// SPDX-License-Identifier: GPL-2.0
/* pci_sun4v.c: SUN4V specific PCI controller support.
 *
 * Copyright (C) 2006, 2007, 2008 David S. Miller (davem@davemloft.net)
 */

#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/pci.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/percpu.h>
#include <linux/irq.h>
#include <linux/msi.h>
#include <linux/export.h>
#include <linux/log2.h>
#include <linux/of_device.h>
#include <linux/dma-map-ops.h>
#include <asm/iommu-common.h>

#include <asm/iommu.h>
#include <asm/irq.h>
#include <asm/hypervisor.h>
#include <asm/prom.h>

#include "pci_impl.h"
#include "iommu_common.h"
#include "kernel.h"

#include "pci_sun4v.h"

#define DRIVER_NAME     "pci_sun4v"
#define PFX             DRIVER_NAME ": "

static unsigned long vpci_major;
static unsigned long vpci_minor;

struct vpci_version {
        unsigned long major;
        unsigned long minor;
};

/* Ordered from largest major to lowest */
static struct vpci_version vpci_versions[] = {
        { .major = 2, .minor = 0 },
        { .major = 1, .minor = 1 },
};

static unsigned long vatu_major = 1;
static unsigned long vatu_minor = 1;

#define PGLIST_NENTS    (PAGE_SIZE / sizeof(u64))

struct iommu_batch {
        struct device   *dev;           /* Device mapping is for.       */
        unsigned long   prot;           /* IOMMU page protections       */
        unsigned long   entry;          /* Index into IOTSB.            */
        u64             *pglist;        /* List of physical pages       */
        unsigned long   npages;         /* Number of pages in list.     */
};

static DEFINE_PER_CPU(struct iommu_batch, iommu_batch);
static int iommu_batch_initialized;

/* Interrupts must be disabled.  */
static inline void iommu_batch_start(struct device *dev, unsigned long prot, unsigned long entry)
{
        struct iommu_batch *p = this_cpu_ptr(&iommu_batch);

        p->dev          = dev;
        p->prot         = prot;
        p->entry        = entry;
        p->npages       = 0;
}

static inline bool iommu_use_atu(struct iommu *iommu, u64 mask)
{
        return iommu->atu && mask > DMA_BIT_MASK(32);
}

/* Interrupts must be disabled.  */
static long iommu_batch_flush(struct iommu_batch *p, u64 mask)
{
        struct pci_pbm_info *pbm = p->dev->archdata.host_controller;
        u64 *pglist = p->pglist;
        u64 index_count;
        unsigned long devhandle = pbm->devhandle;
        unsigned long prot = p->prot;
        unsigned long entry = p->entry;
        unsigned long npages = p->npages;
        unsigned long iotsb_num;
        unsigned long ret;
        long num;

        /* VPCI maj=1, min=[0,1] only supports read and write */
        if (vpci_major < 2)
                prot &= (HV_PCI_MAP_ATTR_READ | HV_PCI_MAP_ATTR_WRITE);

        while (npages != 0) {
                if (!iommu_use_atu(pbm->iommu, mask)) {
                        num = pci_sun4v_iommu_map(devhandle,
                                                  HV_PCI_TSBID(0, entry),
                                                  npages,
                                                  prot,
                                                  __pa(pglist));
                        if (unlikely(num < 0)) {
                                pr_err_ratelimited("%s: IOMMU map of [%08lx:%08llx:%lx:%lx:%lx] failed with status %ld\n",
                                                   __func__,
                                                   devhandle,
                                                   HV_PCI_TSBID(0, entry),
                                                   npages, prot, __pa(pglist),
                                                   num);
                                return -1;
                        }
                } else {
                        index_count = HV_PCI_IOTSB_INDEX_COUNT(npages, entry),
                        iotsb_num = pbm->iommu->atu->iotsb->iotsb_num;
                        ret = pci_sun4v_iotsb_map(devhandle,
                                                  iotsb_num,
                                                  index_count,
                                                  prot,
                                                  __pa(pglist),
                                                  &num);
                        if (unlikely(ret != HV_EOK)) {
                                pr_err_ratelimited("%s: ATU map of [%08lx:%lx:%llx:%lx:%lx] failed with status %ld\n",
                                                   __func__,
                                                   devhandle, iotsb_num,
                                                   index_count, prot,
                                                   __pa(pglist), ret);
                                return -1;
                        }
                }
                entry += num;
                npages -= num;
                pglist += num;
        }

        p->entry = entry;
        p->npages = 0;

        return 0;
}

static inline void iommu_batch_new_entry(unsigned long entry, u64 mask)
{
        struct iommu_batch *p = this_cpu_ptr(&iommu_batch);

        if (p->entry + p->npages == entry)
                return;
        if (p->entry != ~0UL)
                iommu_batch_flush(p, mask);
        p->entry = entry;
}

/* Interrupts must be disabled.  */
static inline long iommu_batch_add(u64 phys_page, u64 mask)
{
        struct iommu_batch *p = this_cpu_ptr(&iommu_batch);

        BUG_ON(p->npages >= PGLIST_NENTS);

        p->pglist[p->npages++] = phys_page;
        if (p->npages == PGLIST_NENTS)
                return iommu_batch_flush(p, mask);

        return 0;
}

/* Interrupts must be disabled.  */
static inline long iommu_batch_end(u64 mask)
{
        struct iommu_batch *p = this_cpu_ptr(&iommu_batch);

