On 4/30/26 9:12 PM, Mukesh Ojha wrote: > The firmware memory regions in qcom_adsp, qcom_pas and qcom_wcnss are > mapped using devm_ioremap_wc() / devm_ioremap_resource_wc(), which > return void __iomem *. However, the mem_region (and dtb_mem_region) > fields in the respective driver structs were declared as plain void *, > causing sparse to flag address space mismatches: > > qcom_q6v5_adsp.c:639:26: warning: incorrect type in assignment (different > address spaces) > qcom_q6v5_adsp.c:639:26: expected void *mem_region > qcom_q6v5_adsp.c:639:26: got void [noderef] __iomem * > qcom_q6v5_pas.c:141:45: warning: incorrect type in argument 2 (different > address spaces) > qcom_q6v5_pas.c:141:45: expected void const volatile [noderef] __iomem *src > qcom_q6v5_pas.c:141:45: got void * > qcom_q6v5_pas.c:637:25: warning: incorrect type in assignment (different > address spaces) > qcom_q6v5_pas.c:637:25: expected void *mem_region > qcom_q6v5_pas.c:637:25: got void [noderef] __iomem * > qcom_q6v5_pas.c:654:29: warning: incorrect type in assignment (different > address spaces) > qcom_q6v5_pas.c:654:29: expected void *dtb_mem_region > qcom_q6v5_pas.c:654:29: got void [noderef] __iomem * > qcom_wcnss.c:540:27: warning: incorrect type in assignment (different address > spaces) > qcom_wcnss.c:540:27: expected void *mem_region > qcom_wcnss.c:540:27: got void [noderef] __iomem * > > Fix this by annotating the struct fields with __iomem to correctly > reflect the address space of the underlying mapping. > > These regions are subsequently passed to qcom_mdt_load(), > qcom_mdt_load_no_init() and qcom_mdt_pas_load(), all of which take > void * and use plain memcpy()/memset() internally to write firmware > segments into the region. This is intentional and safe: the mappings > are write-combining (WC), which on arm64 permits bulk CPU stores > without requiring the memcpy_toio()/memset_io() accessors. Changing > the MDT loader API to accept void __iomem * would be a more invasive > change and would affect callers.
Zooming out a bit more, should we even be ioremapping these regions in the first place? Are they not just RAM/Normal Memory in arm parlance? Would switching to devm_memremap(, MEMREMAP_WC) (like we do in RMTFS today) be an even better solution here? Konrad
