/*
 * 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, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 *
 * Copyright (C) 2013 Freescale Semiconductor, Inc.
 * Author: Varun Sethi <varun.sethi@freescale.com>
 *
 */

#define pr_fmt(fmt)    "fsl-pamu-domain: %s: " fmt, __func__

#include "fsl_pamu_domain.h"

#include <sysdev/fsl_pci.h>

/*
 * Global spinlock that needs to be held while
 * configuring PAMU.
 */
static DEFINE_SPINLOCK(iommu_lock);

static struct kmem_cache *fsl_pamu_domain_cache;
static struct kmem_cache *iommu_devinfo_cache;
static DEFINE_SPINLOCK(device_domain_lock);

struct iommu_device pamu_iommu; /* IOMMU core code handle */

static struct fsl_dma_domain *to_fsl_dma_domain(struct iommu_domain *dom)
{
        return container_of(dom, struct fsl_dma_domain, iommu_domain);
}

static int __init iommu_init_mempool(void)
{
        fsl_pamu_domain_cache = kmem_cache_create("fsl_pamu_domain",
                                                  sizeof(struct fsl_dma_domain),
                                                  0,
                                                  SLAB_HWCACHE_ALIGN,
                                                  NULL);
        if (!fsl_pamu_domain_cache) {
                pr_debug("Couldn't create fsl iommu_domain cache\n");
                return -ENOMEM;
        }

        iommu_devinfo_cache = kmem_cache_create("iommu_devinfo",
                                                sizeof(struct device_domain_info),
                                                0,
                                                SLAB_HWCACHE_ALIGN,
                                                NULL);
        if (!iommu_devinfo_cache) {
                pr_debug("Couldn't create devinfo cache\n");
                kmem_cache_destroy(fsl_pamu_domain_cache);
                return -ENOMEM;
        }

        return 0;
}

static phys_addr_t get_phys_addr(struct fsl_dma_domain *dma_domain, dma_addr_t iova)
{
        u32 win_cnt = dma_domain->win_cnt;
        struct dma_window *win_ptr = &dma_domain->win_arr[0];
        struct iommu_domain_geometry *geom;

        geom = &dma_domain->iommu_domain.geometry;

        if (!win_cnt || !dma_domain->geom_size) {
                pr_debug("Number of windows/geometry not configured for the domain\n");
                return 0;
        }

        if (win_cnt > 1) {
                u64 subwin_size;
                dma_addr_t subwin_iova;
                u32 wnd;

                subwin_size = dma_domain->geom_size >> ilog2(win_cnt);
                subwin_iova = iova & ~(subwin_size - 1);
                wnd = (subwin_iova - geom->aperture_start) >> ilog2(subwin_size);
                win_ptr = &dma_domain->win_arr[wnd];
        }

        if (win_ptr->valid)
                return win_ptr->paddr + (iova & (win_ptr->size - 1));

        return 0;
}

static int map_subwins(int liodn, struct fsl_dma_domain *dma_domain)
{
        struct dma_window *sub_win_ptr = &dma_domain->win_arr[0];
        int i, ret;
        unsigned long rpn, flags;

        for (i = 0; i < dma_domain->win_cnt; i++) {
                if (sub_win_ptr[i].valid) {
                        rpn = sub_win_ptr[i].paddr >> PAMU_PAGE_SHIFT;
                        spin_lock_irqsave(&iommu_lock, flags);
                        ret = pamu_config_spaace(liodn, dma_domain->win_cnt, i,
                                                 sub_win_ptr[i].size,
                                                 ~(u32)0,
                                                 rpn,
                                                 dma_domain->snoop_id,
                                                 dma_domain->stash_id,
                                                 (i > 0) ? 1 : 0,
                                                 sub_win_ptr[i].prot);
                        spin_unlock_irqrestore(&iommu_lock, flags);
                        if (ret) {
                                pr_debug("SPAACE configuration failed for liodn %d\n",
                                         liodn);
                                return ret;
                        }
                }
        }

        return ret;
}

static int map_win(int liodn, struct fsl_dma_domain *dma_domain)
{
        int ret;
        struct dma_window *wnd = &dma_domain->win_arr[0];
        phys_addr_t wnd_addr = dma_domain->iommu_domain.geometry.aperture_start;
        unsigned long flags;

        spin_lock_irqsave(&iommu_lock, flags);
        ret = pamu_config_ppaace(liodn, wnd_addr,
                                 wnd->size,
                                 ~(u32)0,
                                 wnd->paddr >> PAMU_PAGE_SHIFT,
                                 dma_domain->snoop_id, dma_domain->stash_id,
                                 0, wnd->prot);
        spin_unlock_irqrestore(&iommu_lock, flags);
        if (ret)
                pr_debug("PAACE configuration failed for liodn %d\n", liodn);

        return ret;
}

/* Map the DMA window corresponding to the LIODN */
static int map_liodn(int liodn, struct fsl_dma_domain *dma_domain)
{
        if (dma_domain->win_cnt > 1)
                return map_subwins(liodn, dma_domain);
        else
                return map_win(liodn, dma_domain);
}

