include/linux/swiotlb.h - kernel/common - Git at Google

 /* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __LINUX_SWIOTLB_H
 #define __LINUX_SWIOTLB_H

 #include <linux/device.h>
 #include <linux/dma-direction.h>
 #include <linux/init.h>
 #include <linux/types.h>
 #include <linux/limits.h>
 #include <linux/spinlock.h>
 #include <linux/workqueue.h>

 struct device;
 struct page;
 struct scatterlist;

 #define SWIOTLB_VERBOSE	(1 << 0) /* verbose initialization */
 #define SWIOTLB_FORCE	(1 << 1) /* force bounce buffering */
 #define SWIOTLB_ANY	(1 << 2) /* allow any memory for the buffer */

 /*
  * Maximum allowable number of contiguous slabs to map,
  * must be a power of 2.  What is the appropriate value ?
  * The complexity of {map,unmap}_single is linearly dependent on this value.
  */
 #define IO_TLB_SEGSIZE	128

 /*
  * log of the size of each IO TLB slab.  The number of slabs is command line
  * controllable.
  */
 #define IO_TLB_SHIFT 11
 #define IO_TLB_SIZE (1 << IO_TLB_SHIFT)

 /* default to 64MB */
 #define IO_TLB_DEFAULT_SIZE (64UL<<20)

 unsigned long swiotlb_size_or_default(void);
 void __init swiotlb_init_remap(bool addressing_limit, unsigned int flags,
 	int (*remap)(void *tlb, unsigned long nslabs));
 int swiotlb_init_late(size_t size, gfp_t gfp_mask,
 	int (*remap)(void *tlb, unsigned long nslabs));
 extern void __init swiotlb_update_mem_attributes(void);

 phys_addr_t swiotlb_tbl_map_single(struct device *hwdev, phys_addr_t phys,
 		size_t mapping_size, size_t alloc_size,
 		unsigned int alloc_aligned_mask, enum dma_data_direction dir,
 		unsigned long attrs);

 extern void swiotlb_tbl_unmap_single(struct device *hwdev,
 				     phys_addr_t tlb_addr,
 				     size_t mapping_size,
 				     enum dma_data_direction dir,
 				     unsigned long attrs);

 void swiotlb_sync_single_for_device(struct device *dev, phys_addr_t tlb_addr,
 		size_t size, enum dma_data_direction dir);
 void swiotlb_sync_single_for_cpu(struct device *dev, phys_addr_t tlb_addr,
 		size_t size, enum dma_data_direction dir);
 dma_addr_t swiotlb_map(struct device *dev, phys_addr_t phys,
 		size_t size, enum dma_data_direction dir, unsigned long attrs);

 #ifdef CONFIG_SWIOTLB

 /**
  * 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.
  * @end:	The end 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.
  * @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 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.
  * @node:	Member of the IO TLB memory pool list.
  * @rcu:	RCU head for swiotlb_dyn_free().
  * @transient:  %true if transient memory pool.
  */
 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;
 #ifdef CONFIG_SWIOTLB_DYNAMIC
 	struct list_head node;
 	struct rcu_head rcu;
 	bool transient;
 #endif
 };

 /**
  * struct io_tlb_mem - Software IO TLB allocator
  * @defpool:	Default (initial) IO TLB memory pool descriptor.
  * @pool:	IO TLB memory pool descriptor (if not dynamic).
  * @nslabs:	Total number of IO TLB slabs in all pools.
  * @debugfs:	The dentry to debugfs.
  * @force_bounce: %true if swiotlb bouncing is forced
  * @for_alloc:  %true if the pool is used for memory allocation
  * @can_grow:	%true if more pools can be allocated dynamically.
  * @phys_limit:	Maximum allowed physical address.
  * @lock:	Lock to synchronize changes to the list.
  * @pools:	List of IO TLB memory pool descriptors (if dynamic).
  * @dyn_alloc:	Dynamic IO TLB pool allocation work.
  * @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.
  * @used_hiwater: The high water mark for total_used.  Used only for reporting
  *		in debugfs.
  */
 struct io_tlb_mem {
 	struct io_tlb_pool defpool;
 	unsigned long nslabs;
 	struct dentry *debugfs;
 	bool force_bounce;
 	bool for_alloc;
 #ifdef CONFIG_SWIOTLB_DYNAMIC
 	bool can_grow;
 	u64 phys_limit;
 	spinlock_t lock;
 	struct list_head pools;
 	struct work_struct dyn_alloc;
 #endif
 #ifdef CONFIG_DEBUG_FS
 	atomic_long_t total_used;
 	atomic_long_t used_hiwater;
 #endif
 };

