[PATCH v5 4/9] swiotlb: separate memory pool data from other allocator data
Petr Tesarik
petrtesarik at huaweicloud.com
Mon Jul 24 05:12:40 PDT 2023
From: Petr Tesarik <petr.tesarik.ext at huawei.com>
Carve out memory pool specific fields from struct io_tlb_mem. The original
struct now contains shared data for the whole allocator, while the new
struct io_tlb_pool contains data that is specific to one memory pool of
(potentially) many.
Signed-off-by: Petr Tesarik <petr.tesarik.ext at huawei.com>
---
include/linux/device.h | 2 +-
include/linux/swiotlb.h | 45 +++++++----
kernel/dma/swiotlb.c | 175 +++++++++++++++++++++++++---------------
3 files changed, 140 insertions(+), 82 deletions(-)
diff --git a/include/linux/device.h b/include/linux/device.h
index bbaeabd04b0d..d9754a68ba95 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -625,7 +625,7 @@ struct device_physical_location {
* @dma_pools: Dma pools (if dma'ble device).
* @dma_mem: Internal for coherent mem override.
* @cma_area: Contiguous memory area for dma allocations
- * @dma_io_tlb_mem: Pointer to the swiotlb pool used. Not for driver use.
+ * @dma_io_tlb_mem: Software IO TLB allocator. Not for driver use.
* @archdata: For arch-specific additions.
* @of_node: Associated device tree node.
* @fwnode: Associated device node supplied by platform firmware.
diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h
index b122ad90660d..fd01a0870b38 100644
--- a/include/linux/swiotlb.h
+++ b/include/linux/swiotlb.h
@@ -62,8 +62,7 @@ dma_addr_t swiotlb_map(struct device *dev, phys_addr_t phys,
#ifdef CONFIG_SWIOTLB
/**
- * struct io_tlb_mem - IO TLB Memory Pool Descriptor
- *
+ * struct io_tlb_pool - IO TLB memory pool descriptor
* @start: The start address of the swiotlb memory pool. Used to do a quick
* range check to see if the memory was in fact allocated by this
* API.
@@ -73,15 +72,34 @@ dma_addr_t swiotlb_map(struct device *dev, phys_addr_t phys,
* @vaddr: The vaddr of the swiotlb memory pool. The swiotlb memory pool
* may be remapped in the memory encrypted case and store virtual
* address for bounce buffer operation.
- * @nslabs: The number of IO TLB blocks (in groups of 64) between @start and
- * @end. For default swiotlb, this is command line adjustable via
- * setup_io_tlb_npages.
+ * @nslabs: The number of IO TLB slots between @start and @end. For the
+ * default swiotlb, this can be adjusted with a boot parameter,
+ * see setup_io_tlb_npages().
+ * @late_alloc: %true if allocated using the page allocator.
+ * @nareas: Number of areas in the pool.
+ * @area_nslabs: Number of slots in each area.
+ * @areas: Array of memory area descriptors.
+ * @slots: Array of slot descriptors.
+ */
+struct io_tlb_pool {
+ phys_addr_t start;
+ phys_addr_t end;
+ void *vaddr;
+ unsigned long nslabs;
+ bool late_alloc;
+ unsigned int nareas;
+ unsigned int area_nslabs;
+ struct io_tlb_area *areas;
+ struct io_tlb_slot *slots;
+};
+
+/**
+ * struct io_tlb_mem - Software IO TLB allocator
+ * @defpool: Default (initial) IO TLB memory pool descriptor.
+ * @nslabs: Total number of IO TLB slabs in all pools.
* @debugfs: The dentry to debugfs.
- * @late_alloc: %true if allocated using the page allocator
* @force_bounce: %true if swiotlb bouncing is forced
* @for_alloc: %true if the pool is used for memory allocation
- * @nareas: The area number in the pool.
- * @area_nslabs: The slot number in the area.
* @total_used: The total number of slots in the pool that are currently used
* across all areas. Used only for calculating used_hiwater in
* debugfs.
