€•³VŒsphinx.addnodes”Œdocument”“”)”}”(Œ rawsource”Œ”Œchildren”]”(Œ translations”Œ LanguagesNode”“”)”}”(hhh]”(hŒ pending_xref”“”)”}”(hhh]”Œdocutils.nodes”ŒText”“”ŒChinese (Simplified)”…””}”Œparent”hsbaŒ attributes”}”(Œids”]”Œclasses”]”Œnames”]”Œdupnames”]”Œbackrefs”]”Œ refdomain”Œstd”Œreftype”Œdoc”Œ reftarget”Œ&/translations/zh_CN/driver-api/usb/dma”Œmodname”NŒ classname”NŒ refexplicit”ˆuŒtagname”hhh ubh)”}”(hhh]”hŒChinese (Traditional)”…””}”hh2sbah}”(h]”h ]”h"]”h$]”h&]”Œ refdomain”h)Œreftype”h+Œ reftarget”Œ&/translations/zh_TW/driver-api/usb/dma”Œmodname”NŒ classname”NŒ refexplicit”ˆuh1hhh ubh)”}”(hhh]”hŒItalian”…””}”hhFsbah}”(h]”h ]”h"]”h$]”h&]”Œ refdomain”h)Œreftype”h+Œ reftarget”Œ&/translations/it_IT/driver-api/usb/dma”Œmodname”NŒ classname”NŒ refexplicit”ˆuh1hhh ubh)”}”(hhh]”hŒJapanese”…””}”hhZsbah}”(h]”h ]”h"]”h$]”h&]”Œ refdomain”h)Œreftype”h+Œ reftarget”Œ&/translations/ja_JP/driver-api/usb/dma”Œmodname”NŒ classname”NŒ refexplicit”ˆuh1hhh ubh)”}”(hhh]”hŒKorean”…””}”hhnsbah}”(h]”h ]”h"]”h$]”h&]”Œ refdomain”h)Œreftype”h+Œ reftarget”Œ&/translations/ko_KR/driver-api/usb/dma”Œmodname”NŒ classname”NŒ refexplicit”ˆuh1hhh ubh)”}”(hhh]”hŒPortuguese (Brazilian)”…””}”hh‚sbah}”(h]”h ]”h"]”h$]”h&]”Œ refdomain”h)Œreftype”h+Œ reftarget”Œ&/translations/pt_BR/driver-api/usb/dma”Œmodname”NŒ classname”NŒ refexplicit”ˆuh1hhh ubh)”}”(hhh]”hŒSpanish”…””}”hh–sbah}”(h]”h ]”h"]”h$]”h&]”Œ refdomain”h)Œreftype”h+Œ reftarget”Œ&/translations/sp_SP/driver-api/usb/dma”Œmodname”NŒ classname”NŒ refexplicit”ˆuh1hhh ubeh}”(h]”h ]”h"]”h$]”h&]”Œcurrent_language”ŒEnglish”uh1h hhŒ _document”hŒsource”NŒline”NubhŒsection”“”)”}”(hhh]”(hŒtitle”“”)”}”(hŒUSB DMA”h]”hŒUSB DMA”…””}”(hh¼h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hºhh·h²hh³Œ@/var/lib/git/docbuild/linux/Documentation/driver-api/usb/dma.rst”h´KubhŒ paragraph”“”)”}”(hŒÞIn Linux 2.5 kernels (and later), USB device drivers have additional control over how DMA may be used to perform I/O operations. The APIs are detailed in the kernel usb programming guide (kerneldoc, from the source code).”h]”hŒÞIn Linux 2.5 kernels (and later), USB device drivers have additional control over how DMA may be used to perform I/O operations. The APIs are detailed in the kernel usb programming guide (kerneldoc, from the source code).”…””}”(hhÍh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´Khh·h²hubh¶)”}”(hhh]”(h»)”}”(hŒ API overview”h]”hŒ API overview”…””}”(hhÞh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hºhhÛh²hh³hÊh´K ubhÌ)”}”(hX The big picture is that USB drivers can continue to ignore most DMA issues, though they still must provide DMA-ready buffers (see Documentation/core-api/dma-api-howto.rst). That's how they've worked through the 2.4 (and earlier) kernels, or they can now be DMA-aware.”h]”hXThe big picture is that USB drivers can continue to ignore most DMA issues, though they still must provide DMA-ready buffers (see Documentation/core-api/dma-api-howto.rst). That’s how they’ve worked through the 2.4 (and earlier) kernels, or they can now be DMA-aware.”…””}”(hhìh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´K hhÛh²hubhÌ)”}”(hŒDMA-aware usb drivers:”h]”hŒDMA-aware usb drivers:”…””}”(hhúh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´KhhÛh²hubhŒ bullet_list”“”)”}”(hhh]”(hŒ list_item”“”)”}”(hŒŠNew calls enable DMA-aware drivers, letting them allocate dma buffers and manage dma mappings for existing dma-ready buffers (see below). ”h]”hÌ)”}”(hŒ‰New calls enable DMA-aware drivers, letting them allocate dma buffers and manage dma mappings for existing dma-ready buffers (see below).”h]”hŒ‰New calls enable DMA-aware drivers, letting them allocate dma buffers and manage dma mappings for existing dma-ready buffers (see below).”