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815 lines
22 KiB
815 lines
22 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* Dynamic DMA mapping support. |
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* |
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* This implementation is a fallback for platforms that do not support |
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* I/O TLBs (aka DMA address translation hardware). |
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* Copyright (C) 2000 Asit Mallick <[email protected]> |
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* Copyright (C) 2000 Goutham Rao <[email protected]> |
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* Copyright (C) 2000, 2003 Hewlett-Packard Co |
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* David Mosberger-Tang <[email protected]> |
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* |
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* 03/05/07 davidm Switch from PCI-DMA to generic device DMA API. |
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* 00/12/13 davidm Rename to swiotlb.c and add mark_clean() to avoid |
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* unnecessary i-cache flushing. |
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* 04/07/.. ak Better overflow handling. Assorted fixes. |
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* 05/09/10 linville Add support for syncing ranges, support syncing for |
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* DMA_BIDIRECTIONAL mappings, miscellaneous cleanup. |
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* 08/12/11 beckyb Add highmem support |
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*/ |
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|
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#define pr_fmt(fmt) "software IO TLB: " fmt |
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|
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#include <linux/cache.h> |
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#include <linux/dma-direct.h> |
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#include <linux/dma-map-ops.h> |
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#include <linux/mm.h> |
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#include <linux/export.h> |
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#include <linux/spinlock.h> |
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#include <linux/string.h> |
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#include <linux/swiotlb.h> |
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#include <linux/pfn.h> |
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#include <linux/types.h> |
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#include <linux/ctype.h> |
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#include <linux/highmem.h> |
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#include <linux/gfp.h> |
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#include <linux/scatterlist.h> |
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#include <linux/mem_encrypt.h> |
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#include <linux/set_memory.h> |
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#ifdef CONFIG_DEBUG_FS |
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#include <linux/debugfs.h> |
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#endif |
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|
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#include <asm/io.h> |
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#include <asm/dma.h> |
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|
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#include <linux/init.h> |
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#include <linux/memblock.h> |
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#include <linux/iommu-helper.h> |
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|
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#define CREATE_TRACE_POINTS |
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#include <trace/events/swiotlb.h> |
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|
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#define SLABS_PER_PAGE (1 << (PAGE_SHIFT - IO_TLB_SHIFT)) |
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|
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/* |
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* Minimum IO TLB size to bother booting with. Systems with mainly |
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* 64bit capable cards will only lightly use the swiotlb. If we can't |
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* allocate a contiguous 1MB, we're probably in trouble anyway. |
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*/ |
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#define IO_TLB_MIN_SLABS ((1<<20) >> IO_TLB_SHIFT) |
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|
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enum swiotlb_force swiotlb_force; |
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|
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/* |
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* Used to do a quick range check in swiotlb_tbl_unmap_single and |
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* swiotlb_tbl_sync_single_*, to see if the memory was in fact allocated by this |