@@ -89,18 +107,11 @@ dma_addr_t swiotlb_map(struct device *dev, phys_addr_t phys,
* in debugfs.
*/
struct io_tlb_mem {
- phys_addr_t start;
- phys_addr_t end;
- void *vaddr;
+ struct io_tlb_pool defpool;
unsigned long nslabs;
struct dentry *debugfs;
- bool late_alloc;
bool force_bounce;
bool for_alloc;
- unsigned int nareas;
- unsigned int area_nslabs;
- struct io_tlb_area *areas;
- struct io_tlb_slot *slots;
#ifdef CONFIG_DEBUG_FS
atomic_long_t total_used;
atomic_long_t used_hiwater;
@@ -122,7 +133,7 @@ static inline bool is_swiotlb_buffer(struct device *dev, phys_addr_t paddr)
{
struct io_tlb_mem *mem = dev->dma_io_tlb_mem;
- return mem && paddr >= mem->start && paddr < mem->end;
+ return mem && paddr >= mem->defpool.start && paddr < mem->defpool.end;
}
static inline bool is_swiotlb_force_bounce(struct device *dev)
diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index 7eafb8ceb577..11bacde00df7 100644
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -209,7 +209,7 @@ void __init swiotlb_adjust_size(unsigned long size)
void swiotlb_print_info(void)
{
- struct io_tlb_mem *mem = &io_tlb_default_mem;
+ struct io_tlb_pool *mem = &io_tlb_default_mem.defpool;
if (!mem->nslabs) {
pr_warn("No low mem\n");
@@ -238,7 +238,7 @@ static inline unsigned long nr_slots(u64 val)
*/
void __init swiotlb_update_mem_attributes(void)
{
- struct io_tlb_mem *mem = &io_tlb_default_mem;
+ struct io_tlb_pool *mem = &io_tlb_default_mem.defpool;
unsigned long bytes;
if (!mem->nslabs || mem->late_alloc)
@@ -247,9 +247,8 @@ void __init swiotlb_update_mem_attributes(void)
set_memory_decrypted((unsigned long)mem->vaddr, bytes >> PAGE_SHIFT);
}
-static void swiotlb_init_io_tlb_mem(struct io_tlb_mem *mem, phys_addr_t start,
- unsigned long nslabs, unsigned int flags,
- bool late_alloc, unsigned int nareas)
+static void swiotlb_init_io_tlb_pool(struct io_tlb_pool *mem, phys_addr_t start,
+ unsigned long nslabs, bool late_alloc, unsigned int nareas)
{
void *vaddr = phys_to_virt(start);
unsigned long bytes = nslabs << IO_TLB_SHIFT, i;
@@ -261,8 +260,6 @@ static void swiotlb_init_io_tlb_mem(struct io_tlb_mem *mem, phys_addr_t start,
mem->nareas = nareas;
mem->area_nslabs = nslabs / mem->nareas;
- mem->force_bounce = swiotlb_force_bounce || (flags & SWIOTLB_FORCE);
-
for (i = 0; i < mem->nareas; i++) {
spin_lock_init(&mem->areas[i].lock);
mem->areas[i].index = 0;
@@ -319,7 +316,7 @@ static void __init *swiotlb_memblock_alloc(unsigned long nslabs,
void __init swiotlb_init_remap(bool addressing_limit, unsigned int flags,
int (*remap)(void *tlb, unsigned long nslabs))
{
- struct io_tlb_mem *mem = &io_tlb_default_mem;
+ struct io_tlb_pool *mem = &io_tlb_default_mem.defpool;
unsigned long nslabs;
unsigned int nareas;
size_t alloc_size;
@@ -330,6 +327,9 @@ void __init swiotlb_init_remap(bool addressing_limit, unsigned int flags,
if (swiotlb_force_disable)
return;
+ io_tlb_default_mem.force_bounce =
