// SPDX-License-Identifier: GPL-2.0-or-later

#include <linux/kernel.h>
#include <linux/ioport.h>
#include <linux/bitmap.h>
#include <linux/pci.h>

#include <asm/opal.h>

#include "pci.h"

/* for pci_dev_is_added() */
#include "../../../../drivers/pci/pci.h"

/*
 * The majority of the complexity in supporting SR-IOV on PowerNV comes from
 * the need to put the MMIO space for each VF into a separate PE. Internally
 * the PHB maps MMIO addresses to a specific PE using the "Memory BAR Table".
 * The MBT historically only applied to the 64bit MMIO window of the PHB
 * so it's common to see it referred to as the "M64BT".
 *
 * An MBT entry stores the mapped range as an <base>,<mask> pair. This forces
 * the address range that we want to map to be power-of-two sized and aligned.
 * For conventional PCI devices this isn't really an issue since PCI device BARs
 * have the same requirement.
 *
 * For a SR-IOV BAR things are a little more awkward since size and alignment
 * are not coupled. The alignment is set based on the the per-VF BAR size, but
 * the total BAR area is: number-of-vfs * per-vf-size. The number of VFs
 * isn't necessarily a power of two, so neither is the total size. To fix that
 * we need to finesse (read: hack) the Linux BAR allocator so that it will
 * allocate the SR-IOV BARs in a way that lets us map them using the MBT.
 *
 * The changes to size and alignment that we need to do depend on the "mode"
 * of MBT entry that we use. We only support SR-IOV on PHB3 (IODA2) and above,
 * so as a baseline we can assume that we have the following BAR modes
 * available:
 *
 *   NB: $PE_COUNT is the number of PEs that the PHB supports.
 *
 * a) A segmented BAR that splits the mapped range into $PE_COUNT equally sized
 *    segments. The n'th segment is mapped to the n'th PE.
 * b) An un-segmented BAR that maps the whole address range to a specific PE.
 *
 *
 * We prefer to use mode a) since it only requires one MBT entry per SR-IOV BAR
 * For comparison b) requires one entry per-VF per-BAR, or:
 * (num-vfs * num-sriov-bars) in total. To use a) we need the size of each segment
 * to equal the size of the per-VF BAR area. So:
 *
 *      new_size = per-vf-size * number-of-PEs
 *
 * The alignment for the SR-IOV BAR also needs to be changed from per-vf-size
 * to "new_size", calculated above. Implementing this is a convoluted process
 * which requires several hooks in the PCI core:
 *
 * 1. In pcibios_add_device() we call pnv_pci_ioda_fixup_iov().
 *
 *    At this point the device has been probed and the device's BARs are sized,
 *    but no resource allocations have been done. The SR-IOV BARs are sized
 *    based on the maximum number of VFs supported by the device and we need
 *    to increase that to new_size.
 *
 * 2. Later, when Linux actually assigns resources it tries to make the resource
 *    allocations for each PCI bus as compact as possible. As a part of that it
 *    sorts the BARs on a bus by their required alignment, which is calculated
 *    using pci_resource_alignment().
 *
 *    For IOV resources this goes:
 *    pci_resource_alignment()
 *        pci_sriov_resource_alignment()
 *            pcibios_sriov_resource_alignment()
 *                pnv_pci_iov_resource_alignment()
 *
 *    Our hook overrides the default alignment, equal to the per-vf-size, with
