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    Subject[PATCH 3.16 074/127] powerpc/iommu/ddw: Fix endianness
    Date
    3.16-stable review patch.  If anyone has any objections, please let me know.

    ------------------

    From: Alexey Kardashevskiy <aik@ozlabs.ru>

    commit 9410e0185e65394c0c6d046033904b53b97a9423 upstream.

    rtas_call() accepts and returns values in CPU endianness.
    The ddw_query_response and ddw_create_response structs members are
    defined and treated as BE but as they are passed to rtas_call() as
    (u32 *) and they get byteswapped automatically, the data is CPU-endian.
    This fixes ddw_query_response and ddw_create_response definitions and use.

    of_read_number() is designed to work with device tree cells - it assumes
    the input is big-endian and returns data in CPU-endian. However due
    to the ddw_create_response struct fix, create.addr_hi/lo are already
    CPU-endian so do not byteswap them.

    ddw_avail is a pointer to the "ibm,ddw-applicable" property which contains
    3 cells which are big-endian as it is a device tree. rtas_call() accepts
    a RTAS token in CPU-endian. This makes use of of_property_read_u32_array
    to byte swap and avoid the need for a number of be32_to_cpu calls.

    Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
    [aik: folded Anton's patch with of_property_read_u32_array]
    Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
    Acked-by: Anton Blanchard <anton@samba.org>
    Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

    ---
    arch/powerpc/platforms/pseries/iommu.c | 51 ++++++++++++++++++---------------
    1 file changed, 28 insertions(+), 23 deletions(-)

    --- a/arch/powerpc/platforms/pseries/iommu.c
    +++ b/arch/powerpc/platforms/pseries/iommu.c
    @@ -329,16 +329,16 @@ struct direct_window {

    /* Dynamic DMA Window support */
    struct ddw_query_response {
    - __be32 windows_available;
    - __be32 largest_available_block;
    - __be32 page_size;
    - __be32 migration_capable;
    + u32 windows_available;
    + u32 largest_available_block;
    + u32 page_size;
    + u32 migration_capable;
    };

    struct ddw_create_response {
    - __be32 liobn;
    - __be32 addr_hi;
    - __be32 addr_lo;
    + u32 liobn;
    + u32 addr_hi;
    + u32 addr_lo;
    };

    static LIST_HEAD(direct_window_list);
    @@ -725,16 +725,18 @@ static void remove_ddw(struct device_nod
    {
    struct dynamic_dma_window_prop *dwp;
    struct property *win64;
    - const u32 *ddw_avail;
    + u32 ddw_avail[3];
    u64 liobn;
    - int len, ret = 0;
    + int ret = 0;
    +
    + ret = of_property_read_u32_array(np, "ibm,ddw-applicable",
    + &ddw_avail[0], 3);

    - ddw_avail = of_get_property(np, "ibm,ddw-applicable", &len);
    win64 = of_find_property(np, DIRECT64_PROPNAME, NULL);
    if (!win64)
    return;

    - if (!ddw_avail || len < 3 * sizeof(u32) || win64->length < sizeof(*dwp))
    + if (ret || win64->length < sizeof(*dwp))
    goto delprop;

    dwp = win64->value;
    @@ -872,8 +874,9 @@ static int create_ddw(struct pci_dev *de

    do {
    /* extra outputs are LIOBN and dma-addr (hi, lo) */
    - ret = rtas_call(ddw_avail[1], 5, 4, (u32 *)create, cfg_addr,
    - BUID_HI(buid), BUID_LO(buid), page_shift, window_shift);
    + ret = rtas_call(ddw_avail[1], 5, 4, (u32 *)create,
    + cfg_addr, BUID_HI(buid), BUID_LO(buid),
    + page_shift, window_shift);
    } while (rtas_busy_delay(ret));
    dev_info(&dev->dev,
    "ibm,create-pe-dma-window(%x) %x %x %x %x %x returned %d "
    @@ -910,7 +913,7 @@ static u64 enable_ddw(struct pci_dev *de
    int page_shift;
    u64 dma_addr, max_addr;
    struct device_node *dn;
    - const u32 *uninitialized_var(ddw_avail);
    + u32 ddw_avail[3];
    struct direct_window *window;
    struct property *win64;
    struct dynamic_dma_window_prop *ddwprop;
    @@ -942,8 +945,9 @@ static u64 enable_ddw(struct pci_dev *de
    * for the given node in that order.
    * the property is actually in the parent, not the PE
    */
    - ddw_avail = of_get_property(pdn, "ibm,ddw-applicable", &len);
    - if (!ddw_avail || len < 3 * sizeof(u32))
    + ret = of_property_read_u32_array(pdn, "ibm,ddw-applicable",
    + &ddw_avail[0], 3);
    + if (ret)
    goto out_failed;

    /*
    @@ -966,11 +970,11 @@ static u64 enable_ddw(struct pci_dev *de
    dev_dbg(&dev->dev, "no free dynamic windows");
    goto out_failed;
    }
    - if (be32_to_cpu(query.page_size) & 4) {
    + if (query.page_size & 4) {
    page_shift = 24; /* 16MB */
    - } else if (be32_to_cpu(query.page_size) & 2) {
    + } else if (query.page_size & 2) {
    page_shift = 16; /* 64kB */
    - } else if (be32_to_cpu(query.page_size) & 1) {
    + } else if (query.page_size & 1) {
    page_shift = 12; /* 4kB */
    } else {
    dev_dbg(&dev->dev, "no supported direct page size in mask %x",
    @@ -980,7 +984,7 @@ static u64 enable_ddw(struct pci_dev *de
    /* verify the window * number of ptes will map the partition */
    /* check largest block * page size > max memory hotplug addr */
    max_addr = memory_hotplug_max();
    - if (be32_to_cpu(query.largest_available_block) < (max_addr >> page_shift)) {
    + if (query.largest_available_block < (max_addr >> page_shift)) {
    dev_dbg(&dev->dev, "can't map partiton max 0x%llx with %u "
    "%llu-sized pages\n", max_addr, query.largest_available_block,
    1ULL << page_shift);
    @@ -1006,8 +1010,9 @@ static u64 enable_ddw(struct pci_dev *de
    if (ret != 0)
    goto out_free_prop;

    - ddwprop->liobn = create.liobn;
    - ddwprop->dma_base = cpu_to_be64(of_read_number(&create.addr_hi, 2));
    + ddwprop->liobn = cpu_to_be32(create.liobn);
    + ddwprop->dma_base = cpu_to_be64(((u64)create.addr_hi << 32) |
    + create.addr_lo);
    ddwprop->tce_shift = cpu_to_be32(page_shift);
    ddwprop->window_shift = cpu_to_be32(len);

    @@ -1039,7 +1044,7 @@ static u64 enable_ddw(struct pci_dev *de
    list_add(&window->list, &direct_window_list);
    spin_unlock(&direct_window_list_lock);

    - dma_addr = of_read_number(&create.addr_hi, 2);
    + dma_addr = be64_to_cpu(ddwprop->dma_base);
    goto out_unlock;

    out_free_window:



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