+ swiotlb_force_bounce || (flags & SWIOTLB_FORCE);
+
if (!default_nareas)
swiotlb_adjust_nareas(num_possible_cpus());
@@ -363,8 +363,9 @@ void __init swiotlb_init_remap(bool addressing_limit, unsigned int flags,
return;
}
- swiotlb_init_io_tlb_mem(mem, __pa(tlb), nslabs, flags, false,
- default_nareas);
+ swiotlb_init_io_tlb_pool(mem, __pa(tlb), nslabs, false,
+ default_nareas);
+ io_tlb_default_mem.nslabs = nslabs;
if (flags & SWIOTLB_VERBOSE)
swiotlb_print_info();
@@ -383,7 +384,7 @@ void __init swiotlb_init(bool addressing_limit, unsigned int flags)
int swiotlb_init_late(size_t size, gfp_t gfp_mask,
int (*remap)(void *tlb, unsigned long nslabs))
{
- struct io_tlb_mem *mem = &io_tlb_default_mem;
+ struct io_tlb_pool *mem = &io_tlb_default_mem.defpool;
unsigned long nslabs = ALIGN(size >> IO_TLB_SHIFT, IO_TLB_SEGSIZE);
unsigned int nareas;
unsigned char *vstart = NULL;
@@ -397,6 +398,8 @@ int swiotlb_init_late(size_t size, gfp_t gfp_mask,
if (swiotlb_force_disable)
return 0;
+ io_tlb_default_mem.force_bounce = swiotlb_force_bounce;
+
if (!default_nareas)
swiotlb_adjust_nareas(num_possible_cpus());
@@ -448,8 +451,9 @@ int swiotlb_init_late(size_t size, gfp_t gfp_mask,
set_memory_decrypted((unsigned long)vstart,
(nslabs << IO_TLB_SHIFT) >> PAGE_SHIFT);
- swiotlb_init_io_tlb_mem(mem, virt_to_phys(vstart), nslabs, 0, true,
- nareas);
+ swiotlb_init_io_tlb_pool(mem, virt_to_phys(vstart), nslabs, true,
+ nareas);
+ io_tlb_default_mem.nslabs = nslabs;
swiotlb_print_info();
return 0;
@@ -463,7 +467,7 @@ int swiotlb_init_late(size_t size, gfp_t gfp_mask,
void __init swiotlb_exit(void)
{
- struct io_tlb_mem *mem = &io_tlb_default_mem;
+ struct io_tlb_pool *mem = &io_tlb_default_mem.defpool;
unsigned long tbl_vaddr;
size_t tbl_size, slots_size;
unsigned int area_order;
@@ -519,7 +523,7 @@ static unsigned int swiotlb_align_offset(struct device *dev, u64 addr)
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;
+ struct io_tlb_pool *mem = &dev->dma_io_tlb_mem->defpool;
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;
@@ -601,7 +605,7 @@ static inline unsigned long get_max_slots(unsigned long boundary_mask)
return nr_slots(boundary_mask + 1);
}
-static unsigned int wrap_area_index(struct io_tlb_mem *mem, unsigned int index)
+static unsigned int wrap_area_index(struct io_tlb_pool *mem, unsigned int index)
{
if (index >= mem->area_nslabs)
return 0;
@@ -645,6 +649,7 @@ static void dec_used(struct io_tlb_mem *mem, unsigned int nslots)
/**
* swiotlb_area_find_slots() - search for slots in one IO TLB memory area
* @dev: Device which maps the buffer.
+ * @pool: Memory pool to be searched.
* @area_index: Index of the IO TLB memory area to be searched.
* @orig_addr: Original (non-bounced) IO buffer address.
* @alloc_size: Total requested size of the bounce buffer,
@@ -657,15 +662,14 @@ static void dec_used(struct io_tlb_mem *mem, unsigned int nslots)
*
* Return: Index of the first allocated slot, or -1 on error.