        BUG_ON(p->npages >= PGLIST_NENTS);

        return iommu_batch_flush(p, mask);
}

static void *dma_4v_alloc_coherent(struct device *dev, size_t size,
                                   dma_addr_t *dma_addrp, gfp_t gfp,
                                   unsigned long attrs)
{
        u64 mask;
        unsigned long flags, order, first_page, npages, n;
        unsigned long prot = 0;
        struct iommu *iommu;
        struct iommu_map_table *tbl;
        struct page *page;
        void *ret;
        long entry;
        int nid;

        size = IO_PAGE_ALIGN(size);
        order = get_order(size);
        if (unlikely(order >= MAX_ORDER))
                return NULL;

        npages = size >> IO_PAGE_SHIFT;

        if (attrs & DMA_ATTR_WEAK_ORDERING)
                prot = HV_PCI_MAP_ATTR_RELAXED_ORDER;

        nid = dev->archdata.numa_node;
        page = alloc_pages_node(nid, gfp, order);
        if (unlikely(!page))
                return NULL;

        first_page = (unsigned long) page_address(page);
        memset((char *)first_page, 0, PAGE_SIZE << order);

        iommu = dev->archdata.iommu;
        mask = dev->coherent_dma_mask;
        if (!iommu_use_atu(iommu, mask))
                tbl = &iommu->tbl;
        else
                tbl = &iommu->atu->tbl;

        entry = iommu_tbl_range_alloc(dev, tbl, npages, NULL,
                                      (unsigned long)(-1), 0);

        if (unlikely(entry == IOMMU_ERROR_CODE))
                goto range_alloc_fail;

        *dma_addrp = (tbl->table_map_base + (entry << IO_PAGE_SHIFT));
        ret = (void *) first_page;
        first_page = __pa(first_page);

        local_irq_save(flags);

        iommu_batch_start(dev,
                          (HV_PCI_MAP_ATTR_READ | prot |
                           HV_PCI_MAP_ATTR_WRITE),
                          entry);

        for (n = 0; n < npages; n++) {
                long err = iommu_batch_add(first_page + (n * PAGE_SIZE), mask);
                if (unlikely(err < 0L))
                        goto iommu_map_fail;
        }

        if (unlikely(iommu_batch_end(mask) < 0L))
                goto iommu_map_fail;

        local_irq_restore(flags);

        return ret;

iommu_map_fail:
        local_irq_restore(flags);
        iommu_tbl_range_free(tbl, *dma_addrp, npages, IOMMU_ERROR_CODE);

range_alloc_fail:
        free_pages(first_page, order);
        return NULL;
}

unsigned long dma_4v_iotsb_bind(unsigned long devhandle,
                                unsigned long iotsb_num,
                                struct pci_bus *bus_dev)
{
        struct pci_dev *pdev;
        unsigned long err;
        unsigned int bus;
        unsigned int device;
        unsigned int fun;

        list_for_each_entry(pdev, &bus_dev->devices, bus_list) {
                if (pdev->subordinate) {
                        /* No need to bind pci bridge */
                        dma_4v_iotsb_bind(devhandle, iotsb_num,
                                          pdev->subordinate);
                } else {
                        bus = bus_dev->number;
                        device = PCI_SLOT(pdev->devfn);
                        fun = PCI_FUNC(pdev->devfn);
                        err = pci_sun4v_iotsb_bind(devhandle, iotsb_num,
                                                   HV_PCI_DEVICE_BUILD(bus,
                                                                       device,
                                                                       fun));

                        /* If bind fails for one device it is going to fail
                         * for rest of the devices because we are sharing
                         * IOTSB. So in case of failure simply return with
                         * error.
                         */
                        if (err)
                                return err;
                }
        }

        return 0;
}

static void dma_4v_iommu_demap(struct device *dev, unsigned long devhandle,
                               dma_addr_t dvma, unsigned long iotsb_num,
                               unsigned long entry, unsigned long npages)
{
        unsigned long num, flags;
        unsigned long ret;

        local_irq_save(flags);
        do {
                if (dvma <= DMA_BIT_MASK(32)) {
                        num = pci_sun4v_iommu_demap(devhandle,
                                                    HV_PCI_TSBID(0, entry),
                                                    npages);
                } else {
                        ret = pci_sun4v_iotsb_demap(devhandle, iotsb_num,
                                                    entry, npages, &num);
                        if (unlikely(ret != HV_EOK)) {
                                pr_err_ratelimited("pci_iotsb_demap() failed with error: %ld\n",
                                                   ret);
                        }
                }
                entry += num;
                npages -= num;
        } while (npages != 0);
        local_irq_restore(flags);
}

static void dma_4v_free_coherent(struct device *dev, size_t size, void *cpu,
                                 dma_addr_t dvma, unsigned long attrs)
{
        struct pci_pbm_info *pbm;
        struct iommu *iommu;
        struct atu *atu;
        struct iommu_map_table *tbl;
        unsigned long order, npages, entry;
        unsigned long iotsb_num;
        u32 devhandle;

        npages = IO_PAGE_ALIGN(size) >> IO_PAGE_SHIFT;
        iommu = dev->archdata.iommu;
        pbm = dev->archdata.host_controller;
        atu = iommu->atu;
        devhandle = pbm->devhandle;

        if (!iommu_use_atu(iommu, dvma)) {
                tbl = &iommu->tbl;
                iotsb_num = 0; /* we don't care for legacy iommu */
        } else {
                tbl = &atu->tbl;
                iotsb_num = atu->iotsb->iotsb_num;
        }
        entry = ((dvma - tbl->table_map_base) >> IO_PAGE_SHIFT);
        dma_4v_iommu_demap(dev, devhandle, dvma, iotsb_num, entry, npages);
        iommu_tbl_range_free(tbl, dvma, npages, IOMMU_ERROR_CODE);
        order = get_order(size);
        if (order < 10)
                free_pages((unsigned long)cpu, order);
}