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* API. |
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*/ |
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phys_addr_t io_tlb_start, io_tlb_end; |
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|
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/* |
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* The number of IO TLB blocks (in groups of 64) between io_tlb_start and |
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* io_tlb_end. This is command line adjustable via setup_io_tlb_npages. |
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*/ |
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static unsigned long io_tlb_nslabs; |
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|
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/* |
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* The number of used IO TLB block |
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*/ |
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static unsigned long io_tlb_used; |
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|
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/* |
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* This is a free list describing the number of free entries available from |
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* each index |
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*/ |
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static unsigned int *io_tlb_list; |
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static unsigned int io_tlb_index; |
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|
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/* |
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* Max segment that we can provide which (if pages are contingous) will |
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* not be bounced (unless SWIOTLB_FORCE is set). |
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*/ |
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static unsigned int max_segment; |
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|
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/* |
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* We need to save away the original address corresponding to a mapped entry |
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* for the sync operations. |
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*/ |
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#define INVALID_PHYS_ADDR (~(phys_addr_t)0) |
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static phys_addr_t *io_tlb_orig_addr; |
|
|
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/* |
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* The mapped buffer's size should be validated during a sync operation. |
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*/ |
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static size_t *io_tlb_orig_size; |
|
|
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/* |
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* Protect the above data structures in the map and unmap calls |
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*/ |
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static DEFINE_SPINLOCK(io_tlb_lock); |
|
|
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static int late_alloc; |
|
|
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static int __init |
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setup_io_tlb_npages(char *str) |
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{ |
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if (isdigit(*str)) { |
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io_tlb_nslabs = simple_strtoul(str, &str, 0); |
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/* avoid tail segment of size < IO_TLB_SEGSIZE */ |
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io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE); |
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} |
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if (*str == ',') |
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++str; |
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if (!strcmp(str, "force")) { |
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swiotlb_force = SWIOTLB_FORCE; |
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} else if (!strcmp(str, "noforce")) { |
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swiotlb_force = SWIOTLB_NO_FORCE; |
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io_tlb_nslabs = 1; |
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} |
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|
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return 0; |
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} |
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early_param("swiotlb", setup_io_tlb_npages); |
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|
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static bool no_iotlb_memory; |
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|
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unsigned long swiotlb_nr_tbl(void) |
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{ |
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return unlikely(no_iotlb_memory) ? 0 : io_tlb_nslabs; |