 *    new_size computed above.
 *
 * 3. When userspace enables VFs for a device:
 *
 *    sriov_enable()
 *       pcibios_sriov_enable()
 *           pnv_pcibios_sriov_enable()
 *
 *    This is where we actually allocate PE numbers for each VF and setup the
 *    MBT mapping for each SR-IOV BAR. In steps 1) and 2) we setup an "arena"
 *    where each MBT segment is equal in size to the VF BAR so we can shift
 *    around the actual SR-IOV BAR location within this arena. We need this
 *    ability because the PE space is shared by all devices on the same PHB.
 *    When using mode a) described above segment 0 in maps to PE#0 which might
 *    be already being used by another device on the PHB.
 *
 *    As a result we need allocate a contigious range of PE numbers, then shift
 *    the address programmed into the SR-IOV BAR of the PF so that the address
 *    of VF0 matches up with the segment corresponding to the first allocated
 *    PE number. This is handled in pnv_pci_vf_resource_shift().
 *
 *    Once all that is done we return to the PCI core which then enables VFs,
 *    scans them and creates pci_devs for each. The init process for a VF is
 *    largely the same as a normal device, but the VF is inserted into the IODA
 *    PE that we allocated for it rather than the PE associated with the bus.
 *
 * 4. When userspace disables VFs we unwind the above in
 *    pnv_pcibios_sriov_disable(). Fortunately this is relatively simple since
 *    we don't need to validate anything, just tear down the mappings and
 *    move SR-IOV resource back to its "proper" location.
 *
 * That's how mode a) works. In theory mode b) (single PE mapping) is less work
 * since we can map each individual VF with a separate BAR. However, there's a
 * few limitations:
 *
 * 1) For IODA2 mode b) has a minimum alignment requirement of 32MB. This makes
 *    it only usable for devices with very large per-VF BARs. Such devices are
 *    similar to Big Foot. They definitely exist, but I've never seen one.
 *
 * 2) The number of MBT entries that we have is limited. PHB3 and PHB4 only
 *    16 total and some are needed for. Most SR-IOV capable network cards can support
 *    more than 16 VFs on each port.
 *
 * We use b) when using a) would use more than 1/4 of the entire 64 bit MMIO
 * window of the PHB.
 *
 *
 *
 * PHB4 (IODA3) added a few new features that would be useful for SR-IOV. It
 * allowed the MBT to map 32bit MMIO space in addition to 64bit which allows
 * us to support SR-IOV BARs in the 32bit MMIO window. This is useful since
 * the Linux BAR allocation will place any BAR marked as non-prefetchable into
 * the non-prefetchable bridge window, which is 32bit only. It also added two
 * new modes:
 *
 * c) A segmented BAR similar to a), but each segment can be individually
 *    mapped to any PE. This is matches how the 32bit MMIO window worked on
 *    IODA1&2.
 *
 * d) A segmented BAR with 8, 64, or 128 segments. This works similarly to a),
 *    but with fewer segments and configurable base PE.
 *
 *    i.e. The n'th segment maps to the (n + base)'th PE.
 *
 *    The base PE is also required to be a multiple of the window size.
 *
 * Unfortunately, the OPAL API doesn't currently (as of skiboot v6.6) allow us
 * to exploit any of the IODA3 features.
 */

