LCOV - code coverage report
Current view: top level - kernel/dma - mapping.c (source / functions) Hit Total Coverage
Test: coverage.info Lines: 0 237 0.0 %
Date: 2023-03-27 20:00:47 Functions: 0 41 0.0 %

          Line data    Source code
       1             : // SPDX-License-Identifier: GPL-2.0
       2             : /*
       3             :  * arch-independent dma-mapping routines
       4             :  *
       5             :  * Copyright (c) 2006  SUSE Linux Products GmbH
       6             :  * Copyright (c) 2006  Tejun Heo <teheo@suse.de>
       7             :  */
       8             : #include <linux/memblock.h> /* for max_pfn */
       9             : #include <linux/acpi.h>
      10             : #include <linux/dma-map-ops.h>
      11             : #include <linux/export.h>
      12             : #include <linux/gfp.h>
      13             : #include <linux/kmsan.h>
      14             : #include <linux/of_device.h>
      15             : #include <linux/slab.h>
      16             : #include <linux/vmalloc.h>
      17             : #include "debug.h"
      18             : #include "direct.h"
      19             : 
      20             : bool dma_default_coherent;
      21             : 
      22             : /*
      23             :  * Managed DMA API
      24             :  */
      25             : struct dma_devres {
      26             :         size_t          size;
      27             :         void            *vaddr;
      28             :         dma_addr_t      dma_handle;
      29             :         unsigned long   attrs;
      30             : };
      31             : 
      32           0 : static void dmam_release(struct device *dev, void *res)
      33             : {
      34           0 :         struct dma_devres *this = res;
      35             : 
      36           0 :         dma_free_attrs(dev, this->size, this->vaddr, this->dma_handle,
      37             :                         this->attrs);
      38           0 : }
      39             : 
      40           0 : static int dmam_match(struct device *dev, void *res, void *match_data)
      41             : {
      42           0 :         struct dma_devres *this = res, *match = match_data;
      43             : 
      44           0 :         if (this->vaddr == match->vaddr) {
      45           0 :                 WARN_ON(this->size != match->size ||
      46             :                         this->dma_handle != match->dma_handle);
      47             :                 return 1;
      48             :         }
      49             :         return 0;
      50             : }
      51             : 
      52             : /**
      53             :  * dmam_free_coherent - Managed dma_free_coherent()
      54             :  * @dev: Device to free coherent memory for
      55             :  * @size: Size of allocation
      56             :  * @vaddr: Virtual address of the memory to free
      57             :  * @dma_handle: DMA handle of the memory to free
      58             :  *
      59             :  * Managed dma_free_coherent().
      60             :  */
      61           0 : void dmam_free_coherent(struct device *dev, size_t size, void *vaddr,
      62             :                         dma_addr_t dma_handle)
      63             : {
      64           0 :         struct dma_devres match_data = { size, vaddr, dma_handle };
      65             : 
      66           0 :         dma_free_coherent(dev, size, vaddr, dma_handle);
      67           0 :         WARN_ON(devres_destroy(dev, dmam_release, dmam_match, &match_data));
      68           0 : }
      69             : EXPORT_SYMBOL(dmam_free_coherent);
      70             : 
      71             : /**
      72             :  * dmam_alloc_attrs - Managed dma_alloc_attrs()
      73             :  * @dev: Device to allocate non_coherent memory for
      74             :  * @size: Size of allocation
      75             :  * @dma_handle: Out argument for allocated DMA handle
      76             :  * @gfp: Allocation flags
      77             :  * @attrs: Flags in the DMA_ATTR_* namespace.
      78             :  *
      79             :  * Managed dma_alloc_attrs().  Memory allocated using this function will be
      80             :  * automatically released on driver detach.
      81             :  *
      82             :  * RETURNS:
      83             :  * Pointer to allocated memory on success, NULL on failure.
      84             :  */
      85           0 : void *dmam_alloc_attrs(struct device *dev, size_t size, dma_addr_t *dma_handle,
      86             :                 gfp_t gfp, unsigned long attrs)
      87             : {
      88             :         struct dma_devres *dr;
      89             :         void *vaddr;
      90             : 
      91           0 :         dr = devres_alloc(dmam_release, sizeof(*dr), gfp);
      92           0 :         if (!dr)
      93             :                 return NULL;
      94             : 
      95           0 :         vaddr = dma_alloc_attrs(dev, size, dma_handle, gfp, attrs);
      96           0 :         if (!vaddr) {
      97           0 :                 devres_free(dr);
      98           0 :                 return NULL;
      99             :         }
     100             : 
     101           0 :         dr->vaddr = vaddr;
     102           0 :         dr->dma_handle = *dma_handle;
     103           0 :         dr->size = size;
     104           0 :         dr->attrs = attrs;
     105             : 
     106           0 :         devres_add(dev, dr);
     107             : 
     108           0 :         return vaddr;
     109             : }
     110             : EXPORT_SYMBOL(dmam_alloc_attrs);
     111             : 
     112             : static bool dma_go_direct(struct device *dev, dma_addr_t mask,
     113             :                 const struct dma_map_ops *ops)
     114             : {
     115             :         if (likely(!ops))
     116             :                 return true;
     117             : #ifdef CONFIG_DMA_OPS_BYPASS
     118             :         if (dev->dma_ops_bypass)
     119             :                 return min_not_zero(mask, dev->bus_dma_limit) >=
     120             :                             dma_direct_get_required_mask(dev);
     121             : #endif
     122             :         return false;
     123             : }
     124             : 
     125             : 
     126             : /*
     127             :  * Check if the devices uses a direct mapping for streaming DMA operations.
