mm: clear MMU mapping for secure os memory [1/1]

PD#SWPL-1631

Problem:
If Cortex A73 accessed memory near secure memory range, an
SError may occur due to prefetch of A73 core.

Solution:
Add clear mmu property for arm platform

Verify:
W400

Change-Id: I2e396f77772aeea231d0bf5f38a81440117ecdd6
Signed-off-by: tao zeng <tao.zeng@amlogic.com>

diff --git a/arch/arm/boot/dts/amlogic/g12b_a311d_w400.dts b/arch/arm/boot/dts/amlogic/g12b_a311d_w400.dts
index 866769b..3913614 100644 (file)
--- a/arch/arm/boot/dts/amlogic/g12b_a311d_w400.dts
+++ b/arch/arm/boot/dts/amlogic/g12b_a311d_w400.dts
@@ -68,6 +68,7 @@
                        size = <0x400000>;
                        alignment = <0x400000>;
                        alloc-ranges = <0x05000000 0x400000>;
+                       clear-map;
                };
 
                secos_reserved:linux,secos {

diff --git a/arch/arm/boot/dts/amlogic/mesong12b.dtsi b/arch/arm/boot/dts/amlogic/mesong12b.dtsi
index 0037257..09fceff 100644 (file)
--- a/arch/arm/boot/dts/amlogic/mesong12b.dtsi
+++ b/arch/arm/boot/dts/amlogic/mesong12b.dtsi
@@ -249,6 +249,7 @@
                in_base_func = <0x82000020>;
                out_base_func = <0x82000021>;
                reserve_mem_size = <0x00300000>;
+               clear_range = <0x05100000 0x200000>;
        };
 
        securitykey {

diff --git a/mm/cma.c b/mm/cma.c
index 86b45e4..23d978d 100644 (file)
--- a/mm/cma.c
+++ b/mm/cma.c
@@ -53,6 +53,7 @@ void cma_init_clear(struct cma *cma, bool clear)
        cma->clear_map = clear;
 }
 
+#ifdef CONFIG_ARM64
 static int clear_cma_pagemap2(struct cma *cma)
 {
        pgd_t *pgd;
@@ -64,8 +65,8 @@ static int clear_cma_pagemap2(struct cma *cma)
        addr = (unsigned long)pfn_to_kaddr(cma->base_pfn);
        end  = addr + cma->count * PAGE_SIZE;
        mm = &init_mm;
-       pgd = pgd_offset(mm, addr);
-       for (; addr < end; addr += PMD_SIZE) {
+       for (; addr < end; addr += SECTION_SIZE) {
+               pgd = pgd_offset(mm, addr);
                if (pgd_none(*pgd) || pgd_bad(*pgd))
                        break;
 
@@ -77,14 +78,25 @@ static int clear_cma_pagemap2(struct cma *cma)
                if (pmd_none(*pmd))
                        break;
 
+               pr_debug("%s, addr:%lx, pgd:%p %llx, pmd:%p %llx\n",
+                       __func__, addr, pgd, pgd_val(*pgd), pmd, pmd_val(*pmd));
                pmd_clear(pmd);
        }
 
        return 0;
 }
+#endif
 
 int setup_cma_full_pagemap(struct cma *cma)
 {
+#ifdef CONFIG_ARM
+       /*
+        * arm already create level 3 mmu mapping for lowmem cma.
+        * And if high mem cma, there is no mapping. So nothing to
+        * do for arch arm.
+        */
+       return 0;
+#elif defined(CONFIG_ARM64)
        struct vm_area_struct vma = {};
        unsigned long addr, size;
        int ret;
@@ -102,6 +114,9 @@ int setup_cma_full_pagemap(struct cma *cma)
                pr_info("%s, remap pte failed:%d, cma:%lx\n",
                        __func__, ret, cma->base_pfn);
        return 0;
+#else
+       #error "NOT supported ARCH"
+#endif
 }
 
 int cma_mmu_op(struct page *page, int count, bool set)
@@ -113,14 +128,14 @@ int cma_mmu_op(struct page *page, int count, bool set)
        unsigned long addr, end;
        struct mm_struct *mm;
 
-       if (!page)
+       if (!page || PageHighMem(page))
                return -EINVAL;
 
        addr = (unsigned long)page_address(page);
        end  = addr + count * PAGE_SIZE;
        mm = &init_mm;
-       pgd = pgd_offset(mm, addr);
        for (; addr < end; addr += PAGE_SIZE) {
+               pgd = pgd_offset(mm, addr);
                if (pgd_none(*pgd) || pgd_bad(*pgd))
                        break;
 
@@ -138,6 +153,15 @@ int cma_mmu_op(struct page *page, int count, bool set)
                else
                        pte_clear(mm, addr, pte);
                pte_unmap(pte);
+       #ifdef CONFIG_ARM
+               pr_debug("%s, add:%lx, pgd:%p %x, pmd:%p %x, pte:%p %x\n",
+                       __func__, addr, pgd, (int)pgd_val(*pgd),
+                       pmd, (int)pmd_val(*pmd), pte, (int)pte_val(*pte));
+       #elif defined(CONFIG_ARM64)
+               pr_debug("%s, add:%lx, pgd:%p %llx, pmd:%p %llx, pte:%p %llx\n",
+                       __func__, addr, pgd, pgd_val(*pgd),
+                       pmd, pmd_val(*pmd), pte, pte_val(*pte));
+       #endif
                page++;
        }
        return 0;