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|
// SPDX-License-Identifier: GPL-2.0-only
/*
* Dynamic DMA mapping support.
*
* This implementation is a fallback for platforms that do not support
* I/O TLBs (aka DMA address translation hardware).
* Copyright (C) 2000 Asit Mallick <Asit.K.Mallick@intel.com>
* Copyright (C) 2000 Goutham Rao <goutham.rao@intel.com>
* Copyright (C) 2000, 2003 Hewlett-Packard Co
* David Mosberger-Tang <davidm@hpl.hp.com>
*
* 03/05/07 davidm Switch from PCI-DMA to generic device DMA API.
* 00/12/13 davidm Rename to swiotlb.c and add mark_clean() to avoid
* unnecessary i-cache flushing.
* 04/07/.. ak Better overflow handling. Assorted fixes.
* 05/09/10 linville Add support for syncing ranges, support syncing for
* DMA_BIDIRECTIONAL mappings, miscellaneous cleanup.
* 08/12/11 beckyb Add highmem support
*/
#define pr_fmt(fmt) "software IO TLB: " fmt
#include <linux/cache.h>
#include <linux/dma-direct.h>
#include <linux/dma-map-ops.h>
#include <linux/mm.h>
#include <linux/export.h>
#include <linux/spinlock.h>
#include <linux/string.h>
#include <linux/swiotlb.h>
#include <linux/pfn.h>
#include <linux/types.h>
#include <linux/ctype.h>
#include <linux/highmem.h>
#include <linux/gfp.h>
#include <linux/scatterlist.h>
#include <linux/mem_encrypt.h>
#include <linux/set_memory.h>
#ifdef CONFIG_DEBUG_FS
#include <linux/debugfs.h>
#endif
#ifdef CONFIG_DMA_RESTRICTED_POOL
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_fdt.h>
#include <linux/of_reserved_mem.h>
#include <linux/slab.h>
#endif
#include <asm/io.h>
#include <asm/dma.h>
#include <linux/init.h>
#include <linux/memblock.h>
#include <linux/iommu-helper.h>
#define CREATE_TRACE_POINTS
#include <trace/events/swiotlb.h>
#define SLABS_PER_PAGE (1 << (PAGE_SHIFT - IO_TLB_SHIFT))
/*
* Minimum IO TLB size to bother booting with. Systems with mainly
* 64bit capable cards will only lightly use the swiotlb. If we can't
* allocate a contiguous 1MB, we're probably in trouble anyway.
*/
#define IO_TLB_MIN_SLABS ((1<<20) >> IO_TLB_SHIFT)
#define INVALID_PHYS_ADDR (~(phys_addr_t)0)
enum swiotlb_force swiotlb_force;
struct io_tlb_mem *io_tlb_default_mem;
/*
* Max segment that we can provide which (if pages are contingous) will
* not be bounced (unless SWIOTLB_FORCE is set).
*/
static unsigned int max_segment;
static unsigned long default_nslabs = IO_TLB_DEFAULT_SIZE >> IO_TLB_SHIFT;
static int __init
setup_io_tlb_npages(char *str)
{
if (isdigit(*str)) {
/* avoid tail segment of size < IO_TLB_SEGSIZE */
default_nslabs =
ALIGN(simple_strtoul(str, &str, 0), IO_TLB_SEGSIZE);
}
if (*str == ',')
++str;
if (!strcmp(str, "force"))
swiotlb_force = SWIOTLB_FORCE;
else if (!strcmp(str, "noforce"))
swiotlb_force = SWIOTLB_NO_FORCE;
return 0;
}
early_param("swiotlb", setup_io_tlb_npages);
unsigned int swiotlb_max_segment(void)
{
return io_tlb_default_mem ? max_segment : 0;
}
EXPORT_SYMBOL_GPL(swiotlb_max_segment);
void swiotlb_set_max_segment(unsigned int val)
{
if (swiotlb_force == SWIOTLB_FORCE)
max_segment = 1;
else
max_segment = rounddown(val, PAGE_SIZE);
}
unsigned long swiotlb_size_or_default(void)
{
return default_nslabs << IO_TLB_SHIFT;
}
void __init swiotlb_adjust_size(unsigned long size)
{
/*
* If swiotlb parameter has not been specified, give a chance to
* architectures such as those supporting memory encryption to
* adjust/expand SWIOTLB size for their use.