*/
-static int swiotlb_area_find_slots(struct device *dev, int area_index,
- phys_addr_t orig_addr, size_t alloc_size,
+static int swiotlb_area_find_slots(struct device *dev, struct io_tlb_pool *pool,
+ int area_index, phys_addr_t orig_addr, size_t alloc_size,
unsigned int alloc_align_mask)
{
- struct io_tlb_mem *mem = dev->dma_io_tlb_mem;
- struct io_tlb_area *area = mem->areas + area_index;
+ struct io_tlb_area *area = pool->areas + area_index;
unsigned long boundary_mask = dma_get_seg_boundary(dev);
dma_addr_t tbl_dma_addr =
- phys_to_dma_unencrypted(dev, mem->start) & boundary_mask;
+ phys_to_dma_unencrypted(dev, pool->start) & boundary_mask;
unsigned long max_slots = get_max_slots(boundary_mask);
unsigned int iotlb_align_mask =
dma_get_min_align_mask(dev) | alloc_align_mask;
@@ -677,7 +681,7 @@ static int swiotlb_area_find_slots(struct device *dev, int area_index,
unsigned int slot_index;
BUG_ON(!nslots);
- BUG_ON(area_index >= mem->nareas);
+ BUG_ON(area_index >= pool->nareas);
/*
* For allocations of PAGE_SIZE or larger only look for page aligned
@@ -694,19 +698,19 @@ static int swiotlb_area_find_slots(struct device *dev, int area_index,
stride = (iotlb_align_mask >> IO_TLB_SHIFT) + 1;
spin_lock_irqsave(&area->lock, flags);
- if (unlikely(nslots > mem->area_nslabs - area->used))
+ if (unlikely(nslots > pool->area_nslabs - area->used))
goto not_found;
- slot_base = area_index * mem->area_nslabs;
+ slot_base = area_index * pool->area_nslabs;
index = area->index;
- for (slots_checked = 0; slots_checked < mem->area_nslabs; ) {
+ for (slots_checked = 0; slots_checked < pool->area_nslabs; ) {
slot_index = slot_base + index;
if (orig_addr &&
(slot_addr(tbl_dma_addr, slot_index) &
iotlb_align_mask) != (orig_addr & iotlb_align_mask)) {
- index = wrap_area_index(mem, index + 1);
+ index = wrap_area_index(pool, index + 1);
slots_checked++;
continue;
}
@@ -719,10 +723,10 @@ static int swiotlb_area_find_slots(struct device *dev, int area_index,
if (!iommu_is_span_boundary(slot_index, nslots,
nr_slots(tbl_dma_addr),
max_slots)) {
- if (mem->slots[slot_index].list >= nslots)
+ if (pool->slots[slot_index].list >= nslots)
goto found;
}
- index = wrap_area_index(mem, index + stride);
+ index = wrap_area_index(pool, index + stride);
slots_checked += stride;
}
@@ -732,58 +736,79 @@ static int swiotlb_area_find_slots(struct device *dev, int area_index,
found:
for (i = slot_index; i < slot_index + nslots; i++) {
- mem->slots[i].list = 0;
- mem->slots[i].alloc_size = alloc_size - (offset +
+ pool->slots[i].list = 0;
+ pool->slots[i].alloc_size = alloc_size - (offset +
((i - slot_index) << IO_TLB_SHIFT));
}
for (i = slot_index - 1;
io_tlb_offset(i) != IO_TLB_SEGSIZE - 1 &&
- mem->slots[i].list; i--)
- mem->slots[i].list = ++count;
+ pool->slots[i].list; i--)
+ pool->slots[i].list = ++count;
/*
* Update the indices to avoid searching in the next round.
*/
- area->index = wrap_area_index(mem, index + nslots);
+ area->index = wrap_area_index(pool, index + nslots);
area->used += nslots;
spin_unlock_irqrestore(&area->lock, flags);
- inc_used_and_hiwater(mem, nslots);
+ inc_used_and_hiwater(dev->dma_io_tlb_mem, nslots);
return slot_index;
}
/**
- * swiotlb_find_slots() - search for slots in the whole swiotlb
+ * swiotlb_pool_find_slots() - search for slots in one memory pool
* @dev: Device which maps the buffer.
+ * @pool: Memory pool to be searched.
* @orig_addr: Original (non-bounced) IO buffer address.
* @alloc_size: Total requested size of the bounce buffer,
* including initial alignment padding.
