!dram) {
                pr_err("missing DRAM information\n");
                return -ENODEV;
        }

        /* Try to find matching DRAM window for phyaddr */
        for (i = 0; i < dram->num_cs; i++) {
                const struct mbus_dram_window *cs = dram->cs + i;

                if (cs->base <= phyaddr &&
                        phyaddr <= (cs->base + cs->size - 1)) {
                        *target = dram->mbus_dram_target_id;
                        *attr = cs->mbus_attr;
                        return 0;
                }
        }

        pr_err("invalid dram address %pa\n", &phyaddr);
        return -EINVAL;
}
EXPORT_SYMBOL_GPL(mvebu_mbus_get_dram_win_info);

int mvebu_mbus_get_io_win_info(phys_addr_t phyaddr, u32 *size, u8 *target,
                               u8 *attr)
{
        int win;

        for (win = 0; win < mbus_state.soc->num_wins; win++) {
                u64 wbase;
                int enabled;

                mvebu_mbus_read_window(&mbus_state, win, &enabled, &wbase,
                                       size, target, attr, NULL);

                if (!enabled)
                        continue;

                if (wbase <= phyaddr && phyaddr <= wbase + *size)
                        return win;
        }

        return -EINVAL;
}
EXPORT_SYMBOL_GPL(mvebu_mbus_get_io_win_info);

static __init int mvebu_mbus_debugfs_init(void)
{
        struct mvebu_mbus_state *s = &mbus_state;

        /*
         * If no base has been initialized, doesn't make sense to
         * register the debugfs entries. We may be on a multiplatform
         * kernel that isn't running a Marvell EBU SoC.
         */
        if (!s->mbuswins_base)
                return 0;

        s->debugfs_root = debugfs_create_dir("mvebu-mbus", NULL);
        if (s->debugfs_root) {
                s->debugfs_sdram = debugfs_create_file("sdram", S_IRUGO,
                                                       s->debugfs_root, NULL,
                                                       &mvebu_sdram_debug_fops);
                s->debugfs_devs = debugfs_create_file("devices", S_IRUGO,
                                                      s->debugfs_root, NULL,
                                                      &mvebu_devs_debug_fops);
        }

        return 0;
}
fs_initcall(mvebu_mbus_debugfs_init);

static int mvebu_mbus_suspend(void)
{
        struct mvebu_mbus_state *s = &mbus_state;
        int win;

        if (!s->mbusbridge_base)
                return -ENODEV;

        for (win = 0; win < s->soc->num_wins; win++) {
                void __iomem *addr = s->mbuswins_base +
                        s->soc->win_cfg_offset(win);
                void __iomem *addr_rmp;

                s->wins[win].base = readl(addr + WIN_BASE_OFF);
                s->wins[win].ctrl = readl(addr + WIN_CTRL_OFF);

                if (!mvebu_mbus_window_is_remappable(s, win))
                        continue;

                addr_rmp = s->mbuswins_base +
                        s->soc->win_remap_offset(win);

                s->wins[win].remap_lo = readl(addr_rmp + WIN_REMAP_LO_OFF);
                s->wins[win].remap_hi = readl(addr_rmp + WIN_REMAP_HI_OFF);
        }

        s->mbus_bridge_ctrl = readl(s->mbusbridge_base +
                                    MBUS_BRIDGE_CTRL_OFF);
        s->mbus_bridge_base = readl(s->mbusbridge_base +
                                    MBUS_BRIDGE_BASE_OFF);

        return 0;
}

static void mvebu_mbus_resume(void)
{
        struct mvebu_mbus_state *s = &mbus_state;
        int win;

        writel(s->mbus_bridge_ctrl,
               s->mbusbridge_base + MBUS_BRIDGE_CTRL_OFF);
        writel(s->mbus_bridge_base,
               s->mbusbridge_base + MBUS_BRIDGE_BASE_OFF);

        for (win = 0; win < s->soc->num_wins; win++) {
                void __iomem *addr = s->mbuswins_base +
                        s->soc->win_cfg_offset(win);
                void __iomem *addr_rmp;

                writel(s->wins[win].base, addr + WIN_BASE_OFF);
                writel(s->wins[win].ctrl, addr + WIN_CTRL_OFF);

                if (!mvebu_mbus_window_is_remappable(s, win))
                        continue;

                addr_rmp = s->mbuswins_base +
                        s->soc->win_remap_offset(win);

                writel(s->wins[win].remap_lo, addr_rmp + WIN_REMAP_LO_OFF);
                writel(s->wins[win].remap_hi, addr_rmp + WIN_REMAP_HI_OFF);
        }
}

static struct syscore_ops mvebu_mbus_syscore_ops = {
        .suspend        = mvebu_mbus_suspend,
        .resume         = mvebu_mbus_resume,
};