     128             :  * This allows IOMMU drivers to set a bypass mode if the DMA mask is large
     129             :  * enough.
     130             :  */
     131             : static inline bool dma_alloc_direct(struct device *dev,
     132             :                 const struct dma_map_ops *ops)
     133             : {
     134           0 :         return dma_go_direct(dev, dev->coherent_dma_mask, ops);
     135             : }
     136             : 
     137             : static inline bool dma_map_direct(struct device *dev,
     138             :                 const struct dma_map_ops *ops)
     139             : {
     140           0 :         return dma_go_direct(dev, *dev->dma_mask, ops);
     141             : }
     142             : 
     143           0 : dma_addr_t dma_map_page_attrs(struct device *dev, struct page *page,
     144             :                 size_t offset, size_t size, enum dma_data_direction dir,
     145             :                 unsigned long attrs)
     146             : {
     147           0 :         const struct dma_map_ops *ops = get_dma_ops(dev);
     148             :         dma_addr_t addr;
     149             : 
     150           0 :         BUG_ON(!valid_dma_direction(dir));
     151             : 
     152           0 :         if (WARN_ON_ONCE(!dev->dma_mask))
     153             :                 return DMA_MAPPING_ERROR;
     154             : 
     155           0 :         if (dma_map_direct(dev, ops) ||
     156             :             arch_dma_map_page_direct(dev, page_to_phys(page) + offset + size))
     157           0 :                 addr = dma_direct_map_page(dev, page, offset, size, dir, attrs);
     158             :         else
     159             :                 addr = ops->map_page(dev, page, offset, size, dir, attrs);
     160           0 :         kmsan_handle_dma(page, offset, size, dir);
     161           0 :         debug_dma_map_page(dev, page, offset, size, dir, addr, attrs);
     162             : 
     163           0 :         return addr;
     164             : }
     165             : EXPORT_SYMBOL(dma_map_page_attrs);
     166             : 
     167           0 : void dma_unmap_page_attrs(struct device *dev, dma_addr_t addr, size_t size,
     168             :                 enum dma_data_direction dir, unsigned long attrs)
     169             : {
     170           0 :         const struct dma_map_ops *ops = get_dma_ops(dev);
     171             : 
     172           0 :         BUG_ON(!valid_dma_direction(dir));
     173           0 :         if (dma_map_direct(dev, ops) ||
     174             :             arch_dma_unmap_page_direct(dev, addr + size))
     175           0 :                 dma_direct_unmap_page(dev, addr, size, dir, attrs);
     176             :         else if (ops->unmap_page)
     177             :                 ops->unmap_page(dev, addr, size, dir, attrs);
     178           0 :         debug_dma_unmap_page(dev, addr, size, dir);
     179           0 : }
     180             : EXPORT_SYMBOL(dma_unmap_page_attrs);
     181             : 
     182           0 : static int __dma_map_sg_attrs(struct device *dev, struct scatterlist *sg,
     183             :          int nents, enum dma_data_direction dir, unsigned long attrs)
     184             : {
     185           0 :         const struct dma_map_ops *ops = get_dma_ops(dev);
     186             :         int ents;
     187             : 
     188           0 :         BUG_ON(!valid_dma_direction(dir));
     189             : 
     190           0 :         if (WARN_ON_ONCE(!dev->dma_mask))
     191             :                 return 0;
     192             : 
     193           0 :         if (dma_map_direct(dev, ops) ||
     194             :             arch_dma_map_sg_direct(dev, sg, nents))
     195           0 :                 ents = dma_direct_map_sg(dev, sg, nents, dir, attrs);
     196             :         else
     197             :                 ents = ops->map_sg(dev, sg, nents, dir, attrs);
     198             : 
     199           0 :         if (ents > 0) {
     200             :                 kmsan_handle_dma_sg(sg, nents, dir);
     201             :                 debug_dma_map_sg(dev, sg, nents, ents, dir, attrs);
     202           0 :         } else if (WARN_ON_ONCE(ents != -EINVAL && ents != -ENOMEM &&
     203             :                                 ents != -EIO && ents != -EREMOTEIO)) {
     204             :                 return -EIO;
     205             :         }
     206             : 
     207             :         return ents;
     208             : }
     209             : 
     210             : /**
     211             :  * dma_map_sg_attrs - Map the given buffer for DMA
     212             :  * @dev:        The device for which to perform the DMA operation
     213             :  * @sg:         The sg_table object describing the buffer
     214             :  * @nents:      Number of entries to map
     215             :  * @dir:        DMA direction
     216             :  * @attrs:      Optional DMA attributes for the map operation
     217             :  *
     218             :  * Maps a buffer described by a scatterlist passed in the sg argument with
     219             :  * nents segments for the @dir DMA operation by the @dev device.
     220             :  *
     221             :  * Returns the number of mapped entries (which can be less than nents)
     222             :  * on success. Zero is returned for any error.
     223             :  *
     224             :  * dma_unmap_sg_attrs() should be used to unmap the buffer with the
     225             :  * original sg and original nents (not the value returned by this funciton).