…””}”(hjh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´Khjubah}”(h]”h ]”h"]”h$]”h&]”uh1j hj h²hh³hÊh´Nubj)”}”(hŒ¬URBs have an additional "transfer_dma" field, as well as a transfer_flags bit saying if it's valid. (Control requests also have "setup_dma", but drivers must not use it.) ”h]”hÌ)”}”(hŒ«URBs have an additional "transfer_dma" field, as well as a transfer_flags bit saying if it's valid. (Control requests also have "setup_dma", but drivers must not use it.)”h]”hŒµURBs have an additional “transfer_dma†field, as well as a transfer_flags bit saying if it’s valid. (Control requests also have “setup_dmaâ€, but drivers must not use it.)”…””}”(hj+h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´Khj'ubah}”(h]”h ]”h"]”h$]”h&]”uh1j hj h²hh³hÊh´Nubj)”}”(hŒ"usbcore" will map this DMA address, if a DMA-aware driver didn't do it first and set ``URB_NO_TRANSFER_DMA_MAP``. HCDs don't manage dma mappings for URBs. ”h]”hÌ)”}”(hŒœ"usbcore" will map this DMA address, if a DMA-aware driver didn't do it first and set ``URB_NO_TRANSFER_DMA_MAP``. HCDs don't manage dma mappings for URBs.”h]”(hŒ\“usbcore†will map this DMA address, if a DMA-aware driver didn’t do it first and set ”…””}”(hjCh²hh³Nh´NubhŒliteral”“”)”}”(hŒ``URB_NO_TRANSFER_DMA_MAP``”h]”hŒURB_NO_TRANSFER_DMA_MAP”…””}”(hjMh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jKhjCubhŒ-. HCDs don’t manage dma mappings for URBs.”…””}”(hjCh²hh³Nh´Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´Khj?ubah}”(h]”h ]”h"]”h$]”h&]”uh1j hj h²hh³hÊh´Nubj)”}”(hŒÇThere's a new "generic DMA API", parts of which are usable by USB device drivers. Never use dma_set_mask() on any USB interface or device; that would potentially break all devices sharing that bus. ”h]”hÌ)”}”(hŒÆThere's a new "generic DMA API", parts of which are usable by USB device drivers. Never use dma_set_mask() on any USB interface or device; that would potentially break all devices sharing that bus.”h]”hŒÌThere’s a new “generic DMA APIâ€, parts of which are usable by USB device drivers. Never use dma_set_mask() on any USB interface or device; that would potentially break all devices sharing that bus.”…””}”(hjoh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´Khjkubah}”(h]”h ]”h"]”h$]”h&]”uh1j hj h²hh³hÊh´Nubeh}”(h]”h ]”h"]”h$]”h&]”Œbullet”Œ-”uh1jh³hÊh´KhhÛh²hubeh}”(h]”Œ api-overview”ah ]”h"]”Œ api overview”ah$]”h&]”uh1hµhh·h²hh³hÊh´K ubh¶)”}”(hhh]”(h»)”}”(hŒEliminating copies”h]”hŒEliminating copies”…””}”(hj–h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hºhj“h²hh³hÊh´K"ubhÌ)”}”(hŒˆIt's good to avoid making CPUs copy data needlessly. The costs can add up, and effects like cache-trashing can impose subtle penalties.”h]”hŒŠIt’s good to avoid making CPUs copy data needlessly. The costs can add up, and effects like cache-trashing can impose subtle penalties.”