static int __init mvebu_mbus_common_init(struct mvebu_mbus_state *mbus,
                                         phys_addr_t mbuswins_phys_base,
                                         size_t mbuswins_size,
                                         phys_addr_t sdramwins_phys_base,
                                         size_t sdramwins_size,
                                         phys_addr_t mbusbridge_phys_base,
                                         size_t mbusbridge_size,
                                         bool is_coherent)
{
        int win;

        mbus->mbuswins_base = ioremap(mbuswins_phys_base, mbuswins_size);
        if (!mbus->mbuswins_base)
                return -ENOMEM;

        mbus->sdramwins_base = ioremap(sdramwins_phys_base, sdramwins_size);
        if (!mbus->sdramwins_base) {
                iounmap(mbus_state.mbuswins_base);
                return -ENOMEM;
        }

        mbus->sdramwins_phys_base = sdramwins_phys_base;

        if (mbusbridge_phys_base) {
                mbus->mbusbridge_base = ioremap(mbusbridge_phys_base,
                                                mbusbridge_size);
                if (!mbus->mbusbridge_base) {
                        iounmap(mbus->sdramwins_base);
                        iounmap(mbus->mbuswins_base);
                        return -ENOMEM;
                }
        } else
                mbus->mbusbridge_base = NULL;

        for (win = 0; win < mbus->soc->num_wins; win++)
                mvebu_mbus_disable_window(mbus, win);

        mbus->soc->setup_cpu_target(mbus);
        mvebu_mbus_setup_cpu_target_nooverlap(mbus);

        if (is_coherent)
                writel(UNIT_SYNC_BARRIER_ALL,
                       mbus->mbuswins_base + UNIT_SYNC_BARRIER_OFF);

        register_syscore_ops(&mvebu_mbus_syscore_ops);

        return 0;
}

int __init mvebu_mbus_init(const char *soc, phys_addr_t mbuswins_phys_base,
                           size_t mbuswins_size,
                           phys_addr_t sdramwins_phys_base,
                           size_t sdramwins_size)
{
        const struct of_device_id *of_id;

        for (of_id = of_mvebu_mbus_ids; of_id->compatible[0]; of_id++)
                if (!strcmp(of_id->compatible, soc))
                        break;

        if (!of_id->compatible[0]) {
                pr_err("could not find a matching SoC family\n");
                return -ENODEV;
        }

        mbus_state.soc = of_id->data;

        return mvebu_mbus_common_init(&mbus_state,
                        mbuswins_phys_base,
                        mbuswins_size,
                        sdramwins_phys_base,
                        sdramwins_size, 0, 0, false);
}

#ifdef CONFIG_OF
/*
 * The window IDs in the ranges DT property have the following format:
 *  - bits 28 to 31: MBus custom field
 *  - bits 24 to 27: window target ID
 *  - bits 16 to 23: window attribute ID
 *  - bits  0 to 15: unused
 */
#define CUSTOM(id) (((id) & 0xF0000000) >> 24)
#define TARGET(id) (((id) & 0x0F000000) >> 24)
#define ATTR(id)   (((id) & 0x00FF0000) >> 16)

static int __init mbus_dt_setup_win(struct mvebu_mbus_state *mbus,
                                    u32 base, u32 size,
                                    u8 target, u8 attr)
{
        if (!mvebu_mbus_window_conflicts(mbus, base, size, target, attr)) {
                pr_err("cannot add window '%04x:%04x', conflicts with another window\n",
                       target, attr);
                return -EBUSY;
        }

        if (mvebu_mbus_alloc_window(mbus, base, size, MVEBU_MBUS_NO_REMAP,
                                    target, attr)) {
                pr_err("cannot add window '%04x:%04x', too many windows\n",
                       target, attr);
                return -ENOMEM;
        }
        return 0;
}

static int __init
mbus_parse_ranges(struct device_node *node,
                  int *addr_cells, int *c_addr_cells, int *c_size_cells,
                  int *cell_count, const __be32 **ranges_start,
                  const __be32 **ranges_end)
{
        const __be32 *prop;
        int ranges_len, tuple_len;

        /* Allow a node with no 'ranges' property */
        *ranges_start = of_get_property(node, "ranges", &ranges_len);
        if (*ranges_start == NULL) {
                *addr_cells = *c_addr_cells = *c_size_cells = *cell_count = 0;
                *ranges_start = *ranges_end = NULL;
                return 0;
        }
        *ranges_end = *ranges_start + ranges_len / sizeof(__be32);

        *addr_cells = of_n_addr_cells(node);

        prop = of_get_property(node, "#address-cells", NULL);
        *c_addr_cells = be32_to_cpup(prop);

        prop = of_get_property(node, "#size-cells", NULL);
        *c_size_cells = be32_to_cpup(prop);