     226             :  */
     227           0 : unsigned int dma_map_sg_attrs(struct device *dev, struct scatterlist *sg,
     228             :                     int nents, enum dma_data_direction dir, unsigned long attrs)
     229             : {
     230             :         int ret;
     231             : 
     232           0 :         ret = __dma_map_sg_attrs(dev, sg, nents, dir, attrs);
     233           0 :         if (ret < 0)
     234             :                 return 0;
     235           0 :         return ret;
     236             : }
     237             : EXPORT_SYMBOL(dma_map_sg_attrs);
     238             : 
     239             : /**
     240             :  * dma_map_sgtable - Map the given buffer for DMA
     241             :  * @dev:        The device for which to perform the DMA operation
     242             :  * @sgt:        The sg_table object describing the buffer
     243             :  * @dir:        DMA direction
     244             :  * @attrs:      Optional DMA attributes for the map operation
     245             :  *
     246             :  * Maps a buffer described by a scatterlist stored in the given sg_table
     247             :  * object for the @dir DMA operation by the @dev device. After success, the
     248             :  * ownership for the buffer is transferred to the DMA domain.  One has to
     249             :  * call dma_sync_sgtable_for_cpu() or dma_unmap_sgtable() to move the
     250             :  * ownership of the buffer back to the CPU domain before touching the
     251             :  * buffer by the CPU.
     252             :  *
     253             :  * Returns 0 on success or a negative error code on error. The following
     254             :  * error codes are supported with the given meaning:
     255             :  *
     256             :  *   -EINVAL            An invalid argument, unaligned access or other error
     257             :  *                      in usage. Will not succeed if retried.
     258             :  *   -ENOMEM            Insufficient resources (like memory or IOVA space) to
     259             :  *                      complete the mapping. Should succeed if retried later.
     260             :  *   -EIO               Legacy error code with an unknown meaning. eg. this is
     261             :  *                      returned if a lower level call returned
     262             :  *                      DMA_MAPPING_ERROR.
     263             :  *   -EREMOTEIO         The DMA device cannot access P2PDMA memory specified
     264             :  *                      in the sg_table. This will not succeed if retried.
     265             :  */
     266           0 : int dma_map_sgtable(struct device *dev, struct sg_table *sgt,
     267             :                     enum dma_data_direction dir, unsigned long attrs)
     268             : {
     269             :         int nents;
     270             : 
     271           0 :         nents = __dma_map_sg_attrs(dev, sgt->sgl, sgt->orig_nents, dir, attrs);
     272           0 :         if (nents < 0)
     273             :                 return nents;
     274           0 :         sgt->nents = nents;
     275           0 :         return 0;
     276             : }
     277             : EXPORT_SYMBOL_GPL(dma_map_sgtable);
     278             : 
     279           0 : void dma_unmap_sg_attrs(struct device *dev, struct scatterlist *sg,
     280             :                                       int nents, enum dma_data_direction dir,
     281             :                                       unsigned long attrs)
     282             : {
     283           0 :         const struct dma_map_ops *ops = get_dma_ops(dev);
     284             : 
     285           0 :         BUG_ON(!valid_dma_direction(dir));
     286           0 :         debug_dma_unmap_sg(dev, sg, nents, dir);
     287           0 :         if (dma_map_direct(dev, ops) ||
     288             :             arch_dma_unmap_sg_direct(dev, sg, nents))
     289             :                 dma_direct_unmap_sg(dev, sg, nents, dir, attrs);
     290             :         else if (ops->unmap_sg)
     291             :                 ops->unmap_sg(dev, sg, nents, dir, attrs);
     292           0 : }
     293             : EXPORT_SYMBOL(dma_unmap_sg_attrs);
     294             : 
     295           0 : dma_addr_t dma_map_resource(struct device *dev, phys_addr_t phys_addr,
     296             :                 size_t size, enum dma_data_direction dir, unsigned long attrs)
     297             : {
     298           0 :         const struct dma_map_ops *ops = get_dma_ops(dev);
     299           0 :         dma_addr_t addr = DMA_MAPPING_ERROR;
     300             : 
     301           0 :         BUG_ON(!valid_dma_direction(dir));
     302             : 
     303           0 :         if (WARN_ON_ONCE(!dev->dma_mask))
     304             :                 return DMA_MAPPING_ERROR;
     305             : 
     306           0 :         if (dma_map_direct(dev, ops))
     307           0 :                 addr = dma_direct_map_resource(dev, phys_addr, size, dir, attrs);
     308             :         else if (ops->map_resource)
     309             :                 addr = ops->map_resource(dev, phys_addr, size, dir, attrs);
     310             : 
     311           0 :         debug_dma_map_resource(dev, phys_addr, size, dir, addr, attrs);
     312           0 :         return addr;
     313             : }
     314             : EXPORT_SYMBOL(dma_map_resource);
     315             : 
     316           0 : void dma_unmap_resource(struct device *dev, dma_addr_t addr, size_t size,
     317             :                 enum dma_data_direction dir, unsigned long attrs)
     318             : {
     319           0 :         const struct dma_map_ops *ops = get_dma_ops(dev);