static void pnv_pci_ioda_fixup_iov_resources(struct pci_dev *pdev)
{
        struct pnv_phb *phb = pci_bus_to_pnvhb(pdev->bus);
        struct resource *res;
        int i;
        resource_size_t vf_bar_sz;
        struct pnv_iov_data *iov;
        int mul;

        iov = kzalloc(sizeof(*iov), GFP_KERNEL);
        if (!iov)
                goto disable_iov;
        pdev->dev.archdata.iov_data = iov;
        mul = phb->ioda.total_pe_num;

        for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
                res = &pdev->resource[i + PCI_IOV_RESOURCES];
                if (!res->flags || res->parent)
                        continue;
                if (!pnv_pci_is_m64_flags(res->flags)) {
                        dev_warn(&pdev->dev, "Don't support SR-IOV with non M64 VF BAR%d: %pR. \n",
                                 i, res);
                        goto disable_iov;
                }

                vf_bar_sz = pci_iov_resource_size(pdev, i + PCI_IOV_RESOURCES);

                /*
                 * Generally, one segmented M64 BAR maps one IOV BAR. However,
                 * if a VF BAR is too large we end up wasting a lot of space.
                 * If each VF needs more than 1/4 of the default m64 segment
                 * then each VF BAR should be mapped in single-PE mode to reduce
                 * the amount of space required. This does however limit the
                 * number of VFs we can support.
                 *
                 * The 1/4 limit is arbitrary and can be tweaked.
                 */
                if (vf_bar_sz > (phb->ioda.m64_segsize >> 2)) {
                        /*
                         * On PHB3, the minimum size alignment of M64 BAR in
                         * single mode is 32MB. If this VF BAR is smaller than
                         * 32MB, but still too large for a segmented window
                         * then we can't map it and need to disable SR-IOV for
                         * this device.
                         */
                        if (vf_bar_sz < SZ_32M) {
                                pci_err(pdev, "VF BAR%d: %pR can't be mapped in single PE mode\n",
                                        i, res);
                                goto disable_iov;
                        }

                        iov->m64_single_mode[i] = true;
                        continue;
                }

                /*
                 * This BAR can be mapped with one segmented window, so adjust
                 * te resource size to accommodate.
                 */
                pci_dbg(pdev, " Fixing VF BAR%d: %pR to\n", i, res);
                res->end = res->start + vf_bar_sz * mul - 1;
                pci_dbg(pdev, "                       %pR\n", res);

                pci_info(pdev, "VF BAR%d: %pR (expanded to %d VFs for PE alignment)",
                         i, res, mul);

                iov->need_shift = true;
        }

        return;

disable_iov:
        /* Save ourselves some MMIO space by disabling the unusable BARs */
        for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
                res = &pdev->resource[i + PCI_IOV_RESOURCES];
                res->flags = 0;
                res->end = res->start - 1;
        }

        pdev->dev.archdata.iov_data = NULL;
        kfree(iov);
}

void pnv_pci_ioda_fixup_iov(struct pci_dev *pdev)
{
        if (WARN_ON(pci_dev_is_added(pdev)))
                return;

        if (pdev->is_virtfn) {
                struct pnv_ioda_pe *pe = pnv_ioda_get_pe(pdev);

                /*
                 * VF PEs are single-device PEs so their pdev pointer needs to
                 * be set. The pdev doesn't exist when the PE is allocated (in
                 * (pcibios_sriov_enable()) so we fix it up here.
                 */
                pe->pdev = pdev;
                WARN_ON(!(pe->flags & PNV_IODA_PE_VF));
        } else if (pdev->is_physfn) {
                /*
                 * For PFs adjust their allocated IOV resources to match what
                 * the PHB can support using it's M64 BAR table.
                 */
                pnv_pci_ioda_fixup_iov_resources(pdev);
        }
}

resource_size_t pnv_pci_iov_resource_alignment(struct pci_dev *pdev,
                                                      int resno)
{
        resource_size_t align = pci_iov_resource_size(pdev, resno);
        struct pnv_phb *phb = pci_bus_to_pnvhb(pdev->bus);
        struct pnv_iov_data *iov = pnv_iov_get(pdev);

        /*
         * iov can be null if we have an SR-IOV device with IOV BAR that can't
         * be placed in the m64 space (i.e. The BAR is 32bit or non-prefetch).
         * In that case we don't allow VFs to be enabled since one of their
         * BARs would not be placed in the correct PE.
         */
        if (!iov)
                return align;

        /*
         * If we're using single mode then we can just use the native VF BAR
         * alignment. We validated that it's possible to use a single PE
         * window above when we did the fixup.
         */
        if (iov->m64_single_mode[resno - PCI_IOV_RESOURCES])
                return align;