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} |
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EXPORT_SYMBOL_GPL(swiotlb_nr_tbl); |
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|
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unsigned int swiotlb_max_segment(void) |
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{ |
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return unlikely(no_iotlb_memory) ? 0 : max_segment; |
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} |
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EXPORT_SYMBOL_GPL(swiotlb_max_segment); |
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|
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void swiotlb_set_max_segment(unsigned int val) |
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{ |
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if (swiotlb_force == SWIOTLB_FORCE) |
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max_segment = 1; |
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else |
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max_segment = rounddown(val, PAGE_SIZE); |
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} |
|
|
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unsigned long swiotlb_size_or_default(void) |
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{ |
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unsigned long size; |
|
|
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size = io_tlb_nslabs << IO_TLB_SHIFT; |
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|
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return size ? size : (IO_TLB_DEFAULT_SIZE); |
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} |
|
|
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void __init swiotlb_adjust_size(unsigned long new_size) |
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{ |
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unsigned long size; |
|
|
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/* |
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* If swiotlb parameter has not been specified, give a chance to |
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* architectures such as those supporting memory encryption to |
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* adjust/expand SWIOTLB size for their use. |
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*/ |
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if (!io_tlb_nslabs) { |
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size = ALIGN(new_size, IO_TLB_SIZE); |
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io_tlb_nslabs = size >> IO_TLB_SHIFT; |
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io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE); |
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|
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pr_info("SWIOTLB bounce buffer size adjusted to %luMB", size >> 20); |
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} |
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} |
|
|
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void swiotlb_print_info(void) |
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{ |
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unsigned long bytes = io_tlb_nslabs << IO_TLB_SHIFT; |
|
|
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if (no_iotlb_memory) { |
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pr_warn("No low mem\n"); |
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return; |
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} |
|
|
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pr_info("mapped [mem %pa-%pa] (%luMB)\n", &io_tlb_start, &io_tlb_end, |
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bytes >> 20); |
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} |
|
|
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static inline unsigned long io_tlb_offset(unsigned long val) |
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{ |
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return val & (IO_TLB_SEGSIZE - 1); |
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} |
|
|
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static inline unsigned long nr_slots(u64 val) |
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{ |
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return DIV_ROUND_UP(val, IO_TLB_SIZE); |
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} |
|
|
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/* |
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* Early SWIOTLB allocation may be too early to allow an architecture to |
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* perform the desired operations. This function allows the architecture to |
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* call SWIOTLB when the operations are possible. It needs to be called |
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* before the SWIOTLB memory is used. |
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*/ |
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void __init swiotlb_update_mem_attributes(void) |
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{ |
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void *vaddr; |
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unsigned long bytes; |
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|