     320             : 
     321           0 :         BUG_ON(!valid_dma_direction(dir));
     322           0 :         if (!dma_map_direct(dev, ops) && ops->unmap_resource)
     323             :                 ops->unmap_resource(dev, addr, size, dir, attrs);
     324           0 :         debug_dma_unmap_resource(dev, addr, size, dir);
     325           0 : }
     326             : EXPORT_SYMBOL(dma_unmap_resource);
     327             : 
     328           0 : void dma_sync_single_for_cpu(struct device *dev, dma_addr_t addr, size_t size,
     329             :                 enum dma_data_direction dir)
     330             : {
     331           0 :         const struct dma_map_ops *ops = get_dma_ops(dev);
     332             : 
     333           0 :         BUG_ON(!valid_dma_direction(dir));
     334           0 :         if (dma_map_direct(dev, ops))
     335           0 :                 dma_direct_sync_single_for_cpu(dev, addr, size, dir);
     336             :         else if (ops->sync_single_for_cpu)
     337             :                 ops->sync_single_for_cpu(dev, addr, size, dir);
     338           0 :         debug_dma_sync_single_for_cpu(dev, addr, size, dir);
     339           0 : }
     340             : EXPORT_SYMBOL(dma_sync_single_for_cpu);
     341             : 
     342           0 : void dma_sync_single_for_device(struct device *dev, dma_addr_t addr,
     343             :                 size_t size, enum dma_data_direction dir)
     344             : {
     345           0 :         const struct dma_map_ops *ops = get_dma_ops(dev);
     346             : 
     347           0 :         BUG_ON(!valid_dma_direction(dir));
     348           0 :         if (dma_map_direct(dev, ops))
     349           0 :                 dma_direct_sync_single_for_device(dev, addr, size, dir);
     350             :         else if (ops->sync_single_for_device)
     351             :                 ops->sync_single_for_device(dev, addr, size, dir);
     352           0 :         debug_dma_sync_single_for_device(dev, addr, size, dir);
     353           0 : }
     354             : EXPORT_SYMBOL(dma_sync_single_for_device);
     355             : 
     356           0 : void dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
     357             :                     int nelems, enum dma_data_direction dir)
     358             : {
     359           0 :         const struct dma_map_ops *ops = get_dma_ops(dev);
     360             : 
     361           0 :         BUG_ON(!valid_dma_direction(dir));
     362           0 :         if (dma_map_direct(dev, ops))
     363             :                 dma_direct_sync_sg_for_cpu(dev, sg, nelems, dir);
     364             :         else if (ops->sync_sg_for_cpu)
     365             :                 ops->sync_sg_for_cpu(dev, sg, nelems, dir);
     366           0 :         debug_dma_sync_sg_for_cpu(dev, sg, nelems, dir);
     367           0 : }
     368             : EXPORT_SYMBOL(dma_sync_sg_for_cpu);
     369             : 
     370           0 : void dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
     371             :                        int nelems, enum dma_data_direction dir)
     372             : {
     373           0 :         const struct dma_map_ops *ops = get_dma_ops(dev);
     374             : 
     375           0 :         BUG_ON(!valid_dma_direction(dir));
     376           0 :         if (dma_map_direct(dev, ops))
     377             :                 dma_direct_sync_sg_for_device(dev, sg, nelems, dir);
     378             :         else if (ops->sync_sg_for_device)
     379             :                 ops->sync_sg_for_device(dev, sg, nelems, dir);
     380           0 :         debug_dma_sync_sg_for_device(dev, sg, nelems, dir);
     381           0 : }
     382             : EXPORT_SYMBOL(dma_sync_sg_for_device);
     383             : 
     384             : /*
     385             :  * The whole dma_get_sgtable() idea is fundamentally unsafe - it seems
     386             :  * that the intention is to allow exporting memory allocated via the
     387             :  * coherent DMA APIs through the dma_buf API, which only accepts a
     388             :  * scattertable.  This presents a couple of problems:
     389             :  * 1. Not all memory allocated via the coherent DMA APIs is backed by
     390             :  *    a struct page
     391             :  * 2. Passing coherent DMA memory into the streaming APIs is not allowed
     392             :  *    as we will try to flush the memory through a different alias to that
     393             :  *    actually being used (and the flushes are redundant.)
     394             :  */
     395           0 : int dma_get_sgtable_attrs(struct device *dev, struct sg_table *sgt,
     396             :                 void *cpu_addr, dma_addr_t dma_addr, size_t size,
     397             :                 unsigned long attrs)
     398             : {
     399           0 :         const struct dma_map_ops *ops = get_dma_ops(dev);
     400             : 
     401           0 :         if (dma_alloc_direct(dev, ops))
     402           0 :                 return dma_direct_get_sgtable(dev, sgt, cpu_addr, dma_addr,
     403             :                                 size, attrs);
     404             :         if (!ops->get_sgtable)
     405             :                 return -ENXIO;
     406             :         return ops->get_sgtable(dev, sgt, cpu_addr, dma_addr, size, attrs);
     407             : }
     408             : EXPORT_SYMBOL(dma_get_sgtable_attrs);
     409             : 
     410             : #ifdef CONFIG_MMU
     411             : /*
     412             :  * Return the page attributes used for mapping dma_alloc_* memory, either in
     413             :  * kernel space if remapping is needed, or to userspace through dma_mmap_*.