        /*
         * On PowerNV platform, IOV BAR is mapped by M64 BAR to enable the
         * SR-IOV. While from hardware perspective, the range mapped by M64
         * BAR should be size aligned.
         *
         * This function returns the total IOV BAR size if M64 BAR is in
         * Shared PE mode or just VF BAR size if not.
         * If the M64 BAR is in Single PE mode, return the VF BAR size or
         * M64 segment size if IOV BAR size is less.
         */
        return phb->ioda.total_pe_num * align;
}

static int pnv_pci_vf_release_m64(struct pci_dev *pdev, u16 num_vfs)
{
        struct pnv_iov_data   *iov;
        struct pnv_phb        *phb;
        int window_id;

        phb = pci_bus_to_pnvhb(pdev->bus);
        iov = pnv_iov_get(pdev);

        for_each_set_bit(window_id, iov->used_m64_bar_mask, MAX_M64_BARS) {
                opal_pci_phb_mmio_enable(phb->opal_id,
                                         OPAL_M64_WINDOW_TYPE,
                                         window_id,
                                         0);

                clear_bit(window_id, &phb->ioda.m64_bar_alloc);
        }

        return 0;
}


/*
 * PHB3 and beyond support segmented windows. The window's address range
 * is subdivided into phb->ioda.total_pe_num segments and there's a 1-1
 * mapping between PEs and segments.
 */
static int64_t pnv_ioda_map_m64_segmented(struct pnv_phb *phb,
                                          int window_id,
                                          resource_size_t start,
                                          resource_size_t size)
{
        int64_t rc;

        rc = opal_pci_set_phb_mem_window(phb->opal_id,
                                         OPAL_M64_WINDOW_TYPE,
                                         window_id,
                                         start,
                                         0, /* unused */
                                         size);
        if (rc)
                goto out;

        rc = opal_pci_phb_mmio_enable(phb->opal_id,
                                      OPAL_M64_WINDOW_TYPE,
                                      window_id,
                                      OPAL_ENABLE_M64_SPLIT);
out:
        if (rc)
                pr_err("Failed to map M64 window #%d: %lld\n", window_id, rc);

        return rc;
}

static int64_t pnv_ioda_map_m64_single(struct pnv_phb *phb,
                                       int pe_num,
                                       int window_id,
                                       resource_size_t start,
                                       resource_size_t size)
{
        int64_t rc;

        /*
         * The API for setting up m64 mmio windows seems to have been designed
         * with P7-IOC in mind. For that chip each M64 BAR (window) had a fixed
         * split of 8 equally sized segments each of which could individually
         * assigned to a PE.
         *
         * The problem with this is that the API doesn't have any way to
         * communicate the number of segments we want on a BAR. This wasn't
         * a problem for p7-ioc since you didn't have a choice, but the
         * single PE windows added in PHB3 don't map cleanly to this API.
         *
         * As a result we've got this slightly awkward process where we
         * call opal_pci_map_pe_mmio_window() to put the single in single
         * PE mode, and set the PE for the window before setting the address
         * bounds. We need to do it this way because the single PE windows
         * for PHB3 have different alignment requirements on PHB3.
         */
        rc = opal_pci_map_pe_mmio_window(phb->opal_id,
                                         pe_num,
                                         OPAL_M64_WINDOW_TYPE,
                                         window_id,
                                         0);
        if (rc)
                goto out;

        /*
         * NB: In single PE mode the window needs to be aligned to 32MB
         */
        rc = opal_pci_set_phb_mem_window(phb->opal_id,
                                         OPAL_M64_WINDOW_TYPE,
                                         window_id,
                                         start,
                                         0, /* ignored by FW, m64 is 1-1 */
                                         size);
        if (rc)
                goto out;

        /*
         * Now actually enable it. We specified the BAR should be in "non-split"
         * mode so FW will validate that the BAR is in single PE mode.
         */
        rc = opal_pci_phb_mmio_enable(phb->opal_id,
                                      OPAL_M64_WINDOW_TYPE,
                                      window_id,
                                      OPAL_ENABLE_M64_NON_SPLIT);
out:
        if (rc)
                pr_err("Error mapping single PE BAR\n");

        return rc;
}

static int pnv_pci_alloc_m64_bar(struct pnv_phb *phb, struct pnv_iov_data *iov)
{
        int win;

        do {
                win = find_next_zero_bit(&phb->ioda.m64_bar_alloc,
                                phb->ioda.m64_bar_idx + 1, 0);