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if (no_iotlb_memory || late_alloc) |
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return; |
|
|
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vaddr = phys_to_virt(io_tlb_start); |
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bytes = PAGE_ALIGN(io_tlb_nslabs << IO_TLB_SHIFT); |
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set_memory_decrypted((unsigned long)vaddr, bytes >> PAGE_SHIFT); |
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memset(vaddr, 0, bytes); |
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} |
|
|
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int __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose) |
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{ |
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unsigned long i, bytes; |
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size_t alloc_size; |
|
|
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bytes = nslabs << IO_TLB_SHIFT; |
|
|
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io_tlb_nslabs = nslabs; |
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io_tlb_start = __pa(tlb); |
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io_tlb_end = io_tlb_start + bytes; |
|
|
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/* |
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* Allocate and initialize the free list array. This array is used |
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* to find contiguous free memory regions of size up to IO_TLB_SEGSIZE |
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* between io_tlb_start and io_tlb_end. |
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*/ |
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alloc_size = PAGE_ALIGN(io_tlb_nslabs * sizeof(int)); |
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io_tlb_list = memblock_alloc(alloc_size, PAGE_SIZE); |
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if (!io_tlb_list) |
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panic("%s: Failed to allocate %zu bytes align=0x%lx\n", |
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__func__, alloc_size, PAGE_SIZE); |
|
|
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alloc_size = PAGE_ALIGN(io_tlb_nslabs * sizeof(phys_addr_t)); |
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io_tlb_orig_addr = memblock_alloc(alloc_size, PAGE_SIZE); |
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if (!io_tlb_orig_addr) |
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panic("%s: Failed to allocate %zu bytes align=0x%lx\n", |
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__func__, alloc_size, PAGE_SIZE); |
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|
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alloc_size = PAGE_ALIGN(io_tlb_nslabs * sizeof(size_t)); |
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io_tlb_orig_size = memblock_alloc(alloc_size, PAGE_SIZE); |
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if (!io_tlb_orig_size) |
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panic("%s: Failed to allocate %zu bytes align=0x%lx\n", |
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__func__, alloc_size, PAGE_SIZE); |
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|
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for (i = 0; i < io_tlb_nslabs; i++) { |
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io_tlb_list[i] = IO_TLB_SEGSIZE - io_tlb_offset(i); |
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io_tlb_orig_addr[i] = INVALID_PHYS_ADDR; |
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io_tlb_orig_size[i] = 0; |
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} |
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io_tlb_index = 0; |
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no_iotlb_memory = false; |
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|
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if (verbose) |
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swiotlb_print_info(); |
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|
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swiotlb_set_max_segment(io_tlb_nslabs << IO_TLB_SHIFT); |
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return 0; |
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} |
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|
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/* |
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* Statically reserve bounce buffer space and initialize bounce buffer data |
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* structures for the software IO TLB used to implement the DMA API. |
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*/ |
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void __init |
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swiotlb_init(int verbose) |
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{ |
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size_t default_size = IO_TLB_DEFAULT_SIZE; |
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unsigned char *vstart; |
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unsigned long bytes; |
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|
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if (!io_tlb_nslabs) { |
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io_tlb_nslabs = (default_size >> IO_TLB_SHIFT); |
