diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/admin-guide/cifs/usage.rst | 2 | ||||
| -rw-r--r-- | Documentation/block/ublk.rst | 77 | ||||
| -rw-r--r-- | Documentation/devicetree/bindings/pmem/pmem-region.txt | 65 | ||||
| -rw-r--r-- | Documentation/devicetree/bindings/pmem/pmem-region.yaml | 48 | ||||
| -rw-r--r-- | Documentation/filesystems/proc.rst | 4 | ||||
| -rw-r--r-- | Documentation/gpu/nouveau.rst | 2 | ||||
| -rw-r--r-- | Documentation/process/embargoed-hardware-issues.rst | 1 |
7 files changed, 132 insertions, 67 deletions
diff --git a/Documentation/admin-guide/cifs/usage.rst b/Documentation/admin-guide/cifs/usage.rst index c09674a75a9e..d989ae5778ba 100644 --- a/Documentation/admin-guide/cifs/usage.rst +++ b/Documentation/admin-guide/cifs/usage.rst @@ -270,6 +270,8 @@ configured for Unix Extensions (and the client has not disabled illegal Windows/NTFS/SMB characters to a remap range (this mount parameter is the default for SMB3). This remap (``mapposix``) range is also compatible with Mac (and "Services for Mac" on some older Windows). +When POSIX Extensions for SMB 3.1.1 are negotiated, remapping is automatically +disabled. CIFS VFS Mount Options ====================== diff --git a/Documentation/block/ublk.rst b/Documentation/block/ublk.rst index c368e1081b41..8c4030bcabb6 100644 --- a/Documentation/block/ublk.rst +++ b/Documentation/block/ublk.rst @@ -352,6 +352,83 @@ For reaching best IO performance, ublk server should align its segment parameter of `struct ublk_param_segment` with backend for avoiding unnecessary IO split, which usually hurts io_uring performance. +Auto Buffer Registration +------------------------ + +The ``UBLK_F_AUTO_BUF_REG`` feature automatically handles buffer registration +and unregistration for I/O requests, which simplifies the buffer management +process and reduces overhead in the ublk server implementation. + +This is another feature flag for using zero copy, and it is compatible with +``UBLK_F_SUPPORT_ZERO_COPY``. + +Feature Overview +~~~~~~~~~~~~~~~~ + +This feature automatically registers request buffers to the io_uring context +before delivering I/O commands to the ublk server and unregisters them when +completing I/O commands. This eliminates the need for manual buffer +registration/unregistration via ``UBLK_IO_REGISTER_IO_BUF`` and +``UBLK_IO_UNREGISTER_IO_BUF`` commands, then IO handling in ublk server +can avoid dependency on the two uring_cmd operations. + +IOs can't be issued concurrently to io_uring if there is any dependency +among these IOs. So this way not only simplifies ublk server implementation, +but also makes concurrent IO handling becomes possible by removing the +dependency on buffer registration & unregistration commands. + +Usage Requirements +~~~~~~~~~~~~~~~~~~ + +1. The ublk server must create a sparse buffer table on the same ``io_ring_ctx`` + used for ``UBLK_IO_FETCH_REQ`` and ``UBLK_IO_COMMIT_AND_FETCH_REQ``. If + uring_cmd is issued on a different ``io_ring_ctx``, manual buffer + unregistration is required. + +2. Buffer registration data must be passed via uring_cmd's ``sqe->addr`` with the + following structure:: + + struct ublk_auto_buf_reg { + __u16 index; /* Buffer index for registration */ + __u8 flags; /* Registration flags */ + __u8 reserved0; /* Reserved for future use */ + __u32 reserved1; /* Reserved for future use */ + }; + + ublk_auto_buf_reg_to_sqe_addr() is for converting the above structure into + ``sqe->addr``. + +3. All reserved fields in ``ublk_auto_buf_reg`` must be zeroed. + +4. Optional flags can be passed via ``ublk_auto_buf_reg.flags``. + +Fallback Behavior +~~~~~~~~~~~~~~~~~ + +If auto buffer registration fails: + +1. When ``UBLK_AUTO_BUF_REG_FALLBACK`` is enabled: + + - The uring_cmd is completed + - ``UBLK_IO_F_NEED_REG_BUF`` is set in ``ublksrv_io_desc.op_flags`` + - The ublk server must manually deal with the failure, such as, register + the buffer manually, or using user copy feature for retrieving the data + for handling ublk IO + +2. If fallback is not enabled: + + - The ublk I/O request fails silently + - The uring_cmd won't be completed + +Limitations +~~~~~~~~~~~ + +- Requires same ``io_ring_ctx`` for all operations +- May require manual buffer management in fallback cases +- io_ring_ctx buffer table has a max size of 16K, which may not be enough + in case that too many ublk devices are handled by this single io_ring_ctx + and each one has very large queue depth + References ========== diff --git a/Documentation/devicetree/bindings/pmem/pmem-region.txt b/Documentation/devicetree/bindings/pmem/pmem-region.txt deleted file mode 100644 index cd79975e85ec..000000000000 --- a/Documentation/devicetree/bindings/pmem/pmem-region.txt +++ /dev/null @@ -1,65 +0,0 @@ -Device-tree bindings for persistent memory regions ------------------------------------------------------ - -Persistent memory refers to a class of memory devices that are: - - a) Usable as main system memory (i.e. cacheable), and - b) Retain their contents across power failure. - -Given b) it is best to think of persistent memory as a kind of memory mapped -storage device. To ensure data integrity the operating system needs to manage -persistent regions separately