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2022-08-25hid: intel-ish-hid: ishtp: Fix ishtp client sending disordered messageEven Xu1-29/+39
There is a timing issue captured during ishtp client sending stress tests. It was observed during stress tests that ISH firmware is getting out of ordered messages. This is a rare scenario as the current set of ISH client drivers don't send much data to firmware. But this may not be the case going forward. When message size is bigger than IPC MTU, ishtp splits the message into fragments and uses serialized async method to send message fragments. The call stack: ishtp_cl_send_msg_ipc->ipc_tx_callback(first fregment)-> ishtp_send_msg(with callback)->write_ipc_to_queue-> write_ipc_from_queue->callback->ipc_tx_callback(next fregment)...... When an ipc write complete interrupt is received, driver also calls write_ipc_from_queue->ipc_tx_callback in ISR to start sending of next fragment. Through ipc_tx_callback uses spin_lock to protect message splitting, as the serialized sending method will call back to ipc_tx_callback again, so it doesn't put sending under spin_lock, it causes driver cannot guarantee all fragments be sent in order. Considering this scenario: ipc_tx_callback just finished a fragment splitting, and not call ishtp_send_msg yet, there is a write complete interrupt happens, then ISR->write_ipc_from_queue ->ipc_tx_callback->ishtp_send_msg->write_ipc_to_queue...... Because ISR has higher exec priority than normal thread, this causes the new fragment be sent out before previous fragment. This disordered message causes invalid message to firmware. The solution is, to send fragments synchronously: Use ishtp_write_message writing fragments into tx queue directly one by one, instead of ishtp_send_msg only writing one fragment with completion callback. As no completion callback be used, so change ipc_tx_callback to ipc_tx_send. Signed-off-by: Even Xu <even.xu@intel.com> Acked-by: Srinivas Pandruvada <srinivas.pandruvada@intel.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2021-06-14HID: intel-ish-hid: ishtp: Add dma_no_cache_snooping() callbackEven Xu1-0/+18
Different platforms have different DMA capability, on most of platforms, DMA support cache snooping. But few platforms, such as ElkhartLake (EHL), don't support cache snooping which requires cache flush from driver. So add a hardware level callback to let ishtp driver know if cache flush is needed. As most of platform support cache snooping, so driver will not do cache flush by default, until platform implements this callback and return true explicitly. Acked-by: Pandruvada, Srinivas <srinivas.pandruvada@intel.com> Signed-off-by: Even Xu <even.xu@intel.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2021-04-07HID: intel-ish-hid: Fix a little doc-rotLee Jones1-1/+1
Fixes the following W=1 kernel build warning(s): drivers/hid/intel-ish-hid/ishtp/client.c:121: warning: Function parameter or member 'cl_device' not described in 'ishtp_cl_allocate' drivers/hid/intel-ish-hid/ishtp/client.c:121: warning: Excess function parameter 'dev' description in 'ishtp_cl_allocate' Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: Benjamin Tissoires <benjamin.tissoires@redhat.com> Cc: Lee Jones <lee.jones@linaro.org> Cc: linux-input@vger.kernel.org Signed-off-by: Lee Jones <lee.jones@linaro.org> Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
2021-04-07HID: intel-ish-hid: Remove unused variable 'err'Lee Jones1-2/+1
Fixes the following W=1 kernel build warning(s): drivers/hid/intel-ish-hid/ishtp/client.c: In function ‘ishtp_cl_disconnect’: drivers/hid/intel-ish-hid/ishtp/client.c:266:6: warning: variable ‘err’ set but not used [-Wunused-but-set-variable] Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: Benjamin Tissoires <benjamin.tissoires@redhat.com> Cc: linux-input@vger.kernel.org Signed-off-by: Lee Jones <lee.jones@linaro.org> Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
2019-06-05treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 288Thomas Gleixner1-10/+1
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms and conditions of the gnu general public license version 2 as published by the free software foundation this program is distributed in the hope it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 263 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Alexios Zavras <alexios.zavras@intel.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190529141901.208660670@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-03-19HID: intel-ish-hid: Add interface functions for struct ishtp_clSrinivas Pandruvada1-0/+42