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io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE); |
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} |
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|
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bytes = io_tlb_nslabs << IO_TLB_SHIFT; |
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|
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/* Get IO TLB memory from the low pages */ |
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vstart = memblock_alloc_low(PAGE_ALIGN(bytes), PAGE_SIZE); |
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if (vstart && !swiotlb_init_with_tbl(vstart, io_tlb_nslabs, verbose)) |
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return; |
|
|
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if (io_tlb_start) { |
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memblock_free_early(io_tlb_start, |
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PAGE_ALIGN(io_tlb_nslabs << IO_TLB_SHIFT)); |
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io_tlb_start = 0; |
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} |
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pr_warn("Cannot allocate buffer"); |
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no_iotlb_memory = true; |
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} |
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|
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/* |
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* Systems with larger DMA zones (those that don't support ISA) can |
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* initialize the swiotlb later using the slab allocator if needed. |
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* This should be just like above, but with some error catching. |
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*/ |
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int |
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swiotlb_late_init_with_default_size(size_t default_size) |
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{ |
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unsigned long bytes, req_nslabs = io_tlb_nslabs; |
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unsigned char *vstart = NULL; |
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unsigned int order; |
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int rc = 0; |
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|
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if (!io_tlb_nslabs) { |
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io_tlb_nslabs = (default_size >> IO_TLB_SHIFT); |
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io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE); |
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} |
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|
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/* |
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* Get IO TLB memory from the low pages |
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*/ |
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order = get_order(io_tlb_nslabs << IO_TLB_SHIFT); |
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io_tlb_nslabs = SLABS_PER_PAGE << order; |
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bytes = io_tlb_nslabs << IO_TLB_SHIFT; |
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|
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while ((SLABS_PER_PAGE << order) > IO_TLB_MIN_SLABS) { |
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vstart = (void *)__get_free_pages(GFP_DMA | __GFP_NOWARN, |
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order); |
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if (vstart) |
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break; |
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order--; |
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} |
|
|
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if (!vstart) { |
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io_tlb_nslabs = req_nslabs; |
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return -ENOMEM; |
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} |
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if (order != get_order(bytes)) { |
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pr_warn("only able to allocate %ld MB\n", |
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(PAGE_SIZE << order) >> 20); |
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io_tlb_nslabs = SLABS_PER_PAGE << order; |
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} |
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rc = swiotlb_late_init_with_tbl(vstart, io_tlb_nslabs); |
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if (rc) |
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free_pages((unsigned long)vstart, order); |
|
|
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return rc; |
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} |
|
|
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static void swiotlb_cleanup(void) |
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{ |
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io_tlb_end = 0; |
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io_tlb_start = 0; |
