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Mukesh OjhaandAbel Vesa
10f1ad07c0
Qualcomm remoteproc drivers such as qcom_q6v5_mss, which do not use the Peripheral Authentication Service (PAS), always map the MBA region before use and unmap it once the usage is complete. This behavior was introduced to avoid issues seen in the past where speculative accesses from the application processor to the MBA region after it was assigned to the remote Q6 led to an XPU violation. The issue was mitigated by unmapping the region before handing control to the remote Q6. Currently, most Qualcomm SoCs using the PAS driver run either with a standalone QHEE or the Gunyah hypervisor. In these environments, the hypervisor unmaps the Q6 memory from HLOS Stage-2 and remaps it into the Q6 Stage-2 page table. As a result, speculative accesses from HLOS cannot reach the region even if it remains mapped in HLOS Stage-1; therefore, XPU violations cannot occur. However, when the same SoC runs Linux at EL2, Linux itself must perform the unmapping to avoid such issues. It is still correct to apply this mapping/ unmapping sequence even for SoCs that run under Gunyah, so this behavior should not be conditional. Introduce qcom_pas_ctx_map() in qcom_pas.h to centralise the ioremap_wc pattern used by both qcom_q6v5_pas and qcom_mdt_pas_load, and use it in both places. Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com> Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com> Signed-off-by: Mukesh Ojha <mukesh.ojha@oss.qualcomm.com> Link: https://lore.kernel.org/r/20260724182858.1868271-5-mukesh.ojha@oss.qualcomm.com Signed-off-by: Bjorn Andersson <andersson@kernel.org>