     414             :  */
     415           0 : pgprot_t dma_pgprot(struct device *dev, pgprot_t prot, unsigned long attrs)
     416             : {
     417           0 :         if (dev_is_dma_coherent(dev))
     418           0 :                 return prot;
     419             : #ifdef CONFIG_ARCH_HAS_DMA_WRITE_COMBINE
     420             :         if (attrs & DMA_ATTR_WRITE_COMBINE)
     421             :                 return pgprot_writecombine(prot);
     422             : #endif
     423             :         return pgprot_dmacoherent(prot);
     424             : }
     425             : #endif /* CONFIG_MMU */
     426             : 
     427             : /**
     428             :  * dma_can_mmap - check if a given device supports dma_mmap_*
     429             :  * @dev: device to check
     430             :  *
     431             :  * Returns %true if @dev supports dma_mmap_coherent() and dma_mmap_attrs() to
     432             :  * map DMA allocations to userspace.
     433             :  */
     434           0 : bool dma_can_mmap(struct device *dev)
     435             : {
     436           0 :         const struct dma_map_ops *ops = get_dma_ops(dev);
     437             : 
     438           0 :         if (dma_alloc_direct(dev, ops))
     439           0 :                 return dma_direct_can_mmap(dev);
     440             :         return ops->mmap != NULL;
     441             : }
     442             : EXPORT_SYMBOL_GPL(dma_can_mmap);
     443             : 
     444             : /**
     445             :  * dma_mmap_attrs - map a coherent DMA allocation into user space
     446             :  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
     447             :  * @vma: vm_area_struct describing requested user mapping
     448             :  * @cpu_addr: kernel CPU-view address returned from dma_alloc_attrs
     449             :  * @dma_addr: device-view address returned from dma_alloc_attrs
     450             :  * @size: size of memory originally requested in dma_alloc_attrs
     451             :  * @attrs: attributes of mapping properties requested in dma_alloc_attrs
     452             :  *
     453             :  * Map a coherent DMA buffer previously allocated by dma_alloc_attrs into user
     454             :  * space.  The coherent DMA buffer must not be freed by the driver until the
     455             :  * user space mapping has been released.
     456             :  */
     457           0 : int dma_mmap_attrs(struct device *dev, struct vm_area_struct *vma,
     458             :                 void *cpu_addr, dma_addr_t dma_addr, size_t size,
     459             :                 unsigned long attrs)
     460             : {
     461           0 :         const struct dma_map_ops *ops = get_dma_ops(dev);
     462             : 
     463           0 :         if (dma_alloc_direct(dev, ops))
     464           0 :                 return dma_direct_mmap(dev, vma, cpu_addr, dma_addr, size,
     465             :                                 attrs);
     466             :         if (!ops->mmap)
     467             :                 return -ENXIO;
     468             :         return ops->mmap(dev, vma, cpu_addr, dma_addr, size, attrs);
     469             : }
     470             : EXPORT_SYMBOL(dma_mmap_attrs);
     471             : 
     472           0 : u64 dma_get_required_mask(struct device *dev)
     473             : {
     474           0 :         const struct dma_map_ops *ops = get_dma_ops(dev);
     475             : 
     476           0 :         if (dma_alloc_direct(dev, ops))
     477           0 :                 return dma_direct_get_required_mask(dev);
     478             :         if (ops->get_required_mask)
     479             :                 return ops->get_required_mask(dev);
     480             : 
     481             :         /*
     482             :          * We require every DMA ops implementation to at least support a 32-bit
     483             :          * DMA mask (and use bounce buffering if that isn't supported in
     484             :          * hardware).  As the direct mapping code has its own routine to
     485             :          * actually report an optimal mask we default to 32-bit here as that
     486             :          * is the right thing for most IOMMUs, and at least not actively
     487             :          * harmful in general.
     488             :          */
     489             :         return DMA_BIT_MASK(32);
     490             : }
     491             : EXPORT_SYMBOL_GPL(dma_get_required_mask);
     492             : 
     493           0 : void *dma_alloc_attrs(struct device *dev, size_t size, dma_addr_t *dma_handle,
     494             :                 gfp_t flag, unsigned long attrs)
     495             : {
     496           0 :         const struct dma_map_ops *ops = get_dma_ops(dev);
     497             :         void *cpu_addr;
     498             : 
     499           0 :         WARN_ON_ONCE(!dev->coherent_dma_mask);
     500             : 
     501             :         /*
     502             :          * DMA allocations can never be turned back into a page pointer, so
     503             :          * requesting compound pages doesn't make sense (and can't even be
     504             :          * supported at all by various backends).