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io_tlb_nslabs = 0; |
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max_segment = 0; |
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} |
|
|
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int |
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swiotlb_late_init_with_tbl(char *tlb, unsigned long nslabs) |
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{ |
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unsigned long i, bytes; |
|
|
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bytes = nslabs << IO_TLB_SHIFT; |
|
|
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io_tlb_nslabs = nslabs; |
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io_tlb_start = virt_to_phys(tlb); |
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io_tlb_end = io_tlb_start + bytes; |
|
|
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set_memory_decrypted((unsigned long)tlb, bytes >> PAGE_SHIFT); |
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memset(tlb, 0, bytes); |
|
|
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/* |
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* Allocate and initialize the free list array. This array is used |
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* to find contiguous free memory regions of size up to IO_TLB_SEGSIZE |
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* between io_tlb_start and io_tlb_end. |
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*/ |
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io_tlb_list = (unsigned int *)__get_free_pages(GFP_KERNEL, |
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get_order(io_tlb_nslabs * sizeof(int))); |
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if (!io_tlb_list) |
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goto cleanup3; |
|
|
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io_tlb_orig_addr = (phys_addr_t *) |
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__get_free_pages(GFP_KERNEL, |
|
get_order(io_tlb_nslabs * |
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sizeof(phys_addr_t))); |
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if (!io_tlb_orig_addr) |
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goto cleanup4; |
|
|
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io_tlb_orig_size = (size_t *) |
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__get_free_pages(GFP_KERNEL, |
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get_order(io_tlb_nslabs * |
|
sizeof(size_t))); |
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if (!io_tlb_orig_size) |
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goto cleanup5; |
|
|
|
|
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for (i = 0; i < io_tlb_nslabs; i++) { |
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io_tlb_list[i] = IO_TLB_SEGSIZE - io_tlb_offset(i); |
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io_tlb_orig_addr[i] = INVALID_PHYS_ADDR; |
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io_tlb_orig_size[i] = 0; |
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} |
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io_tlb_index = 0; |
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no_iotlb_memory = false; |
|
|
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swiotlb_print_info(); |
|
|
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late_alloc = 1; |
|
|
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swiotlb_set_max_segment(io_tlb_nslabs << IO_TLB_SHIFT); |
|
|
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return 0; |
|
|
|
cleanup5: |
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free_pages((unsigned long)io_tlb_orig_addr, get_order(io_tlb_nslabs * |
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sizeof(phys_addr_t))); |
|
|
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cleanup4: |
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free_pages((unsigned long)io_tlb_list, get_order(io_tlb_nslabs * |
|
sizeof(int))); |
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io_tlb_list = NULL; |
|
cleanup3: |
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swiotlb_cleanup(); |
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return -ENOMEM; |
|
} |
|
|
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void __init swiotlb_exit(void) |
|
{ |
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if (!io_tlb_orig_addr) |
|
return; |
|
|
|
if (late_alloc) { |
|
free_pages((unsigned long)io_tlb_orig_size, |
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get_order(io_tlb_nslabs * sizeof(size_t))); |
|
free_pages((unsigned long)io_tlb_orig_addr, |
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get_order(io_tlb_nslabs * sizeof(phys_addr_t))); |
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free_pages((unsigned long)io_tlb_list, get_order(io_tlb_nslabs * |
|
sizeof(int))); |
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free_pages((unsigned long)phys_to_virt(io_tlb_start), |
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get_order(io_tlb_nslabs << IO_TLB_SHIFT)); |
|
} else { |
|
memblock_free_late(__pa(io_tlb_orig_addr), |
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PAGE_ALIGN(io_tlb_nslabs * sizeof(phys_addr_t))); |
|
memblock_free_late(__pa(io_tlb_orig_size), |
|
PAGE_ALIGN(io_tlb_nslabs * sizeof(size_t))); |
|
memblock_free_late(__pa(io_tlb_list), |