/* Update window/subwindow mapping for the LIODN */
static int update_liodn(int liodn, struct fsl_dma_domain *dma_domain, u32 wnd_nr)
{
        int ret;
        struct dma_window *wnd = &dma_domain->win_arr[wnd_nr];
        unsigned long flags;

        spin_lock_irqsave(&iommu_lock, flags);
        if (dma_domain->win_cnt > 1) {
                ret = pamu_config_spaace(liodn, dma_domain->win_cnt, wnd_nr,
                                         wnd->size,
                                         ~(u32)0,
                                         wnd->paddr >> PAMU_PAGE_SHIFT,
                                         dma_domain->snoop_id,
                                         dma_domain->stash_id,
                                         (wnd_nr > 0) ? 1 : 0,
                                         wnd->prot);
                if (ret)
                        pr_debug("Subwindow reconfiguration failed for liodn %d\n",
                                 liodn);
        } else {
                phys_addr_t wnd_addr;

                wnd_addr = dma_domain->iommu_domain.geometry.aperture_start;

                ret = pamu_config_ppaace(liodn, wnd_addr,
                                         wnd->size,
                                         ~(u32)0,
                                         wnd->paddr >> PAMU_PAGE_SHIFT,
                                         dma_domain->snoop_id, dma_domain->stash_id,
                                         0, wnd->prot);
                if (ret)
                        pr_debug("Window reconfiguration failed for liodn %d\n",
                                 liodn);
        }

        spin_unlock_irqrestore(&iommu_lock, flags);

        return ret;
}

static int update_liodn_stash(int liodn, struct fsl_dma_domain *dma_domain,
                              u32 val)
{
        int ret = 0, i;
        unsigned long flags;

        spin_lock_irqsave(&iommu_lock, flags);
        if (!dma_domain->win_arr) {
                pr_debug("Windows not configured, stash destination update failed for liodn %d\n",
                         liodn);
                spin_unlock_irqrestore(&iommu_lock, flags);
                return -EINVAL;
        }

        for (i = 0; i < dma_domain->win_cnt; i++) {
                ret = pamu_update_paace_stash(liodn, i, val);
                if (ret) {
                        pr_debug("Failed to update SPAACE %d field for liodn %d\n ",
                                 i, liodn);
                        spin_unlock_irqrestore(&iommu_lock, flags);
                        return ret;
                }
        }

        spin_unlock_irqrestore(&iommu_lock, flags);

        return ret;
}

/* Set the geometry parameters for a LIODN */
static int pamu_set_liodn(int liodn, struct device *dev,
                          struct fsl_dma_domain *dma_domain,
                          struct iommu_domain_geometry *geom_attr,
                          u32 win_cnt)
{
        phys_addr_t window_addr, window_size;
        phys_addr_t subwin_size;
        int ret = 0, i;
        u32 omi_index = ~(u32)0;
        unsigned long flags;

        /*
         * Configure the omi_index at the geometry setup time.
         * This is a static value which depends on the type of
         * device and would not change thereafter.
         */
        get_ome_index(&omi_index, dev);

        window_addr = geom_attr->aperture_start;
        window_size = dma_domain->geom_size;

        spin_lock_irqsave(&iommu_lock, flags);
        ret = pamu_disable_liodn(liodn);
        if (!ret)
                ret = pamu_config_ppaace(liodn, window_addr, window_size, omi_index,
                                         0, dma_domain->snoop_id,
                                         dma_domain->stash_id, win_cnt, 0);
        spin_unlock_irqrestore(&iommu_lock, flags);
        if (ret) {
                pr_debug("PAACE configuration failed for liodn %d, win_cnt =%d\n",
                         liodn, win_cnt);
                return ret;
        }

