[PATCH] armv8: cache_v8: Fix pgtables setup when MMU is already enabled

[Pali Rohár]

When MMU is already enabled then dcache_enable() does not call mmu_setup()
and so setup_all_pgtables() is also never called.

In this situation when some driver calls mmu_set_region_dcache_behaviour()
function then U-Boot crashes with error message:

    Emergency page table not setup.

Fix this issue by explicitly calling setup_all_pgtables() in dcache_enable()
function near condition for mmu_setup().

This change fixes chainloading U-Boot from U-Boot on Turris Mox board which
uses mvneta ethernet driver which calls mmu_set_region_dcache_behaviour().

Signed-off-by: Pali Rohár <pali at kernel.org>
---
 arch/arm/cpu/armv8/cache_v8.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/arm/cpu/armv8/cache_v8.c b/arch/arm/cpu/armv8/cache_v8.c
index e4736e564366..2a226fd0633d 100644
--- a/arch/arm/cpu/armv8/cache_v8.c
+++ b/arch/arm/cpu/armv8/cache_v8.c
@@ -503,6 +503,10 @@ void dcache_enable(void)
 		mmu_setup();
 	}
 
+	/* Set up page tables only once (it is done also by mmu_setup()) */
+	if (!gd->arch.tlb_fillptr)
+		setup_all_pgtables();
+
 	set_sctlr(get_sctlr() | CR_C);
 }
 
-- 
2.20.1