#define IO_TLB_SEGSIZE 128
/*
- * log of the size of each IO TLB slab. The number of slabs is command line controllable.
+ * log of the size of each IO TLB slab. The number of slabs is command line
+ * controllable.
*/
#define IO_TLB_SHIFT 11
int swiotlb_force;
/*
- * Used to do a quick range check in swiotlb_unmap_single and swiotlb_sync_single_*, to see
- * if the memory was in fact allocated by this API.
+ * Used to do a quick range check in swiotlb_unmap_single and
+ * swiotlb_sync_single_*, to see if the memory was in fact allocated by this
+ * API.
*/
static char *io_tlb_start, *io_tlb_end;
/*
- * The number of IO TLB blocks (in groups of 64) betweeen io_tlb_start and io_tlb_end.
- * This is command line adjustable via setup_io_tlb_npages.
- * Default to 64MB.
+ * The number of IO TLB blocks (in groups of 64) betweeen io_tlb_start and
+ * io_tlb_end. This is command line adjustable via setup_io_tlb_npages.
*/
-static unsigned long io_tlb_nslabs = 32768;
+static unsigned long io_tlb_nslabs;
-/*
+/*
* When the IOMMU overflows we return a fallback buffer. This sets the size.
*/
static unsigned long io_tlb_overflow = 32*1024;
-void *io_tlb_overflow_buffer;
+void *io_tlb_overflow_buffer;
/*
- * This is a free list describing the number of free entries available from each index
+ * This is a free list describing the number of free entries available from
+ * each index
*/
static unsigned int *io_tlb_list;
static unsigned int io_tlb_index;
/*
- * We need to save away the original address corresponding to a mapped entry for the sync
- * operations.
+ * We need to save away the original address corresponding to a mapped entry
+ * for the sync operations.
*/
static unsigned char **io_tlb_orig_addr;
/*
* Protect the above data structures in the map and unmap calls
*/
-static spinlock_t io_tlb_lock = SPIN_LOCK_UNLOCKED;
+static DEFINE_SPINLOCK(io_tlb_lock);
static int __init
-setup_io_tlb_npages (char *str)
+setup_io_tlb_npages(char *str)
{
- if (isdigit(*str)) {
- io_tlb_nslabs = simple_strtoul(str, &str, 0) << (PAGE_SHIFT - IO_TLB_SHIFT);
+ if (isdigit(*str)) {
+ io_tlb_nslabs = simple_strtoul(str, &str, 0) <<
+ (PAGE_SHIFT - IO_TLB_SHIFT);
/* avoid tail segment of size < IO_TLB_SEGSIZE */
io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE);
}
/* make io_tlb_overflow tunable too? */
/*
- * Statically reserve bounce buffer space and initialize bounce buffer data structures for
- * the software IO TLB used to implement the PCI DMA API.
+ * Statically reserve bounce buffer space and initialize bounce buffer data
+ * structures for the software IO TLB used to implement the PCI DMA API.
*/
void
-swiotlb_init (void)
+swiotlb_init_with_default_size (size_t default_size)
{
unsigned long i;
+ if (!io_tlb_nslabs) {
+ io_tlb_nslabs = (default_size >> PAGE_SHIFT);
+ io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE);
+ }
+
/*
* Get IO TLB memory from the low pages
*/
- io_tlb_start = alloc_bootmem_low_pages(io_tlb_nslabs * (1 << IO_TLB_SHIFT));
+ io_tlb_start = alloc_bootmem_low_pages(io_tlb_nslabs *
+ (1 << IO_TLB_SHIFT));
if (!io_tlb_start)
panic("Cannot allocate SWIOTLB buffer");
io_tlb_end = io_tlb_start + io_tlb_nslabs * (1 << IO_TLB_SHIFT);
io_tlb_list[i] = IO_TLB_SEGSIZE - OFFSET(i, IO_TLB_SEGSIZE);
io_tlb_index = 0;
io_tlb_orig_addr = alloc_bootmem(io_tlb_nslabs * sizeof(char *));
-
- /*
- * Get the overflow emergency buffer
+
+ /*
+ * Get the overflow emergency buffer
*/
- io_tlb_overflow_buffer = alloc_bootmem_low(io_tlb_overflow);
+ io_tlb_overflow_buffer = alloc_bootmem_low(io_tlb_overflow);
printk(KERN_INFO "Placing software IO TLB between 0x%lx - 0x%lx\n",
virt_to_phys(io_tlb_start), virt_to_phys(io_tlb_end));
}
-static inline int address_needs_mapping(struct device *hwdev, dma_addr_t addr)
-{
- dma_addr_t mask = 0xffffffff;
- if (hwdev && hwdev->dma_mask)
- mask = *hwdev->dma_mask;
- return (addr & ~mask) != 0;
-}
+void
+swiotlb_init (void)
+{
+ swiotlb_init_with_default_size(64 * (1<<20)); /* default to 64MB */
+}
+
+static inline int
+address_needs_mapping(struct device *hwdev, dma_addr_t addr)
+{
+ dma_addr_t mask = 0xffffffff;
+ /* If the device has a mask, use it, otherwise default to 32 bits */
+ if (hwdev && hwdev->dma_mask)
+ mask = *hwdev->dma_mask;
+ return (addr & ~mask) != 0;
+}
/*
* Allocates bounce buffer and returns its kernel virtual address.