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PAGE_ALIGN(io_tlb_nslabs * sizeof(int))); |
|
memblock_free_late(io_tlb_start, |
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PAGE_ALIGN(io_tlb_nslabs << IO_TLB_SHIFT)); |
|
} |
|
swiotlb_cleanup(); |
|
} |
|
|
|
/* |
|
* Bounce: copy the swiotlb buffer from or back to the original dma location |
|
*/ |
|
static void swiotlb_bounce(phys_addr_t orig_addr, phys_addr_t tlb_addr, |
|
size_t size, enum dma_data_direction dir) |
|
{ |
|
unsigned long pfn = PFN_DOWN(orig_addr); |
|
unsigned char *vaddr = phys_to_virt(tlb_addr); |
|
|
|
if (PageHighMem(pfn_to_page(pfn))) { |
|
/* The buffer does not have a mapping. Map it in and copy */ |
|
unsigned int offset = orig_addr & ~PAGE_MASK; |
|
char *buffer; |
|
unsigned int sz = 0; |
|
unsigned long flags; |
|
|
|
while (size) { |
|
sz = min_t(size_t, PAGE_SIZE - offset, size); |
|
|
|
local_irq_save(flags); |
|
buffer = kmap_atomic(pfn_to_page(pfn)); |
|
if (dir == DMA_TO_DEVICE) |
|
memcpy(vaddr, buffer + offset, sz); |
|
else |
|
memcpy(buffer + offset, vaddr, sz); |
|
kunmap_atomic(buffer); |
|
local_irq_restore(flags); |
|
|
|
size -= sz; |
|
pfn++; |
|
vaddr += sz; |
|
offset = 0; |
|
} |
|
} else if (dir == DMA_TO_DEVICE) { |
|
memcpy(vaddr, phys_to_virt(orig_addr), size); |
|
} else { |
|
memcpy(phys_to_virt(orig_addr), vaddr, size); |
|
} |
|
} |
|
|
|
#define slot_addr(start, idx) ((start) + ((idx) << IO_TLB_SHIFT)) |
|
|
|
/* |
|
* Return the offset into a iotlb slot required to keep the device happy. |
|
*/ |
|
static unsigned int swiotlb_align_offset(struct device *dev, u64 addr) |
|
{ |
|
return addr & dma_get_min_align_mask(dev) & (IO_TLB_SIZE - 1); |
|
} |
|
|
|
/* |
|
* Carefully handle integer overflow which can occur when boundary_mask == ~0UL. |
|
*/ |
|
static inline unsigned long get_max_slots(unsigned long boundary_mask) |
|
{ |
|
if (boundary_mask == ~0UL) |
|
return 1UL << (BITS_PER_LONG - IO_TLB_SHIFT); |
|
return nr_slots(boundary_mask + 1); |
|
} |
|
|
|
static unsigned int wrap_index(unsigned int index) |
|
{ |
|
if (index >= io_tlb_nslabs) |
|
return 0; |
|
return index; |
|
} |
|
|
|
/* |
|
* Find a suitable number of IO TLB entries size that will fit this request and |
|
* allocate a buffer from that IO TLB pool. |
|
*/ |
|
static int find_slots(struct device *dev, phys_addr_t orig_addr, |
|
size_t alloc_size) |
|
{ |
|
unsigned long boundary_mask = dma_get_seg_boundary(dev); |
|
dma_addr_t tbl_dma_addr = |
|
phys_to_dma_unencrypted(dev, io_tlb_start) & boundary_mask; |
|
unsigned long max_slots = get_max_slots(boundary_mask); |
|
unsigned int iotlb_align_mask = |
|
dma_get_min_align_mask(dev) & ~(IO_TLB_SIZE - 1); |
|
unsigned int nslots = nr_slots(alloc_size), stride; |
|
unsigned int index, wrap, count = 0, i; |
|
unsigned long flags; |
|
|
|
BUG_ON(!nslots); |
|
|
|
/* |
|
* For mappings with an alignment requirement don't bother looping to |
|
* unaligned slots once we found an aligned one. For allocations of |
|
* PAGE_SIZE or larger only look for page aligned allocations. |
|
*/ |
|
stride = (iotlb_align_mask >> IO_TLB_SHIFT) + 1; |
|
if (alloc_size >= PAGE_SIZE) |
|
stride = max(stride, stride << (PAGE_SHIFT - IO_TLB_SHIFT)); |
|
|
|
spin_lock_irqsave(&io_tlb_lock, flags); |
|
if (unlikely(nslots > io_tlb_nslabs - io_tlb_used)) |
|
goto not_found; |
|
|
|
index = wrap = wrap_index(ALIGN(io_tlb_index, stride)); |
|
do { |
|
if ((slot_addr(tbl_dma_addr, index) & iotlb_align_mask) != |
|
(orig_addr & iotlb_align_mask)) { |
|
index = wrap_index(index + 1); |
|
continue; |
|
} |
|
|
|
/* |
|
* 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 (!iommu_is_span_boundary(index, nslots, |
|
nr_slots(tbl_dma_addr), |
|
max_slots)) { |
|
if (io_tlb_list[index] >= nslots) |
|
goto found; |
|
} |
|
index = wrap_index(index + stride); |
|
} while (index != wrap); |
|
|
|
not_found: |
|
spin_unlock_irqrestore(&io_tlb_lock, flags); |
|
return -1; |
|
|
|
found: |
|
for (i = index; i < index + nslots; i++) |
|
io_tlb_list[i] = 0; |
|
for (i = index - 1; |
|
io_tlb_offset(i) != IO_TLB_SEGSIZE - 1 && |
|
io_tlb_list[i]; i--) |
|
io_tlb_list[i] = ++count; |
|
|
|
/* |
|
* Update the indices to avoid searching in the next round. |
|
*/ |
|
if (index + nslots < io_tlb_nslabs) |
|
io_tlb_index = index + nslots; |
|
else |
|
io_tlb_index = 0; |
|
io_tlb_used += nslots; |
|
|
|
spin_unlock_irqrestore(&io_tlb_lock, flags); |
|
return index; |
|
} |
|
|
|
phys_addr_t swiotlb_tbl_map_single(struct device *dev, phys_addr_t orig_addr, |
|
size_t mapping_size, size_t alloc_size, |
|
enum dma_data_direction dir, unsigned long attrs) |
|
{ |
|
unsigned int offset = swiotlb_align_offset(dev, orig_addr); |
|
unsigned int i; |
|
int index; |
|
phys_addr_t tlb_addr; |
|
|
|
if (no_iotlb_memory) |
|
panic("Can not allocate SWIOTLB buffer earlier and can't now provide you with the DMA bounce buffer"); |
|
|
|
if (mem_encrypt_active()) |
|
pr_warn_once("Memory encryption is active and system is using DMA bounce buffers\n"); |
|
|
|
if (mapping_size > alloc_size) { |
|
dev_warn_once(dev, "Invalid sizes (mapping: %zd bytes, alloc: %zd bytes)", |
|
mapping_size, alloc_size); |
|
return (phys_addr_t)DMA_MAPPING_ERROR; |
|
} |
|
|
|
index = find_slots(dev, orig_addr, alloc_size + offset); |
|
if (index == -1) { |
|
if (!(attrs & DMA_ATTR_NO_WARN)) |
|
dev_warn_ratelimited(dev, |
|
"swiotlb buffer is full (sz: %zd bytes), total %lu (slots), used %lu (slots)\n", |
|
alloc_size, io_tlb_nslabs, io_tlb_used); |
|
return (phys_addr_t)DMA_MAPPING_ERROR; |