*/
if (default_nslabs != IO_TLB_DEFAULT_SIZE >> IO_TLB_SHIFT)
return;
size = ALIGN(size, IO_TLB_SIZE);
default_nslabs = ALIGN(size >> IO_TLB_SHIFT, IO_TLB_SEGSIZE);
pr_info("SWIOTLB bounce buffer size adjusted to %luMB", size >> 20);
}
void swiotlb_print_info(void)
{
struct io_tlb_mem *mem = io_tlb_default_mem;
if (!mem) {
pr_warn("No low mem\n");
return;
}
pr_info("mapped [mem %pa-%pa] (%luMB)\n", &mem->start, &mem->end,
(mem->nslabs << IO_TLB_SHIFT) >> 20);
}
static inline unsigned long io_tlb_offset(unsigned long val)
{
return val & (IO_TLB_SEGSIZE - 1);
}
static inline unsigned long nr_slots(u64 val)
{
return DIV_ROUND_UP(val, IO_TLB_SIZE);
}
/*
* Early SWIOTLB allocation may be too early to allow an architecture to
* perform the desired operations. This function allows the architecture to
* call SWIOTLB when the operations are possible. It needs to be called
* before the SWIOTLB memory is used.
*/
void __init swiotlb_update_mem_attributes(void)
{
struct io_tlb_mem *mem = io_tlb_default_mem;
void *vaddr;
unsigned long bytes;
if (!mem || mem->late_alloc)
return;
vaddr = phys_to_virt(mem->start);
bytes = PAGE_ALIGN(mem->nslabs << IO_TLB_SHIFT);
set_memory_decrypted((unsigned long)vaddr, bytes >> PAGE_SHIFT);
memset(vaddr, 0, bytes);
}
static void swiotlb_init_io_tlb_mem(struct io_tlb_mem *mem, phys_addr_t start,
unsigned long nslabs, bool late_alloc)
{
void *vaddr = phys_to_virt(start);
unsigned long bytes = nslabs << IO_TLB_SHIFT, i;
mem->nslabs = nslabs;
mem->start = start;
mem->end = mem->start + bytes;
mem->index = 0;
mem->late_alloc = late_alloc;
if (swiotlb_force == SWIOTLB_FORCE)
mem->force_bounce = true;
spin_lock_init(&mem->lock);
for (i = 0; i < mem->nslabs; i++) {
mem->slots[i].list = IO_TLB_SEGSIZE - io_tlb_offset(i);
mem->slots[i].orig_addr = INVALID_PHYS_ADDR;
mem->slots[i].alloc_size = 0;
}
memset(vaddr, 0, bytes);
}
int __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose)
{
struct io_tlb_mem *mem;
size_t alloc_size;
if (swiotlb_force == SWIOTLB_NO_FORCE)
return 0;
/* protect against double initialization */
if (WARN_ON_ONCE(io_tlb_default_mem))
return -ENOMEM;
alloc_size = PAGE_ALIGN(struct_size(mem, slots, nslabs));
mem = memblock_alloc(alloc_size, PAGE_SIZE);
if (!mem)
panic("%s: Failed to allocate %zu bytes align=0x%lx\n",
__func__, alloc_size, PAGE_SIZE);
swiotlb_init_io_tlb_mem(mem, __pa(tlb), nslabs, false);
io_tlb_default_mem = mem;
if (verbose)
swiotlb_print_info();
swiotlb_set_max_segment(mem->nslabs << IO_TLB_SHIFT);
return 0;
}
/*
* Statically reserve bounce buffer space and initialize bounce buffer data
* structures for the software IO TLB used to implement the DMA API.
*/
void __init
swiotlb_init(int verbose)
{
size_t bytes = PAGE_ALIGN(default_nslabs << IO_TLB_SHIFT);
void *tlb;
if (swiotlb_force == SWIOTLB_NO_FORCE)
return;
/* Get IO TLB memory from the low pages */
tlb = memblock_alloc_low(bytes, PAGE_SIZE);
if (!tlb)
goto fail;
if (swiotlb_init_with_tbl(tlb, default_nslabs, verbose))
goto fail_free_mem;
return;
fail_free_mem:
memblock_free_early(__pa(tlb), bytes);
fail:
pr_warn("Cannot allocate buffer");
}
/*
* 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.