* @alloc_align_mask: Required alignment of the allocated buffer.
*
- * Search through the whole software IO TLB to find a sequence of slots that
- * match the allocation constraints.
+ * Search through one memory pool to find a sequence of slots that match the
+ * allocation constraints.
*
* Return: Index of the first allocated slot, or -1 on error.
*/
-static int swiotlb_find_slots(struct device *dev, phys_addr_t orig_addr,
- size_t alloc_size, unsigned int alloc_align_mask)
+static int swiotlb_pool_find_slots(struct device *dev, struct io_tlb_pool *pool,
+ phys_addr_t orig_addr, size_t alloc_size,
+ unsigned int alloc_align_mask)
{
- struct io_tlb_mem *mem = dev->dma_io_tlb_mem;
- int start = raw_smp_processor_id() & (mem->nareas - 1);
+ int start = raw_smp_processor_id() & (pool->nareas - 1);
int i = start, index;
do {
- index = swiotlb_area_find_slots(dev, i, orig_addr, alloc_size,
- alloc_align_mask);
+ index = swiotlb_area_find_slots(dev, pool, i, orig_addr,
+ alloc_size, alloc_align_mask);
if (index >= 0)
return index;
- if (++i >= mem->nareas)
+ if (++i >= pool->nareas)
i = 0;
} while (i != start);
return -1;
}
+/**
+ * swiotlb_find_slots() - search for slots in the whole swiotlb
+ * @dev: Device which maps the buffer.
+ * @orig_addr: Original (non-bounced) IO buffer address.
+ * @alloc_size: Total requested size of the bounce buffer,
+ * including initial alignment padding.
+ * @alloc_align_mask: Required alignment of the allocated buffer.
+ *
+ * Search through the whole software IO TLB to find a sequence of slots that
+ * match the allocation constraints.
+ *
+ * Return: Index of the first allocated slot, or -1 on error.
+ */
+static int swiotlb_find_slots(struct device *dev, phys_addr_t orig_addr,
+ size_t alloc_size, unsigned int alloc_align_mask)
+{
+ return swiotlb_pool_find_slots(dev, &dev->dma_io_tlb_mem->defpool,
+ orig_addr, alloc_size, alloc_align_mask);
+}
+
#ifdef CONFIG_DEBUG_FS
/**
@@ -802,6 +827,24 @@ static unsigned long mem_used(struct io_tlb_mem *mem)
#else /* !CONFIG_DEBUG_FS */
+/**
+ * mem_pool_used() - get number of used slots in a memory pool
+ * @pool: Software IO TLB memory pool.
+ *
+ * The result is not accurate, see mem_used().
+ *
+ * Return: Approximate number of used slots.
+ */
+static unsigned long mem_pool_used(struct io_tlb_pool *pool)
+{
+ int i;
+ unsigned long used = 0;
+
+ for (i = 0; i < pool->nareas; i++)
+ used += pool->areas[i].used;
+ return used;
+}
+
/**
* mem_used() - get number of used slots in an allocator
* @mem: Software IO TLB allocator.
@@ -813,12 +856,7 @@ static unsigned long mem_used(struct io_tlb_mem *mem)
*/
static unsigned long mem_used(struct io_tlb_mem *mem)
{
- int i;
- unsigned long used = 0;
-
- for (i = 0; i < mem->nareas; i++)
- used += mem->areas[i].used;
- return used;
+ return mem_pool_used(&mem->defpool);
}
#endif /* CONFIG_DEBUG_FS */
@@ -830,6 +868,7 @@ phys_addr_t swiotlb_tbl_map_single(struct device *dev, phys_addr_t orig_addr,
{
struct io_tlb_mem *mem = dev->dma_io_tlb_mem;
unsigned int offset = swiotlb_align_offset(dev, orig_addr);
+ struct io_tlb_pool *pool;
unsigned int i;
int index;
phys_addr_t tlb_addr;
@@ -864,9 +903,10 @@ phys_addr_t swiotlb_tbl_map_single(struct device *dev, phys_addr_t orig_addr,
* This is needed when we sync the memory. Then we sync the buffer if
* needed.
