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72b1fe6c |
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25-May-2023 |
Tejun Heo <tj@kernel.org> |
net: wwan: t7xx: Use alloc_ordered_workqueue() to create ordered workqueues BACKGROUND ========== When multiple work items are queued to a workqueue, their execution order doesn't match the queueing order. They may get executed in any order and simultaneously. When fully serialized execution - one by one in the queueing order - is needed, an ordered workqueue should be used which can be created with alloc_ordered_workqueue(). However, alloc_ordered_workqueue() was a later addition. Before it, an ordered workqueue could be obtained by creating an UNBOUND workqueue with @max_active==1. This originally was an implementation side-effect which was broken by 4c16bd327c74 ("workqueue: restore WQ_UNBOUND/max_active==1 to be ordered"). Because there were users that depended on the ordered execution, 5c0338c68706 ("workqueue: restore WQ_UNBOUND/max_active==1 to be ordered") made workqueue allocation path to implicitly promote UNBOUND workqueues w/ @max_active==1 to ordered workqueues. While this has worked okay, overloading the UNBOUND allocation interface this way creates other issues. It's difficult to tell whether a given workqueue actually needs to be ordered and users that legitimately want a min concurrency level wq unexpectedly gets an ordered one instead. With planned UNBOUND workqueue updates to improve execution locality and more prevalence of chiplet designs which can benefit from such improvements, this isn't a state we wanna be in forever. This patch series audits all callsites that create an UNBOUND workqueue w/ @max_active==1 and converts them to alloc_ordered_workqueue() as necessary. WHAT TO LOOK FOR ================ The conversions are from alloc_workqueue(WQ_UNBOUND | flags, 1, args..) to alloc_ordered_workqueue(flags, args...) which don't cause any functional changes. If you know that fully ordered execution is not necessary, please let me know. I'll drop the conversion and instead add a comment noting the fact to reduce confusion while conversion is in progress. If you aren't fully sure, it's completely fine to let the conversion through. The behavior will stay exactly the same and we can always reconsider later. As there are follow-up workqueue core changes, I'd really appreciate if the patch can be routed through the workqueue tree w/ your acks. Thanks. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Chandrashekar Devegowda <chandrashekar.devegowda@intel.com> Cc: Intel Corporation <linuxwwan@intel.com> Cc: Chiranjeevi Rapolu <chiranjeevi.rapolu@linux.intel.com> Cc: Liu Haijun <haijun.liu@mediatek.com> Cc: M Chetan Kumar <m.chetan.kumar@linux.intel.com> Cc: Ricardo Martinez <ricardo.martinez@linux.intel.com> Cc: Loic Poulain <loic.poulain@linaro.org> Cc: Sergey Ryazanov <ryazanov.s.a@gmail.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: "David S. Miller" <davem@davemloft.net> Cc: Eric Dumazet <edumazet@google.com> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Paolo Abeni <pabeni@redhat.com> Cc: netdev@vger.kernel.org
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de49ea38 |
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06-May-2022 |
Haijun Liu <haijun.liu@mediatek.com> |
net: wwan: t7xx: Device deep sleep lock/unlock Introduce the mechanism to lock/unlock the device 'deep sleep' mode. When the PCIe link state is L1.2 or L2, the host side still can keep the device is in D0 state from the host side point of view. At the same time, if the device's 'deep sleep' mode is unlocked, the device will go to 'deep sleep' while it is still in D0 state on the host side. Signed-off-by: Haijun Liu <haijun.liu@mediatek.com> Signed-off-by: Chandrashekar Devegowda <chandrashekar.devegowda@intel.com> Co-developed-by: Ricardo Martinez <ricardo.martinez@linux.intel.com> Signed-off-by: Ricardo Martinez <ricardo.martinez@linux.intel.com> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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d642b012 |
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06-May-2022 |
Haijun Liu <haijun.liu@mediatek.com> |
net: wwan: t7xx: Add data path interface Data Path Modem AP Interface (DPMAIF) HIF layer provides methods for initialization, ISR, control and event handling of TX/RX flows. DPMAIF TX Exposes the 'dmpaif_tx_send_skb' function which can be used by the network device to transmit packets. The uplink data management uses a Descriptor Ring Buffer (DRB). First DRB entry is a message type that will be followed by 1 or more normal DRB entries. Message type DRB will hold the skb information and each normal DRB entry holds a pointer to the skb payload. DPMAIF RX The downlink buffer management uses Buffer Address Table (BAT) and Packet Information Table (PIT) rings. The BAT ring holds the address of skb data buffer for the HW to use, while the PIT contains metadata about a whole network packet including a reference to the BAT entry holding the data buffer address. The driver reads the PIT and BAT entries written by the modem, when reaching a threshold, the driver will reload the PIT and BAT rings. Signed-off-by: Haijun Liu <haijun.liu@mediatek.com> Signed-off-by: Chandrashekar Devegowda <chandrashekar.devegowda@intel.com> Co-developed-by: Ricardo Martinez <ricardo.martinez@linux.intel.com> Signed-off-by: Ricardo Martinez <ricardo.martinez@linux.intel.com> Reviewed-by: Loic Poulain <loic.poulain@linaro.org> Reviewed-by: Sergey Ryazanov <ryazanov.s.a@gmail.com> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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