Hi Fabio,
On Tue, Mar 19, 2024 at 09:13:12AM -0300, Fabio Estevam wrote:
Hi Pierre,
On Tue, Mar 19, 2024 at 8:39 AM Pierre-Clément Tosi ptosi@google.com wrote:
This means gd->arch.tlb_addr pointing to the live PTs during setup_pgtables().
In arch/arm/cpu/armv8, setup_all_pgtables() runs with SCTLR_ELx.M unset.
In arch/arm/cpu/armv8/fsl-layerscape, setup_pgtables() is called twice:
- early_mmu_setup() calls it with SCTLR_ELx.M unset;
- final_mmu_setup() overwrites gd->arch.tlb_addr before calling it iff CFG_SYS_MEM_RESERVE_SECURE is defined i.e. if CONFIG_SYS_SOC="fsl-layerscape" so that <asm/arch-fsl-layerscape/config.h> gets auto-included through <include/config.h>.
So can CONFIG_FSL_LAYERSCAPE be set while CONFIG_SYS_SOC != "fsl-layerscape"?
No, this cannot happen.
Thanks for confirming.
For clarity, it might then make sense to drop that #ifdef in final_mmu_setup().
Only the following Layerscape SoCs select CONFIG_FSL_LAYERSCAPE in arch/arm/cpu/armv8/fsl-layerscape/Kconfig: LS1012A, LS1028A, LS1043A, LS1046A, LS1088A, LS2080A, LX2162A and LX2160A
I saw the original boot problem with the i.MX8QX.
The i.MX8QX is part of the i.MX family, not the Layerscape family.
Sure.
To be clear, the concern here was that split_block() doesn't perform what the CPU architecture requires when modifying page tables that the MMU is using and the question therefore was: can setup_pgtables() be called on such live PTs?
For most AArch64 U-Boot ports (including the i.MX family), the answer is trivial because they use the arch code i.e. setup_all_pgtables(). However, as fsl-layerscape re-implements mmu_setup(), it had to be looked at separately, hence my question, which you answered above.
HTH,