…””}”(hj¤h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´K$hj“h²hubj )”}”(hhh]”(j)”}”(hXèIf you're doing lots of small data transfers from the same buffer all the time, that can really burn up resources on systems which use an IOMMU to manage the DMA mappings. It can cost MUCH more to set up and tear down the IOMMU mappings with each request than perform the I/O! For those specific cases, USB has primitives to allocate less expensive memory. They work like kmalloc and kfree versions that give you the right kind of addresses to store in urb->transfer_buffer and urb->transfer_dma. You'd also set ``URB_NO_TRANSFER_DMA_MAP`` in urb->transfer_flags:: void *usb_alloc_coherent (struct usb_device *dev, size_t size, int mem_flags, dma_addr_t *dma); void usb_free_coherent (struct usb_device *dev, size_t size, void *addr, dma_addr_t dma); Most drivers should **NOT** be using these primitives; they don't need to use this type of memory ("dma-coherent"), and memory returned from :c:func:`kmalloc` will work just fine. The memory buffer returned is "dma-coherent"; sometimes you might need to force a consistent memory access ordering by using memory barriers. It's not using a streaming DMA mapping, so it's good for small transfers on systems where the I/O would otherwise thrash an IOMMU mapping. (See Documentation/core-api/dma-api-howto.rst for definitions of "coherent" and "streaming" DMA mappings.) Asking for 1/Nth of a page (as well as asking for N pages) is reasonably space-efficient. On most systems the memory returned will be uncached, because the semantics of dma-coherent memory require either bypassing CPU caches or using cache hardware with bus-snooping support. While x86 hardware has such bus-snooping, many other systems use software to flush cache lines to prevent DMA conflicts. ”h]”(hÌ)”}”(hXIf you're doing lots of small data transfers from the same buffer all the time, that can really burn up resources on systems which use an IOMMU to manage the DMA mappings. It can cost MUCH more to set up and tear down the IOMMU mappings with each request than perform the I/O!”h]”hXIf you’re doing lots of small data transfers from the same buffer all the time, that can really burn up resources on systems which use an IOMMU to manage the DMA mappings. It can cost MUCH more to set up and tear down the IOMMU mappings with each request than perform the I/O!”…””}”(hj¹h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´K'hjµubhÌ)”}”(hX For those specific cases, USB has primitives to allocate less expensive memory. They work like kmalloc and kfree versions that give you the right kind of addresses to store in urb->transfer_buffer and urb->transfer_dma. You'd also set ``URB_NO_TRANSFER_DMA_MAP`` in urb->transfer_flags::”h]”(hŒîFor those specific cases, USB has primitives to allocate less expensive memory. They work like kmalloc and kfree versions that give you the right kind of addresses to store in urb->transfer_buffer and urb->transfer_dma. You’d also set ”…””}”(hjÇh²hh³Nh´NubjL)”}”(hŒ``URB_NO_TRANSFER_DMA_MAP``”h]”hŒURB_NO_TRANSFER_DMA_MAP”…””}”(hjÏh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jKhjÇubhŒ in urb->transfer_flags:”…””}”(hjÇh²hh³Nh´Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´K,hjµubhŒ literal_block”“”)”}”(hŒÊvoid *usb_alloc_coherent (struct usb_device *dev, size_t size, int mem_flags, dma_addr_t *dma); void usb_free_coherent (struct usb_device *dev, size_t size, void *addr, dma_addr_t dma);”h]”hŒÊvoid *usb_alloc_coherent (struct usb_device *dev, size_t size, int mem_flags, dma_addr_t *dma); void usb_free_coherent (struct usb_device *dev, size_t size, void *addr, dma_addr_t dma);”…””}”hjésbah}”(h]”h ]”h"]”h$]”h&]”Œ xml:space”Œpreserve”uh1jçh³hÊh´K1hjµubhÌ)”}”(hŒ³Most drivers should **NOT** be using these primitives; they don't need to use this type of memory ("dma-coherent"), and memory returned from :c:func:`kmalloc` will work just fine.”h]”(hŒMost drivers should ”…””}”(hjùh²hh³Nh´NubhŒstrong”“”)”}”(hŒ**NOT**”h]”hŒNOT”…””}”(hjh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jhjùubhŒx be using these primitives; they don’t need to use this type of memory (“dma-coherentâ€), and memory returned from ”…””}”(hjùh²hh³Nh´Nubh)”}”(hŒ:c:func:`kmalloc`”h]”jL)”}”(hjh]”hŒ kmalloc()”…””}”(hjh²hh³Nh´Nubah}”(h]”h ]”(Œxref”Œc”Œc-func”eh"]”h$]”h&]”uh1jKhjubah}”(h]”h ]”h"]”h$]”h&]”Œrefdoc”Œdriver-api/usb/dma”Œ refdomain”j$Œreftype”Œfunc”Œ refexplicit”‰Œrefwarn”‰Œ reftarget”Œkmalloc”uh1hh³hÊh´K7hjùubhŒ will work just fine.”…””}”(hjùh²hh³Nh´Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´K7hjµubhÌ)”}”(hX…The memory buffer returned is "dma-coherent"; sometimes you might need to force a consistent memory access ordering by using memory barriers. It's not using a streaming DMA mapping, so it's good for small transfers on systems where the I/O would otherwise thrash an IOMMU mapping. (See Documentation/core-api/dma-api-howto.rst for definitions of "coherent" and "streaming" DMA mappings.)”h]”hX•The memory buffer returned is “dma-coherentâ€; sometimes you might need to force a consistent memory access ordering by using memory barriers. It’s not using a streaming DMA mapping, so it’s good for small transfers on systems where the I/O would otherwise thrash an IOMMU mapping. (See Documentation/core-api/dma-api-howto.rst for definitions of “coherent†and “streaming†DMA mappings.)”…””}”(hjBh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´K;hjµubhÌ)”}”(hŒYAsking for 1/Nth of a page (as well as asking for N pages) is reasonably space-efficient.”h]”hŒYAsking for 1/Nth of a page (as well as asking for N pages) is reasonably space-efficient.”…””}”(hjPh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´KBhjµubhÌ)”}”(hX3On most systems the memory returned will be uncached, because the semantics of dma-coherent memory require either bypassing CPU caches or using cache hardware with bus-snooping support. While x86 hardware has such bus-snooping, many other systems use software to flush cache lines to prevent DMA conflicts.”h]”hX3On most systems the memory returned will be uncached, because the semantics of dma-coherent memory require either bypassing CPU caches or using cache hardware with bus-snooping support. While x86 hardware has such bus-snooping, many other systems use software to flush cache lines to prevent DMA conflicts.”…””}”(hj^h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´KEhjµubeh}”(h]”h ]”h"]”h$]”h&]”uh1j hj²h²hh³hÊh´Nubj)”}”(hXžDevices on some EHCI controllers could handle DMA to/from high memory. Unfortunately, the current Linux DMA infrastructure doesn't have a sane way to expose these capabilities ... and in any case, HIGHMEM is mostly a design wart specific to x86_32. So your best bet is to ensure you never pass a highmem buffer into a USB driver. That's easy; it's the default behavior. Just don't override it; e.g. with ``NETIF_F_HIGHDMA``. This may force your callers to do some bounce buffering, copying from high memory to "normal" DMA memory. If you can come up with a good way to fix this issue (for x86_32 machines with over 1 GByte of memory), feel free to submit patches. ”h]”(hÌ)”}”(hŒFDevices on some EHCI controllers could handle DMA to/from high memory.”h]”hŒFDevices on some EHCI controllers could handle DMA to/from high memory.”