[PATCH] ARM: stm32mp: Fix dram_bank_mmu_setup() for LMB located above ram_top

[Patrice Chotard]

Previously, all LMB marked with LMB_NOMAP (above and below ram_top)
are considered as invalid entry in TLB.

Since commit 1a48b0be93d4 ("lmb: prohibit allocations above ram_top
 even from same bank") all LMB located above ram_top are now marked
LMB_NOOVERWRITE and no more LMB_MAP.

This area above ram_top is reserved for OPTEE and must not be cacheable,
otherwise this leads to a Panic on some boards (Issue on STM32MP135F-DK).

Restore previous behavior by marking invalid entry all TLB above ram_top.

Fixes: 1a48b0be93d4 ("lmb: prohibit allocations above ram_top even from same 
bank")

Signed-off-by: Patrice Chotard <patrice.chot...@foss.st.com>
cc: Sughosh Ganu <sughosh.g...@linaro.org>
---

 arch/arm/mach-stm32mp/stm32mp1/cpu.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/arch/arm/mach-stm32mp/stm32mp1/cpu.c 
b/arch/arm/mach-stm32mp/stm32mp1/cpu.c
index 62cc98910a7..cb1b84c9af9 100644
--- a/arch/arm/mach-stm32mp/stm32mp1/cpu.c
+++ b/arch/arm/mach-stm32mp/stm32mp1/cpu.c
@@ -53,6 +53,7 @@ void dram_bank_mmu_setup(int bank)
        struct bd_info *bd = gd->bd;
        int     i;
        phys_addr_t start;
+       phys_addr_t addr;
        phys_size_t size;
        bool use_lmb = false;
        enum dcache_option option;
@@ -77,8 +78,12 @@ void dram_bank_mmu_setup(int bank)
        for (i = start >> MMU_SECTION_SHIFT;
             i < (start >> MMU_SECTION_SHIFT) + (size >> MMU_SECTION_SHIFT);
             i++) {
+               addr = i << MMU_SECTION_SHIFT;
                option = DCACHE_DEFAULT_OPTION;
-               if (use_lmb && lmb_is_reserved_flags(i << MMU_SECTION_SHIFT, 
LMB_NOMAP))
+               if (use_lmb &&
+                   (lmb_is_reserved_flags(i << MMU_SECTION_SHIFT, LMB_NOMAP) ||
+                   addr >= gd->ram_top)
+                  )
                        option = 0; /* INVALID ENTRY in TLB */
                set_section_dcache(i, option);
        }
-- 
2.25.1