*/
static void *
-map_single (struct device *hwdev, char *buffer, size_t size, int dir)
+map_single(struct device *hwdev, char *buffer, size_t size, int dir)
{
unsigned long flags;
char *dma_addr;
int i;
/*
- * For mappings greater than a page size, we limit the stride (and hence alignment)
- * to a page size.
+ * For mappings greater than a page, we limit the stride (and
+ * hence alignment) to a page size.
*/
nslots = ALIGN(size, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT;
- if (size > (1 << PAGE_SHIFT))
+ if (size > PAGE_SIZE)
stride = (1 << (PAGE_SHIFT - IO_TLB_SHIFT));
else
stride = 1;
BUG();
/*
- * Find suitable number of IO TLB entries size that will fit this request and
- * allocate a buffer from that IO TLB pool.
+ * Find suitable number of IO TLB entries size that will fit this
+ * request and allocate a buffer from that IO TLB pool.
*/
spin_lock_irqsave(&io_tlb_lock, flags);
{
do {
/*
- * If we find a slot that indicates we have 'nslots' number of
- * contiguous buffers, we allocate the buffers from that slot and
- * mark the entries as '0' indicating unavailable.
+ * If we find a slot that indicates we have 'nslots'
+ * number of contiguous buffers, we allocate the
+ * buffers from that slot and mark the entries as '0'
+ * indicating unavailable.
*/
if (io_tlb_list[index] >= nslots) {
int count = 0;
for (i = index; i < (int) (index + nslots); i++)
io_tlb_list[i] = 0;
- for (i = index - 1; (OFFSET(i, IO_TLB_SEGSIZE) != IO_TLB_SEGSIZE -1)
- && io_tlb_list[i]; i--)
+ for (i = index - 1; (OFFSET(i, IO_TLB_SEGSIZE) != IO_TLB_SEGSIZE -1) && io_tlb_list[i]; i--)
io_tlb_list[i] = ++count;
dma_addr = io_tlb_start + (index << IO_TLB_SHIFT);
/*
- * Update the indices to avoid searching in the next round.
+ * Update the indices to avoid searching in
+ * the next round.
*/
io_tlb_index = ((index + nslots) < io_tlb_nslabs
? (index + nslots) : 0);
spin_unlock_irqrestore(&io_tlb_lock, flags);
/*
- * Save away the mapping from the original address to the DMA address. This is
- * needed when we sync the memory. Then we sync the buffer if needed.
+ * Save away the mapping from the original address to the DMA address.
+ * This is needed when we sync the memory. Then we sync the buffer if
+ * needed.
*/
io_tlb_orig_addr[index] = buffer;
if (dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL)
* dma_addr is the kernel virtual address of the bounce buffer to unmap.