                if (win >= phb->ioda.m64_bar_idx + 1)
                        return -1;
        } while (test_and_set_bit(win, &phb->ioda.m64_bar_alloc));

        set_bit(win, iov->used_m64_bar_mask);

        return win;
}

static int pnv_pci_vf_assign_m64(struct pci_dev *pdev, u16 num_vfs)
{
        struct pnv_iov_data   *iov;
        struct pnv_phb        *phb;
        unsigned int           win;
        struct resource       *res;
        int                    i, j;
        int64_t                rc;
        resource_size_t        size, start;
        int                    base_pe_num;

        phb = pci_bus_to_pnvhb(pdev->bus);
        iov = pnv_iov_get(pdev);

        for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
                res = &pdev->resource[i + PCI_IOV_RESOURCES];
                if (!res->flags || !res->parent)
                        continue;

                /* don't need single mode? map everything in one go! */
                if (!iov->m64_single_mode[i]) {
                        win = pnv_pci_alloc_m64_bar(phb, iov);
                        if (win < 0)
                                goto m64_failed;

                        size = resource_size(res);
                        start = res->start;

                        rc = pnv_ioda_map_m64_segmented(phb, win, start, size);
                        if (rc)
                                goto m64_failed;

                        continue;
                }

                /* otherwise map each VF with single PE BARs */
                size = pci_iov_resource_size(pdev, PCI_IOV_RESOURCES + i);
                base_pe_num = iov->vf_pe_arr[0].pe_number;

                for (j = 0; j < num_vfs; j++) {
                        win = pnv_pci_alloc_m64_bar(phb, iov);
                        if (win < 0)
                                goto m64_failed;

                        start = res->start + size * j;
                        rc = pnv_ioda_map_m64_single(phb, win,
                                                     base_pe_num + j,
                                                     start,
                                                     size);
                        if (rc)
                                goto m64_failed;
                }
        }
        return 0;

m64_failed:
        pnv_pci_vf_release_m64(pdev, num_vfs);
        return -EBUSY;
}

static void pnv_ioda_release_vf_PE(struct pci_dev *pdev)
{
        struct pnv_phb        *phb;
        struct pnv_ioda_pe    *pe, *pe_n;

        phb = pci_bus_to_pnvhb(pdev->bus);

        if (!pdev->is_physfn)
                return;

        /* FIXME: Use pnv_ioda_release_pe()? */
        list_for_each_entry_safe(pe, pe_n, &phb->ioda.pe_list, list) {
                if (pe->parent_dev != pdev)
                        continue;

                pnv_pci_ioda2_release_pe_dma(pe);

                /* Remove from list */
                mutex_lock(&phb->ioda.pe_list_mutex);
                list_del(&pe->list);
                mutex_unlock(&phb->ioda.pe_list_mutex);

                pnv_ioda_deconfigure_pe(phb, pe);

                pnv_ioda_free_pe(pe);
        }
}

static int pnv_pci_vf_resource_shift(struct pci_dev *dev, int offset)
{
        struct resource *res, res2;
        struct pnv_iov_data *iov;
        resource_size_t size;
        u16 num_vfs;
        int i;

        if (!dev->is_physfn)
                return -EINVAL;
        iov = pnv_iov_get(dev);

        /*
         * "offset" is in VFs.  The M64 windows are sized so that when they
         * are segmented, each segment is the same size as the IOV BAR.
         * Each segment is in a separate PE, and the high order bits of the
         * address are the PE number.  Therefore, each VF's BAR is in a
         * separate PE, and changing the IOV BAR start address changes the
         * range of PEs the VFs are in.
         */
        num_vfs = iov->num_vfs;
        for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
                res = &dev->resource[i + PCI_IOV_RESOURCES];
                if (!res->flags || !res->parent)
                        continue;
                if (iov->m64_single_mode[i])
                        continue;