static dma_addr_t dma_4v_map_page(struct device *dev, struct page *page,
                                  unsigned long offset, size_t sz,
                                  enum dma_data_direction direction,
                                  unsigned long attrs)
{
        struct iommu *iommu;
        struct atu *atu;
        struct iommu_map_table *tbl;
        u64 mask;
        unsigned long flags, npages, oaddr;
        unsigned long i, base_paddr;
        unsigned long prot;
        dma_addr_t bus_addr, ret;
        long entry;

        iommu = dev->archdata.iommu;
        atu = iommu->atu;

        if (unlikely(direction == DMA_NONE))
                goto bad;

        oaddr = (unsigned long)(page_address(page) + offset);
        npages = IO_PAGE_ALIGN(oaddr + sz) - (oaddr & IO_PAGE_MASK);
        npages >>= IO_PAGE_SHIFT;

        mask = *dev->dma_mask;
        if (!iommu_use_atu(iommu, mask))
                tbl = &iommu->tbl;
        else
                tbl = &atu->tbl;

        entry = iommu_tbl_range_alloc(dev, tbl, npages, NULL,
                                      (unsigned long)(-1), 0);

        if (unlikely(entry == IOMMU_ERROR_CODE))
                goto bad;

        bus_addr = (tbl->table_map_base + (entry << IO_PAGE_SHIFT));
        ret = bus_addr | (oaddr & ~IO_PAGE_MASK);
        base_paddr = __pa(oaddr & IO_PAGE_MASK);
        prot = HV_PCI_MAP_ATTR_READ;
        if (direction != DMA_TO_DEVICE)
                prot |= HV_PCI_MAP_ATTR_WRITE;

        if (attrs & DMA_ATTR_WEAK_ORDERING)
                prot |= HV_PCI_MAP_ATTR_RELAXED_ORDER;

        local_irq_save(flags);

        iommu_batch_start(dev, prot, entry);

        for (i = 0; i < npages; i++, base_paddr += IO_PAGE_SIZE) {
                long err = iommu_batch_add(base_paddr, mask);
                if (unlikely(err < 0L))
                        goto iommu_map_fail;
        }
        if (unlikely(iommu_batch_end(mask) < 0L))
                goto iommu_map_fail;

        local_irq_restore(flags);

        return ret;

bad:
        if (printk_ratelimit())
                WARN_ON(1);
        return DMA_MAPPING_ERROR;

iommu_map_fail:
        local_irq_restore(flags);
        iommu_tbl_range_free(tbl, bus_addr, npages, IOMMU_ERROR_CODE);
        return DMA_MAPPING_ERROR;
}

static void dma_4v_unmap_page(struct device *dev, dma_addr_t bus_addr,
                              size_t sz, enum dma_data_direction direction,
                              unsigned long attrs)
{
        struct pci_pbm_info *pbm;
        struct iommu *iommu;
        struct atu *atu;
        struct iommu_map_table *tbl;
        unsigned long npages;
        unsigned long iotsb_num;
        long entry;
        u32 devhandle;

        if (unlikely(direction == DMA_NONE)) {
                if (printk_ratelimit())
                        WARN_ON(1);
                return;
        }

        iommu = dev->archdata.iommu;
        pbm = dev->archdata.host_controller;
        atu = iommu->atu;
        devhandle = pbm->devhandle;

        npages = IO_PAGE_ALIGN(bus_addr + sz) - (bus_addr & IO_PAGE_MASK);
        npages >>= IO_PAGE_SHIFT;
        bus_addr &= IO_PAGE_MASK;

        if (bus_addr <= DMA_BIT_MASK(32)) {
                iotsb_num = 0; /* we don't care for legacy iommu */
                tbl = &iommu->tbl;
        } else {
                iotsb_num = atu->iotsb->iotsb_num;
                tbl = &atu->tbl;
        }
        entry = (bus_addr - tbl->table_map_base) >> IO_PAGE_SHIFT;
        dma_4v_iommu_demap(dev, devhandle, bus_addr, iotsb_num, entry, npages);
        iommu_tbl_range_free(tbl, bus_addr, npages, IOMMU_ERROR_CODE);
}

static int dma_4v_map_sg(struct device *dev, struct scatterlist *sglist,
                         int nelems, enum dma_data_direction direction,
                         unsigned long attrs)
{
        struct scatterlist *s, *outs, *segstart;
        unsigned long flags, handle, prot;
        dma_addr_t dma_next = 0, dma_addr;
        unsigned int max_seg_size;
        unsigned long seg_boundary_size;
        int outcount, incount, i;
        struct iommu *iommu;
        struct atu *atu;
        struct iommu_map_table *tbl;
        u64 mask;
        unsigned long base_shift;
        long err;

        BUG_ON(direction == DMA_NONE);

        iommu = dev->archdata.iommu;
        if (nelems == 0 || !iommu)
                return 0;
        atu = iommu->atu;

        prot = HV_PCI_MAP_ATTR_READ;
        if (direction != DMA_TO_DEVICE)
                prot |= HV_PCI_MAP_ATTR_WRITE;

        if (attrs & DMA_ATTR_WEAK_ORDERING)
                prot |= HV_PCI_MAP_ATTR_RELAXED_ORDER;

        outs = s = segstart = &sglist[0];
        outcount = 1;
        incount = nelems;
        handle = 0;