 #ifdef CONFIG_SWIOTLB_DYNAMIC

 struct io_tlb_pool *swiotlb_find_pool(struct device *dev, phys_addr_t paddr);

 #else

 static inline struct io_tlb_pool *swiotlb_find_pool(struct device *dev,
 						    phys_addr_t paddr)
 {
 	return &dev->dma_io_tlb_mem->defpool;
 }

 #endif

 /**
  * is_swiotlb_buffer() - check if a physical address belongs to a swiotlb
  * @dev:        Device which has mapped the buffer.
  * @paddr:      Physical address within the DMA buffer.
  *
  * Check if @paddr points into a bounce buffer.
  *
  * Return:
  * * %true if @paddr points into a bounce buffer
  * * %false otherwise
  */
 static inline bool is_swiotlb_buffer(struct device *dev, phys_addr_t paddr)
 {
 	struct io_tlb_mem *mem = dev->dma_io_tlb_mem;

 	if (!mem)
 		return false;

 #ifdef CONFIG_SWIOTLB_DYNAMIC
 	/*
 	 * All SWIOTLB buffer addresses must have been returned by
 	 * swiotlb_tbl_map_single() and passed to a device driver.
 	 * If a SWIOTLB address is checked on another CPU, then it was
 	 * presumably loaded by the device driver from an unspecified private
 	 * data structure. Make sure that this load is ordered before reading
 	 * dev->dma_uses_io_tlb here and mem->pools in swiotlb_find_pool().
 	 *
 	 * This barrier pairs with smp_mb() in swiotlb_find_slots().
 	 */
 	smp_rmb();
 	return READ_ONCE(dev->dma_uses_io_tlb) &&
 		swiotlb_find_pool(dev, paddr);
 #else
 	return paddr >= mem->defpool.start && paddr < mem->defpool.end;
 #endif
 }

 static inline bool is_swiotlb_force_bounce(struct device *dev)
 {
 	struct io_tlb_mem *mem = dev->dma_io_tlb_mem;

 	return mem && mem->force_bounce;
 }

 void swiotlb_init(bool addressing_limited, unsigned int flags);
 void __init swiotlb_exit(void);
 void swiotlb_dev_init(struct device *dev);
 size_t swiotlb_max_mapping_size(struct device *dev);
 bool is_swiotlb_allocated(void);
 bool is_swiotlb_active(struct device *dev);
 void __init swiotlb_adjust_size(unsigned long size);
 phys_addr_t default_swiotlb_base(void);
 phys_addr_t default_swiotlb_limit(void);
 #else
 static inline void swiotlb_init(bool addressing_limited, unsigned int flags)
 {
 }

 static inline void swiotlb_dev_init(struct device *dev)
 {
 }

 static inline bool is_swiotlb_buffer(struct device *dev, phys_addr_t paddr)
 {
 	return false;
 }
 static inline bool is_swiotlb_force_bounce(struct device *dev)
 {
 	return false;
 }
 static inline void swiotlb_exit(void)
 {
 }
 static inline size_t swiotlb_max_mapping_size(struct device *dev)
 {
 	return SIZE_MAX;
 }

 static inline bool is_swiotlb_allocated(void)
 {
 	return false;
 }

 static inline bool is_swiotlb_active(struct device *dev)
 {
 	return false;
 }

 static inline void swiotlb_adjust_size(unsigned long size)
 {
 }

 static inline phys_addr_t default_swiotlb_base(void)
 {
 	return 0;
 }

 static inline phys_addr_t default_swiotlb_limit(void)
 {
 	return 0;
 }
 #endif /* CONFIG_SWIOTLB */

 extern void swiotlb_print_info(void);

 #ifdef CONFIG_DMA_RESTRICTED_POOL
 struct page *swiotlb_alloc(struct device *dev, size_t size);
 bool swiotlb_free(struct device *dev, struct page *page, size_t size);

 static inline bool is_swiotlb_for_alloc(struct device *dev)
 {
 	return dev->dma_io_tlb_mem->for_alloc;
 }
 #else
 static inline struct page *swiotlb_alloc(struct device *dev, size_t size)
 {
 	return NULL;
 }
 static inline bool swiotlb_free(struct device *dev, struct page *page,
 				size_t size)
 {
 	return false;
 }
 static inline bool is_swiotlb_for_alloc(struct device *dev)
 {
 	return false;
 }
 #endif /* CONFIG_DMA_RESTRICTED_POOL */