*/
static void
-unmap_single (struct device *hwdev, char *dma_addr, size_t size, int dir)
+unmap_single(struct device *hwdev, char *dma_addr, size_t size, int dir)
{
unsigned long flags;
- int i, nslots = ALIGN(size, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT;
+ int i, count, nslots = ALIGN(size, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT;
int index = (dma_addr - io_tlb_start) >> IO_TLB_SHIFT;
char *buffer = io_tlb_orig_addr[index];
/*
* First, sync the memory before unmapping the entry
*/
- if ((dir == DMA_FROM_DEVICE) || (dir == DMA_BIDIRECTIONAL))
+ if (buffer && ((dir == DMA_FROM_DEVICE) || (dir == DMA_BIDIRECTIONAL)))
/*
- * bounce... copy the data back into the original buffer * and delete the
- * bounce buffer.
+ * bounce... copy the data back into the original buffer * and
+ * delete the bounce buffer.
*/
memcpy(buffer, dma_addr, size);
/*
- * Return the buffer to the free list by setting the corresponding entries to
- * indicate the number of contigous entries available. While returning the
- * entries to the free list, we merge the entries with slots below and above the
- * pool being returned.
+ * Return the buffer to the free list by setting the corresponding
+ * entries to indicate the number of contigous entries available.
+ * While returning the entries to the free list, we merge the entries
+ * with slots below and above the pool being returned.
*/
spin_lock_irqsave(&io_tlb_lock, flags);
{
- int count = ((index + nslots) < ALIGN(index + 1, IO_TLB_SEGSIZE) ?
- io_tlb_list[index + nslots] : 0);
+ count = ((index + nslots) < ALIGN(index + 1, IO_TLB_SEGSIZE) ?
+ io_tlb_list[index + nslots] : 0);
/*
- * Step 1: return the slots to the free list, merging the slots with
- * superceeding slots
+ * Step 1: return the slots to the free list, merging the
+ * slots with superceeding slots
*/
for (i = index + nslots - 1; i >= index; i--)
io_tlb_list[i] = ++count;
/*
- * Step 2: merge the returned slots with the preceding slots, if
- * available (non zero)
+ * Step 2: merge the returned slots with the preceding slots,
+ * if available (non zero)
*/
- for (i = index - 1; (OFFSET(i, IO_TLB_SEGSIZE) != IO_TLB_SEGSIZE -1) &&
- io_tlb_list[i]; i--)
+ for (i = index - 1; (OFFSET(i, IO_TLB_SEGSIZE) != IO_TLB_SEGSIZE -1) && io_tlb_list[i]; i--)
io_tlb_list[i] = ++count;
}
spin_unlock_irqrestore(&io_tlb_lock, flags);
}
static void
-sync_single (struct device *hwdev, char *dma_addr, size_t size, int dir)
+sync_single(struct device *hwdev, char *dma_addr, size_t size, int dir)
{
int index = (dma_addr - io_tlb_start) >> IO_TLB_SHIFT;
char *buffer = io_tlb_orig_addr[index];
}
void *
-swiotlb_alloc_coherent (struct device *hwdev, size_t size, dma_addr_t *dma_handle, int flags)
+swiotlb_alloc_coherent(struct device *hwdev, size_t size,
+ dma_addr_t *dma_handle, int flags)
{
unsigned long dev_addr;
void *ret;
+ int order = get_order(size);
- /* XXX fix me: the DMA API should pass us an explicit DMA mask instead: */
+ /*
+ * XXX fix me: the DMA API should pass us an explicit DMA mask
+ * instead, or use ZONE_DMA32 (ia64 overloads ZONE_DMA to be a ~32
+ * bit range instead of a 16MB one).
+ */
flags |= GFP_DMA;
- ret = (void *)__get_free_pages(flags, get_order(size));
- if (!ret)
- return NULL;
+ ret = (void *)__get_free_pages(flags, order);
+ if (ret && address_needs_mapping(hwdev, virt_to_phys(ret))) {
+ /*
+ * The allocated memory isn't reachable by the device.
+ * Fall back on swiotlb_map_single().
+ */
+ free_pages((unsigned long) ret, order);
+ ret = NULL;
+ }
+ if (!ret) {
+ /*
+ * We are either out of memory or the device can't DMA
+ * to GFP_DMA memory; fall back on
+ * swiotlb_map_single(), which will grab memory from
+ * the lowest available address range.
