On Fri, 12 Sept 2025 at 09:38, Anshul Dalal <[email protected]> wrote: > > Hi Ilias, > > On Fri Sep 12, 2025 at 12:03 PM IST, Ilias Apalodimas wrote: > > Hi Anshul, > > > > On Fri, 5 Sept 2025 at 11:19, Anshul Dalal <[email protected]> wrote: > >> > >> For armv8, U-Boot uses a static map defined as 'mem_map' for configuring > >> the MMU as part of mmu_setup. > >> > >> But since the exact configuration of memory banks might not be known at > >> build time, many platforms such as imx9, versal2 etc. utilize > >> gd->bd->bi_dram to configure the static map at runtime. > >> > >> Therefore this patch adds a new API mem_map_fix_dram_banks that modifies > >> the static map in a similar way. Allowing for anyone to map all dram > >> banks by just passing the index to last entry in their mem_map and it's > >> length. > >> > >> Signed-off-by: Anshul Dalal <[email protected]> > >> --- > >> arch/arm/cpu/armv8/cache_v8.c | 27 +++++++++++++++++++++++++++ > >> arch/arm/include/asm/armv8/mmu.h | 10 ++++++++++ > >> 2 files changed, 37 insertions(+) > >> > >> diff --git a/arch/arm/cpu/armv8/cache_v8.c b/arch/arm/cpu/armv8/cache_v8.c > >> index 6e662395a83..edb895da1f2 100644 > >> --- a/arch/arm/cpu/armv8/cache_v8.c > >> +++ b/arch/arm/cpu/armv8/cache_v8.c > >> @@ -58,6 +58,33 @@ static int get_effective_el(void) > >> return el; > >> } > >> > >> +int mem_map_fix_dram_banks(unsigned int index, unsigned int len, u64 > >> attrs) > >> +{ > >> + unsigned int i; > >> + int ret = fdtdec_setup_memory_banksize(); > >> + > >> + if (ret) { > >> + printf("%s: Failed to setup dram banks\n", __func__); > >> + return ret; > >> + } > >> + > >> + if (index + CONFIG_NR_DRAM_BANKS >= len) { > >> + printf("%s: Not sufficient space in memory map\n", > >> __func__); > >> + return -ENOMEM; > >> + } > > > > The length of the mem_map array is configured at compile time. > > So this is going to fail for all existing boards unless someone > > explicitly changes the size of their struct mm_region. > > I think if we go down that path, we need to change the error message > > as well and point them to the right direction > > > >> + > >> + for (i = 0; i < CONFIG_NR_DRAM_BANKS; i++) { > >> + mem_map[index].virt = gd->bd->bi_dram[i].start; > >> + mem_map[index].phys = gd->bd->bi_dram[i].start; > >> + mem_map[index].size = gd->bd->bi_dram[i].size; > >> + mem_map[index].attrs = attrs; > >> + index++; > >> + } > >> + > >> + mem_map[index] = (const struct mm_region){ 0 }; > > > > Why do you need the const? > > Can we do > > memset(&mem_map[index], 0, sizeof(mem_map[index])); > > instead? > > > > Yeah, we could do that instead. But it essentially achieves the same > thing, right?
Yes, i just find it a bit easier to read Cheers /Ilias > > Regards, > Anshul