     505             :          */
     506           0 :         if (WARN_ON_ONCE(flag & __GFP_COMP))
     507             :                 return NULL;
     508             : 
     509             :         if (dma_alloc_from_dev_coherent(dev, size, dma_handle, &cpu_addr))
     510             :                 return cpu_addr;
     511             : 
     512             :         /* let the implementation decide on the zone to allocate from: */
     513           0 :         flag &= ~(__GFP_DMA | __GFP_DMA32 | __GFP_HIGHMEM);
     514             : 
     515           0 :         if (dma_alloc_direct(dev, ops))
     516           0 :                 cpu_addr = dma_direct_alloc(dev, size, dma_handle, flag, attrs);
     517             :         else if (ops->alloc)
     518             :                 cpu_addr = ops->alloc(dev, size, dma_handle, flag, attrs);
     519             :         else
     520             :                 return NULL;
     521             : 
     522           0 :         debug_dma_alloc_coherent(dev, size, *dma_handle, cpu_addr, attrs);
     523           0 :         return cpu_addr;
     524             : }
     525             : EXPORT_SYMBOL(dma_alloc_attrs);
     526             : 
     527           0 : void dma_free_attrs(struct device *dev, size_t size, void *cpu_addr,
     528             :                 dma_addr_t dma_handle, unsigned long attrs)
     529             : {
     530           0 :         const struct dma_map_ops *ops = get_dma_ops(dev);
     531             : 
     532             :         if (dma_release_from_dev_coherent(dev, get_order(size), cpu_addr))
     533             :                 return;
     534             :         /*
     535             :          * On non-coherent platforms which implement DMA-coherent buffers via
     536             :          * non-cacheable remaps, ops->free() may call vunmap(). Thus getting
     537             :          * this far in IRQ context is a) at risk of a BUG_ON() or trying to
     538             :          * sleep on some machines, and b) an indication that the driver is
     539             :          * probably misusing the coherent API anyway.
     540             :          */
     541           0 :         WARN_ON(irqs_disabled());
     542             : 
     543           0 :         if (!cpu_addr)
     544             :                 return;
     545             : 
     546           0 :         debug_dma_free_coherent(dev, size, cpu_addr, dma_handle);
     547           0 :         if (dma_alloc_direct(dev, ops))
     548           0 :                 dma_direct_free(dev, size, cpu_addr, dma_handle, attrs);
     549             :         else if (ops->free)
     550             :                 ops->free(dev, size, cpu_addr, dma_handle, attrs);
     551             : }
     552             : EXPORT_SYMBOL(dma_free_attrs);
     553             : 
     554           0 : static struct page *__dma_alloc_pages(struct device *dev, size_t size,
     555             :                 dma_addr_t *dma_handle, enum dma_data_direction dir, gfp_t gfp)
     556             : {
     557           0 :         const struct dma_map_ops *ops = get_dma_ops(dev);
     558             : 
     559           0 :         if (WARN_ON_ONCE(!dev->coherent_dma_mask))
     560             :                 return NULL;
     561           0 :         if (WARN_ON_ONCE(gfp & (__GFP_DMA | __GFP_DMA32 | __GFP_HIGHMEM)))
     562             :                 return NULL;
     563           0 :         if (WARN_ON_ONCE(gfp & __GFP_COMP))
     564             :                 return NULL;
     565             : 
     566           0 :         size = PAGE_ALIGN(size);
     567           0 :         if (dma_alloc_direct(dev, ops))
     568           0 :                 return dma_direct_alloc_pages(dev, size, dma_handle, dir, gfp);
     569             :         if (!ops->alloc_pages)
     570             :                 return NULL;
     571             :         return ops->alloc_pages(dev, size, dma_handle, dir, gfp);
     572             : }
     573             : 
     574           0 : struct page *dma_alloc_pages(struct device *dev, size_t size,
     575             :                 dma_addr_t *dma_handle, enum dma_data_direction dir, gfp_t gfp)
     576             : {
     577           0 :         struct page *page = __dma_alloc_pages(dev, size, dma_handle, dir, gfp);
     578             : 
     579             :         if (page)
     580             :                 debug_dma_map_page(dev, page, 0, size, dir, *dma_handle, 0);
     581           0 :         return page;
     582             : }
     583             : EXPORT_SYMBOL_GPL(dma_alloc_pages);
     584             : 
     585             : static void __dma_free_pages(struct device *dev, size_t size, struct page *page,
     586             :                 dma_addr_t dma_handle, enum dma_data_direction dir)
     587             : {
     588           0 :         const struct dma_map_ops *ops = get_dma_ops(dev);
     589             : 
     590           0 :         size = PAGE_ALIGN(size);
     591           0 :         if (dma_alloc_direct(dev, ops))
     592           0 :                 dma_direct_free_pages(dev, size, page, dma_handle, dir);
     593             :         else if (ops->free_pages)
     594             :                 ops->free_pages(dev, size, page, dma_handle, dir);
     595             : }
     596             : 
     597           0 : void dma_free_pages(struct device *dev, size_t size, struct page *page,
     598             :                 dma_addr_t dma_handle, enum dma_data_direction dir)
     599             : {
     600           0 :         debug_dma_unmap_page(dev, dma_handle, size, dir);
     601           0 :         __dma_free_pages(dev, size, page, dma_handle, dir);
     602           0 : }
     603             : EXPORT_SYMBOL_GPL(dma_free_pages);
     604             : 
     605           0 : int dma_mmap_pages(struct device *dev, struct vm_area_struct *vma,
     606             :                 size_t size, struct page *page)
     607             : {
     608           0 :         unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;
     609             : 
     610           0 :         if (vma->vm_pgoff >= count || vma_pages(vma) > count - vma->vm_pgoff)
     611             :                 return -ENXIO;
     612           0 :         return remap_pfn_range(vma, vma->vm_start,
     613           0 :                                page_to_pfn(page) + vma->vm_pgoff,
     614           0 :                                vma_pages(vma) << PAGE_SHIFT, vma->vm_page_prot);