        /* Init first segment length for backout at failure */
        outs->dma_length = 0;

        local_irq_save(flags);

        iommu_batch_start(dev, prot, ~0UL);

        max_seg_size = dma_get_max_seg_size(dev);
        seg_boundary_size = dma_get_seg_boundary_nr_pages(dev, IO_PAGE_SHIFT);

        mask = *dev->dma_mask;
        if (!iommu_use_atu(iommu, mask))
                tbl = &iommu->tbl;
        else
                tbl = &atu->tbl;

        base_shift = tbl->table_map_base >> IO_PAGE_SHIFT;

        for_each_sg(sglist, s, nelems, i) {
                unsigned long paddr, npages, entry, out_entry = 0, slen;

                slen = s->length;
                /* Sanity check */
                if (slen == 0) {
                        dma_next = 0;
                        continue;
                }
                /* Allocate iommu entries for that segment */
                paddr = (unsigned long) SG_ENT_PHYS_ADDRESS(s);
                npages = iommu_num_pages(paddr, slen, IO_PAGE_SIZE);
                entry = iommu_tbl_range_alloc(dev, tbl, npages,
                                              &handle, (unsigned long)(-1), 0);

                /* Handle failure */
                if (unlikely(entry == IOMMU_ERROR_CODE)) {
                        pr_err_ratelimited("iommu_alloc failed, iommu %p paddr %lx npages %lx\n",
                                           tbl, paddr, npages);
                        goto iommu_map_failed;
                }

                iommu_batch_new_entry(entry, mask);

                /* Convert entry to a dma_addr_t */
                dma_addr = tbl->table_map_base + (entry << IO_PAGE_SHIFT);
                dma_addr |= (s->offset & ~IO_PAGE_MASK);

                /* Insert into HW table */
                paddr &= IO_PAGE_MASK;
                while (npages--) {
                        err = iommu_batch_add(paddr, mask);
                        if (unlikely(err < 0L))
                                goto iommu_map_failed;
                        paddr += IO_PAGE_SIZE;
                }

                /* If we are in an open segment, try merging */
                if (segstart != s) {
                        /* We cannot merge if:
                         * - allocated dma_addr isn't contiguous to previous allocation
                         */
                        if ((dma_addr != dma_next) ||
                            (outs->dma_length + s->length > max_seg_size) ||
                            (is_span_boundary(out_entry, base_shift,
                                              seg_boundary_size, outs, s))) {
                                /* Can't merge: create a new segment */
                                segstart = s;
                                outcount++;
                                outs = sg_next(outs);
                        } else {
                                outs->dma_length += s->length;
                        }
                }

                if (segstart == s) {
                        /* This is a new segment, fill entries */
                        outs->dma_address = dma_addr;
                        outs->dma_length = slen;
                        out_entry = entry;
                }

                /* Calculate next page pointer for contiguous check */
                dma_next = dma_addr + slen;
        }

        err = iommu_batch_end(mask);

        if (unlikely(err < 0L))
                goto iommu_map_failed;

        local_irq_restore(flags);

        if (outcount < incount) {
                outs = sg_next(outs);
                outs->dma_address = DMA_MAPPING_ERROR;
                outs->dma_length = 0;
        }

        return outcount;

iommu_map_failed:
        for_each_sg(sglist, s, nelems, i) {
                if (s->dma_length != 0) {
                        unsigned long vaddr, npages;

                        vaddr = s->dma_address & IO_PAGE_MASK;
                        npages = iommu_num_pages(s->dma_address, s->dma_length,
                                                 IO_PAGE_SIZE);
                        iommu_tbl_range_free(tbl, vaddr, npages,
                                             IOMMU_ERROR_CODE);
                        /* XXX demap? XXX */
                        s->dma_address = DMA_MAPPING_ERROR;
                        s->dma_length = 0;
                }
                if (s == outs)
                        break;
        }
        local_irq_restore(flags);

        return 0;
}

static void dma_4v_unmap_sg(struct device *dev, struct scatterlist *sglist,
                            int nelems, enum dma_data_direction direction,
                            unsigned long attrs)
{
        struct pci_pbm_info *pbm;
        struct scatterlist *sg;
        struct iommu *iommu;
        struct atu *atu;
        unsigned long flags, entry;
        unsigned long iotsb_num;
        u32 devhandle;

        BUG_ON(direction == DMA_NONE);

        iommu = dev->archdata.iommu;
        pbm = dev->archdata.host_controller;
        atu = iommu->atu;
        devhandle = pbm->devhandle;
        
        local_irq_save(flags);

        sg = sglist;
        while (nelems--) {
                dma_addr_t dma_handle = sg->dma_address;
                unsigned int len = sg->dma_length;
                unsigned long npages;
                struct iommu_map_table *tbl;
                unsigned long shift = IO_PAGE_SHIFT;

                if (!len)
                        break;
                npages = iommu_num_pages(dma_handle, len, IO_PAGE_SIZE);

                if (dma_handle <= DMA_BIT_MASK(32)) {
                        iotsb_num = 0; /* we don't care for legacy iommu */
                        tbl = &iommu->tbl;
                } else {
                        iotsb_num = atu->iotsb->iotsb_num;
                        tbl = &atu->tbl;
                }
                entry = ((dma_handle - tbl->table_map_base) >> shift);
                dma_4v_iommu_demap(dev, devhandle, dma_handle, iotsb_num,
                                   entry, npages);
                iommu_tbl_range_free(tbl, dma_handle, npages,
                                     IOMMU_ERROR_CODE);
                sg = sg_next(sg);
        }

        local_irq_restore(flags);
}

static int dma_4v_supported(struct device *dev, u64 device_mask)
{
        struct iommu *iommu = dev->archdata.iommu;

        if (ali_sound_dma_hack(dev, device_mask))
                return 1;
        if (device_mask < iommu->dma_addr_mask)
                return 0;
        return 1;
}

static const struct dma_map_ops sun4v_dma_ops = {
        .alloc                          = dma_4v_alloc_coherent,
        .free                           = dma_4v_free_coherent,
        .map_page                       = dma_4v_map_page,
        .unmap_page                     = dma_4v_unmap_page,
        .map_sg                         = dma_4v_map_sg,
        .unmap_sg                       = dma_4v_unmap_sg,
        .dma_supported                  = dma_4v_supported,
};

static void pci_sun4v_scan_bus(struct pci_pbm_info *pbm, struct device *parent)
{
        struct property *prop;
        struct device_node *dp;

        dp = pbm->op->dev.of_node;
        prop = of_find_property(dp, "66mhz-capable", NULL);
        pbm->is_66mhz_capable = (prop != NULL);
        pbm->pci_bus = pci_scan_one_pbm(pbm, parent);