to the normal memory pool. To aid with that this -binding provides a standardised interface for discovering where persistent -memory regions exist inside the physical address space. - -Bindings for the region nodes: ------------------------------ - -Required properties: - - compatible = "pmem-region" - - - reg = <base, size>; - The reg property should specify an address range that is - translatable to a system physical address range. This address - range should be mappable as normal system memory would be - (i.e cacheable). - - If the reg property contains multiple address ranges - each address range will be treated as though it was specified - in a separate device node. Having multiple address ranges in a - node implies no special relationship between the two ranges. - -Optional properties: - - Any relevant NUMA associativity properties for the target platform. - - - volatile; This property indicates that this region is actually - backed by non-persistent memory. This lets the OS know that it - may skip the cache flushes required to ensure data is made - persistent after a write. - - If this property is absent then the OS must assume that the region - is backed by non-volatile memory. - -Examples: --------------------- - - /* - * This node specifies one 4KB region spanning from - * 0x5000 to 0x5fff that is backed by non-volatile memory. - */ - pmem@5000 { - compatible = "pmem-region"; - reg = <0x00005000 0x00001000>; - }; - - /* - * This node specifies two 4KB regions that are backed by - * volatile (normal) memory. - */ - pmem@6000 { - compatible = "pmem-region"; - reg = < 0x00006000 0x00001000 - 0x00008000 0x00001000 >; - volatile; - }; - diff --git a/Documentation/devicetree/bindings/pmem/pmem-region.yaml b/Documentation/devicetree/bindings/pmem/pmem-region.yaml new file mode 100644 index 000000000000..bd0f0c793f03 --- /dev/null +++ b/Documentation/devicetree/bindings/pmem/pmem-region.yaml @@ -0,0 +1,48 @@ +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/pmem-region.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +maintainers: + - Oliver O'Halloran <oohall@gmail.com> + +title: Persistent Memory Regions + +description: | + Persistent memory refers to a class of memory devices that are: + + a) Usable as main system memory (i.e. cacheable), and + b) Retain their contents across power failure. + + Given b) it is best to think of persistent memory as a kind of memory mapped + storage device. To ensure data integrity the operating system needs to manage + persistent regions separately to the normal memory pool. To aid with that this + binding provides a standardised interface for discovering where persistent + memory regions exist inside the physical address space. + +properties: + compatible: + const: pmem-region + + reg: + maxItems: 1 + + volatile: + description: + Indicates the region is volatile (non-persistent) and the OS can skip + cache flushes for writes + type: boolean + +required: + - compatible + - reg + +additionalProperties: false + +examples: + - | + pmem@5000 { + compatible = "pmem-region"; + reg = <0x00005000 0x00001000>; + }; diff --git a/Documentation/filesystems/proc.rst b/Documentation/filesystems/proc.rst index 2a17865dfe39..5236cb52e357 100644 --- a/Documentation/filesystems/proc.rst +++ b/Documentation/filesystems/proc.rst @@ -584,7 +584,6 @@ encoded manner. The codes are the following: ms may share gd stack segment growns down pf pure PFN range - dw disabled write to the mapped file lo pages are locked in memory io memory mapped I/O area sr sequential read advise provided @@ -607,8 +606,11 @@ encoded manner. The codes are the following: mt arm64 MTE allocation tags are enabled um userfaultfd missing tracking uw userfaultfd wr-protect tracking + ui userfaultfd minor fault ss shadow/guarded control stack page sl sealed + lf lock on fault pages + dp always lazily freeable mapping == ======================================= Note that there is no guarantee that every flag and associated mnemonic will diff --git a/Documentation/gpu/nouveau.rst b/Documentation/gpu/nouveau.rst index b8c801e0068c..cab2e81013bc 100644 --- a/Documentation/gpu/nouveau.rst +++ b/Documentation/gpu/nouveau.rst @@ -25,7 +25,7 @@ providing a consistent API to upper layers of the driver stack. GSP Support ------------------------ -.. kernel-doc:: drivers/gpu/drm/nouveau/nvkm/subdev/gsp/r535.c +.. kernel-doc:: drivers/gpu/drm/nouveau/nvkm/subdev/gsp/rm/r535/rpc.c :doc: GSP message queue element .. kernel-doc:: drivers/gpu/drm/nouveau/include/nvkm/subdev/gsp.h diff --git a/Documentation/process/embargoed-hardware-issues.rst b/Documentation/process/embargoed-hardware-issues.rst index da6bf0f6d01e..34e00848e0da 100644 --- a/Documentation/process/embargoed-hardware-issues.rst +++ b/Documentation/process/embargoed-hardware-issues.rst @@ -290,6 +290,7 @@ an involved disclosed party. The current ambassadors list: AMD Tom Lendacky <thomas.lendacky@amd.com> Ampere Darren Hart <darren@os.amperecomputing.com> ARM Catalin Marinas <catalin.marinas@arm.com> + IBM Power Madhavan Srinivasan <maddy@linux.ibm.com> IBM Z Christian Borntraeger <borntraeger@de.ibm.com> Intel Tony Luck <tony.luck@intel.com> Qualcomm Trilok Soni <quic_tsoni@quicinc.com> |