[U-Boot] [PATCH v4 08/11] armv8: layerscape: Fix the sequence of changing MMU table

This patch follows the break-before-make process when making changes to MMU table. MMU is disabled before changing TTBR to avoid any potential race condition.
Signed-off-by: York Sun york.sun@nxp.com
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Changes in v4: Revert the change of C bit in v3 patch.
Changes in v3: Instead of flushing d-cache, following the break-before-make process to change MMU table.
Changes in v2: None
arch/arm/cpu/armv8/fsl-layerscape/cpu.c | 15 ++++----------- 1 file changed, 4 insertions(+), 11 deletions(-)
diff --git a/arch/arm/cpu/armv8/fsl-layerscape/cpu.c b/arch/arm/cpu/armv8/fsl-layerscape/cpu.c index 800ad62..afb6cd1 100644 --- a/arch/arm/cpu/armv8/fsl-layerscape/cpu.c +++ b/arch/arm/cpu/armv8/fsl-layerscape/cpu.c @@ -181,21 +181,14 @@ static inline void final_mmu_setup(void) setup_pgtables(); gd->arch.tlb_addr = tlb_addr_save;
- /* flush new MMU table */ - flush_dcache_range(gd->arch.tlb_addr, - gd->arch.tlb_addr + gd->arch.tlb_size); + /* Disable cache and MMU */ + dcache_disable(); /* TLBs are invalidated */ + invalidate_icache_all();
/* point TTBR to the new table */ set_ttbr_tcr_mair(el, gd->arch.tlb_addr, get_tcr(el, NULL, NULL), MEMORY_ATTRIBUTES); - /* - * EL3 MMU is already enabled, just need to invalidate TLB to load the - * new table. The new table is compatible with the current table, if - * MMU somehow walks through the new table before invalidation TLB, - * it still works. So we don't need to turn off MMU here. - * When EL2 MMU table is created by calling this function, MMU needs - * to be enabled. - */ + set_sctlr(get_sctlr() | CR_M); }
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York Sun