2 Commits

Author	SHA1	Message	Date
Stephen Boyd	f6ea568f0d	firmware: qcom_scm: Reduce locking section for __get_convention() ... We shouldn't need to hold this spinlock here around the entire SCM call into the firmware and back. Instead, we should be able to query the firmware, potentially in parallel with other CPUs making the same convention detection firmware call, and then grab the lock to update the calling convention detected. The convention doesn't change at runtime so calling into firmware more than once is possibly wasteful but simpler. Besides, this is the slow path, not the fast path where we've already detected the convention used. More importantly, this allows us to add more logic here to workaround the case where the firmware call to check for availability isn't implemented in the firmware at all. In that case we can check the firmware node compatible string and force a calling convention. Note that we remove the 'has_queried' logic that is repeated twice. That could lead to the calling convention being printed multiple times to the kernel logs if the bool is true but __query_convention() is running on multiple CPUs. We also shorten the time where the lock is held, but we keep the lock held around the printk because it doesn't seem hugely important to drop it for that. Cc: Elliot Berman <eberman@codeaurora.org> Cc: Brian Masney <masneyb@onstation.org> Cc: Stephan Gerhold <stephan@gerhold.net> Cc: Jeffrey Hugo <jhugo@codeaurora.org> Cc: Douglas Anderson <dianders@chromium.org> Fixes: 9a434cee77 ("firmware: qcom_scm: Dynamically support SMCCC and legacy conventions") Signed-off-by: Stephen Boyd <swboyd@chromium.org> Link: https://lore.kernel.org/r/20210223214539.1336155-3-swboyd@chromium.org Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>	2021-04-06 21:25:23 -05:00
Elliot Berman	9a434cee77	firmware: qcom_scm: Dynamically support SMCCC and legacy conventions ... Dynamically support SMCCCC and legacy conventions by detecting which convention to use at runtime. qcom_scm_call_atomic and qcom_scm_call can then be moved in qcom_scm.c and use underlying convention backend as appropriate. Thus, rename qcom_scm-64,-32 to reflect that they are backends for -smc and -legacy, respectively. Also add support for making SCM calls earlier than when SCM driver probes to support use cases such as qcom_scm_set_cold_boot_addr. Support is added by lazily initializing the convention and guarding the query with a spin lock. The limitation of these early SCM calls is that they cannot use DMA, as in the case of >4 arguments for SMC convention and any non-atomic call for legacy convention. Tested-by: Brian Masney <masneyb@onstation.org> # arm32 Tested-by: Stephan Gerhold <stephan@gerhold.net> Signed-off-by: Elliot Berman <eberman@codeaurora.org> Link: https://lore.kernel.org/r/1578431066-19600-18-git-send-email-eberman@codeaurora.org Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>	2020-01-07 22:14:43 -08:00