+ */
+ dma_addr_t handle;
+ handle = swiotlb_map_single(NULL, NULL, size, DMA_FROM_DEVICE);
+ if (dma_mapping_error(handle))
+ return NULL;
+
+ ret = phys_to_virt(handle);
+ }
memset(ret, 0, size);
dev_addr = virt_to_phys(ret);
- if (address_needs_mapping(hwdev,dev_addr))
- panic("swiotlb_alloc_consistent: allocated memory is out of range for device");
+
+ /* Confirm address can be DMA'd by device */
+ if (address_needs_mapping(hwdev, dev_addr)) {
+ printk("hwdev DMA mask = 0x%016Lx, dev_addr = 0x%016lx\n",
+ (unsigned long long)*hwdev->dma_mask, dev_addr);
+ panic("swiotlb_alloc_coherent: allocated memory is out of "
+ "range for device");
+ }
*dma_handle = dev_addr;
return ret;
}
void
-swiotlb_free_coherent (struct device *hwdev, size_t size, void *vaddr, dma_addr_t dma_handle)
+swiotlb_free_coherent(struct device *hwdev, size_t size, void *vaddr,
+ dma_addr_t dma_handle)
{
- free_pages((unsigned long) vaddr, get_order(size));
+ if (!(vaddr >= (void *)io_tlb_start
+ && vaddr < (void *)io_tlb_end))
+ free_pages((unsigned long) vaddr, get_order(size));
+ else
+ /* DMA_TO_DEVICE to avoid memcpy in unmap_single */
+ swiotlb_unmap_single (hwdev, dma_handle, size, DMA_TO_DEVICE);
}
-static void swiotlb_full(struct device *dev, size_t size, int dir, int do_panic)
+static void
+swiotlb_full(struct device *dev, size_t size, int dir, int do_panic)
{
- /*
+ /*
* Ran out of IOMMU space for this operation. This is very bad.
* Unfortunately the drivers cannot handle this operation properly.
* unless they check for pci_dma_mapping_error (most don't)
* When the mapping is small enough return a static buffer to limit
- * the damage, or panic when the transfer is too big.
- */
-
- printk(KERN_ERR
- "PCI-DMA: Out of SW-IOMMU space for %lu bytes at device %s\n",
- size, dev ? dev->bus_id : "?");
+ * the damage, or panic when the transfer is too big.
+ */
+ printk(KERN_ERR "PCI-DMA: Out of SW-IOMMU space for %lu bytes at "
+ "device %s\n", size, dev ? dev->bus_id : "?");
if (size > io_tlb_overflow && do_panic) {
if (dir == PCI_DMA_FROMDEVICE || dir == PCI_DMA_BIDIRECTIONAL)
panic("PCI-DMA: Memory would be corrupted\n");
- if (dir == PCI_DMA_TODEVICE || dir == PCI_DMA_BIDIRECTIONAL)
- panic("PCI-DMA: Random memory would be DMAed\n");
- }
-}
+ if (dir == PCI_DMA_TODEVICE || dir == PCI_DMA_BIDIRECTIONAL)
+ panic("PCI-DMA: Random memory would be DMAed\n");
+ }
+}
/*
- * Map a single buffer of the indicated size for DMA in streaming mode. The PCI address
- * to use is returned.
+ * Map a single buffer of the indicated size for DMA in streaming mode. The
+ * PCI address to use is returned.
*
- * Once the device is given the dma address, the device owns this memory until either
- * swiotlb_unmap_single or swiotlb_dma_sync_single is performed.
+ * Once the device is given the dma address, the device owns this memory until
+ * either swiotlb_unmap_single or swiotlb_dma_sync_single is performed.
*/
dma_addr_t
-swiotlb_map_single (struct device *hwdev, void *ptr, size_t size, int dir)
+swiotlb_map_single(struct device *hwdev, void *ptr, size_t size, int dir)
{
unsigned long dev_addr = virt_to_phys(ptr);
- void *map;
+ void *map;
if (dir == DMA_NONE)
BUG();
/*
- * Check if the PCI device can DMA to ptr... if so, just return ptr
+ * If the pointer passed in happens to be in the device's DMA window,
+ * we can safely return the device addr and not worry about bounce
+ * buffering it.
