€•²      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)”…””}”Œparent”hsbaŒ
attributes”}”(Œids”]”Œclasses”]”Œnames”]”Œdupnames”]”Œbackrefs”]”Œ	refdomain”Œstd”Œreftype”Œdoc”Œ	reftarget”Œ1/translations/zh_CN/driver-api/cxl/allocation/dax”Œmodname”NŒ	classname”NŒrefexplicit”ˆuŒtagname”hhhubh)”}”(hhh]”hŒChinese (Traditional)”…””}”hh2sbah}”(h]”h ]”h"]”h$]”h&]”Œ	refdomain”h)Œreftype”h+Œ	reftarget”Œ1/translations/zh_TW/driver-api/cxl/allocation/dax”Œmodname”NŒ	classname”NŒrefexplicit”ˆuh1hhhubh)”}”(hhh]”hŒItalian”…””}”hhFsbah}”(h]”h ]”h"]”h$]”h&]”Œ	refdomain”h)Œreftype”h+Œ	reftarget”Œ1/translations/it_IT/driver-api/cxl/allocation/dax”Œmodname”NŒ	classname”NŒrefexplicit”ˆuh1hhhubh)”}”(hhh]”hŒJapanese”…””}”hhZsbah}”(h]”h ]”h"]”h$]”h&]”Œ	refdomain”h)Œreftype”h+Œ	reftarget”Œ1/translations/ja_JP/driver-api/cxl/allocation/dax”Œmodname”NŒ	classname”NŒrefexplicit”ˆuh1hhhubh)”}”(hhh]”hŒKorean”…””}”hhnsbah}”(h]”h ]”h"]”h$]”h&]”Œ	refdomain”h)Œreftype”h+Œ	reftarget”Œ1/translations/ko_KR/driver-api/cxl/allocation/dax”Œmodname”NŒ	classname”NŒrefexplicit”ˆuh1hhhubh)”}”(hhh]”hŒSpanish”…””}”hh‚sbah}”(h]”h ]”h"]”h$]”h&]”Œ	refdomain”h)Œreftype”h+Œ	reftarget”Œ1/translations/sp_SP/driver-api/cxl/allocation/dax”Œmodname”NŒ	classname”NŒrefexplicit”ˆuh1hhhubeh}”(h]”h ]”h"]”h$]”h&]”Œcurrent_language”ŒEnglish”uh1h
hhŒ	_document”hŒsource”NŒline”NubhŒcomment”“”)”}”(hŒ SPDX-License-Identifier: GPL-2.0”h]”hŒ SPDX-License-Identifier: GPL-2.0”…””}”hh£sbah}”(h]”h ]”h"]”h$]”h&]”Œ	xml:space”Œpreserve”uh1h¡hhhžhhŸŒK/var/lib/git/docbuild/linux/Documentation/driver-api/cxl/allocation/dax.rst”h KubhŒsection”“”)”}”(hhh]”(hŒtitle”“”)”}”(hŒDAX Devices”h]”hŒDAX Devices”…””}”(hh»hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h¹hh¶hžhhŸh³h KubhŒ	paragraph”“”)”}”(hŒêCXL capacity exposed as a DAX device can be accessed directly via mmap.
Users may wish to use this interface mechanism to write their own userland
CXL allocator, or to managed shared or persistent memory regions across multiple
hosts.”h]”hŒêCXL capacity exposed as a DAX device can be accessed directly via mmap.
Users may wish to use this interface mechanism to write their own userland
CXL allocator, or to managed shared or persistent memory regions across multiple
hosts.”…””}”(hhËhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÉhŸh³h Khh¶hžhubhÊ)”}”(hŒ˜If the capacity is shared across hosts or persistent, appropriate flushing
mechanisms must be employed unless the region supports Snoop Back-Invalidate.”h]”hŒ˜If the capacity is shared across hosts or persistent, appropriate flushing
mechanisms must be employed unless the region supports Snoop Back-Invalidate.”…””}”(hhÙhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÉhŸh³h Khh¶hžhubhÊ)”}”(hŒNote that mappings must be aligned (size and base) to the dax device's base
alignment, which is typically 2MB - but maybe be configured larger.”h]”hŒ‘Note that mappings must be aligned (size and base) to the dax deviceâ€™s base
alignment, which is typically 2MB - but maybe be configured larger.”…””}”(hhçhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÉhŸh³h Khh¶hžhubhŒliteral_block”“”)”}”(hX  #include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <sys/mman.h>
#include <fcntl.h>
#include <unistd.h>