                /*
                 * The actual IOV BAR range is determined by the start address
                 * and the actual size for num_vfs VFs BAR.  This check is to
                 * make sure that after shifting, the range will not overlap
                 * with another device.
                 */
                size = pci_iov_resource_size(dev, i + PCI_IOV_RESOURCES);
                res2.flags = res->flags;
                res2.start = res->start + (size * offset);
                res2.end = res2.start + (size * num_vfs) - 1;

                if (res2.end > res->end) {
                        dev_err(&dev->dev, "VF BAR%d: %pR would extend past %pR (trying to enable %d VFs shifted by %d)\n",
                                i, &res2, res, num_vfs, offset);
                        return -EBUSY;
                }
        }

        /*
         * Since M64 BAR shares segments among all possible 256 PEs,
         * we have to shift the beginning of PF IOV BAR to make it start from
         * the segment which belongs to the PE number assigned to the first VF.
         * This creates a "hole" in the /proc/iomem which could be used for
         * allocating other resources so we reserve this area below and
         * release when IOV is released.
         */
        for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
                res = &dev->resource[i + PCI_IOV_RESOURCES];
                if (!res->flags || !res->parent)
                        continue;
                if (iov->m64_single_mode[i])
                        continue;

                size = pci_iov_resource_size(dev, i + PCI_IOV_RESOURCES);
                res2 = *res;
                res->start += size * offset;

                dev_info(&dev->dev, "VF BAR%d: %pR shifted to %pR (%sabling %d VFs shifted by %d)\n",
                         i, &res2, res, (offset > 0) ? "En" : "Dis",
                         num_vfs, offset);

                if (offset < 0) {
                        devm_release_resource(&dev->dev, &iov->holes[i]);
                        memset(&iov->holes[i], 0, sizeof(iov->holes[i]));
                }

                pci_update_resource(dev, i + PCI_IOV_RESOURCES);

                if (offset > 0) {
                        iov->holes[i].start = res2.start;
                        iov->holes[i].end = res2.start + size * offset - 1;
                        iov->holes[i].flags = IORESOURCE_BUS;
                        iov->holes[i].name = "pnv_iov_reserved";
                        devm_request_resource(&dev->dev, res->parent,
                                        &iov->holes[i]);
                }
        }
        return 0;
}

static void pnv_pci_sriov_disable(struct pci_dev *pdev)
{
        u16                    num_vfs, base_pe;
        struct pnv_iov_data   *iov;

        iov = pnv_iov_get(pdev);
        num_vfs = iov->num_vfs;
        base_pe = iov->vf_pe_arr[0].pe_number;

        if (WARN_ON(!iov))
                return;

        /* Release VF PEs */
        pnv_ioda_release_vf_PE(pdev);

        /* Un-shift the IOV BARs if we need to */
        if (iov->need_shift)
                pnv_pci_vf_resource_shift(pdev, -base_pe);

        /* Release M64 windows */
        pnv_pci_vf_release_m64(pdev, num_vfs);
}

static void pnv_ioda_setup_vf_PE(struct pci_dev *pdev, u16 num_vfs)
{
        struct pnv_phb        *phb;
        struct pnv_ioda_pe    *pe;
        int                    pe_num;
        u16                    vf_index;
        struct pnv_iov_data   *iov;
        struct pci_dn         *pdn;

        if (!pdev->is_physfn)
                return;

        phb = pci_bus_to_pnvhb(pdev->bus);
        pdn = pci_get_pdn(pdev);
        iov = pnv_iov_get(pdev);

        /* Reserve PE for each VF */
        for (vf_index = 0; vf_index < num_vfs; vf_index++) {
                int vf_devfn = pci_iov_virtfn_devfn(pdev, vf_index);
                int vf_bus = pci_iov_virtfn_bus(pdev, vf_index);
                struct pci_dn *vf_pdn;

                pe = &iov->vf_pe_arr[vf_index];
                pe->phb = phb;
                pe->flags = PNV_IODA_PE_VF;
                pe->pbus = NULL;
                pe->parent_dev = pdev;
                pe->mve_number = -1;
                pe->rid = (vf_bus << 8) | vf_devfn;

                pe_num = pe->pe_number;
                pe_info(pe, "VF %04d:%02d:%02d.%d associated with PE#%x\n",
                        pci_domain_nr(pdev->bus), pdev->bus->number,
                        PCI_SLOT(vf_devfn), PCI_FUNC(vf_devfn), pe_num);

                if (pnv_ioda_configure_pe(phb, pe)) {
                        /* XXX What do we do here ? */
                        pnv_ioda_free_pe(pe);
                        pe->pdev = NULL;
                        continue;
                }