*/
- if (!address_needs_mapping(hwdev, dev_addr) && !swiotlb_force)
- /*
- * Device is bit capable of DMA'ing to the buffer... just return the PCI
- * address of ptr
- */
+ if (!address_needs_mapping(hwdev, dev_addr) && !swiotlb_force)
return dev_addr;
/*
- * get a bounce buffer:
+ * Oh well, have to allocate and map a bounce buffer.
*/
map = map_single(hwdev, ptr, size, dir);
- if (!map) {
- swiotlb_full(hwdev, size, dir, 1);
- map = io_tlb_overflow_buffer;
+ if (!map) {
+ swiotlb_full(hwdev, size, dir, 1);
+ map = io_tlb_overflow_buffer;
}
dev_addr = virt_to_phys(map);
/*
- * Ensure that the address returned is DMA'ble:
+ * Ensure that the address returned is DMA'ble
*/
if (address_needs_mapping(hwdev, dev_addr))
panic("map_single: bounce buffer is not DMA'ble");
* flush them when they get mapped into an executable vm-area.
*/
static void
-mark_clean (void *addr, size_t size)
+mark_clean(void *addr, size_t size)
{
unsigned long pg_addr, end;
}
/*
- * Unmap a single streaming mode DMA translation. The dma_addr and size must match what
- * was provided for in a previous swiotlb_map_single call. All other usages are
- * undefined.
+ * Unmap a single streaming mode DMA translation. The dma_addr and size must
+ * match what was provided for in a previous swiotlb_map_single call. All
+ * other usages are undefined.
*
- * After this call, reads by the cpu to the buffer are guaranteed to see whatever the
- * device wrote there.
+ * After this call, reads by the cpu to the buffer are guaranteed to see
+ * whatever the device wrote there.
*/
void
-swiotlb_unmap_single (struct device *hwdev, dma_addr_t dev_addr, size_t size, int dir)
+swiotlb_unmap_single(struct device *hwdev, dma_addr_t dev_addr, size_t size,
+ int dir)
{
char *dma_addr = phys_to_virt(dev_addr);
}
/*
- * Make physical memory consistent for a single streaming mode DMA translation after a
- * transfer.
+ * Make physical memory consistent for a single streaming mode DMA translation
+ * after a transfer.
*
- * If you perform a swiotlb_map_single() but wish to interrogate the buffer using the cpu,
- * yet do not wish to teardown the PCI dma mapping, you must call this function before
- * doing so. At the next point you give the PCI dma address back to the card, you must
- * first perform a swiotlb_dma_sync_for_device, and then the device again owns the buffer
+ * If you perform a swiotlb_map_single() but wish to interrogate the buffer
+ * using the cpu, yet do not wish to teardown the PCI dma mapping, you must
+ * call this function before doing so. At the next point you give the PCI dma
+ * address back to the card, you must first perform a
+ * swiotlb_dma_sync_for_device, and then the device again owns the buffer
*/
void
-swiotlb_sync_single_for_cpu (struct device *hwdev, dma_addr_t dev_addr, size_t size, int dir)
+swiotlb_sync_single_for_cpu(struct device *hwdev, dma_addr_t dev_addr,
+ size_t size, int dir)
{
char *dma_addr = phys_to_virt(dev_addr);
}
void
-swiotlb_sync_single_for_device (struct device *hwdev, dma_addr_t dev_addr, size_t size, int dir)
+swiotlb_sync_single_for_device(struct device *hwdev, dma_addr_t dev_addr,
+ size_t size, int dir)
{
char *dma_addr = phys_to_virt(dev_addr);
}
/*
- * Map a set of buffers described by scatterlist in streaming mode for DMA. This is the
- * scatter-gather version of the above swiotlb_map_single interface. Here the scatter
- * gather list elements are each tagged with the appropriate dma address and length. They
- * are obtained via sg_dma_{address,length}(SG).
+ * Map a set of buffers described by scatterlist in streaming mode for DMA.
+ * This is the scatter-gather version of the above swiotlb_map_single
+ * interface. Here the scatter gather list elements are each tagged with the
+ * appropriate dma address and length. They are obtained via
+ * sg_dma_{address,length}(SG).
*
* NOTE: An implementation may be able to use a smaller number of
* DMA address/length pairs than there are SG table elements.
* The routine returns the number of addr/length pairs actually
* used, at most nents.