        /* XXX register error interrupt handlers XXX */
}

static unsigned long probe_existing_entries(struct pci_pbm_info *pbm,
                                            struct iommu_map_table *iommu)
{
        struct iommu_pool *pool;
        unsigned long i, pool_nr, cnt = 0;
        u32 devhandle;

        devhandle = pbm->devhandle;
        for (pool_nr = 0; pool_nr < iommu->nr_pools; pool_nr++) {
                pool = &(iommu->pools[pool_nr]);
                for (i = pool->start; i <= pool->end; i++) {
                        unsigned long ret, io_attrs, ra;

                        ret = pci_sun4v_iommu_getmap(devhandle,
                                                     HV_PCI_TSBID(0, i),
                                                     &io_attrs, &ra);
                        if (ret == HV_EOK) {
                                if (page_in_phys_avail(ra)) {
                                        pci_sun4v_iommu_demap(devhandle,
                                                              HV_PCI_TSBID(0,
                                                              i), 1);
                                } else {
                                        cnt++;
                                        __set_bit(i, iommu->map);
                                }
                        }
                }
        }
        return cnt;
}

static int pci_sun4v_atu_alloc_iotsb(struct pci_pbm_info *pbm)
{
        struct atu *atu = pbm->iommu->atu;
        struct atu_iotsb *iotsb;
        void *table;
        u64 table_size;
        u64 iotsb_num;
        unsigned long order;
        unsigned long err;

        iotsb = kzalloc(sizeof(*iotsb), GFP_KERNEL);
        if (!iotsb) {
                err = -ENOMEM;
                goto out_err;
        }
        atu->iotsb = iotsb;

        /* calculate size of IOTSB */
        table_size = (atu->size / IO_PAGE_SIZE) * 8;
        order = get_order(table_size);
        table = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
        if (!table) {
                err = -ENOMEM;
                goto table_failed;
        }
        iotsb->table = table;
        iotsb->ra = __pa(table);
        iotsb->dvma_size = atu->size;
        iotsb->dvma_base = atu->base;
        iotsb->table_size = table_size;
        iotsb->page_size = IO_PAGE_SIZE;

        /* configure and register IOTSB with HV */
        err = pci_sun4v_iotsb_conf(pbm->devhandle,
                                   iotsb->ra,
                                   iotsb->table_size,
                                   iotsb->page_size,
                                   iotsb->dvma_base,
                                   &iotsb_num);
        if (err) {
                pr_err(PFX "pci_iotsb_conf failed error: %ld\n", err);
                goto iotsb_conf_failed;
        }
        iotsb->iotsb_num = iotsb_num;

        err = dma_4v_iotsb_bind(pbm->devhandle, iotsb_num, pbm->pci_bus);
        if (err) {
                pr_err(PFX "pci_iotsb_bind failed error: %ld\n", err);
                goto iotsb_conf_failed;
        }

        return 0;

iotsb_conf_failed:
        free_pages((unsigned long)table, order);
table_failed:
        kfree(iotsb);
out_err:
        return err;
}

static int pci_sun4v_atu_init(struct pci_pbm_info *pbm)
{
        struct atu *atu = pbm->iommu->atu;
        unsigned long err;
        const u64 *ranges;
        u64 map_size, num_iotte;
        u64 dma_mask;
        const u32 *page_size;
        int len;

        ranges = of_get_property(pbm->op->dev.of_node, "iommu-address-ranges",
                                 &len);
        if (!ranges) {
                pr_err(PFX "No iommu-address-ranges\n");
                return -EINVAL;
        }

        page_size = of_get_property(pbm->op->dev.of_node, "iommu-pagesizes",
                                    NULL);
        if (!page_size) {
                pr_err(PFX "No iommu-pagesizes\n");
                return -EINVAL;
        }

        /* There are 4 iommu-address-ranges supported. Each range is pair of
         * {base, size}. The ranges[0] and ranges[1] are 32bit address space
         * while ranges[2] and ranges[3] are 64bit space.  We want to use 64bit
         * address ranges to support 64bit addressing. Because 'size' for
         * address ranges[2] and ranges[3] are same we can select either of
         * ranges[2] or ranges[3] for mapping. However due to 'size' is too
         * large for OS to allocate IOTSB we are using fix size 32G
         * (ATU_64_SPACE_SIZE) which is more than enough for all PCIe devices
         * to share.
         */
        atu->ranges = (struct atu_ranges *)ranges;
        atu->base = atu->ranges[3].base;
        atu->size = ATU_64_SPACE_SIZE;

        /* Create IOTSB */
        err = pci_sun4v_atu_alloc_iotsb(pbm);
        if (err) {
                pr_err(PFX "Error creating ATU IOTSB\n");
                return err;
        }

