On 11.09.2023 19:41, Stephan Gerhold wrote: > Most of the reserved firmware memory on MSM8916 can be relocated when > respecting the required alignment. To avoid having to precompute the > reserved memory regions in every board DT, describe the actual > requirements (size, alignment, alloc-ranges) using the dynamic reserved > memory allocation. > > This approach has several advantages: > > 1. We can define "templates" for the reserved memory regions in > msm8916.dtsi and keep only device-specific details in the board DT. > This is useful for the "mpss" region size for example, which varies > from device to device. It is no longer necessary to redefine all > firmware regions to shift their addresses. > > 2. When some of the functionality (e.g. WCNSS, Modem, Venus) is not > enabled or needed for a device, the reserved memory can stay > disabled, freeing up the unused reservation for Linux. > > 3. Devices with special requirements for one of the firmware regions > are handled automatically. For example, msm8916-longcheer-l8150 > has non-relocatable "wcnss" firmware that must be loaded exactly > at address 0x8b600000. When this is defined as a static region, > the other dynamic allocations automatically adjust to a different > place with suitable alignment. > > All in all this approach significantly reduces the boilerplate necessary > to define the different firmware regions, and makes it easier to enable > functionality on the different devices. > > Signed-off-by: Stephan Gerhold <stephan@xxxxxxxxxxx> > --- [...] > > mpss_mem: mpss@86800000 { > + /* > + * The memory region for the mpss firmware is generally > + * relocatable and could be allocated dynamically. > + * However, many firmware versions tend to fail when > + * loaded to some special addresses, so it is hard to > + * define reliable alloc-ranges. > + * > + * alignment = <0x0 0x400000>; > + * alloc-ranges = <0x0 0x86800000 0x0 0x8000000>; > + */ Do we know of any devices that this would actually work on? Konrad