#define DEVICE_PATH "/dev/dax0.0" // Replace DAX device path
#define DEVICE_SIZE (4ULL * 1024 * 1024 * 1024) // 4GB

int main() {
    int fd;
    void* mapped_addr;

    /* Open the DAX device */
    fd = open(DEVICE_PATH, O_RDWR);
    if (fd < 0) {
        perror("open");
        return -1;
    }

    /* Map the device into memory */
    mapped_addr = mmap(NULL, DEVICE_SIZE, PROT_READ | PROT_WRITE,
                       MAP_SHARED, fd, 0);
    if (mapped_addr == MAP_FAILED) {
        perror("mmap");
        close(fd);
        return -1;
    }

    printf("Mapped address: %p\n", mapped_addr);

    /* You can now access the device through the mapped address */
    uint64_t* ptr = (uint64_t*)mapped_addr;
    *ptr = 0x1234567890abcdef; // Write a value to the device
    printf("Value at address %p: 0x%016llx\n", ptr, *ptr);

    /* Clean up */
    munmap(mapped_addr, DEVICE_SIZE);
    close(fd);
    return 0;
}”h]”hX  #include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <sys/mman.h>
#include <fcntl.h>
#include <unistd.h>

#define DEVICE_PATH "/dev/dax0.0" // Replace DAX device path
#define DEVICE_SIZE (4ULL * 1024 * 1024 * 1024) // 4GB

int main() {
    int fd;
    void* mapped_addr;

    /* Open the DAX device */
    fd = open(DEVICE_PATH, O_RDWR);
    if (fd < 0) {
        perror("open");
        return -1;
    }

    /* Map the device into memory */
    mapped_addr = mmap(NULL, DEVICE_SIZE, PROT_READ | PROT_WRITE,
                       MAP_SHARED, fd, 0);
    if (mapped_addr == MAP_FAILED) {
        perror("mmap");
        close(fd);
        return -1;
    }

    printf("Mapped address: %p\n", mapped_addr);

    /* You can now access the device through the mapped address */
    uint64_t* ptr = (uint64_t*)mapped_addr;
    *ptr = 0x1234567890abcdef; // Write a value to the device
    printf("Value at address %p: 0x%016llx\n", ptr, *ptr);

    /* Clean up */
    munmap(mapped_addr, DEVICE_SIZE);
    close(fd);
    return 0;
}”…””}”hh÷sbah}”(h]”h ]”h"]”h$]”h&]”h±h²uh1hõhŸh³h Khh¶hžhubeh}”(h]”Œdax-devices”ah ]”h"]”Œdax devices”ah$]”h&]”uh1h´hhhžhhŸh³h Kubeh}”(h]”h ]”h"]”h$]”h&]”Œsource”h³uh1hŒcurrent_source”NŒcurrent_line”NŒsettings”Œdocutils.frontend”ŒValues”“”)”}”(h¹NŒ	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”j0  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”h³Œ_destination”NŒ_config_files”]”Œ7/var/lib/git/docbuild/linux/Documentation/docutils.conf”aŒfile_insertion_enabled”ˆŒraw_enabled”KŒline_length_limit”M'Œ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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”‰Œenv”NubŒreporter”NŒindirect_targets”]”Œsubstitution_defs”}”Œsubstitution_names”}”Œrefnames”}”Œrefids”}”Œnameids”}”j
  j  sŒ	nametypes”}”j
  ‰sh}”j  h¶sŒ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.