        /* Create ATU iommu map.
         * One bit represents one iotte in IOTSB table.
         */
        dma_mask = (roundup_pow_of_two(atu->size) - 1UL);
        num_iotte = atu->size / IO_PAGE_SIZE;
        map_size = num_iotte / 8;
        atu->tbl.table_map_base = atu->base;
        atu->dma_addr_mask = dma_mask;
        atu->tbl.map = kzalloc(map_size, GFP_KERNEL);
        if (!atu->tbl.map)
                return -ENOMEM;

        iommu_tbl_pool_init(&atu->tbl, num_iotte, IO_PAGE_SHIFT,
                            NULL, false /* no large_pool */,
                            0 /* default npools */,
                            false /* want span boundary checking */);

        return 0;
}

static int pci_sun4v_iommu_init(struct pci_pbm_info *pbm)
{
        static const u32 vdma_default[] = { 0x80000000, 0x80000000 };
        struct iommu *iommu = pbm->iommu;
        unsigned long num_tsb_entries, sz;
        u32 dma_mask, dma_offset;
        const u32 *vdma;

        vdma = of_get_property(pbm->op->dev.of_node, "virtual-dma", NULL);
        if (!vdma)
                vdma = vdma_default;

        if ((vdma[0] | vdma[1]) & ~IO_PAGE_MASK) {
                printk(KERN_ERR PFX "Strange virtual-dma[%08x:%08x].\n",
                       vdma[0], vdma[1]);
                return -EINVAL;
        }

        dma_mask = (roundup_pow_of_two(vdma[1]) - 1UL);
        num_tsb_entries = vdma[1] / IO_PAGE_SIZE;

        dma_offset = vdma[0];

        /* Setup initial software IOMMU state. */
        spin_lock_init(&iommu->lock);
        iommu->ctx_lowest_free = 1;
        iommu->tbl.table_map_base = dma_offset;
        iommu->dma_addr_mask = dma_mask;

        /* Allocate and initialize the free area map.  */
        sz = (num_tsb_entries + 7) / 8;
        sz = (sz + 7UL) & ~7UL;
        iommu->tbl.map = kzalloc(sz, GFP_KERNEL);
        if (!iommu->tbl.map) {
                printk(KERN_ERR PFX "Error, kmalloc(arena.map) failed.\n");
                return -ENOMEM;
        }
        iommu_tbl_pool_init(&iommu->tbl, num_tsb_entries, IO_PAGE_SHIFT,
                            NULL, false /* no large_pool */,
                            0 /* default npools */,
                            false /* want span boundary checking */);
        sz = probe_existing_entries(pbm, &iommu->tbl);
        if (sz)
                printk("%s: Imported %lu TSB entries from OBP\n",
                       pbm->name, sz);

        return 0;
}

#ifdef CONFIG_PCI_MSI
struct pci_sun4v_msiq_entry {
        u64             version_type;
#define MSIQ_VERSION_MASK               0xffffffff00000000UL
#define MSIQ_VERSION_SHIFT              32
#define MSIQ_TYPE_MASK                  0x00000000000000ffUL
#define MSIQ_TYPE_SHIFT                 0
#define MSIQ_TYPE_NONE                  0x00
#define MSIQ_TYPE_MSG                   0x01
#define MSIQ_TYPE_MSI32                 0x02
#define MSIQ_TYPE_MSI64                 0x03
#define MSIQ_TYPE_INTX                  0x08
#define MSIQ_TYPE_NONE2                 0xff

        u64             intx_sysino;
        u64             reserved1;
        u64             stick;
        u64             req_id;  /* bus/device/func */
#define MSIQ_REQID_BUS_MASK             0xff00UL
#define MSIQ_REQID_BUS_SHIFT            8
#define MSIQ_REQID_DEVICE_MASK          0x00f8UL
#define MSIQ_REQID_DEVICE_SHIFT         3
#define MSIQ_REQID_FUNC_MASK            0x0007UL
#define MSIQ_REQID_FUNC_SHIFT           0

        u64             msi_address;

        /* The format of this value is message type dependent.
         * For MSI bits 15:0 are the data from the MSI packet.
         * For MSI-X bits 31:0 are the data from the MSI packet.
         * For MSG, the message code and message routing code where:
         *      bits 39:32 is the bus/device/fn of the msg target-id
         *      bits 18:16 is the message routing code
         *      bits 7:0 is the message code
         * For INTx the low order 2-bits are:
         *      00 - INTA
         *      01 - INTB
         *      10 - INTC
         *      11 - INTD
         */
        u64             msi_data;

        u64             reserved2;
};

static int pci_sun4v_get_head(struct pci_pbm_info *pbm, unsigned long msiqid,
                              unsigned long *head)
{
        unsigned long err, limit;

        err = pci_sun4v_msiq_gethead(pbm->devhandle, msiqid, head);
        if (unlikely(err))
                return -ENXIO;

        limit = pbm->msiq_ent_count * sizeof(struct pci_sun4v_msiq_entry);
        if (unlikely(*head >= limit))
                return -EFBIG;

        return 0;
}

static int pci_sun4v_dequeue_msi(struct pci_pbm_info *pbm,
                                 unsigned long msiqid, unsigned long *head,
                                 unsigned long *msi)
{
        struct pci_sun4v_msiq_entry *ep;
        unsigned long err, type;

        /* Note: void pointer arithmetic, 'head' is a byte offset  */
        ep = (pbm->msi_queues + ((msiqid - pbm->msiq_first) *
                                 (pbm->msiq_ent_count *
                                  sizeof(struct pci_sun4v_msiq_entry))) +
              *head);

        if ((ep->version_type & MSIQ_TYPE_MASK) == 0)
                return 0;

        type = (ep->version_type & MSIQ_TYPE_MASK) >> MSIQ_TYPE_SHIFT;
        if (unlikely(type != MSIQ_TYPE_MSI32 &&
                     type != MSIQ_TYPE_MSI64))
                return -EINVAL;