        if (win_cnt > 1) {
                subwin_size = window_size >> ilog2(win_cnt);
                for (i = 0; i < win_cnt; i++) {
                        spin_lock_irqsave(&iommu_lock, flags);
                        ret = pamu_disable_spaace(liodn, i);
                        if (!ret)
                                ret = pamu_config_spaace(liodn, win_cnt, i,
                                                         subwin_size, omi_index,
                                                         0, dma_domain->snoop_id,
                                                         dma_domain->stash_id,
                                                         0, 0);
                        spin_unlock_irqrestore(&iommu_lock, flags);
                        if (ret) {
                                pr_debug("SPAACE configuration failed for liodn %d\n",
                                         liodn);
                                return ret;
                        }
                }
        }

        return ret;
}

static int check_size(u64 size, dma_addr_t iova)
{
        /*
         * Size must be a power of two and at least be equal
         * to PAMU page size.
         */
        if ((size & (size - 1)) || size < PAMU_PAGE_SIZE) {
                pr_debug("Size too small or not a power of two\n");
                return -EINVAL;
        }

        /* iova must be page size aligned */
        if (iova & (size - 1)) {
                pr_debug("Address is not aligned with window size\n");
                return -EINVAL;
        }

        return 0;
}

static struct fsl_dma_domain *iommu_alloc_dma_domain(void)
{
        struct fsl_dma_domain *domain;

        domain = kmem_cache_zalloc(fsl_pamu_domain_cache, GFP_KERNEL);
        if (!domain)
                return NULL;

        domain->stash_id = ~(u32)0;
        domain->snoop_id = ~(u32)0;
        domain->win_cnt = pamu_get_max_subwin_cnt();
        domain->geom_size = 0;

        INIT_LIST_HEAD(&domain->devices);

        spin_lock_init(&domain->domain_lock);

        return domain;
}

static void remove_device_ref(struct device_domain_info *info, u32 win_cnt)
{
        unsigned long flags;

        list_del(&info->link);
        spin_lock_irqsave(&iommu_lock, flags);
        if (win_cnt > 1)
                pamu_free_subwins(info->liodn);
        pamu_disable_liodn(info->liodn);
        spin_unlock_irqrestore(&iommu_lock, flags);
        spin_lock_irqsave(&device_domain_lock, flags);
        info->dev->archdata.iommu_domain = NULL;
        kmem_cache_free(iommu_devinfo_cache, info);
        spin_unlock_irqrestore(&device_domain_lock, flags);
}

static void detach_device(struct device *dev, struct fsl_dma_domain *dma_domain)
{
        struct device_domain_info *info, *tmp;
        unsigned long flags;

        spin_lock_irqsave(&dma_domain->domain_lock, flags);
        /* Remove the device from the domain device list */
        list_for_each_entry_safe(info, tmp, &dma_domain->devices, link) {
                if (!dev || (info->dev == dev))
                        remove_device_ref(info, dma_domain->win_cnt);
        }
        spin_unlock_irqrestore(&dma_domain->domain_lock, flags);
}

static void attach_device(struct fsl_dma_domain *dma_domain, int liodn, struct device *dev)
{
        struct device_domain_info *info, *old_domain_info;
        unsigned long flags;

        spin_lock_irqsave(&device_domain_lock, flags);
        /*
         * Check here if the device is already attached to domain or not.
         * If the device is already attached to a domain detach it.
         */
        old_domain_info = dev->archdata.iommu_domain;
        if (old_domain_info && old_domain_info->domain != dma_domain) {
                spin_unlock_irqrestore(&device_domain_lock, flags);
                detach_device(dev, old_domain_info->domain);
                spin_lock_irqsave(&device_domain_lock, flags);
        }

        info = kmem_cache_zalloc(iommu_devinfo_cache, GFP_ATOMIC);

        info->dev = dev;
        info->liodn = liodn;
        info->domain = dma_domain;

        list_add(&info->link, &dma_domain->devices);
        /*
         * In case of devices with multiple LIODNs just store
         * the info for the first LIODN as all
         * LIODNs share the same domain
         */
        if (!dev->archdata.iommu_domain)
                dev->archdata.iommu_domain = info;
        spin_unlock_irqrestore(&device_domain_lock, flags);
}

static phys_addr_t fsl_pamu_iova_to_phys(struct iommu_domain *domain,
                                         dma_addr_t iova)
{
        struct fsl_dma_domain *dma_domain = to_fsl_dma_domain(domain);

        if (iova < domain->geometry.aperture_start ||
            iova > domain->geometry.aperture_end)
                return 0;

        return get_phys_addr(dma_domain, iova);
}

static bool fsl_pamu_capable(enum iommu_cap cap)
{
        return cap == IOMMU_CAP_CACHE_COHERENCY;
}

static void fsl_pamu_domain_free(struct iommu_domain *domain)
{
        struct fsl_dma_domain *dma_domain = to_fsl_dma_domain(domain);