*/
int
swiotlb_late_init_with_default_size(size_t default_size)
{
unsigned long nslabs =
ALIGN(default_size >> IO_TLB_SHIFT, IO_TLB_SEGSIZE);
unsigned long bytes;
unsigned char *vstart = NULL;
unsigned int order;
int rc = 0;
if (swiotlb_force == SWIOTLB_NO_FORCE)
return 0;
/*
* Get IO TLB memory from the low pages
*/
order = get_order(nslabs << IO_TLB_SHIFT);
nslabs = SLABS_PER_PAGE << order;
bytes = nslabs << IO_TLB_SHIFT;
while ((SLABS_PER_PAGE << order) > IO_TLB_MIN_SLABS) {
vstart = (void *)__get_free_pages(GFP_DMA | __GFP_NOWARN,
order);
if (vstart)
break;
order--;
}
if (!vstart)
return -ENOMEM;
if (order != get_order(bytes)) {
pr_warn("only able to allocate %ld MB\n",
(PAGE_SIZE << order) >> 20);
nslabs = SLABS_PER_PAGE << order;
}
rc = swiotlb_late_init_with_tbl(vstart, nslabs);
if (rc)
free_pages((unsigned long)vstart, order);
return rc;
}
int
swiotlb_late_init_with_tbl(char *tlb, unsigned long nslabs)
{
struct io_tlb_mem *mem;
unsigned long bytes = nslabs << IO_TLB_SHIFT;
if (swiotlb_force == SWIOTLB_NO_FORCE)
return 0;
/* protect against double initialization */
if (WARN_ON_ONCE(io_tlb_default_mem))
return -ENOMEM;
mem = (void *)__get_free_pages(GFP_KERNEL,
get_order(struct_size(mem, slots, nslabs)));
if (!mem)
return -ENOMEM;
memset(mem, 0, sizeof(*mem));
set_memory_decrypted((unsigned long)tlb, bytes >> PAGE_SHIFT);
swiotlb_init_io_tlb_mem(mem, virt_to_phys(tlb), nslabs, true);
io_tlb_default_mem = mem;
swiotlb_print_info();
swiotlb_set_max_segment(mem->nslabs << IO_TLB_SHIFT);
return 0;
}
void __init swiotlb_exit(void)
{
struct io_tlb_mem *mem = io_tlb_default_mem;
size_t size;
if (!mem)
return;
size = struct_size(mem, slots, mem->nslabs);
if (mem->late_alloc)
free_pages((unsigned long)mem, get_order(size));
else
memblock_free_late(__pa(mem), PAGE_ALIGN(size));
io_tlb_default_mem = NULL;
}
/*
* 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);
}
/*
* Bounce: copy the swiotlb buffer from or back to the original dma location
*/
static void swiotlb_bounce(struct device *dev, phys_addr_t tlb_addr, size_t size,
enum dma_data_direction dir)
{
struct io_tlb_mem *mem = dev->dma_io_tlb_mem;
int index = (tlb_addr - mem->start) >> IO_TLB_SHIFT;
phys_addr_t orig_addr = mem->slots[index].orig_addr;
size_t alloc_size = mem->slots[index].alloc_size;
unsigned long pfn = PFN_DOWN(orig_addr);
unsigned char *vaddr = phys_to_virt(tlb_addr);
unsigned int tlb_offset, orig_addr_offset;
if (orig_addr == INVALID_PHYS_ADDR)
return;
tlb_offset = tlb_addr & (IO_TLB_SIZE - 1);
orig_addr_offset = swiotlb_align_offset(dev, orig_addr);
if (tlb_offset < orig_addr_offset) {
dev_WARN_ONCE(dev, 1,
"Access before mapping start detected. orig offset %u, requested offset %u.\n",
orig_addr_offset, tlb_offset);
return;
}
tlb_offset -= orig_addr_offset;
if (tlb_offset > alloc_size) {
dev_WARN_ONCE(dev, 1,
"Buffer overflow detected. Allocation size: %zu. Mapping size: %zu+%u.\n",
alloc_size, size, tlb_offset);
return;
}
orig_addr += tlb_offset;
alloc_size -= tlb_offset;
if (size > alloc_size) {
dev_WARN_ONCE(dev, 1,
"Buffer overflow detected. Allocation size: %zu. Mapping size: %zu.\n",
alloc_size, size);
size = alloc_size;
}
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))