*/
+ pool = &mem->defpool;
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;
+ pool->slots[index + i].orig_addr = slot_addr(orig_addr, i);
+ tlb_addr = slot_addr(pool->start, index) + offset;
/*
* When dir == DMA_FROM_DEVICE we could omit the copy from the orig
* to the tlb buffer, if we knew for sure the device will
@@ -880,7 +920,7 @@ phys_addr_t swiotlb_tbl_map_single(struct device *dev, phys_addr_t orig_addr,
static void swiotlb_release_slots(struct device *dev, phys_addr_t tlb_addr)
{
- struct io_tlb_mem *mem = dev->dma_io_tlb_mem;
+ struct io_tlb_pool *mem = &dev->dma_io_tlb_mem->defpool;
unsigned long flags;
unsigned int offset = swiotlb_align_offset(dev, tlb_addr);
int index = (tlb_addr - offset - mem->start) >> IO_TLB_SHIFT;
@@ -924,7 +964,7 @@ static void swiotlb_release_slots(struct device *dev, phys_addr_t tlb_addr)
area->used -= nslots;
spin_unlock_irqrestore(&area->lock, flags);
- dec_used(mem, nslots);
+ dec_used(dev->dma_io_tlb_mem, nslots);
}
/*
@@ -1026,7 +1066,7 @@ EXPORT_SYMBOL_GPL(is_swiotlb_active);
*/
phys_addr_t default_swiotlb_base(void)
{
- return io_tlb_default_mem.start;
+ return io_tlb_default_mem.defpool.start;
}
/**
@@ -1036,7 +1076,7 @@ phys_addr_t default_swiotlb_base(void)
*/
phys_addr_t default_swiotlb_limit(void)
{
- return io_tlb_default_mem.end - 1;
+ return io_tlb_default_mem.defpool.end - 1;
}
#ifdef CONFIG_DEBUG_FS
@@ -1112,6 +1152,7 @@ static inline void swiotlb_create_debugfs_files(struct io_tlb_mem *mem,
struct page *swiotlb_alloc(struct device *dev, size_t size)
{
struct io_tlb_mem *mem = dev->dma_io_tlb_mem;
+ struct io_tlb_pool *pool;
phys_addr_t tlb_addr;
int index;
@@ -1122,7 +1163,8 @@ struct page *swiotlb_alloc(struct device *dev, size_t size)
if (index == -1)
return NULL;
- tlb_addr = slot_addr(mem->start, index);
+ pool = &mem->defpool;
+ tlb_addr = slot_addr(pool->start, index);
return pfn_to_page(PFN_DOWN(tlb_addr));
}
@@ -1159,29 +1201,34 @@ static int rmem_swiotlb_device_init(struct reserved_mem *rmem,
* to it.
*/
if (!mem) {
+ struct io_tlb_pool *pool;
+
mem = kzalloc(sizeof(*mem), GFP_KERNEL);
if (!mem)
return -ENOMEM;
+ pool = &mem->defpool;
- mem->slots = kcalloc(nslabs, sizeof(*mem->slots), GFP_KERNEL);
- if (!mem->slots) {
+ pool->slots = kcalloc(nslabs, sizeof(*pool->slots), GFP_KERNEL);
+ if (!pool->slots) {
kfree(mem);
return -ENOMEM;
}
- mem->areas = kcalloc(nareas, sizeof(*mem->areas),
+ pool->areas = kcalloc(nareas, sizeof(*pool->areas),
GFP_KERNEL);
- if (!mem->areas) {
- kfree(mem->slots);
+ if (!pool->areas) {
+ kfree(pool->slots);
kfree(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, SWIOTLB_FORCE,
- false, nareas);
+ swiotlb_init_io_tlb_pool(pool, rmem->base, nslabs,
+ false, nareas);
+ mem->force_bounce = true;
mem->for_alloc = true;
+ mem->nslabs = nslabs;
rmem->priv = mem;
--
2.25.1
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