*
- * Device ownership issues as mentioned above for swiotlb_map_single are the same here.
+ * Device ownership issues as mentioned above for swiotlb_map_single are the
+ * same here.
*/
int
-swiotlb_map_sg (struct device *hwdev, struct scatterlist *sg, int nelems, int dir)
+swiotlb_map_sg(struct device *hwdev, struct scatterlist *sg, int nelems,
+ int dir)
{
void *addr;
unsigned long dev_addr;
if (swiotlb_force || address_needs_mapping(hwdev, dev_addr)) {
sg->dma_address = (dma_addr_t) virt_to_phys(map_single(hwdev, addr, sg->length, dir));
if (!sg->dma_address) {
- /* Don't panic here, we expect pci_map_sg users
+ /* Don't panic here, we expect map_sg users
to do proper error handling. */
- swiotlb_full(hwdev, sg->length, dir, 0);
+ swiotlb_full(hwdev, sg->length, dir, 0);
swiotlb_unmap_sg(hwdev, sg - i, i, dir);
sg[0].dma_length = 0;
return 0;
}
/*
- * Unmap a set of streaming mode DMA translations. Again, cpu read rules concerning calls
- * here are the same as for swiotlb_unmap_single() above.
+ * Unmap a set of streaming mode DMA translations. Again, cpu read rules
+ * concerning calls here are the same as for swiotlb_unmap_single() above.
*/
void
-swiotlb_unmap_sg (struct device *hwdev, struct scatterlist *sg, int nelems, int dir)
+swiotlb_unmap_sg(struct device *hwdev, struct scatterlist *sg, int nelems,
+ int dir)
{
int i;
}
/*
- * Make physical memory consistent for a set of streaming mode DMA translations after a
- * transfer.
+ * Make physical memory consistent for a set of streaming mode DMA translations
+ * after a transfer.
*
- * The same as swiotlb_sync_single_* but for a scatter-gather list, same rules and
- * usage.
+ * The same as swiotlb_sync_single_* but for a scatter-gather list, same rules
+ * and usage.
*/
void
-swiotlb_sync_sg_for_cpu (struct device *hwdev, struct scatterlist *sg, int nelems, int dir)
+swiotlb_sync_sg_for_cpu(struct device *hwdev, struct scatterlist *sg,
+ int nelems, int dir)
{
int i;
for (i = 0; i < nelems; i++, sg++)
if (sg->dma_address != SG_ENT_PHYS_ADDRESS(sg))
- sync_single(hwdev, (void *) sg->dma_address, sg->dma_length, dir);
+ sync_single(hwdev, (void *) sg->dma_address,
+ sg->dma_length, dir);
}
void
-swiotlb_sync_sg_for_device (struct device *hwdev, struct scatterlist *sg, int nelems, int dir)
+swiotlb_sync_sg_for_device(struct device *hwdev, struct scatterlist *sg,
+ int nelems, int dir)
{
int i;
for (i = 0; i < nelems; i++, sg++)
if (sg->dma_address != SG_ENT_PHYS_ADDRESS(sg))
- sync_single(hwdev, (void *) sg->dma_address, sg->dma_length, dir);
+ sync_single(hwdev, (void *) sg->dma_address,
+ sg->dma_length, dir);
}
int
-swiotlb_dma_mapping_error (dma_addr_t dma_addr)
+swiotlb_dma_mapping_error(dma_addr_t dma_addr)
{
return (dma_addr == virt_to_phys(io_tlb_overflow_buffer));
}
/*
- * Return whether the given PCI device DMA address mask can be supported properly. For
- * example, if your device can only drive the low 24-bits during PCI bus mastering, then
- * you would pass 0x00ffffff as the mask to this function.
+ * Return whether the given PCI device DMA address mask can be supported
+ * properly. For example, if your device can only drive the low 24-bits
+ * during PCI bus mastering, then you would pass 0x00ffffff as the mask to
+ * this function.
*/
int
swiotlb_dma_supported (struct device *hwdev, u64 mask)
{
- return 1;
+ return (virt_to_phys (io_tlb_end) - 1) <= mask;
}
EXPORT_SYMBOL(swiotlb_init);
git://git.onelab.eu / linux-2.6.git / blobdiff