                /* Put PE to the list */
                mutex_lock(&phb->ioda.pe_list_mutex);
                list_add_tail(&pe->list, &phb->ioda.pe_list);
                mutex_unlock(&phb->ioda.pe_list_mutex);

                /* associate this pe to it's pdn */
                list_for_each_entry(vf_pdn, &pdn->parent->child_list, list) {
                        if (vf_pdn->busno == vf_bus &&
                            vf_pdn->devfn == vf_devfn) {
                                vf_pdn->pe_number = pe_num;
                                break;
                        }
                }

                pnv_pci_ioda2_setup_dma_pe(phb, pe);
        }
}

static int pnv_pci_sriov_enable(struct pci_dev *pdev, u16 num_vfs)
{
        struct pnv_ioda_pe    *base_pe;
        struct pnv_iov_data   *iov;
        struct pnv_phb        *phb;
        int                    ret;
        u16                    i;

        phb = pci_bus_to_pnvhb(pdev->bus);
        iov = pnv_iov_get(pdev);

        /*
         * There's a calls to IODA2 PE setup code littered throughout. We could
         * probably fix that, but we'd still have problems due to the
         * restriction inherent on IODA1 PHBs.
         *
         * NB: We class IODA3 as IODA2 since they're very similar.
         */
        if (phb->type != PNV_PHB_IODA2) {
                pci_err(pdev, "SR-IOV is not supported on this PHB\n");
                return -ENXIO;
        }

        if (!iov) {
                dev_info(&pdev->dev, "don't support this SRIOV device with non 64bit-prefetchable IOV BAR\n");
                return -ENOSPC;
        }

        /* allocate a contigious block of PEs for our VFs */
        base_pe = pnv_ioda_alloc_pe(phb, num_vfs);
        if (!base_pe) {
                pci_err(pdev, "Unable to allocate PEs for %d VFs\n", num_vfs);
                return -EBUSY;
        }

        iov->vf_pe_arr = base_pe;
        iov->num_vfs = num_vfs;

        /* Assign M64 window accordingly */
        ret = pnv_pci_vf_assign_m64(pdev, num_vfs);
        if (ret) {
                dev_info(&pdev->dev, "Not enough M64 window resources\n");
                goto m64_failed;
        }

        /*
         * When using one M64 BAR to map one IOV BAR, we need to shift
         * the IOV BAR according to the PE# allocated to the VFs.
         * Otherwise, the PE# for the VF will conflict with others.
         */
        if (iov->need_shift) {
                ret = pnv_pci_vf_resource_shift(pdev, base_pe->pe_number);
                if (ret)
                        goto shift_failed;
        }

        /* Setup VF PEs */
        pnv_ioda_setup_vf_PE(pdev, num_vfs);

        return 0;

shift_failed:
        pnv_pci_vf_release_m64(pdev, num_vfs);

m64_failed:
        for (i = 0; i < num_vfs; i++)
                pnv_ioda_free_pe(&iov->vf_pe_arr[i]);

        return ret;
}

int pnv_pcibios_sriov_disable(struct pci_dev *pdev)
{
        pnv_pci_sriov_disable(pdev);

        /* Release PCI data */
        remove_sriov_vf_pdns(pdev);
        return 0;
}

int pnv_pcibios_sriov_enable(struct pci_dev *pdev, u16 num_vfs)
{
        /* Allocate PCI data */
        add_sriov_vf_pdns(pdev);

        return pnv_pci_sriov_enable(pdev, num_vfs);
}