 #endif /* __LINUX_SWIOTLB_H */
	/* SPDX-License-Identifier: GPL-2.0 */
	#ifndef __LINUX_SWIOTLB_H
	#define __LINUX_SWIOTLB_H

	#include <linux/device.h>
	#include <linux/dma-direction.h>
	#include <linux/init.h>
	#include <linux/types.h>
	#include <linux/limits.h>
	#include <linux/spinlock.h>
	#include <linux/workqueue.h>

	struct device;
	struct page;
	struct scatterlist;

	#define SWIOTLB_VERBOSE (1 << 0) /* verbose initialization */
	#define SWIOTLB_FORCE (1 << 1) /* force bounce buffering */
	#define SWIOTLB_ANY (1 << 2) /* allow any memory for the buffer */

	/*
	* Maximum allowable number of contiguous slabs to map,
	* must be a power of 2. What is the appropriate value ?
	* The complexity of {map,unmap}_single is linearly dependent on this value.
	*/
	#define IO_TLB_SEGSIZE 128

	/*
	* log of the size of each IO TLB slab. The number of slabs is command line
	* controllable.
	*/
	#define IO_TLB_SHIFT 11
	#define IO_TLB_SIZE (1 << IO_TLB_SHIFT)

	/* default to 64MB */
	#define IO_TLB_DEFAULT_SIZE (64UL<<20)

	unsigned long swiotlb_size_or_default(void);
	void __init swiotlb_init_remap(bool addressing_limit, unsigned int flags,
	int (remap)(void tlb, unsigned long nslabs));
	int swiotlb_init_late(size_t size, gfp_t gfp_mask,
	int (remap)(void tlb, unsigned long nslabs));
	extern void __init swiotlb_update_mem_attributes(void);

	phys_addr_t swiotlb_tbl_map_single(struct device *hwdev, phys_addr_t phys,
	size_t mapping_size, size_t alloc_size,
	unsigned int alloc_aligned_mask, enum dma_data_direction dir,
	unsigned long attrs);

	extern void swiotlb_tbl_unmap_single(struct device *hwdev,
	phys_addr_t tlb_addr,
	size_t mapping_size,
	enum dma_data_direction dir,
	unsigned long attrs);

	void swiotlb_sync_single_for_device(struct device *dev, phys_addr_t tlb_addr,
	size_t size, enum dma_data_direction dir);
	void swiotlb_sync_single_for_cpu(struct device *dev, phys_addr_t tlb_addr,
	size_t size, enum dma_data_direction dir);
	dma_addr_t swiotlb_map(struct device *dev, phys_addr_t phys,
	size_t size, enum dma_data_direction dir, unsigned long attrs);

	#ifdef CONFIG_SWIOTLB

	/**
	* 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.
	* @end: The end 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.
	* @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 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.
	* @node: Member of the IO TLB memory pool list.
	* @rcu: RCU head for swiotlb_dyn_free().
	* @transient: %true if transient memory pool.
	*/
	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;
	#ifdef CONFIG_SWIOTLB_DYNAMIC
	struct list_head node;
	struct rcu_head rcu;
	bool transient;
	#endif
	};

	/**
	* struct io_tlb_mem - Software IO TLB allocator
	* @defpool: Default (initial) IO TLB memory pool descriptor.
	* @pool: IO TLB memory pool descriptor (if not dynamic).
	* @nslabs: Total number of IO TLB slabs in all pools.
	* @debugfs: The dentry to debugfs.
	* @force_bounce: %true if swiotlb bouncing is forced
	* @for_alloc: %true if the pool is used for memory allocation
	* @can_grow: %true if more pools can be allocated dynamically.
	* @phys_limit: Maximum allowed physical address.
	* @lock: Lock to synchronize changes to the list.
	* @pools: List of IO TLB memory pool descriptors (if dynamic).
	* @dyn_alloc: Dynamic IO TLB pool allocation work.
	* @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.
	* @used_hiwater: The high water mark for total_used. Used only for reporting
	* in debugfs.
	*/
	struct io_tlb_mem {
	struct io_tlb_pool defpool;
	unsigned long nslabs;
	struct dentry *debugfs;
	bool force_bounce;
	bool for_alloc;
	#ifdef CONFIG_SWIOTLB_DYNAMIC
	bool can_grow;
	u64 phys_limit;
	spinlock_t lock;
	struct list_head pools;
	struct work_struct dyn_alloc;
	#endif
	#ifdef CONFIG_DEBUG_FS
	atomic_long_t total_used;
	atomic_long_t used_hiwater;
	#endif
	};

