€•¦5      Œsphinx.addnodes”Œdocument”“”)”}”(Œ	rawsource”Œ ”Œchildren”]”(Œtranslations”ŒLanguagesNode”“”)”}”(hhh]”(h Œpending_xref”“”)”}”(hhh]”Œdocutils.nodes”ŒText”“”ŒChinese (Simplified)”…””}”(hhŒparent”hubaŒ
attributes”}”(Œids”]”Œclasses”]”Œnames”]”Œdupnames”]”Œbackrefs”]”Œ	refdomain”Œstd”Œreftype”Œdoc”Œ	reftarget”Œ)/translations/zh_CN/driver-api/io-mapping”Œmodname”NŒ	classname”NŒrefexplicit”ˆuŒtagname”hhhubh)”}”(hhh]”hŒChinese (Traditional)”…””}”(hhhh2ubah}”(h]”h ]”h"]”h$]”h&]”Œ	refdomain”h)Œreftype”h+Œ	reftarget”Œ)/translations/zh_TW/driver-api/io-mapping”Œmodname”NŒ	classname”NŒrefexplicit”ˆuh1hhhubh)”}”(hhh]”hŒItalian”…””}”(hhhhFubah}”(h]”h ]”h"]”h$]”h&]”Œ	refdomain”h)Œreftype”h+Œ	reftarget”Œ)/translations/it_IT/driver-api/io-mapping”Œmodname”NŒ	classname”NŒrefexplicit”ˆuh1hhhubh)”}”(hhh]”hŒJapanese”…””}”(hhhhZubah}”(h]”h ]”h"]”h$]”h&]”Œ	refdomain”h)Œreftype”h+Œ	reftarget”Œ)/translations/ja_JP/driver-api/io-mapping”Œmodname”NŒ	classname”NŒrefexplicit”ˆuh1hhhubh)”}”(hhh]”hŒKorean”…””}”(hhhhnubah}”(h]”h ]”h"]”h$]”h&]”Œ	refdomain”h)Œreftype”h+Œ	reftarget”Œ)/translations/ko_KR/driver-api/io-mapping”Œmodname”NŒ	classname”NŒrefexplicit”ˆuh1hhhubh)”}”(hhh]”hŒSpanish”…””}”(hhhh‚ubah}”(h]”h ]”h"]”h$]”h&]”Œ	refdomain”h)Œreftype”h+Œ	reftarget”Œ)/translations/sp_SP/driver-api/io-mapping”Œmodname”NŒ	classname”NŒrefexplicit”ˆuh1hhhubeh}”(h]”h ]”h"]”h$]”h&]”Œcurrent_language”ŒEnglish”uh1h
hhŒ	_document”hŒsource”NŒline”NubhŒsection”“”)”}”(hhh]”(hŒtitle”“”)”}”(hŒThe io_mapping functions”h]”hŒThe io_mapping functions”…””}”(hhªhh¨hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h¦hh£hžhhŸŒC/var/lib/git/docbuild/linux/Documentation/driver-api/io-mapping.rst”h Kubh¢)”}”(hhh]”(h§)”}”(hŒAPI”h]”hŒAPI”…””}”(hh¼hhºhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h¦hh·hžhhŸh¶h KubhŒ	paragraph”“”)”}”(hXd  The io_mapping functions in linux/io-mapping.h provide an abstraction for
efficiently mapping small regions of an I/O device to the CPU. The initial
usage is to support the large graphics aperture on 32-bit processors where
ioremap_wc cannot be used to statically map the entire aperture to the CPU
as it would consume too much of the kernel address space.”h]”hXd  The io_mapping functions in linux/io-mapping.h provide an abstraction for
efficiently mapping small regions of an I/O device to the CPU. The initial
usage is to support the large graphics aperture on 32-bit processors where
ioremap_wc cannot be used to statically map the entire aperture to the CPU
as it would consume too much of the kernel address space.”…””}”(hhÌhhÊhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÈhŸh¶h Khh·hžhubhÉ)”}”(hŒ@A mapping object is created during driver initialization using::”h]”hŒ?A mapping object is created during driver initialization using:”…””}”(hŒ?A mapping object is created during driver initialization using:”hhØhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÈhŸh¶h Khh·hžhubhŒliteral_block”“”)”}”(hŒwstruct io_mapping *io_mapping_create_wc(unsigned long base,
                                        unsigned long size)”h]”hŒwstruct io_mapping *io_mapping_create_wc(unsigned long base,
                                        unsigned long size)”…””}”(hhhhéubah}”(h]”h ]”h"]”h$]”h&]”Œ	xml:space”Œpreserve”uh1hçhŸh¶h Khh·hžhubhÉ)”}”(hŒŒ'base' is the bus address of the region to be made
mappable, while 'size' indicates how large a mapping region to
enable. Both are in bytes.”h]”hŒ”â€˜baseâ€™ is the bus address of the region to be made
mappable, while â€˜sizeâ€™ indicates how large a mapping region to
enable. Both are in bytes.”…””}”(hhûhhùhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÈhŸh¶h Khh·hžhubhÉ)”}”(hŒThis _wc variant provides a mapping which may only be used with
io_mapping_map_atomic_wc(), io_mapping_map_local_wc() or
io_mapping_map_wc().”h]”hŒThis _wc variant provides a mapping which may only be used with
io_mapping_map_atomic_wc(), io_mapping_map_local_wc() or