        /* remove all the devices from the device list */
        detach_device(NULL, dma_domain);

        dma_domain->enabled = 0;
        dma_domain->mapped = 0;

        kmem_cache_free(fsl_pamu_domain_cache, dma_domain);
}

static struct iommu_domain *fsl_pamu_domain_alloc(unsigned type)
{
        struct fsl_dma_domain *dma_domain;

        if (type != IOMMU_DOMAIN_UNMANAGED)
                return NULL;

        dma_domain = iommu_alloc_dma_domain();
        if (!dma_domain) {
                pr_debug("dma_domain allocation failed\n");
                return NULL;
        }
        /* defaul geometry 64 GB i.e. maximum system address */
        dma_domain->iommu_domain. geometry.aperture_start = 0;
        dma_domain->iommu_domain.geometry.aperture_end = (1ULL << 36) - 1;
        dma_domain->iommu_domain.geometry.force_aperture = true;

        return &dma_domain->iommu_domain;
}

/* Configure geometry settings for all LIODNs associated with domain */
static int pamu_set_domain_geometry(struct fsl_dma_domain *dma_domain,
                                    struct iommu_domain_geometry *geom_attr,
                                    u32 win_cnt)
{
        struct device_domain_info *info;
        int ret = 0;

        list_for_each_entry(info, &dma_domain->devices, link) {
                ret = pamu_set_liodn(info->liodn, info->dev, dma_domain,
                                     geom_attr, win_cnt);
                if (ret)
                        break;
        }

        return ret;
}

/* Update stash destination for all LIODNs associated with the domain */
static int update_domain_stash(struct fsl_dma_domain *dma_domain, u32 val)
{
        struct device_domain_info *info;
        int ret = 0;

        list_for_each_entry(info, &dma_domain->devices, link) {
                ret = update_liodn_stash(info->liodn, dma_domain, val);
                if (ret)
                        break;
        }

        return ret;
}

/* Update domain mappings for all LIODNs associated with the domain */
static int update_domain_mapping(struct fsl_dma_domain *dma_domain, u32 wnd_nr)
{
        struct device_domain_info *info;
        int ret = 0;

        list_for_each_entry(info, &dma_domain->devices, link) {
                ret = update_liodn(info->liodn, dma_domain, wnd_nr);
                if (ret)
                        break;
        }
        return ret;
}

static int disable_domain_win(struct fsl_dma_domain *dma_domain, u32 wnd_nr)
{
        struct device_domain_info *info;
        int ret = 0;

        list_for_each_entry(info, &dma_domain->devices, link) {
                if (dma_domain->win_cnt == 1 && dma_domain->enabled) {
                        ret = pamu_disable_liodn(info->liodn);
                        if (!ret)
                                dma_domain->enabled = 0;
                } else {
                        ret = pamu_disable_spaace(info->liodn, wnd_nr);
                }
        }

        return ret;
}

static void fsl_pamu_window_disable(struct iommu_domain *domain, u32 wnd_nr)
{
        struct fsl_dma_domain *dma_domain = to_fsl_dma_domain(domain);
        unsigned long flags;
        int ret;

        spin_lock_irqsave(&dma_domain->domain_lock, flags);
        if (!dma_domain->win_arr) {
                pr_debug("Number of windows not configured\n");
                spin_unlock_irqrestore(&dma_domain->domain_lock, flags);
                return;
        }

        if (wnd_nr >= dma_domain->win_cnt) {
                pr_debug("Invalid window index\n");
                spin_unlock_irqrestore(&dma_domain->domain_lock, flags);
                return;
        }

        if (dma_domain->win_arr[wnd_nr].valid) {
                ret = disable_domain_win(dma_domain, wnd_nr);
                if (!ret) {
                        dma_domain->win_arr[wnd_nr].valid = 0;
                        dma_domain->mapped--;
                }
        }

        spin_unlock_irqrestore(&dma_domain->domain_lock, flags);
}

static int fsl_pamu_window_enable(struct iommu_domain *domain, u32 wnd_nr,
                                  phys_addr_t paddr, u64 size, int prot)
{
        struct fsl_dma_domain *dma_domain = to_fsl_dma_domain(domain);
        struct dma_window *wnd;
        int pamu_prot = 0;
        int ret;
        unsigned long flags;
        u64 win_size;