	#ifdef CONFIG_SWIOTLB_DYNAMIC

	struct io_tlb_pool swiotlb_find_pool(struct device dev, phys_addr_t paddr);

	#else

	static inline struct io_tlb_pool swiotlb_find_pool(struct device dev,
	phys_addr_t paddr)
	{
	return &dev->dma_io_tlb_mem->defpool;
	}

	#endif

	/**
	* is_swiotlb_buffer() - check if a physical address belongs to a swiotlb
	* @dev: Device which has mapped the buffer.
	* @paddr: Physical address within the DMA buffer.
	*
	* Check if @paddr points into a bounce buffer.
	*
	* Return:
	* * %true if @paddr points into a bounce buffer
	* * %false otherwise
	*/
	static inline bool is_swiotlb_buffer(struct device *dev, phys_addr_t paddr)
	{
	struct io_tlb_mem *mem = dev->dma_io_tlb_mem;

	if (!mem)
	return false;

	#ifdef CONFIG_SWIOTLB_DYNAMIC
	/*
	* All SWIOTLB buffer addresses must have been returned by
	* swiotlb_tbl_map_single() and passed to a device driver.
	* If a SWIOTLB address is checked on another CPU, then it was
	* presumably loaded by the device driver from an unspecified private
	* data structure. Make sure that this load is ordered before reading
	* dev->dma_uses_io_tlb here and mem->pools in swiotlb_find_pool().
	*
	* This barrier pairs with smp_mb() in swiotlb_find_slots().
	*/
	smp_rmb();
	return READ_ONCE(dev->dma_uses_io_tlb) &&
	swiotlb_find_pool(dev, paddr);
	#else
	return paddr >= mem->defpool.start && paddr < mem->defpool.end;
	#endif
	}

	static inline bool is_swiotlb_force_bounce(struct device *dev)
	{
	struct io_tlb_mem *mem = dev->dma_io_tlb_mem;

	return mem && mem->force_bounce;
	}

	void swiotlb_init(bool addressing_limited, unsigned int flags);
	void __init swiotlb_exit(void);
	void swiotlb_dev_init(struct device *dev);
	size_t swiotlb_max_mapping_size(struct device *dev);
	bool is_swiotlb_allocated(void);
	bool is_swiotlb_active(struct device *dev);
	void __init swiotlb_adjust_size(unsigned long size);
	phys_addr_t default_swiotlb_base(void);
	phys_addr_t default_swiotlb_limit(void);
	#else
	static inline void swiotlb_init(bool addressing_limited, unsigned int flags)
	{
	}

	static inline void swiotlb_dev_init(struct device *dev)
	{
	}

	static inline bool is_swiotlb_buffer(struct device *dev, phys_addr_t paddr)
	{
	return false;
	}
	static inline bool is_swiotlb_force_bounce(struct device *dev)
	{
	return false;
	}
	static inline void swiotlb_exit(void)
	{
	}
	static inline size_t swiotlb_max_mapping_size(struct device *dev)
	{
	return SIZE_MAX;
	}

	static inline bool is_swiotlb_allocated(void)
	{
	return false;
	}

	static inline bool is_swiotlb_active(struct device *dev)
	{
	return false;
	}

	static inline void swiotlb_adjust_size(unsigned long size)
	{
	}

	static inline phys_addr_t default_swiotlb_base(void)
	{
	return 0;
	}

	static inline phys_addr_t default_swiotlb_limit(void)
	{
	return 0;
	}
	#endif /* CONFIG_SWIOTLB */

	extern void swiotlb_print_info(void);

	#ifdef CONFIG_DMA_RESTRICTED_POOL
	struct page swiotlb_alloc(struct device dev, size_t size);
	bool swiotlb_free(struct device dev, struct page page, size_t size);

	static inline bool is_swiotlb_for_alloc(struct device *dev)
	{
	return dev->dma_io_tlb_mem->for_alloc;
	}
	#else
	static inline struct page swiotlb_alloc(struct device dev, size_t size)
	{
	return NULL;
	}
	static inline bool swiotlb_free(struct device dev, struct page page,
	size_t size)
	{
	return false;
	}
	static inline bool is_swiotlb_for_alloc(struct device *dev)
	{
	return false;
	}
	#endif /* CONFIG_DMA_RESTRICTED_POOL */

	#endif /* __LINUX_SWIOTLB_H */