No more map the reserved region with "no-map" property by marking the corresponding TLB entries with invalid entry (=0) to avoid speculative access.
The device tree parsing done in lmb_init_and_reserve() takes a long time when it is executed without data cache, so it is called in enable_caches() before to disable it.
This patch fixes an issue where predictive read access on secure DDR OP-TEE reserved area are caught by firewall.
Series-cc: marex Series-cc: pch Series-cc: marek.bykowski@gmail.com Series-cc: Ard Biesheuvel ardb@kernel.org Series-cc: Etienne Carriere etienne.carriere@linaro.org
Signed-off-by: Patrick Delaunay patrick.delaunay@foss.st.com ---
(no changes since v3)
Changes in v3: - call lmb_init_and_reserve when data cache is activated in enable_caches() - drop v2 patch "arm: cache: cp15: don't map the reserved region with no-map property"
Changes in v2: - NEW: update in stm32mp specific MMU setup functions
arch/arm/mach-stm32mp/cpu.c | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-)
diff --git a/arch/arm/mach-stm32mp/cpu.c b/arch/arm/mach-stm32mp/cpu.c index 8115d58b19..592bfd413d 100644 --- a/arch/arm/mach-stm32mp/cpu.c +++ b/arch/arm/mach-stm32mp/cpu.c @@ -12,6 +12,7 @@ #include <env.h> #include <init.h> #include <log.h> +#include <lmb.h> #include <misc.h> #include <net.h> #include <asm/io.h> @@ -90,6 +91,8 @@ */ u8 early_tlb[PGTABLE_SIZE] __section(".data") __aligned(0x4000);
+struct lmb lmb; + #if !defined(CONFIG_SPL) || defined(CONFIG_SPL_BUILD) #ifndef CONFIG_TFABOOT static void security_init(void) @@ -221,6 +224,8 @@ void dram_bank_mmu_setup(int bank) int i; phys_addr_t start; phys_size_t size; + bool use_lmb = false; + enum dcache_option option;
if (IS_ENABLED(CONFIG_SPL_BUILD)) { start = ALIGN_DOWN(STM32_SYSRAM_BASE, MMU_SECTION_SIZE); @@ -229,6 +234,7 @@ void dram_bank_mmu_setup(int bank) /* bd->bi_dram is available only after relocation */ start = bd->bi_dram[bank].start; size = bd->bi_dram[bank].size; + use_lmb = true; } else { /* mark cacheable and executable the beggining of the DDR */ start = STM32_DDR_BASE; @@ -237,8 +243,12 @@ void dram_bank_mmu_setup(int bank)
for (i = start >> MMU_SECTION_SHIFT; i < (start >> MMU_SECTION_SHIFT) + (size >> MMU_SECTION_SHIFT); - i++) - set_section_dcache(i, DCACHE_DEFAULT_OPTION); + i++) { + option = DCACHE_DEFAULT_OPTION; + if (use_lmb && lmb_is_reserved_flags(&lmb, i << MMU_SECTION_SHIFT, LMB_NOMAP)) + option = 0; /* INVALID ENTRY in TLB */ + set_section_dcache(i, option); + } } /* * initialize the MMU and activate cache in SPL or in U-Boot pre-reloc stage @@ -302,6 +312,9 @@ int arch_cpu_init(void)
void enable_caches(void) { + /* parse device tree when data cache is still activated */ + lmb_init_and_reserve(&lmb, gd->bd, (void *)gd->fdt_blob); + /* I-cache is already enabled in start.S: icache_enable() not needed */
/* deactivate the data cache, early enabled in arch_cpu_init() */