     615             : }
     616             : EXPORT_SYMBOL_GPL(dma_mmap_pages);
     617             : 
     618           0 : static struct sg_table *alloc_single_sgt(struct device *dev, size_t size,
     619             :                 enum dma_data_direction dir, gfp_t gfp)
     620             : {
     621             :         struct sg_table *sgt;
     622             :         struct page *page;
     623             : 
     624           0 :         sgt = kmalloc(sizeof(*sgt), gfp);
     625           0 :         if (!sgt)
     626             :                 return NULL;
     627           0 :         if (sg_alloc_table(sgt, 1, gfp))
     628             :                 goto out_free_sgt;
     629           0 :         page = __dma_alloc_pages(dev, size, &sgt->sgl->dma_address, dir, gfp);
     630           0 :         if (!page)
     631             :                 goto out_free_table;
     632           0 :         sg_set_page(sgt->sgl, page, PAGE_ALIGN(size), 0);
     633             :         sg_dma_len(sgt->sgl) = sgt->sgl->length;
     634           0 :         return sgt;
     635             : out_free_table:
     636           0 :         sg_free_table(sgt);
     637             : out_free_sgt:
     638           0 :         kfree(sgt);
     639           0 :         return NULL;
     640             : }
     641             : 
     642           0 : struct sg_table *dma_alloc_noncontiguous(struct device *dev, size_t size,
     643             :                 enum dma_data_direction dir, gfp_t gfp, unsigned long attrs)
     644             : {
     645           0 :         const struct dma_map_ops *ops = get_dma_ops(dev);
     646             :         struct sg_table *sgt;
     647             : 
     648           0 :         if (WARN_ON_ONCE(attrs & ~DMA_ATTR_ALLOC_SINGLE_PAGES))
     649             :                 return NULL;
     650           0 :         if (WARN_ON_ONCE(gfp & __GFP_COMP))
     651             :                 return NULL;
     652             : 
     653             :         if (ops && ops->alloc_noncontiguous)
     654             :                 sgt = ops->alloc_noncontiguous(dev, size, dir, gfp, attrs);
     655             :         else
     656           0 :                 sgt = alloc_single_sgt(dev, size, dir, gfp);
     657             : 
     658           0 :         if (sgt) {
     659           0 :                 sgt->nents = 1;
     660           0 :                 debug_dma_map_sg(dev, sgt->sgl, sgt->orig_nents, 1, dir, attrs);
     661             :         }
     662             :         return sgt;
     663             : }
     664             : EXPORT_SYMBOL_GPL(dma_alloc_noncontiguous);
     665             : 
     666           0 : static void free_single_sgt(struct device *dev, size_t size,
     667             :                 struct sg_table *sgt, enum dma_data_direction dir)
     668             : {
     669           0 :         __dma_free_pages(dev, size, sg_page(sgt->sgl), sgt->sgl->dma_address,
     670             :                          dir);
     671           0 :         sg_free_table(sgt);
     672           0 :         kfree(sgt);
     673           0 : }
     674             : 
     675           0 : void dma_free_noncontiguous(struct device *dev, size_t size,
     676             :                 struct sg_table *sgt, enum dma_data_direction dir)
     677             : {
     678           0 :         const struct dma_map_ops *ops = get_dma_ops(dev);
     679             : 
     680           0 :         debug_dma_unmap_sg(dev, sgt->sgl, sgt->orig_nents, dir);
     681             :         if (ops && ops->free_noncontiguous)
     682             :                 ops->free_noncontiguous(dev, size, sgt, dir);
     683             :         else
     684           0 :                 free_single_sgt(dev, size, sgt, dir);
     685           0 : }
     686             : EXPORT_SYMBOL_GPL(dma_free_noncontiguous);
     687             : 
     688           0 : void *dma_vmap_noncontiguous(struct device *dev, size_t size,
     689             :                 struct sg_table *sgt)
     690             : {
     691           0 :         const struct dma_map_ops *ops = get_dma_ops(dev);
     692           0 :         unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;
     693             : 
     694             :         if (ops && ops->alloc_noncontiguous)
     695             :                 return vmap(sgt_handle(sgt)->pages, count, VM_MAP, PAGE_KERNEL);
     696           0 :         return page_address(sg_page(sgt->sgl));
     697             : }
     698             : EXPORT_SYMBOL_GPL(dma_vmap_noncontiguous);
     699             : 
     700           0 : void dma_vunmap_noncontiguous(struct device *dev, void *vaddr)
     701             : {
     702           0 :         const struct dma_map_ops *ops = get_dma_ops(dev);
     703             : 
     704             :         if (ops && ops->alloc_noncontiguous)
     705             :                 vunmap(vaddr);
     706           0 : }
     707             : EXPORT_SYMBOL_GPL(dma_vunmap_noncontiguous);
     708             : 
     709           0 : int dma_mmap_noncontiguous(struct device *dev, struct vm_area_struct *vma,
     710             :                 size_t size, struct sg_table *sgt)
     711             : {
     712           0 :         const struct dma_map_ops *ops = get_dma_ops(dev);
     713             : 
     714             :         if (ops && ops->alloc_noncontiguous) {
     715             :                 unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;
     716             : 
     717             :                 if (vma->vm_pgoff >= count ||
     718             :                     vma_pages(vma) > count - vma->vm_pgoff)
     719             :                         return -ENXIO;
     720             :                 return vm_map_pages(vma, sgt_handle(sgt)->pages, count);
     721             :         }
     722           0 :         return dma_mmap_pages(dev, vma, size, sg_page(sgt->sgl));
     723             : }
     724             : EXPORT_SYMBOL_GPL(dma_mmap_noncontiguous);
     725             : 
     726             : static int dma_supported(struct device *dev, u64 mask)
     727             : {
     728           0 :         const struct dma_map_ops *ops = get_dma_ops(dev);
     729             : 
     730             :         /*
     731             :          * ->dma_supported sets the bypass flag, so we must always call
     732             :          * into the method here unless the device is truly direct mapped.