        if (prot & IOMMU_READ)
                pamu_prot |= PAACE_AP_PERMS_QUERY;
        if (prot & IOMMU_WRITE)
                pamu_prot |= PAACE_AP_PERMS_UPDATE;

        spin_lock_irqsave(&dma_domain->domain_lock, flags);
        if (!dma_domain->win_arr) {
                pr_debug("Number of windows not configured\n");
                spin_unlock_irqrestore(&dma_domain->domain_lock, flags);
                return -ENODEV;
        }

        if (wnd_nr >= dma_domain->win_cnt) {
                pr_debug("Invalid window index\n");
                spin_unlock_irqrestore(&dma_domain->domain_lock, flags);
                return -EINVAL;
        }

        win_size = dma_domain->geom_size >> ilog2(dma_domain->win_cnt);
        if (size > win_size) {
                pr_debug("Invalid window size\n");
                spin_unlock_irqrestore(&dma_domain->domain_lock, flags);
                return -EINVAL;
        }

        if (dma_domain->win_cnt == 1) {
                if (dma_domain->enabled) {
                        pr_debug("Disable the window before updating the mapping\n");
                        spin_unlock_irqrestore(&dma_domain->domain_lock, flags);
                        return -EBUSY;
                }

                ret = check_size(size, domain->geometry.aperture_start);
                if (ret) {
                        pr_debug("Aperture start not aligned to the size\n");
                        spin_unlock_irqrestore(&dma_domain->domain_lock, flags);
                        return -EINVAL;
                }
        }

        wnd = &dma_domain->win_arr[wnd_nr];
        if (!wnd->valid) {
                wnd->paddr = paddr;
                wnd->size = size;
                wnd->prot = pamu_prot;

                ret = update_domain_mapping(dma_domain, wnd_nr);
                if (!ret) {
                        wnd->valid = 1;
                        dma_domain->mapped++;
                }
        } else {
                pr_debug("Disable the window before updating the mapping\n");
                ret = -EBUSY;
        }

        spin_unlock_irqrestore(&dma_domain->domain_lock, flags);

        return ret;
}

/*
 * Attach the LIODN to the DMA domain and configure the geometry
 * and window mappings.
 */
static int handle_attach_device(struct fsl_dma_domain *dma_domain,
                                struct device *dev, const u32 *liodn,
                                int num)
{
        unsigned long flags;
        struct iommu_domain *domain = &dma_domain->iommu_domain;
        int ret = 0;
        int i;

        spin_lock_irqsave(&dma_domain->domain_lock, flags);
        for (i = 0; i < num; i++) {
                /* Ensure that LIODN value is valid */
                if (liodn[i] >= PAACE_NUMBER_ENTRIES) {
                        pr_debug("Invalid liodn %d, attach device failed for %pOF\n",
                                 liodn[i], dev->of_node);
                        ret = -EINVAL;
                        break;
                }

                attach_device(dma_domain, liodn[i], dev);
                /*
                 * Check if geometry has already been configured
                 * for the domain. If yes, set the geometry for
                 * the LIODN.
                 */
                if (dma_domain->win_arr) {
                        u32 win_cnt = dma_domain->win_cnt > 1 ? dma_domain->win_cnt : 0;

                        ret = pamu_set_liodn(liodn[i], dev, dma_domain,
                                             &domain->geometry, win_cnt);
                        if (ret)
                                break;
                        if (dma_domain->mapped) {
                                /*
                                 * Create window/subwindow mapping for
                                 * the LIODN.
                                 */
                                ret = map_liodn(liodn[i], dma_domain);
                                if (ret)
                                        break;
                        }
                }
        }
        spin_unlock_irqrestore(&dma_domain->domain_lock, flags);

        return ret;
}

static int fsl_pamu_attach_device(struct iommu_domain *domain,
                                  struct device *dev)
{
        struct fsl_dma_domain *dma_domain = to_fsl_dma_domain(domain);
        const u32 *liodn;
        u32 liodn_cnt;
        int len, ret = 0;
        struct pci_dev *pdev = NULL;
        struct pci_controller *pci_ctl;

