int __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose)
{
void *v_overflow_buffer;
unsigned long i, bytes;
bytes = nslabs << IO_TLB_SHIFT;
io_tlb_nslabs = nslabs;
io_tlb_start = __pa(tlb);
io_tlb_end = io_tlb_start + bytes;
/*
* Get the overflow emergency buffer
*/
v_overflow_buffer = memblock_virt_alloc_low_nopanic(
PAGE_ALIGN(io_tlb_overflow),
PAGE_SIZE);
if (!v_overflow_buffer)
return -ENOMEM;
io_tlb_overflow_buffer = __pa(v_overflow_buffer);
/*
* Allocate and initialize the free list array. This array is used
* to find contiguous free memory regions of size up to IO_TLB_SEGSIZE
* between io_tlb_start and io_tlb_end.
*/
io_tlb_list = memblock_virt_alloc(
PAGE_ALIGN(io_tlb_nslabs * sizeof(int)),
PAGE_SIZE);
io_tlb_orig_addr = memblock_virt_alloc(
PAGE_ALIGN(io_tlb_nslabs * sizeof(phys_addr_t)),
PAGE_SIZE);
for (i = 0; i < io_tlb_nslabs; i++) {
io_tlb_list[i] = IO_TLB_SEGSIZE - OFFSET(i, IO_TLB_SEGSIZE);
io_tlb_orig_addr[i] = INVALID_PHYS_ADDR;
}
io_tlb_index = 0;
if (verbose)
swiotlb_print_info();
swiotlb_set_max_segment(io_tlb_nslabs << IO_TLB_SHIFT);
return 0;
}
void __init
swiotlb_init(int verbose)
{
size_t default_size = IO_TLB_DEFAULT_SIZE;
unsigned char *vstart;
unsigned long bytes;
if (!io_tlb_nslabs) {
io_tlb_nslabs = (default_size >> IO_TLB_SHIFT);
io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE);
}
bytes = io_tlb_nslabs << IO_TLB_SHIFT;
/* Get IO TLB memory from the low pages */
vstart = memblock_virt_alloc_low_nopanic(PAGE_ALIGN(bytes), PAGE_SIZE);
if (vstart && !swiotlb_init_with_tbl(vstart, io_tlb_nslabs, verbose))
return;
if (io_tlb_start)
memblock_free_early(io_tlb_start,
PAGE_ALIGN(io_tlb_nslabs << IO_TLB_SHIFT));
pr_warn("Cannot allocate SWIOTLB buffer");
no_iotlb_memory = true;
}
/*
* Systems with larger DMA zones (those that don't support ISA) can
* initialize the swiotlb later using the slab allocator if needed.
* This should be just like above, but with some error catching.
*/