io_mapping_map_wc().”…””}”(hj	  hj  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÈhŸh¶h Khh·hžhubhÉ)”}”(hŒÂWith this mapping object, individual pages can be mapped either temporarily
or long term, depending on the requirements. Of course, temporary maps are
more efficient. They come in two flavours::”h]”hŒÁWith this mapping object, individual pages can be mapped either temporarily
or long term, depending on the requirements. Of course, temporary maps are
more efficient. They come in two flavours:”…””}”(hŒÁWith this mapping object, individual pages can be mapped either temporarily
or long term, depending on the requirements. Of course, temporary maps are
more efficient. They come in two flavours:”hj  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÈhŸh¶h Khh·hžhubhè)”}”(hŒÞvoid *io_mapping_map_local_wc(struct io_mapping *mapping,
                              unsigned long offset)

void *io_mapping_map_atomic_wc(struct io_mapping *mapping,
                               unsigned long offset)”h]”hŒÞvoid *io_mapping_map_local_wc(struct io_mapping *mapping,
                              unsigned long offset)

void *io_mapping_map_atomic_wc(struct io_mapping *mapping,
                               unsigned long offset)”…””}”(hhhj$  ubah}”(h]”h ]”h"]”h$]”h&]”h÷høuh1hçhŸh¶h Khh·hžhubhÉ)”}”(hX"  'offset' is the offset within the defined mapping region.  Accessing
addresses beyond the region specified in the creation function yields
undefined results. Using an offset which is not page aligned yields an
undefined result. The return value points to a single page in CPU address
space.”h]”hX&  â€˜offsetâ€™ is the offset within the defined mapping region.  Accessing
addresses beyond the region specified in the creation function yields
undefined results. Using an offset which is not page aligned yields an
undefined result. The return value points to a single page in CPU address
space.”…””}”(hj4  hj2  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÈhŸh¶h K%hh·hžhubhÉ)”}”(hŒThis _wc variant returns a write-combining map to the page and may only be
used with mappings created by io_mapping_create_wc()”h]”hŒThis _wc variant returns a write-combining map to the page and may only be
used with mappings created by io_mapping_create_wc()”…””}”(hjB  hj@  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÈhŸh¶h K+hh·hžhubhÉ)”}”(hŒuTemporary mappings are only valid in the context of the caller. The mapping
is not guaranteed to be globally visible.”h]”hŒuTemporary mappings are only valid in the context of the caller. The mapping
is not guaranteed to be globally visible.”…””}”(hjP  hjN  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÈhŸh¶h K.hh·hžhubhÉ)”}”(hŒ˜io_mapping_map_local_wc() has a side effect on X86 32bit as it disables
migration to make the mapping code work. No caller can rely on this side
effect.”h]”hŒ˜io_mapping_map_local_wc() has a side effect on X86 32bit as it disables
migration to make the mapping code work. No caller can rely on this side
effect.”…””}”(hj^  hj\  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÈhŸh¶h K1hh·hžhubhÉ)”}”(hŒ”io_mapping_map_atomic_wc() has the side effect of disabling preemption and
pagefaults. Don't use in new code. Use io_mapping_map_local_wc() instead.”h]”hŒ–io_mapping_map_atomic_wc() has the side effect of disabling preemption and
pagefaults. Donâ€™t use in new code. Use io_mapping_map_local_wc() instead.”…””}”(hjl  hjj  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÈhŸh¶h K5hh·hžhubhÉ)”}”(hŒtNested mappings need to be undone in reverse order because the mapping
code uses a stack for keeping track of them::”h]”hŒsNested mappings need to be undone in reverse order because the mapping
code uses a stack for keeping track of them:”…””}”(hŒsNested mappings need to be undone in reverse order because the mapping
code uses a stack for keeping track of them:”hjx  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÈhŸh¶h K8hh·hžhubhè)”}”(hŒ¡addr1 = io_mapping_map_local_wc(map1, offset1);
addr2 = io_mapping_map_local_wc(map2, offset2);
...