/*
* 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(struct io_tlb_mem *mem, unsigned int index)
{
if (index >= mem->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 swiotlb_find_slots(struct device *dev, phys_addr_t orig_addr,
size_t alloc_size)
{
struct io_tlb_mem *mem = dev->dma_io_tlb_mem;
unsigned long boundary_mask = dma_get_seg_boundary(dev);
dma_addr_t tbl_dma_addr =
phys_to_dma_unencrypted(dev, mem->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 int offset = swiotlb_align_offset(dev, orig_addr);
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(&mem->lock, flags);
if (unlikely(nslots > mem->nslabs - mem->used))
goto not_found;
index = wrap = wrap_index(mem, ALIGN(mem->index, stride));
do {
if (orig_addr &&
(slot_addr(tbl_dma_addr, index) & iotlb_align_mask) !=
(orig_addr & iotlb_align_mask)) {
index = wrap_index(mem, 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 (mem->slots[index].list >= nslots)
goto found;
}
index = wrap_index(mem, index + stride);
} while (index != wrap);
not_found:
spin_unlock_irqrestore(&mem->lock, flags);
return -1;
found:
for (i = index; i < index + nslots; i++) {
mem->slots[i].list = 0;
mem->slots[i].alloc_size =
alloc_size - (offset + ((i - index) << IO_TLB_SHIFT));
}
for (i = index - 1;
io_tlb_offset(i) != IO_TLB_SEGSIZE - 1 &&
mem->slots[i].list; i--)
mem->slots[i].list = ++count;
/*
* Update the indices to avoid searching in the next round.
*/
if (index + nslots < mem->nslabs)
mem->index = index + nslots;
else
mem->index = 0;
mem->used += nslots;
spin_unlock_irqrestore(&mem->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)
{
struct io_tlb_mem *mem = dev->dma_io_tlb_mem;
unsigned int offset = swiotlb_align_offset(dev, orig_addr);
unsigned int i;
int index;
phys_addr_t tlb_addr;
if (!mem)
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 = swiotlb_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, mem->nslabs, mem->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++)
mem->slots[index + i].orig_addr = slot_addr(orig_addr, i);
tlb_addr = slot_addr(mem->start, index) + offset;
if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC) &&
(dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL))
swiotlb_bounce(dev, tlb_addr, mapping_size, DMA_TO_DEVICE);
return tlb_addr;
}
static void swiotlb_release_slots(struct device *dev, phys_addr_t tlb_addr)
{
struct io_tlb_mem *mem = dev->dma_io_tlb_mem;
unsigned long flags;
unsigned int offset = swiotlb_align_offset(dev, tlb_addr);
int index = (tlb_addr - offset - mem->start) >> IO_TLB_SHIFT;
int nslots = nr_slots(mem->slots[index].alloc_size + offset);
int count, i;
/*
* 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(&mem->lock, flags);
if (index + nslots < ALIGN(index + 1, IO_TLB_SEGSIZE))
count = mem->slots[index + nslots].list;
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--) {
mem->slots[i].list = ++count;
mem->slots[i].orig_addr = INVALID_PHYS_ADDR;
mem->slots[i].alloc_size = 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 && mem->slots[i].list;
i--)
mem->slots[i].list = ++count;
mem->used -= nslots;
spin_unlock_irqrestore(&mem->lock, flags);
}
/*
* tlb_addr is the physical address of the bounce buffer to unmap.