Instead of directly accessing members of struct ishtp_cl, create interface functions to access them. Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2019-03-19HID: intel-ish-hid: Simplify ishtp_cl_link()Srinivas Pandruvada1-10/+4
All callers will only use ISHTP_HOST_CLIENT_ID_ANY, so get rid of option to pass this additional id. Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2019-03-19HID: intel-ish-hid: Hide members of struct ishtp_cl_deviceSrinivas Pandruvada1-2/+2
ISH clients don't need to access any field of struct ishtp_cl_device. To avoid this create an interface functions instead where it is required. In the case of ishtp_cl_allocate(), modify the parameters so that the clients don't have to dereference. Clients can also use tracing, here a new interface is added to get the common trace function pointer, instead of direct call. The new interface functions defined in one external header file, named intel-ish-client-if.h. This is the only header files all ISHTP clients must include. Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2018-09-24HID: intel_ish-hid: Enhance API to get ring buffer sizesSrinivas Pandruvada1-0/+24
Added two APIs: - ishtp_cl_get_tx_free_buffer_size: This returns total size available for a client to queue TX data. - ishtp_cl_get_tx_free_rings: This returns total number of TX rings available for a client. Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2017-05-30HID: intel_ish-hid: convert timespec to ktime_tArnd Bergmann1-2/+2
The internal accounting uses 'timespec' based time stamps, which is slightly inefficient and also problematic once we get to the time_t overflow in 2038. When communicating to the firmware, we even get an open-coded 64-bit division that prevents the code from being build-tested on 32-bit architectures and is inefficient due to the double conversion from 64-bit nanoseconds to seconds+nanoseconds and then microseconds. This changes the code to use ktime_t instead. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2017-05-30HID: intel_ish-hid: clarify locking in client codeArnd Bergmann1-26/+17
I was trying to understand this code while working on a warning fix and the locking made no sense: spin_lock_irqsave() is pointless when run inside of an interrupt handler or nested inside of another spin_lock_irq() or spin_lock_irqsave(). Here it turned out that the comment above the function is wrong, as both recv_ishtp_cl_msg_dma() and recv_ishtp_cl_msg() can in fact be called from a work queue rather than an ISR, so we do have to use the irqsave() version once. This fixes the comments accordingly, removes the misleading 'dev_flags' variable and modifies the inner spinlock to not use 'irqsave'. No functional change is intended, this is just for readability and it slightly simplifies the object code. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2017-05-30HID: intel_ish-hid: fix potential uninitialized data usageArnd Bergmann1-0/+2
gcc points out an uninialized pointer dereference that could happen if we ever get to recv_ishtp_cl_msg_dma() or recv_ishtp_cl_msg() with an empty &dev->read_list: drivers/hid/intel-ish-hid/ishtp/client.c: In function 'recv_ishtp_cl_msg_dma': drivers/hid/intel-ish-hid/ishtp/client.c:1049:3: error: 'cl' may be used uninitialized in this function [-Werror=maybe-uninitialized] The warning only appeared in very few randconfig builds, as the spinlocks tend to prevent gcc from tracing the variables. I only saw it in configurations that had neither SMP nor LOCKDEP enabled. As we can see, we only enter the case if 'complete_rb' is non-NULL, and then 'cl' is known to point to complete_rb->cl. Adding another initialization to the same pointer is harmless here and makes it clear to the compiler that the behavior is well-defined. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2016-08-17HID: intel_ish-hid: ISH Transport layerSrinivas Pandruvada1-0/+1054
The ISH transport layer (ishtp) is a bi-directional protocol implemented on the top of PCI based inter processor communication layer. This layer offers: - Connection management - Flow control with the firmware - Multiple client sessions - Client message transfer - Client message reception - DMA for RX and TX for fast data transfer Refer to Documentation/hid/intel-ish-hid.txt for overview of the functionality implemented in this layer. Original-author: Daniel Drubin <daniel.drubin@intel.com> Reviewed-and-tested-by: Ooi, Joyce <joyce.ooi@intel.com> Tested-by: Grant Likely <grant.likely@secretlab.ca> Tested-by: Rann Bar-On <rb6@duke.edu> Tested-by: Atri Bhattacharya <badshah400@aim.com> Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>