io_mapping_unmap_local(addr2);
io_mapping_unmap_local(addr1);”h]”hŒ¡addr1 = io_mapping_map_local_wc(map1, offset1);
addr2 = io_mapping_map_local_wc(map2, offset2);
...
io_mapping_unmap_local(addr2);
io_mapping_unmap_local(addr1);”…””}”(hhhj‡  ubah}”(h]”h ]”h"]”h$]”h&]”h÷høuh1hçhŸh¶h K;hh·hžhubhÉ)”}”(hŒ The mappings are released with::”h]”hŒThe mappings are released with:”…””}”(hŒThe mappings are released with:”hj•  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÈhŸh¶h KAhh·hžhubhè)”}”(hŒRvoid io_mapping_unmap_local(void *vaddr)
void io_mapping_unmap_atomic(void *vaddr)”h]”hŒRvoid io_mapping_unmap_local(void *vaddr)
void io_mapping_unmap_atomic(void *vaddr)”…””}”(hhhj¤  ubah}”(h]”h ]”h"]”h$]”h&]”h÷høuh1hçhŸh¶h KChh·hžhubhÉ)”}”(hŒÄ'vaddr' must be the value returned by the last io_mapping_map_local_wc() or
io_mapping_map_atomic_wc() call. This unmaps the specified mapping and
undoes the side effects of the mapping functions.”h]”hŒÈâ€˜vaddrâ€™ must be the value returned by the last io_mapping_map_local_wc() or
io_mapping_map_atomic_wc() call. This unmaps the specified mapping and
undoes the side effects of the mapping functions.”…””}”(hj´  hj²  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÈhŸh¶h KFhh·hžhubhÉ)”}”(hŒzIf you need to sleep while holding a mapping, you can use the regular
variant, although this may be significantly slower::”h]”hŒyIf you need to sleep while holding a mapping, you can use the regular
variant, although this may be significantly slower:”…””}”(hŒyIf you need to sleep while holding a mapping, you can use the regular
variant, although this may be significantly slower:”hjÀ  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÈhŸh¶h KJhh·hžhubhè)”}”(hŒavoid *io_mapping_map_wc(struct io_mapping *mapping,
                        unsigned long offset)”h]”hŒavoid *io_mapping_map_wc(struct io_mapping *mapping,
                        unsigned long offset)”…””}”(hhhjÏ  ubah}”(h]”h ]”h"]”h$]”h&]”h÷høuh1hçhŸh¶h KMhh·hžhubhÉ)”}”(hŒsThis works like io_mapping_map_atomic/local_wc() except it has no side
effects and the pointer is globally visible.”h]”hŒsThis works like io_mapping_map_atomic/local_wc() except it has no side
effects and the pointer is globally visible.”…””}”(hjß  hjÝ  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÈhŸh¶h KPhh·hžhubhÉ)”}”(hŒ The mappings are released with::”h]”hŒThe mappings are released with:”…””}”(hŒThe mappings are released with:”hjë  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÈhŸh¶h KShh·hžhubhè)”}”(hŒ"void io_mapping_unmap(void *vaddr)”h]”hŒ"void io_mapping_unmap(void *vaddr)”…””}”(hhhjú  ubah}”(h]”h ]”h"]”h$]”h&]”h÷høuh1hçhŸh¶h KUhh·hžhubhÉ)”}”(hŒ.Use for pages mapped with io_mapping_map_wc().”h]”hŒ.Use for pages mapped with io_mapping_map_wc().”…””}”(hj