*/
void swiotlb_tbl_unmap_single(struct device *dev, phys_addr_t tlb_addr,
size_t mapping_size, enum dma_data_direction dir,
unsigned long attrs)
{
/*
* First, sync the memory before unmapping the entry
*/
if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC) &&
(dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL))
swiotlb_bounce(dev, tlb_addr, mapping_size, DMA_FROM_DEVICE);
swiotlb_release_slots(dev, tlb_addr);
}
void swiotlb_sync_single_for_device(struct device *dev, phys_addr_t tlb_addr,
size_t size, enum dma_data_direction dir)
{
if (dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL)
swiotlb_bounce(dev, tlb_addr, size, DMA_TO_DEVICE);
else
BUG_ON(dir != DMA_FROM_DEVICE);
}
void swiotlb_sync_single_for_cpu(struct device *dev, phys_addr_t tlb_addr,
size_t size, enum dma_data_direction dir)
{
if (dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL)
swiotlb_bounce(dev, tlb_addr, size, DMA_FROM_DEVICE);
else
BUG_ON(dir != DMA_TO_DEVICE);
}
/*
* 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, 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(struct device *dev)
{
return dev->dma_io_tlb_mem != NULL;
}
EXPORT_SYMBOL_GPL(is_swiotlb_active);
#ifdef CONFIG_DEBUG_FS
static struct dentry *debugfs_dir;
static void swiotlb_create_debugfs_files(struct io_tlb_mem *mem)
{
debugfs_create_ulong("io_tlb_nslabs", 0400, mem->debugfs, &mem->nslabs);
debugfs_create_ulong("io_tlb_used", 0400, mem->debugfs, &mem->used);
}
static int __init swiotlb_create_default_debugfs(void)
{
struct io_tlb_mem *mem = io_tlb_default_mem;
debugfs_dir = debugfs_create_dir("swiotlb", NULL);
if (mem) {
mem->debugfs = debugfs_dir;
swiotlb_create_debugfs_files(mem);
}
return 0;
}
late_initcall(swiotlb_create_default_debugfs);
#endif
#ifdef CONFIG_DMA_RESTRICTED_POOL
#ifdef CONFIG_DEBUG_FS
static void rmem_swiotlb_debugfs_init(struct reserved_mem *rmem)
{
struct io_tlb_mem *mem = rmem->priv;
mem->debugfs = debugfs_create_dir(rmem->name, debugfs_dir);
swiotlb_create_debugfs_files(mem);
}
#else
static void rmem_swiotlb_debugfs_init(struct reserved_mem *rmem)
{
}
#endif
struct page *swiotlb_alloc(struct device *dev, size_t size)
{
struct io_tlb_mem *mem = dev->dma_io_tlb_mem;
phys_addr_t tlb_addr;
int index;
if (!mem)
return NULL;
index = swiotlb_find_slots(dev, 0, size);
if (index == -1)
return NULL;
tlb_addr = slot_addr(mem->start, index);
return pfn_to_page(PFN_DOWN(tlb_addr));
}
bool swiotlb_free(struct device *dev, struct page *page, size_t size)
{
phys_addr_t tlb_addr = page_to_phys(page);
if (!is_swiotlb_buffer(dev, tlb_addr))
return false;
swiotlb_release_slots(dev, tlb_addr);
return true;
}
static int rmem_swiotlb_device_init(struct reserved_mem *rmem,
struct device *dev)
{
struct io_tlb_mem *mem = rmem->priv;
unsigned long nslabs = rmem->size >> IO_TLB_SHIFT;
/*
* Since multiple devices can share the same pool, the private data,
* io_tlb_mem struct, will be initialized by the first device attached
* to it.
*/
if (!mem) {
mem = kzalloc(struct_size(mem, slots, nslabs), GFP_KERNEL);
if (!mem)
return -ENOMEM;
set_memory_decrypted((unsigned long)phys_to_virt(rmem->base),
rmem->size >> PAGE_SHIFT);
swiotlb_init_io_tlb_mem(mem, rmem->base, nslabs, false);
mem->force_bounce = true;
mem->for_alloc = true;
rmem->priv = mem;
rmem_swiotlb_debugfs_init(rmem);
}
dev->dma_io_tlb_mem = mem;
return 0;
}
static void rmem_swiotlb_device_release(struct reserved_mem *rmem,
struct device *dev)
{
dev->dma_io_tlb_mem = io_tlb_default_mem;
}
static const struct reserved_mem_ops rmem_swiotlb_ops = {
.device_init = rmem_swiotlb_device_init,
.device_release = rmem_swiotlb_device_release,
};
static int __init rmem_swiotlb_setup(struct reserved_mem *rmem)
{
unsigned long node = rmem->fdt_node;
if (of_get_flat_dt_prop(node, "reusable", NULL) ||
of_get_flat_dt_prop(node, "linux,cma-default", NULL) ||
of_get_flat_dt_prop(node, "linux,dma-default", NULL) ||
of_get_flat_dt_prop(node, "no-map", NULL))
return -EINVAL;
if (PageHighMem(pfn_to_page(PHYS_PFN(rmem->base)))) {
pr_err("Restricted DMA pool must be accessible within the linear mapping.");
return -EINVAL;
}
rmem->ops = &rmem_swiotlb_ops;
pr_info("Reserved memory: created restricted DMA pool at %pa, size %ld MiB\n",
&rmem->base, (unsigned long)rmem->size / SZ_1M);
return 0;
}
RESERVEDMEM_OF_DECLARE(dma, "restricted-dma-pool", rmem_swiotlb_setup);
#endif /* CONFIG_DMA_RESTRICTED_POOL */
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