        /*
         * Use LIODN of the PCI controller while attaching a
         * PCI device.
         */
        if (dev_is_pci(dev)) {
                pdev = to_pci_dev(dev);
                pci_ctl = pci_bus_to_host(pdev->bus);
                /*
                 * make dev point to pci controller device
                 * so we can get the LIODN programmed by
                 * u-boot.
                 */
                dev = pci_ctl->parent;
        }

        liodn = of_get_property(dev->of_node, "fsl,liodn", &len);
        if (liodn) {
                liodn_cnt = len / sizeof(u32);
                ret = handle_attach_device(dma_domain, dev, liodn, liodn_cnt);
        } else {
                pr_debug("missing fsl,liodn property at %pOF\n", dev->of_node);
                ret = -EINVAL;
        }

        return ret;
}

static void fsl_pamu_detach_device(struct iommu_domain *domain,
                                   struct device *dev)
{
        struct fsl_dma_domain *dma_domain = to_fsl_dma_domain(domain);
        const u32 *prop;
        int len;
        struct pci_dev *pdev = NULL;
        struct pci_controller *pci_ctl;

        /*
         * Use LIODN of the PCI controller while detaching a
         * PCI device.
         */
        if (dev_is_pci(dev)) {
                pdev = to_pci_dev(dev);
                pci_ctl = pci_bus_to_host(pdev->bus);
                /*
                 * make dev point to pci controller device
                 * so we can get the LIODN programmed by
                 * u-boot.
                 */
                dev = pci_ctl->parent;
        }

        prop = of_get_property(dev->of_node, "fsl,liodn", &len);
        if (prop)
                detach_device(dev, dma_domain);
        else
                pr_debug("missing fsl,liodn property at %pOF\n", dev->of_node);
}

static  int configure_domain_geometry(struct iommu_domain *domain, void *data)
{
        struct iommu_domain_geometry *geom_attr = data;
        struct fsl_dma_domain *dma_domain = to_fsl_dma_domain(domain);
        dma_addr_t geom_size;
        unsigned long flags;

        geom_size = geom_attr->aperture_end - geom_attr->aperture_start + 1;
        /*
         * Sanity check the geometry size. Also, we do not support
         * DMA outside of the geometry.
         */
        if (check_size(geom_size, geom_attr->aperture_start) ||
            !geom_attr->force_aperture) {
                pr_debug("Invalid PAMU geometry attributes\n");
                return -EINVAL;
        }

        spin_lock_irqsave(&dma_domain->domain_lock, flags);
        if (dma_domain->enabled) {
                pr_debug("Can't set geometry attributes as domain is active\n");
                spin_unlock_irqrestore(&dma_domain->domain_lock, flags);
                return  -EBUSY;
        }

        /* Copy the domain geometry information */
        memcpy(&domain->geometry, geom_attr,
               sizeof(struct iommu_domain_geometry));
        dma_domain->geom_size = geom_size;

        spin_unlock_irqrestore(&dma_domain->domain_lock, flags);

        return 0;
}

/* Set the domain stash attribute */
static int configure_domain_stash(struct fsl_dma_domain *dma_domain, void *data)
{
        struct pamu_stash_attribute *stash_attr = data;
        unsigned long flags;
        int ret;

        spin_lock_irqsave(&dma_domain->domain_lock, flags);

        memcpy(&dma_domain->dma_stash, stash_attr,
               sizeof(struct pamu_stash_attribute));

        dma_domain->stash_id = get_stash_id(stash_attr->cache,
                                            stash_attr->cpu);
        if (dma_domain->stash_id == ~(u32)0) {
                pr_debug("Invalid stash attributes\n");
                spin_unlock_irqrestore(&dma_domain->domain_lock, flags);
                return -EINVAL;
        }

        ret = update_domain_stash(dma_domain, dma_domain->stash_id);

        spin_unlock_irqrestore(&dma_domain->domain_lock, flags);

        return ret;
}

/* Configure domain dma state i.e. enable/disable DMA */
static int configure_domain_dma_state(struct fsl_dma_domain *dma_domain, bool enable)
{
        struct device_domain_info *info;
        unsigned long flags;
        int ret;

        spin_lock_irqsave(&dma_domain->domain_lock, flags);

        if (enable && !dma_domain->mapped) {
                pr_debug("Can't enable DMA domain without valid mapping\n");
                spin_unlock_irqrestore(&dma_domain->domain_lock, flags);
                return -ENODEV;
        }

        dma_domain->enabled = enable;
        list_for_each_entry(info, &dma_domain->devices, link) {
                ret = (enable) ? pamu_enable_liodn(info->liodn) :
                        pamu_disable_liodn(info->liodn);
                if (ret)
                        pr_debug("Unable to set dma state for liodn %d",
                                 info->liodn);
        }
        spin_unlock_irqrestore(&dma_domain->domain_lock, flags);

        return 0;
}

static int fsl_pamu_set_domain_attr(struct iommu_domain *domain,
                                    enum iommu_attr attr_type, void *data)
{
        struct fsl_dma_domain *dma_domain = to_fsl_dma_domain(domain);
        int ret = 0;