     733             :          */
     734             :         if (!ops)
     735           0 :                 return dma_direct_supported(dev, mask);
     736             :         if (!ops->dma_supported)
     737             :                 return 1;
     738             :         return ops->dma_supported(dev, mask);
     739             : }
     740             : 
     741           0 : bool dma_pci_p2pdma_supported(struct device *dev)
     742             : {
     743           0 :         const struct dma_map_ops *ops = get_dma_ops(dev);
     744             : 
     745             :         /* if ops is not set, dma direct will be used which supports P2PDMA */
     746             :         if (!ops)
     747             :                 return true;
     748             : 
     749             :         /*
     750             :          * Note: dma_ops_bypass is not checked here because P2PDMA should
     751             :          * not be used with dma mapping ops that do not have support even
     752             :          * if the specific device is bypassing them.
     753             :          */
     754             : 
     755             :         return ops->flags & DMA_F_PCI_P2PDMA_SUPPORTED;
     756             : }
     757             : EXPORT_SYMBOL_GPL(dma_pci_p2pdma_supported);
     758             : 
     759             : #ifdef CONFIG_ARCH_HAS_DMA_SET_MASK
     760             : void arch_dma_set_mask(struct device *dev, u64 mask);
     761             : #else
     762             : #define arch_dma_set_mask(dev, mask)    do { } while (0)
     763             : #endif
     764             : 
     765           0 : int dma_set_mask(struct device *dev, u64 mask)
     766             : {
     767             :         /*
     768             :          * Truncate the mask to the actually supported dma_addr_t width to
     769             :          * avoid generating unsupportable addresses.
     770             :          */
     771           0 :         mask = (dma_addr_t)mask;
     772             : 
     773           0 :         if (!dev->dma_mask || !dma_supported(dev, mask))
     774             :                 return -EIO;
     775             : 
     776             :         arch_dma_set_mask(dev, mask);
     777           0 :         *dev->dma_mask = mask;
     778           0 :         return 0;
     779             : }
     780             : EXPORT_SYMBOL(dma_set_mask);
     781             : 
     782           0 : int dma_set_coherent_mask(struct device *dev, u64 mask)
     783             : {
     784             :         /*
     785             :          * Truncate the mask to the actually supported dma_addr_t width to
     786             :          * avoid generating unsupportable addresses.
     787             :          */
     788           0 :         mask = (dma_addr_t)mask;
     789             : 
     790           0 :         if (!dma_supported(dev, mask))
     791             :                 return -EIO;
     792             : 
     793           0 :         dev->coherent_dma_mask = mask;
     794           0 :         return 0;
     795             : }
     796             : EXPORT_SYMBOL(dma_set_coherent_mask);
     797             : 
     798           0 : size_t dma_max_mapping_size(struct device *dev)
     799             : {
     800           0 :         const struct dma_map_ops *ops = get_dma_ops(dev);
     801           0 :         size_t size = SIZE_MAX;
     802             : 
     803           0 :         if (dma_map_direct(dev, ops))
     804           0 :                 size = dma_direct_max_mapping_size(dev);
     805             :         else if (ops && ops->max_mapping_size)
     806             :                 size = ops->max_mapping_size(dev);
     807             : 
     808           0 :         return size;
     809             : }
     810             : EXPORT_SYMBOL_GPL(dma_max_mapping_size);
     811             : 
     812           0 : size_t dma_opt_mapping_size(struct device *dev)
     813             : {
     814           0 :         const struct dma_map_ops *ops = get_dma_ops(dev);
     815           0 :         size_t size = SIZE_MAX;
     816             : 
     817             :         if (ops && ops->opt_mapping_size)
     818             :                 size = ops->opt_mapping_size();
     819             : 
     820           0 :         return min(dma_max_mapping_size(dev), size);
     821             : }
     822             : EXPORT_SYMBOL_GPL(dma_opt_mapping_size);
     823             : 
     824           0 : bool dma_need_sync(struct device *dev, dma_addr_t dma_addr)
     825             : {
     826           0 :         const struct dma_map_ops *ops = get_dma_ops(dev);
     827             : 
     828           0 :         if (dma_map_direct(dev, ops))
     829           0 :                 return dma_direct_need_sync(dev, dma_addr);
     830             :         return ops->sync_single_for_cpu || ops->sync_single_for_device;
     831             : }
     832             : EXPORT_SYMBOL_GPL(dma_need_sync);
     833             : 
     834           0 : unsigned long dma_get_merge_boundary(struct device *dev)
     835             : {
     836           0 :         const struct dma_map_ops *ops = get_dma_ops(dev);
     837             : 
     838             :         if (!ops || !ops->get_merge_boundary)
     839             :                 return 0;       /* can't merge */
     840             : 
     841             :         return ops->get_merge_boundary(dev);
     842             : }
     843             : EXPORT_SYMBOL_GPL(dma_get_merge_boundary);

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