kernel/linux.git/include/uapi/misc/fastrpc.h, branch v7.3-rc1

misc: fastrpc: Add polling mode support for fastRPC driver

2026-07-31T12:15:53+00:00

For any remote call to DSP, after sending an invocation message, the fastRPC driver waits for a glink response, during which the CPU can enter low power modes. This adds latency to the fastRPC call due to CPU wakeup and scheduling overhead. Add polling mode support where the fastRPC driver polls a shared memory location for completion after sending the invocation, avoiding CPU wakeup and scheduling latency and reducing fastRPC overhead. If the poll times out, the call falls back to the normal interrupt/glink-based completion path. Poll mode is only applied to dynamic modules running in a user PD (handle > FASTRPC_MAX_STATIC_HANDLE), since static/root-PD handles are not expected to benefit from, or require, this optimization. Support is advertised per SoC via fastrpc_soc_data, with a closed exception list for older platforms whose DSP firmware is known to support polling but which otherwise use the default soc_data. Poll mode can be enabled by userspace via the FASTRPC_IOCTL_SET_OPTION ioctl with the FASTRPC_POLL_MODE request id. Since context IDs (ctxid) are allocated from a fixed-size, per-channel cyclic IDR shared by all processes on a DSP, a context ID can be recycled for a new request soon after it is freed. In poll mode the context can be considered complete (and released) as soon as the poll memory is updated, while the corresponding glink COMPLETE response from the DSP may still be in flight. If that response arrives after the ctxid has been reused, it would otherwise match the new context and incorrectly signal completion for it while the DSP may still be operating on the new context's buffers. To prevent this, embed a monotonically increasing per-channel sequence number in the unused upper bits of the ctxid/message context and validate it in the rpmsg callback, dropping any response whose sequence number does not match the current owner of that ctxid slot. Signed-off-by: Ekansh Gupta Signed-off-by: Srinivas Kandagatla Link: https://patch.msgid.link/20260729094352.111065-8-srini@kernel.org Signed-off-by: Greg Kroah-Hartman

misc: fastrpc: Remove kernel-side domain checks from capability ioctl

2025-09-12T13:48:45+00:00

Domain ID in the uAPI is misleading. Remove checks and log messages related to 'domain' field in capability structure. Update UAPI to mark the field as unused. Reviewed-by: Dmitry Baryshkov Reviewed-by: Ekansh Gupta Signed-off-by: Ling Xu Signed-off-by: Srinivas Kandagatla Link: https://lore.kernel.org/r/20250912131302.303199-3-srini@kernel.org Signed-off-by: Greg Kroah-Hartman

Revert "misc: fastrpc: Restrict untrusted app to attach to privileged PD"

2024-08-15T14:59:14+00:00

This reverts commit bab2f5e8fd5d2f759db26b78d9db57412888f187. Joel reported that this commit breaks userspace and stops sensors in SDM845 from working. Also breaks other qcom SoC devices running postmarketOS. Cc: stable Cc: Ekansh Gupta Cc: Dmitry Baryshkov Reported-by: Joel Selvaraj Link: https://lore.kernel.org/r/9a9f5646-a554-4b65-8122-d212bb665c81@umsystem.edu Signed-off-by: Griffin Kroah-Hartman Acked-by: Srinivas Kandagatla Fixes: bab2f5e8fd5d ("misc: fastrpc: Restrict untrusted app to attach to privileged PD") Link: https://lore.kernel.org/r/20240815094920.8242-1-griffin@kroah.com Signed-off-by: Greg Kroah-Hartman

misc: fastrpc: Restrict untrusted app to attach to privileged PD

2024-07-03T14:17:53+00:00

Untrusted application with access to only non-secure fastrpc device node can attach to root_pd or static PDs if it can make the respective init request. This can cause problems as the untrusted application can send bad requests to root_pd or static PDs. Add changes to reject attach to privileged PDs if the request is being made using non-secure fastrpc device node. Fixes: 0871561055e6 ("misc: fastrpc: Add support for audiopd") Cc: stable Signed-off-by: Ekansh Gupta Reviewed-by: Dmitry Baryshkov Signed-off-by: Srinivas Kandagatla Link: https://lore.kernel.org/r/20240628114501.14310-7-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman

misc: fastrpc: Add support for audiopd

2022-11-25T17:45:33+00:00

In order to be able to start the adsp listener for audiopd using adsprpcd, we need to add the corresponding ioctl for creating a static process. On that ioctl call we need to allocate the heap. Allocating the heap needs to be happening only once and needs to be kept between different device open calls, so attach it to the channel context to make sure that remains until the RPMSG driver is removed. Then, if there are any VMIDs associated with the static ADSP process, do a call to SCM to assign it. And then, send all the necessary info related to heap to the DSP. Co-developed-by: Srinivas Kandagatla Signed-off-by: Abel Vesa Signed-off-by: Srinivas Kandagatla Link: https://lore.kernel.org/r/20221125071405.148786-8-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman

misc: fastrpc: Add support to secure memory map

2022-03-18T13:11:00+00:00

This patch adds support to secure memory allocations for DSP. It repurposes the reserved field in struct fastrpc_invoke_args to add attributes to invoke request, for example to setup a secure memory map for dsp. Secure memory is assigned to DSP Virtual Machine IDs using Qualcomm SCM calls. Signed-off-by: Vamsi Krishna Gattupalli Signed-off-by: Srinivas Kandagatla Link: https://lore.kernel.org/r/20220214161002.6831-9-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman

misc: fastrpc: check before loading process to the DSP

2022-03-18T13:11:00+00:00

Reject session if DSP domain is secure, device node is non-secure and signed PD is requested. Secure device node can access DSP without any restriction. Unsigned PD offload is only allowed for the DSP domain that can support unsigned offloading. Signed-off-by: Jeya R Signed-off-by: Srinivas Kandagatla Link: https://lore.kernel.org/r/20220214161002.6831-7-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman

misc: fastrpc: Add support to get DSP capabilities

2022-03-18T13:11:00+00:00

Add support to get DSP capabilities. The capability information is cached on driver. Signed-off-by: Jeya R Signed-off-by: Srinivas Kandagatla Link: https://lore.kernel.org/r/20220214161002.6831-4-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman

misc: fastrpc: add support for FASTRPC_IOCTL_MEM_MAP/UNMAP

2022-03-18T13:11:00+00:00

Add support for IOCTL requests to map and unmap on DSP based on map flags. Signed-off-by: Jeya R Signed-off-by: Srinivas Kandagatla Link: https://lore.kernel.org/r/20220214161002.6831-3-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman

misc: fastrpc: add ioctl for attaching to sensors pd

2020-09-16T15:30:37+00:00

Initializing sensors requires attaching to pd 2. Add an ioctl for that. This corresponds to FASTRPC_INIT_ATTACH_SENSORS in the downstream driver. Signed-off-by: Jonathan Marek Link: https://lore.kernel.org/r/20200908131013.19630-4-jonathan@marek.ca Signed-off-by: Greg Kroah-Hartman