        *cell_count = *addr_cells + *c_addr_cells + *c_size_cells;
        tuple_len = (*cell_count) * sizeof(__be32);

        if (ranges_len % tuple_len) {
                pr_warn("malformed ranges entry '%s'\n", node->name);
                return -EINVAL;
        }
        return 0;
}

static int __init mbus_dt_setup(struct mvebu_mbus_state *mbus,
                                struct device_node *np)
{
        int addr_cells, c_addr_cells, c_size_cells;
        int i, ret, cell_count;
        const __be32 *r, *ranges_start, *ranges_end;

        ret = mbus_parse_ranges(np, &addr_cells, &c_addr_cells,
                                &c_size_cells, &cell_count,
                                &ranges_start, &ranges_end);
        if (ret < 0)
                return ret;

        for (i = 0, r = ranges_start; r < ranges_end; r += cell_count, i++) {
                u32 windowid, base, size;
                u8 target, attr;

                /*
                 * An entry with a non-zero custom field do not
                 * correspond to a static window, so skip it.
                 */
                windowid = of_read_number(r, 1);
                if (CUSTOM(windowid))
                        continue;

                target = TARGET(windowid);
                attr = ATTR(windowid);

                base = of_read_number(r + c_addr_cells, addr_cells);
                size = of_read_number(r + c_addr_cells + addr_cells,
                                      c_size_cells);
                ret = mbus_dt_setup_win(mbus, base, size, target, attr);
                if (ret < 0)
                        return ret;
        }
        return 0;
}

static void __init mvebu_mbus_get_pcie_resources(struct device_node *np,
                                                 struct resource *mem,
                                                 struct resource *io)
{
        u32 reg[2];
        int ret;

        /*
         * These are optional, so we make sure that resource_size(x) will
         * return 0.
         */
        memset(mem, 0, sizeof(struct resource));
        mem->end = -1;
        memset(io, 0, sizeof(struct resource));
        io->end = -1;

        ret = of_property_read_u32_array(np, "pcie-mem-aperture", reg, ARRAY_SIZE(reg));
        if (!ret) {
                mem->start = reg[0];
                mem->end = mem->start + reg[1] - 1;
                mem->flags = IORESOURCE_MEM;
        }

        ret = of_property_read_u32_array(np, "pcie-io-aperture", reg, ARRAY_SIZE(reg));
        if (!ret) {
                io->start = reg[0];
                io->end = io->start + reg[1] - 1;
                io->flags = IORESOURCE_IO;
        }
}

int __init mvebu_mbus_dt_init(bool is_coherent)
{
        struct resource mbuswins_res, sdramwins_res, mbusbridge_res;
        struct device_node *np, *controller;
        const struct of_device_id *of_id;
        const __be32 *prop;
        int ret;

        np = of_find_matching_node_and_match(NULL, of_mvebu_mbus_ids, &of_id);
        if (!np) {
                pr_err("could not find a matching SoC family\n");
                return -ENODEV;
        }

        mbus_state.soc = of_id->data;

        prop = of_get_property(np, "controller", NULL);
        if (!prop) {
                pr_err("required 'controller' property missing\n");
                return -EINVAL;
        }

        controller = of_find_node_by_phandle(be32_to_cpup(prop));
        if (!controller) {
                pr_err("could not find an 'mbus-controller' node\n");
                return -ENODEV;
        }

        if (of_address_to_resource(controller, 0, &mbuswins_res)) {
                pr_err("cannot get MBUS register address\n");
                return -EINVAL;
        }

        if (of_address_to_resource(controller, 1, &sdramwins_res)) {
                pr_err("cannot get SDRAM register address\n");
                return -EINVAL;
        }

        /*
         * Set the resource to 0 so that it can be left unmapped by
         * mvebu_mbus_common_init() if the DT doesn't carry the
         * necessary information. This is needed to preserve backward
         * compatibility.
         */
        memset(&mbusbridge_res, 0, sizeof(mbusbridge_res));

        if (mbus_state.soc->has_mbus_bridge) {
                if (of_address_to_resource(controller, 2, &mbusbridge_res))
                        pr_warn(FW_WARN "deprecated mbus-mvebu Device Tree, suspend/resume will not work\n");
        }

        mbus_state.hw_io_coherency = is_coherent;

        /* Get optional pcie-{mem,io}-aperture properties */
        mvebu_mbus_get_pcie_resources(np, &mbus_state.pcie_mem_aperture,
                                          &mbus_state.pcie_io_aperture);

        ret = mvebu_mbus_common_init(&mbus_state,
                                     mbuswins_res.start,
                                     resource_size(&mbuswins_res),
                                     sdramwins_res.start,
                                     resource_size(&sdramwins_res),
                                     mbusbridge_res.start,
                                     resource_size(&mbusbridge_res),
                                     is_coherent);
        if (ret)
                return ret;

        /* Setup statically declared windows in the DT */
        return mbus_dt_setup(&mbus_state, np);
}
#endif