  hj  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÈhŸh¶h KWhh·hžhubhÉ)”}”(hŒ;At driver close time, the io_mapping object must be freed::”h]”hŒ:At driver close time, the io_mapping object must be freed:”…””}”(hŒ:At driver close time, the io_mapping object must be freed:”hj  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÈhŸh¶h KYhh·hžhubhè)”}”(hŒ0void io_mapping_free(struct io_mapping *mapping)”h]”hŒ0void io_mapping_free(struct io_mapping *mapping)”…””}”(hhhj%  ubah}”(h]”h ]”h"]”h$]”h&]”h÷høuh1hçhŸh¶h K[hh·hžhubeh}”(h]”Œapi”ah ]”h"]”Œapi”ah$]”h&]”uh1h¡hh£hžhhŸh¶h Kubeh}”(h]”Œthe-io-mapping-functions”ah ]”h"]”Œthe io_mapping functions”ah$]”h&]”uh1h¡hhhžhhŸh¶h Kubeh}”(h]”h ]”h"]”h$]”h&]”Œsource”h¶uh1hŒcurrent_source”NŒcurrent_line”NŒsettings”Œdocutils.frontend”ŒValues”“”)”}”(h¦NŒ	generator”NŒ	datestamp”NŒsource_link”NŒ
source_url”NŒtoc_backlinks”Œentry”Œfootnote_backlinks”KŒsectnum_xform”KŒstrip_comments”NŒstrip_elements_with_classes”NŒstrip_classes”NŒreport_level”KŒ
halt_level”KŒexit_status_level”KŒdebug”NŒwarning_stream”NŒ	traceback”ˆŒinput_encoding”Œ	utf-8-sig”Œinput_encoding_error_handler”Œstrict”Œoutput_encoding”Œutf-8”Œoutput_encoding_error_handler”jf  Œerror_encoding”ŒUTF-8”Œerror_encoding_error_handler”Œbackslashreplace”Œlanguage_code”Œen”Œrecord_dependencies”NŒconfig”NŒ	id_prefix”hŒauto_id_prefix”Œid”Œdump_settings”NŒdump_internals”NŒdump_transforms”NŒdump_pseudo_xml”NŒexpose_internals”NŒstrict_visitor”NŒ_disable_config”NŒ_source”h¶Œ_destination”NŒ_config_files”]”Œ7/var/lib/git/docbuild/linux/Documentation/docutils.conf”aŒpep_references”NŒpep_base_url”Œhttps://peps.python.org/”Œpep_file_url_template”Œpep-%04d”Œrfc_references”NŒrfc_base_url”Œ&https://datatracker.ietf.org/doc/html/”Œ	tab_width”KŒtrim_footnote_reference_space”‰Œfile_insertion_enabled”ˆŒraw_enabled”KŒline_length_limit”M'Œsyntax_highlight”Œlong”Œsmart_quotes”ˆŒsmartquotes_locales”]”Œcharacter_level_inline_markup”‰Œdoctitle_xform”‰Œdocinfo_xform”KŒsectsubtitle_xform”‰Œimage_loading”Œlink”Œembed_stylesheet”‰Œcloak_email_addresses”ˆŒsection_self_link”‰Œembed_images”‰Œenv”NubŒreporter”NŒindirect_targets”]”Œsubstitution_defs”}”Œsubstitution_names”}”Œrefnames”}”Œrefids”}”Œnameids”}”(j@  j=  j8  j5  uŒ	nametypes”}”(j@  Nj8  Nuh}”(j=  h£j5  h·uŒfootnote_refs”}”Œcitation_refs”}”Œautofootnotes”]”Œautofootnote_refs”]”Œsymbol_footnotes”]”Œsymbol_footnote_refs”]”Œ	footnotes”]”Œ	citations”]”Œautofootnote_start”KŒsymbol_footnote_start”K Œ
id_counter”Œcollections”ŒCounter”“”}”…”R”Œparse_messages”]”Œtransform_messages”]”Œtransformer”NŒinclude_log”]”Œ
decoration”Nhžhub.