[PATCH 27/27] ARM: mmu64: Use two level pagetables in early code
Sascha Hauer
s.hauer at pengutronix.de
Tue May 16 03:55:37 PDT 2023
On Fri, May 12, 2023 at 01:10:08PM +0200, Sascha Hauer wrote:
> So far we used 1GiB sized sections in the early MMU setup. This has
> the disadvantage that we can't use the MMU in early code when we
> require a finer granularity. Rockchip for example keeps TF-A code
> in the lower memory so the code just skipped MMU initialization.
> Also we can't properly map the OP-TEE space at the end of SDRAM non
> executable.
>
> With this patch we now use two level page tables and can map with 4KiB
> granularity.
>
> The MMU setup in barebox proper changes as well. Instead of disabling
> the MMU for reconfiguration we can now keep the MMU enabled and just
> add the mappings for SDRAM banks not known to the early code.
>
> Signed-off-by: Sascha Hauer <s.hauer at pengutronix.de>
> ---
> arch/arm/cpu/mmu_64.c | 97 ++++++++++---------------------------------
> 1 file changed, 21 insertions(+), 76 deletions(-)
>
> diff --git a/arch/arm/cpu/mmu_64.c b/arch/arm/cpu/mmu_64.c
> index 4b75be621d..3f9b52bbdb 100644
> --- a/arch/arm/cpu/mmu_64.c
> +++ b/arch/arm/cpu/mmu_64.c
> @@ -192,37 +193,25 @@ static void mmu_enable(void)
> void __mmu_init(bool mmu_on)
> {
> struct memory_bank *bank;
> - unsigned int el;
> -
> - if (mmu_on)
> - mmu_disable();
> -
> - ttb = alloc_pte();
> - el = current_el();
> - set_ttbr_tcr_mair(el, (uint64_t)ttb, calc_tcr(el, BITS_PER_VA),
> - MEMORY_ATTRIBUTES);
>
> - pr_debug("ttb: 0x%p\n", ttb);
> + reserve_sdram_region("OP-TEE", 0xf0000000 - OPTEE_SIZE, OPTEE_SIZE);
This line shouldn't be here. I only used that for testing.
Sascha
--
Pengutronix e.K. | |
Steuerwalder Str. 21 | http://www.pengutronix.de/ |
31137 Hildesheim, Germany | Phone: +49-5121-206917-0 |
Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
More information about the barebox
mailing list