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Howlett" Cc: linux-block@vger.kernel.org, rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Andreas Hindborg X-Mailer: b4 0.15-dev X-Developer-Signature: v=1; a=openpgp-sha256; l=3879; i=a.hindborg@kernel.org; h=from:subject:message-id; bh=9wLxYaTCPfOG5uonTZ2h8ocU8FWs+hSDrEKcM2sv5z4=; b=owEBbQKS/ZANAwAKAeG4Gj55KGN3AcsmYgBpklhHteQM6fc3Iu+s7ErTmW5+zxHdbuM7v9MUt WW0qbMjDayJAjMEAAEKAB0WIQQSwflHVr98KhXWwBLhuBo+eShjdwUCaZJYRwAKCRDhuBo+eShj d82UEADCFQq4xg0GLRoFbDArGbCjq1pYimjtXweH1jUHAlgJbGGDkikwcOVePhVAnaq0cdE5BuY FST4N7wGwn5uDWVPQjXpCx3F0A00D312QyAmD8cvTc3vOP3J4jJptfyTx18my0TG3l/QpGh2k6+ VRnt/4++OOUgxoE8WyWXsHSiexrgbP5JGRTRiN48GSZzVsD+hMHSp/+pgp7Xcl0BR+8bGdFiCQm LGiYwXAUL5k3Gqj/IYOdhE00o/x0U8DPQMfes514MGFteRl7clkgSvYEFKWth04xf/u7Ko2u7Ku 9RZFRbrxsRa66tuTEpsFIA6IX/RwvMKZoXDegWKZ8M0TsY7LUUI2V7aNC7bnV2Xv0mertjEooNo Ua16efkXqh+Tx/mi18AdzA0+qemfM30vBYaWJ9xQDcAbSVCfSq+gB9EFg/ft+MzN7AS9w2UdGdt EJyQcDaAUyDI4zCU7pPSm/5GHu52+/vVcaHnTHT8vGfMk1tFZQ4t5d9DTiAS11OUgBMHJqhQEPX F2LkCpJ5bsvfp0U5L+/nuiphEGkRmHRxMhE4MQ2vGaAWhI4jUEAeiJC76C5ficBetddzfL4fS+U ZIk5m9JLWOTZyF3nP1DNE0C1fLiAMjBgV3OOwQg8Bp5j7v0btIbGpJUHAd4dzkHYMBmRMjTb/gX QQhP/zLigZgzM0g== X-Developer-Key: i=a.hindborg@kernel.org; a=openpgp; fpr=3108C10F46872E248D1FB221376EB100563EF7A7 X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: DBDB3C000A X-Stat-Signature: pfjjeciz978to4tztue8dbfk78chzob4 X-Rspam-User: X-HE-Tag: 1771199181-635426 X-HE-Meta: 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 ue9rr2ek VeigV8C9qDONIALjZd1FlYcMKIyhgC3MrDJWVkv/GqceOQFRqNAmsO26LGxJTlC/Hf/BjO9XXjOqheMkhfW9B5OzmmJ9iETKAUMgONhsWEnjwnljnH/kuitkQNYgWT0bMTwcy+LHBIh/bdWIDxM6g/9S8Heg+oD6Qp90zW+umdEF44FAtaDQYoy5u6HtMZxHPPNH7aUArE1GgyolJbg8LJO/ytpJgmMG/6OlNJsVFAfIJ3qpQxIg+NDGQbUIEd4tQXAXH9kYuhigvajB4n11eS0N9OyG0NJ4ey5Z0TvNqmFsieDJilL2jXz5y6MONkdFetumOSuE9t2fQoIwXCIOSHI44CuGse+c4VVy+aSW77RrLb7CV2MNFOrb6K21+HmHLmVdSUSWTfsQIiT4= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: Add support for the `map_queues` callback to the Rust block layer bindings. This callback allows drivers to customize the mapping between CPUs and hardware queues. The callback receives a mutable reference to the `TagSet`, and drivers can use the `TagSet::update_maps` method to configure the mappings for each queue type. Signed-off-by: Andreas Hindborg --- rust/kernel/block/mq/operations.rs | 28 ++++++++++++++++++++++++++-- rust/kernel/block/mq/tag_set.rs | 13 +++++++++++++ 2 files changed, 39 insertions(+), 2 deletions(-) diff --git a/rust/kernel/block/mq/operations.rs b/rust/kernel/block/mq/operations.rs index 3f84ebadec86b..017fad010d174 100644 --- a/rust/kernel/block/mq/operations.rs +++ b/rust/kernel/block/mq/operations.rs @@ -8,7 +8,7 @@ bindings, block::{ error::BlkResult, - mq::{gen_disk::GenDiskRef, request::RequestDataWrapper, IdleRequest, Request}, + mq::{gen_disk::GenDiskRef, request::RequestDataWrapper, IdleRequest, Request, TagSet}, }, error::{from_result, to_result, Result}, prelude::*, @@ -101,6 +101,11 @@ fn report_zones( ) -> Result { Err(ENOTSUPP) } + + /// Called by the kernel to map submission queues to CPU cores. + fn map_queues(_tag_set: &TagSet) { + build_error!(crate::error::VTABLE_DEFAULT_ERROR) + } } /// A vtable for blk-mq to interact with a block device driver. @@ -394,6 +399,21 @@ impl OperationsVTable { }) } + /// This function is called by the C kernel. A pointer to this function is + /// installed in the `blk_mq_ops` vtable for the driver. + /// + /// # Safety + /// + /// This function may only be called by blk-mq C infrastructure. `tag_set` + /// must be a pointer to a valid and initialized `TagSet`. The pointee + /// must be valid for use as a reference at least the duration of this call. + unsafe extern "C" fn map_queues_callback(tag_set: *mut bindings::blk_mq_tag_set) { + // SAFETY: The safety requirements of this function satiesfies the + // requirements of `TagSet::from_ptr`. + let tag_set = unsafe { TagSet::from_ptr(tag_set) }; + T::map_queues(tag_set); + } + const VTABLE: bindings::blk_mq_ops = bindings::blk_mq_ops { queue_rq: Some(Self::queue_rq_callback), queue_rqs: None, @@ -415,7 +435,11 @@ impl OperationsVTable { exit_request: Some(Self::exit_request_callback), cleanup_rq: None, busy: None, - map_queues: None, + map_queues: if T::HAS_MAP_QUEUES { + Some(Self::map_queues_callback) + } else { + None + }, #[cfg(CONFIG_BLK_DEBUG_FS)] show_rq: None, }; diff --git a/rust/kernel/block/mq/tag_set.rs b/rust/kernel/block/mq/tag_set.rs index 600c9c6249123..330ff28c91507 100644 --- a/rust/kernel/block/mq/tag_set.rs +++ b/rust/kernel/block/mq/tag_set.rs @@ -89,6 +89,19 @@ pub fn new( pub(crate) fn raw_tag_set(&self) -> *mut bindings::blk_mq_tag_set { self.inner.get() } + + /// Create a `TagSet` from a raw pointer. + /// + /// # Safety + /// + /// `ptr` must be a pointer to a valid and initialized `TagSet`. There + /// may be no other mutable references to the tag set. The pointee must be + /// live and valid at least for the duration of the returned lifetime `'a`. + pub(crate) unsafe fn from_ptr<'a>(ptr: *mut bindings::blk_mq_tag_set) -> &'a Self { + // SAFETY: By the safety requirements of this function, `ptr` is valid + // for use as a reference for the duration of `'a`. + unsafe { &*(ptr.cast::()) } + } } #[pinned_drop] -- 2.51.2