        switch (attr_type) {
        case DOMAIN_ATTR_GEOMETRY:
                ret = configure_domain_geometry(domain, data);
                break;
        case DOMAIN_ATTR_FSL_PAMU_STASH:
                ret = configure_domain_stash(dma_domain, data);
                break;
        case DOMAIN_ATTR_FSL_PAMU_ENABLE:
                ret = configure_domain_dma_state(dma_domain, *(int *)data);
                break;
        default:
                pr_debug("Unsupported attribute type\n");
                ret = -EINVAL;
                break;
        }

        return ret;
}

static int fsl_pamu_get_domain_attr(struct iommu_domain *domain,
                                    enum iommu_attr attr_type, void *data)
{
        struct fsl_dma_domain *dma_domain = to_fsl_dma_domain(domain);
        int ret = 0;

        switch (attr_type) {
        case DOMAIN_ATTR_FSL_PAMU_STASH:
                memcpy(data, &dma_domain->dma_stash,
                       sizeof(struct pamu_stash_attribute));
                break;
        case DOMAIN_ATTR_FSL_PAMU_ENABLE:
                *(int *)data = dma_domain->enabled;
                break;
        case DOMAIN_ATTR_FSL_PAMUV1:
                *(int *)data = DOMAIN_ATTR_FSL_PAMUV1;
                break;
        default:
                pr_debug("Unsupported attribute type\n");
                ret = -EINVAL;
                break;
        }

        return ret;
}

static struct iommu_group *get_device_iommu_group(struct device *dev)
{
        struct iommu_group *group;

        group = iommu_group_get(dev);
        if (!group)
                group = iommu_group_alloc();

        return group;
}

static  bool check_pci_ctl_endpt_part(struct pci_controller *pci_ctl)
{
        u32 version;

        /* Check the PCI controller version number by readding BRR1 register */
        version = in_be32(pci_ctl->cfg_addr + (PCI_FSL_BRR1 >> 2));
        version &= PCI_FSL_BRR1_VER;
        /* If PCI controller version is >= 0x204 we can partition endpoints */
        return version >= 0x204;
}

/* Get iommu group information from peer devices or devices on the parent bus */
static struct iommu_group *get_shared_pci_device_group(struct pci_dev *pdev)
{
        struct pci_dev *tmp;
        struct iommu_group *group;
        struct pci_bus *bus = pdev->bus;

        /*
         * Traverese the pci bus device list to get
         * the shared iommu group.
         */
        while (bus) {
                list_for_each_entry(tmp, &bus->devices, bus_list) {
                        if (tmp == pdev)
                                continue;
                        group = iommu_group_get(&tmp->dev);
                        if (group)
                                return group;
                }

                bus = bus->parent;
        }

        return NULL;
}

static struct iommu_group *get_pci_device_group(struct pci_dev *pdev)
{
        struct pci_controller *pci_ctl;
        bool pci_endpt_partioning;
        struct iommu_group *group = NULL;

        pci_ctl = pci_bus_to_host(pdev->bus);
        pci_endpt_partioning = check_pci_ctl_endpt_part(pci_ctl);
        /* We can partition PCIe devices so assign device group to the device */
        if (pci_endpt_partioning) {
                group = pci_device_group(&pdev->dev);

                /*
                 * PCIe controller is not a paritionable entity
                 * free the controller device iommu_group.
                 */
                if (pci_ctl->parent->iommu_group)
                        iommu_group_remove_device(pci_ctl->parent);
        } else {
                /*
                 * All devices connected to the controller will share the
                 * PCI controllers device group. If this is the first
                 * device to be probed for the pci controller, copy the
                 * device group information from the PCI controller device
                 * node and remove the PCI controller iommu group.
                 * For subsequent devices, the iommu group information can
                 * be obtained from sibling devices (i.e. from the bus_devices
                 * link list).
                 */
                if (pci_ctl->parent->iommu_group) {
                        group = get_device_iommu_group(pci_ctl->parent);
                        iommu_group_remove_device(pci_ctl->parent);
                } else {
                        group = get_shared_pci_device_group(pdev);
                }
        }

        if (!group)
                group = ERR_PTR(-ENODEV);

        return group;
}

static struct iommu_group *fsl_pamu_device_group(struct device *dev)
{
        struct iommu_group *group = ERR_PTR(-ENODEV);
        int len;