        *msi = ep->msi_data;

        err = pci_sun4v_msi_setstate(pbm->devhandle,

                                     ep->msi_data /* msi_num */,
                                     HV_MSISTATE_IDLE);
        if (unlikely(err))
                return -ENXIO;

        /* Clear the entry.  */
        ep->version_type &= ~MSIQ_TYPE_MASK;

        (*head) += sizeof(struct pci_sun4v_msiq_entry);
        if (*head >=
            (pbm->msiq_ent_count * sizeof(struct pci_sun4v_msiq_entry)))
                *head = 0;

        return 1;
}

static int pci_sun4v_set_head(struct pci_pbm_info *pbm, unsigned long msiqid,
                              unsigned long head)
{
        unsigned long err;

        err = pci_sun4v_msiq_sethead(pbm->devhandle, msiqid, head);
        if (unlikely(err))
                return -EINVAL;

        return 0;
}

static int pci_sun4v_msi_setup(struct pci_pbm_info *pbm, unsigned long msiqid,
                               unsigned long msi, int is_msi64)
{
        if (pci_sun4v_msi_setmsiq(pbm->devhandle, msi, msiqid,
                                  (is_msi64 ?
                                   HV_MSITYPE_MSI64 : HV_MSITYPE_MSI32)))
                return -ENXIO;
        if (pci_sun4v_msi_setstate(pbm->devhandle, msi, HV_MSISTATE_IDLE))
                return -ENXIO;
        if (pci_sun4v_msi_setvalid(pbm->devhandle, msi, HV_MSIVALID_VALID))
                return -ENXIO;
        return 0;
}

static int pci_sun4v_msi_teardown(struct pci_pbm_info *pbm, unsigned long msi)
{
        unsigned long err, msiqid;

        err = pci_sun4v_msi_getmsiq(pbm->devhandle, msi, &msiqid);
        if (err)
                return -ENXIO;

        pci_sun4v_msi_setvalid(pbm->devhandle, msi, HV_MSIVALID_INVALID);

        return 0;
}

static int pci_sun4v_msiq_alloc(struct pci_pbm_info *pbm)
{
        unsigned long q_size, alloc_size, pages, order;
        int i;

        q_size = pbm->msiq_ent_count * sizeof(struct pci_sun4v_msiq_entry);
        alloc_size = (pbm->msiq_num * q_size);
        order = get_order(alloc_size);
        pages = __get_free_pages(GFP_KERNEL | __GFP_COMP, order);
        if (pages == 0UL) {
                printk(KERN_ERR "MSI: Cannot allocate MSI queues (o=%lu).\n",
                       order);
                return -ENOMEM;
        }
        memset((char *)pages, 0, PAGE_SIZE << order);
        pbm->msi_queues = (void *) pages;

        for (i = 0; i < pbm->msiq_num; i++) {
                unsigned long err, base = __pa(pages + (i * q_size));
                unsigned long ret1, ret2;

                err = pci_sun4v_msiq_conf(pbm->devhandle,
                                          pbm->msiq_first + i,
                                          base, pbm->msiq_ent_count);
                if (err) {
                        printk(KERN_ERR "MSI: msiq register fails (err=%lu)\n",
                               err);
                        goto h_error;
                }

                err = pci_sun4v_msiq_info(pbm->devhandle,
                                          pbm->msiq_first + i,
                                          &ret1, &ret2);
                if (err) {
                        printk(KERN_ERR "MSI: Cannot read msiq (err=%lu)\n",
                               err);
                        goto h_error;
                }
                if (ret1 != base || ret2 != pbm->msiq_ent_count) {
                        printk(KERN_ERR "MSI: Bogus qconf "
                               "expected[%lx:%x] got[%lx:%lx]\n",
                               base, pbm->msiq_ent_count,
                               ret1, ret2);
                        goto h_error;
                }
        }

        return 0;

h_error:
        free_pages(pages, order);
        return -EINVAL;
}

static void pci_sun4v_msiq_free(struct pci_pbm_info *pbm)
{
        unsigned long q_size, alloc_size, pages, order;
        int i;

        for (i = 0; i < pbm->msiq_num; i++) {
                unsigned long msiqid = pbm->msiq_first + i;

                (void) pci_sun4v_msiq_conf(pbm->devhandle, msiqid, 0UL, 0);
        }

        q_size = pbm->msiq_ent_count * sizeof(struct pci_sun4v_msiq_entry);
        alloc_size = (pbm->msiq_num * q_size);
        order = get_order(alloc_size);

        pages = (unsigned long) pbm->msi_queues;

        free_pages(pages, order);

        pbm->msi_queues = NULL;
}

static int pci_sun4v_msiq_build_irq(struct pci_pbm_info *pbm,
                                    unsigned long msiqid,
                                    unsigned long devino)
{
        unsigned int irq = sun4v_build_irq(pbm->devhandle, devino);

        if (!irq)
                return -ENOMEM;

        if (pci_sun4v_msiq_setvalid(pbm->devhandle, msiqid, HV_MSIQ_VALID))
                return -EINVAL;
        if (pci_sun4v_msiq_setstate(pbm->devhandle, msiqid, HV_MSIQSTATE_IDLE))
                return -EINVAL;

        return irq;
}

static const struct sparc64_msiq_ops pci_sun4v_msiq_ops = {
        .get_head       =       pci_sun4v_get_head,
        .dequeue_msi    =       pci_sun4v_dequeue_msi,
        .set_head       =       pci_sun4v_set_head,
        .msi_setup      =       pci_sun4v_msi_setup,
        .msi_teardown   =       pci_sun4v_msi_teardown,
        .msiq_alloc     =       pci_sun4v_msiq_alloc,
        .msiq_free      =       pci_sun4v_msiq_free,
        .msiq_build_irq =       pci_sun4v_msiq_build_irq,
};