…””}”(hjvh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´KKhjrubhÌ)”}”(hXdUnfortunately, the current Linux DMA infrastructure doesn't have a sane way to expose these capabilities ... and in any case, HIGHMEM is mostly a design wart specific to x86_32. So your best bet is to ensure you never pass a highmem buffer into a USB driver. That's easy; it's the default behavior. Just don't override it; e.g. with ``NETIF_F_HIGHDMA``.”h]”(hXXUnfortunately, the current Linux DMA infrastructure doesn’t have a sane way to expose these capabilities ... and in any case, HIGHMEM is mostly a design wart specific to x86_32. So your best bet is to ensure you never pass a highmem buffer into a USB driver. That’s easy; it’s the default behavior. Just don’t override it; e.g. with ”…””}”(hj„h²hh³Nh´NubjL)”}”(hŒ``NETIF_F_HIGHDMA``”h]”hŒNETIF_F_HIGHDMA”…””}”(hjŒh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jKhj„ubhŒ.”…””}”(hj„h²hh³Nh´Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´KMhjrubhÌ)”}”(hŒïThis may force your callers to do some bounce buffering, copying from high memory to "normal" DMA memory. If you can come up with a good way to fix this issue (for x86_32 machines with over 1 GByte of memory), feel free to submit patches.”h]”hŒóThis may force your callers to do some bounce buffering, copying from high memory to “normal†DMA memory. If you can come up with a good way to fix this issue (for x86_32 machines with over 1 GByte of memory), feel free to submit patches.”…””}”(hj¤h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´KShjrubeh}”(h]”h ]”h"]”h$]”h&]”uh1j hj²h²hh³hÊh´Nubeh}”(h]”h ]”h"]”h$]”h&]”j‰jŠuh1jh³hÊh´K'hj“h²hubeh}”(h]”Œeliminating-copies”ah ]”h"]”Œeliminating copies”ah$]”h&]”uh1hµhh·h²hh³hÊh´K"ubh¶)”}”(hhh]”(h»)”}”(hŒWorking with existing buffers”h]”hŒWorking with existing buffers”…””}”(hjÉh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hºhjÆh²hh³hÊh´KYubhÌ)”}”(hX*Existing buffers aren't usable for DMA without first being mapped into the DMA address space of the device. However, most buffers passed to your driver can safely be used with such DMA mapping. (See the first section of Documentation/core-api/dma-api-howto.rst, titled "What memory is DMA-able?")”h]”hX0Existing buffers aren’t usable for DMA without first being mapped into the DMA address space of the device. However, most buffers passed to your driver can safely be used with such DMA mapping. (See the first section of Documentation/core-api/dma-api-howto.rst, titled “What memory is DMA-able?â€)”…””}”(hj×h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´K[hjÆh²hubj )”}”(hhh]”j)”}”(hX«When you have the scatterlists which have been mapped for the USB controller, you could use the new ``usb_sg_*()`` calls, which would turn scatterlist into URBs:: int usb_sg_init(struct usb_sg_request *io, struct usb_device *dev, unsigned pipe, unsigned period, struct scatterlist *sg, int nents, size_t length, gfp_t mem_flags); void usb_sg_wait(struct usb_sg_request *io); void usb_sg_cancel(struct usb_sg_request *io); When the USB controller doesn't support DMA, the ``usb_sg_init()`` would try to submit URBs in PIO way as long as the page in scatterlists is not in the Highmem, which could be very rare in modern architectures.”h]”(hÌ)”}”(hŒ¢When you have the scatterlists which have been mapped for the USB controller, you could use the new ``usb_sg_*()`` calls, which would turn scatterlist into URBs::”h]”(hŒdWhen you have the scatterlists which have been mapped for the USB controller, you could use the new ”…””}”(hjìh²hh³Nh´NubjL)”}”(hŒ``usb_sg_*()``”h]”hŒ usb_sg_*()”…””}”(hjôh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jKhjìubhŒ/ calls, which