|
} |
|
|
|
/* |
|
* 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. |
|
*/ |
|
for (i = 0; i < nr_slots(alloc_size + offset); i++) { |
|
io_tlb_orig_addr[index + i] = slot_addr(orig_addr, i); |
|
io_tlb_orig_size[index+i] = alloc_size - (i << IO_TLB_SHIFT); |
|
} |
|
tlb_addr = slot_addr(io_tlb_start, index) + offset; |
|
if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC) && |
|
(dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL)) |
|
swiotlb_bounce(orig_addr, tlb_addr, mapping_size, DMA_TO_DEVICE); |
|
return tlb_addr; |
|
} |
|
|
|
static void validate_sync_size_and_truncate(struct device *hwdev, size_t orig_size, size_t *size) |
|
{ |
|
if (*size > orig_size) { |
|
/* Warn and truncate mapping_size */ |
|
dev_WARN_ONCE(hwdev, 1, |
|
"Attempt for buffer overflow. Original size: %zu. Mapping size: %zu.\n", |
|
orig_size, *size); |
|
*size = orig_size; |
|
} |
|
} |
|
|
|
/* |
|
* tlb_addr is the physical address of the bounce buffer to unmap. |
|
*/ |
|
void swiotlb_tbl_unmap_single(struct device *hwdev, phys_addr_t tlb_addr, |
|
size_t mapping_size, size_t alloc_size, |
|
enum dma_data_direction dir, unsigned long attrs) |
|
{ |
|
unsigned long flags; |
|
unsigned int offset = swiotlb_align_offset(hwdev, tlb_addr); |
|
int i, count, nslots = nr_slots(alloc_size + offset); |
|
int index = (tlb_addr - offset - io_tlb_start) >> IO_TLB_SHIFT; |
|
phys_addr_t orig_addr = io_tlb_orig_addr[index]; |
|
|
|
validate_sync_size_and_truncate(hwdev, io_tlb_orig_size[index], &mapping_size); |
|
|
|
/* |
|
* First, sync the memory before unmapping the entry |
|
*/ |
|
if (orig_addr != INVALID_PHYS_ADDR && |
|
!(attrs & DMA_ATTR_SKIP_CPU_SYNC) && |
|
((dir == DMA_FROM_DEVICE) || (dir == DMA_BIDIRECTIONAL))) |
|
swiotlb_bounce(orig_addr, tlb_addr, mapping_size, DMA_FROM_DEVICE); |
|
|
|
/* |
|
* Return the buffer to the free list by setting the corresponding |
|
* entries to indicate the number of contiguous 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); |
|
if (index + nslots < ALIGN(index + 1, IO_TLB_SEGSIZE)) |
|
count = io_tlb_list[index + nslots]; |
|
else |
|
count = 0; |
|
|
|
/* |
|
* 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; |
|
io_tlb_orig_addr[i] = INVALID_PHYS_ADDR; |
|
io_tlb_orig_size[i] = 0; |
|
} |
|
|
|
/* |
|
* Step 2: merge the returned slots with the preceding slots, if |
|
* available (non zero) |
|
*/ |
|
for (i = index - 1; |
|
io_tlb_offset(i) != IO_TLB_SEGSIZE - 1 && io_tlb_list[i]; |
|
i--) |
|
io_tlb_list[i] = ++count; |
|
io_tlb_used -= nslots; |
|
spin_unlock_irqrestore(&io_tlb_lock, flags); |
|
} |
|
|
|
void swiotlb_tbl_sync_single(struct device *hwdev, phys_addr_t tlb_addr, |
|
size_t size, enum dma_data_direction dir, |
|
enum dma_sync_target target) |
|
{ |
|
int index = (tlb_addr - io_tlb_start) >> IO_TLB_SHIFT; |
|
size_t orig_size = io_tlb_orig_size[index]; |
|
phys_addr_t orig_addr = io_tlb_orig_addr[index]; |
|
|
|
if (orig_addr == INVALID_PHYS_ADDR) |
|
return; |
|
|
|
validate_sync_size_and_truncate(hwdev, orig_size, &size); |
|
|
|
switch (target) { |
|
case SYNC_FOR_CPU: |
|
if (likely(dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL)) |
|
swiotlb_bounce(orig_addr, tlb_addr, |
|
size, DMA_FROM_DEVICE); |
|
else |
|
BUG_ON(dir != DMA_TO_DEVICE); |
|
break; |
|
case SYNC_FOR_DEVICE: |
|
if (likely(dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL)) |
|
swiotlb_bounce(orig_addr, tlb_addr, |
|
size, DMA_TO_DEVICE); |
|
else |
|
BUG_ON(dir != DMA_FROM_DEVICE); |
|
break; |
|
default: |
|
BUG(); |
|
} |
|
} |
|
|
|
/* |
|
* Create a swiotlb mapping for the buffer at @paddr, and in case of DMAing |
|
* to the device copy the data into it as well. |
|
*/ |
|
dma_addr_t swiotlb_map(struct device *dev, phys_addr_t paddr, size_t size, |
|
enum dma_data_direction dir, unsigned long attrs) |
|
{ |
|
phys_addr_t swiotlb_addr; |
|
dma_addr_t dma_addr; |
|
|
|
trace_swiotlb_bounced(dev, phys_to_dma(dev, paddr), size, |
|
swiotlb_force); |
|
|
|
swiotlb_addr = swiotlb_tbl_map_single(dev, paddr, size, size, dir, |
|
attrs); |
|
if (swiotlb_addr == (phys_addr_t)DMA_MAPPING_ERROR) |
|
return DMA_MAPPING_ERROR; |
|
|
|
/* Ensure that the address returned is DMA'ble */ |
|
dma_addr = phys_to_dma_unencrypted(dev, swiotlb_addr); |
|
if (unlikely(!dma_capable(dev, dma_addr, size, true))) { |
|
swiotlb_tbl_unmap_single(dev, swiotlb_addr, size, size, dir, |
|
attrs | DMA_ATTR_SKIP_CPU_SYNC); |
|
dev_WARN_ONCE(dev, 1, |
|
"swiotlb addr %pad+%zu overflow (mask %llx, bus limit %llx).\n", |
|
&dma_addr, size, *dev->dma_mask, dev->bus_dma_limit); |
|
return DMA_MAPPING_ERROR; |
|
} |
|
|
|
if (!dev_is_dma_coherent(dev) && !(attrs & DMA_ATTR_SKIP_CPU_SYNC)) |
|
arch_sync_dma_for_device(swiotlb_addr, size, dir); |
|
return dma_addr; |
|
} |
|
|
|
size_t swiotlb_max_mapping_size(struct device *dev) |
|
{ |
|
return ((size_t)IO_TLB_SIZE) * IO_TLB_SEGSIZE; |
|
} |
|
|
|
bool is_swiotlb_active(void) |
|
{ |
|
/* |
|
* When SWIOTLB is initialized, even if io_tlb_start points to physical |
|
* address zero, io_tlb_end surely doesn't. |
|
*/ |
|
return io_tlb_end != 0; |
|
} |
|
|
|
#ifdef CONFIG_DEBUG_FS |
|
|
|
static int __init swiotlb_create_debugfs(void) |
|
{ |
|
struct dentry *root; |
|
|
|
root = debugfs_create_dir("swiotlb", NULL); |
|
debugfs_create_ulong("io_tlb_nslabs", 0400, root, &io_tlb_nslabs); |
|
debugfs_create_ulong("io_tlb_used", 0400, root, &io_tlb_used); |
|
return 0; |
|
} |
|
|
|
late_initcall(swiotlb_create_debugfs); |
|
|
|
#endif
|
|
|