        /*
         * For platform devices we allocate a separate group for
         * each of the devices.
         */
        if (dev_is_pci(dev))
                group = get_pci_device_group(to_pci_dev(dev));
        else if (of_get_property(dev->of_node, "fsl,liodn", &len))
                group = get_device_iommu_group(dev);

        return group;
}

static int fsl_pamu_add_device(struct device *dev)
{
        struct iommu_group *group;

        group = iommu_group_get_for_dev(dev);
        if (IS_ERR(group))
                return PTR_ERR(group);

        iommu_group_put(group);

        iommu_device_link(&pamu_iommu, dev);

        return 0;
}

static void fsl_pamu_remove_device(struct device *dev)
{
        iommu_device_unlink(&pamu_iommu, dev);
        iommu_group_remove_device(dev);
}

static int fsl_pamu_set_windows(struct iommu_domain *domain, u32 w_count)
{
        struct fsl_dma_domain *dma_domain = to_fsl_dma_domain(domain);
        unsigned long flags;

        int ret;

        spin_lock_irqsave(&dma_domain->domain_lock, flags);
        /* Ensure domain is inactive i.e. DMA should be disabled for the domain */
        if (dma_domain->enabled) {
                pr_debug("Can't set geometry attributes as domain is active\n");
                spin_unlock_irqrestore(&dma_domain->domain_lock, flags);
                return  -EBUSY;
        }

        /* Ensure that the geometry has been set for the domain */
        if (!dma_domain->geom_size) {
                pr_debug("Please configure geometry before setting the number of windows\n");
                spin_unlock_irqrestore(&dma_domain->domain_lock, flags);
                return -EINVAL;
        }

        /*
         * Ensure we have valid window count i.e. it should be less than
         * maximum permissible limit and should be a power of two.
         */
        if (w_count > pamu_get_max_subwin_cnt() || !is_power_of_2(w_count)) {
                pr_debug("Invalid window count\n");
                spin_unlock_irqrestore(&dma_domain->domain_lock, flags);
                return -EINVAL;
        }

        ret = pamu_set_domain_geometry(dma_domain, &domain->geometry,
                                       w_count > 1 ? w_count : 0);
        if (!ret) {
                kfree(dma_domain->win_arr);
                dma_domain->win_arr = kcalloc(w_count,
                                              sizeof(*dma_domain->win_arr),
                                              GFP_ATOMIC);
                if (!dma_domain->win_arr) {
                        spin_unlock_irqrestore(&dma_domain->domain_lock, flags);
                        return -ENOMEM;
                }
                dma_domain->win_cnt = w_count;
        }
        spin_unlock_irqrestore(&dma_domain->domain_lock, flags);

        return ret;
}

static u32 fsl_pamu_get_windows(struct iommu_domain *domain)
{
        struct fsl_dma_domain *dma_domain = to_fsl_dma_domain(domain);

        return dma_domain->win_cnt;
}

static const struct iommu_ops fsl_pamu_ops = {
        .capable        = fsl_pamu_capable,
        .domain_alloc   = fsl_pamu_domain_alloc,
        .domain_free    = fsl_pamu_domain_free,
        .attach_dev     = fsl_pamu_attach_device,
        .detach_dev     = fsl_pamu_detach_device,
        .domain_window_enable = fsl_pamu_window_enable,
        .domain_window_disable = fsl_pamu_window_disable,
        .domain_get_windows = fsl_pamu_get_windows,
        .domain_set_windows = fsl_pamu_set_windows,
        .iova_to_phys   = fsl_pamu_iova_to_phys,
        .domain_set_attr = fsl_pamu_set_domain_attr,
        .domain_get_attr = fsl_pamu_get_domain_attr,
        .add_device     = fsl_pamu_add_device,
        .remove_device  = fsl_pamu_remove_device,
        .device_group   = fsl_pamu_device_group,
};

int __init pamu_domain_init(void)
{
        int ret = 0;

        ret = iommu_init_mempool();
        if (ret)
                return ret;

        ret = iommu_device_sysfs_add(&pamu_iommu, NULL, NULL, "iommu0");
        if (ret)
                return ret;

        iommu_device_set_ops(&pamu_iommu, &fsl_pamu_ops);

        ret = iommu_device_register(&pamu_iommu);
        if (ret) {
                iommu_device_sysfs_remove(&pamu_iommu);
                pr_err("Can't register iommu device\n");
                return ret;
        }

        bus_set_iommu(&platform_bus_type, &fsl_pamu_ops);
        bus_set_iommu(&pci_bus_type, &fsl_pamu_ops);

        return ret;
}