would turn scatterlist into URBs:”…””}”(hjìh²hh³Nh´Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´K`hjèubjè)”}”(hXint usb_sg_init(struct usb_sg_request *io, struct usb_device *dev, unsigned pipe, unsigned period, struct scatterlist *sg, int nents, size_t length, gfp_t mem_flags); void usb_sg_wait(struct usb_sg_request *io); void usb_sg_cancel(struct usb_sg_request *io);”h]”hXint usb_sg_init(struct usb_sg_request *io, struct usb_device *dev, unsigned pipe, unsigned period, struct scatterlist *sg, int nents, size_t length, gfp_t mem_flags); void usb_sg_wait(struct usb_sg_request *io); void usb_sg_cancel(struct usb_sg_request *io);”…””}”hj sbah}”(h]”h ]”h"]”h$]”h&]”j÷jøuh1jçh³hÊh´KdhjèubhÌ)”}”(hŒÓWhen the USB controller doesn't support DMA, the ``usb_sg_init()`` would try to submit URBs in PIO way as long as the page in scatterlists is not in the Highmem, which could be very rare in modern architectures.”h]”(hŒ3When the USB controller doesn’t support DMA, the ”…””}”(hjh²hh³Nh´NubjL)”}”(hŒ``usb_sg_init()``”h]”hŒ usb_sg_init()”…””}”(hj"h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jKhjubhŒ‘ would try to submit URBs in PIO way as long as the page in scatterlists is not in the Highmem, which could be very rare in modern architectures.”…””}”(hjh²hh³Nh´Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´Klhjèubeh}”(h]”h ]”h"]”h$]”h&]”uh1j hjåh²hh³hÊh´Nubah}”(h]”h ]”h"]”h$]”h&]”j‰jŠuh1jh³hÊh´K`hjÆh²hubeh}”(h]”Œworking-with-existing-buffers”ah ]”h"]”Œworking with existing buffers”ah$]”h&]”uh1hµhh·h²hh³hÊh´KYubeh}”(h]”Œusb-dma”ah ]”h"]”Œusb dma”ah$]”h&]”uh1hµhhh²hh³hÊh´Kubeh}”(h]”h ]”h"]”h$]”h&]”Œsource”hÊuh1hŒcurrent_source”NŒ current_line”NŒsettings”Œdocutils.frontend”ŒValues”“”)”}”(hºNŒ generator”NŒ datestamp”NŒ source_link”NŒ source_url”NŒ toc_backlinks”Œentry”Œfootnote_backlinks”KŒ sectnum_xform”KŒstrip_comments”NŒstrip_elements_with_classes”NŒ strip_classes”NŒ report_level”KŒ halt_level”KŒexit_status_level”KŒdebug”NŒwarning_stream”NŒ traceback”ˆŒinput_encoding”Œ utf-8-sig”Œinput_encoding_error_handler”Œstrict”Œoutput_encoding”Œutf-8”Œoutput_encoding_error_handler”jyŒerror_encoding”Œutf-8”Œerror_encoding_error_handler”Œbackslashreplace”Œ language_code”Œen”Œrecord_dependencies”NŒconfig”NŒ id_prefix”hŒauto_id_prefix”Œid”Œ dump_settings”NŒdump_internals”NŒdump_transforms”NŒdump_pseudo_xml”NŒexpose_internals”NŒstrict_visitor”NŒ_disable_config”NŒ_source”hÊŒ _destination”NŒ _config_files”]”Œ7/var/lib/git/docbuild/linux/Documentation/docutils.conf”aŒfile_insertion_enabled”ˆŒ raw_enabled”KŒline_length_limit”M'Œpep_references”NŒ pep_base_url”Œhttps://peps.python.org/”Œpep_file_url_template”Œpep-%04d”Œrfc_references”NŒ rfc_base_url”Œ&https://datatracker.ietf.org/doc/html/”Œ tab_width”KŒtrim_footnote_reference_space”‰Œsyntax_highlight”Œlong”Œ smart_quotes”ˆŒsmartquotes_locales”]”Œcharacter_level_inline_markup”‰Œdoctitle_xform”‰Œ docinfo_xform”KŒsectsubtitle_xform”‰Œ image_loading”Œlink”Œembed_stylesheet”‰Œcloak_email_addresses”ˆŒsection_self_link”‰Œenv”NubŒreporter”NŒindirect_targets”]”Œsubstitution_defs”}”Œsubstitution_names”}”Œrefnames”}”Œrefids”}”Œnameids”}”(jSjPjjjÃjÀjKjHuŒ nametypes”}”(jS‰j‰jÉjK‰uh}”(jPh·jhÛjÀj“jHjÆuŒ footnote_refs”}”Œ citation_refs”}”Œ autofootnotes”]”Œautofootnote_refs”]”Œsymbol_footnotes”]”Œsymbol_footnote_refs”]”Œ footnotes”]”Œ citations”]”Œautofootnote_start”KŒsymbol_footnote_start”KŒ id_counter”Œ collections”ŒCounter”“”}”…”R”Œparse_messages”]”Œtransform_messages”]”Œ transformer”NŒ include_log”]”Œ decoration”Nh²hub.