static void pci_sun4v_msi_init(struct pci_pbm_info *pbm)
{
        sparc64_pbm_msi_init(pbm, &pci_sun4v_msiq_ops);
}
#else /* CONFIG_PCI_MSI */
static void pci_sun4v_msi_init(struct pci_pbm_info *pbm)
{
}
#endif /* !(CONFIG_PCI_MSI) */

static int pci_sun4v_pbm_init(struct pci_pbm_info *pbm,
                              struct platform_device *op, u32 devhandle)
{
        struct device_node *dp = op->dev.of_node;
        int err;

        pbm->numa_node = of_node_to_nid(dp);

        pbm->pci_ops = &sun4v_pci_ops;
        pbm->config_space_reg_bits = 12;

        pbm->index = pci_num_pbms++;

        pbm->op = op;

        pbm->devhandle = devhandle;

        pbm->name = dp->full_name;

        printk("%s: SUN4V PCI Bus Module\n", pbm->name);
        printk("%s: On NUMA node %d\n", pbm->name, pbm->numa_node);

        pci_determine_mem_io_space(pbm);

        pci_get_pbm_props(pbm);

        err = pci_sun4v_iommu_init(pbm);
        if (err)
                return err;

        pci_sun4v_msi_init(pbm);

        pci_sun4v_scan_bus(pbm, &op->dev);

        /* if atu_init fails its not complete failure.
         * we can still continue using legacy iommu.
         */
        if (pbm->iommu->atu) {
                err = pci_sun4v_atu_init(pbm);
                if (err) {
                        kfree(pbm->iommu->atu);
                        pbm->iommu->atu = NULL;
                        pr_err(PFX "ATU init failed, err=%d\n", err);
                }
        }

        pbm->next = pci_pbm_root;
        pci_pbm_root = pbm;

        return 0;
}

static int pci_sun4v_probe(struct platform_device *op)
{
        const struct linux_prom64_registers *regs;
        static int hvapi_negotiated = 0;
        struct pci_pbm_info *pbm;
        struct device_node *dp;
        struct iommu *iommu;
        struct atu *atu;
        u32 devhandle;
        int i, err = -ENODEV;
        static bool hv_atu = true;

        dp = op->dev.of_node;

        if (!hvapi_negotiated++) {
                for (i = 0; i < ARRAY_SIZE(vpci_versions); i++) {
                        vpci_major = vpci_versions[i].major;
                        vpci_minor = vpci_versions[i].minor;

                        err = sun4v_hvapi_register(HV_GRP_PCI, vpci_major,
                                                   &vpci_minor);
                        if (!err)
                                break;
                }

                if (err) {
                        pr_err(PFX "Could not register hvapi, err=%d\n", err);
                        return err;
                }
                pr_info(PFX "Registered hvapi major[%lu] minor[%lu]\n",
                        vpci_major, vpci_minor);

                err = sun4v_hvapi_register(HV_GRP_ATU, vatu_major, &vatu_minor);
                if (err) {
                        /* don't return an error if we fail to register the
                         * ATU group, but ATU hcalls won't be available.
                         */
                        hv_atu = false;
                } else {
                        pr_info(PFX "Registered hvapi ATU major[%lu] minor[%lu]\n",
                                vatu_major, vatu_minor);
                }

                dma_ops = &sun4v_dma_ops;
        }

        regs = of_get_property(dp, "reg", NULL);
        err = -ENODEV;
        if (!regs) {
                printk(KERN_ERR PFX "Could not find config registers\n");
                goto out_err;
        }
        devhandle = (regs->phys_addr >> 32UL) & 0x0fffffff;

        err = -ENOMEM;
        if (!iommu_batch_initialized) {
                for_each_possible_cpu(i) {
                        unsigned long page = get_zeroed_page(GFP_KERNEL);

                        if (!page)
                                goto out_err;

                        per_cpu(iommu_batch, i).pglist = (u64 *) page;
                }
                iommu_batch_initialized = 1;
        }

        pbm = kzalloc(sizeof(*pbm), GFP_KERNEL);
        if (!pbm) {
                printk(KERN_ERR PFX "Could not allocate pci_pbm_info\n");
                goto out_err;
        }

        iommu = kzalloc(sizeof(struct iommu), GFP_KERNEL);
        if (!iommu) {
                printk(KERN_ERR PFX "Could not allocate pbm iommu\n");
                goto out_free_controller;
        }

        pbm->iommu = iommu;
        iommu->atu = NULL;
        if (hv_atu) {
                atu = kzalloc(sizeof(*atu), GFP_KERNEL);
                if (!atu)
                        pr_err(PFX "Could not allocate atu\n");
                else
                        iommu->atu = atu;
        }

        err = pci_sun4v_pbm_init(pbm, op, devhandle);
        if (err)
                goto out_free_iommu;

        dev_set_drvdata(&op->dev, pbm);

        return 0;

out_free_iommu:
        kfree(iommu->atu);
        kfree(pbm->iommu);

out_free_controller:
        kfree(pbm);

out_err:
        return err;
}

static const struct of_device_id pci_sun4v_match[] = {
        {
                .name = "pci",
                .compatible = "SUNW,sun4v-pci",
        },
        {},
};

static struct platform_driver pci_sun4v_driver = {
        .driver = {
                .name = DRIVER_NAME,
                .of_match_table = pci_sun4v_match,
        },
        .probe          = pci_sun4v_probe,
};

static int __init pci_sun4v_init(void)
{
        return platform_driver_register(&pci_sun4v_driver);
}

subsys_initcall(pci_sun4v_init);