riscv: pgtable: Add custom protection_map init
From: Heiko Stuebner <heiko@...> Date: Sun, 6 Jun 2021 09:04:03 +0000
Commit-Message
Some RISC-V CPU vendors have defined their own PTE attributes to solve non-coherent DMA bus problems. That makes _P/SXXX definitions contain global variables which could be initialized at the early boot stage before setup_vm. This patch is similar to 316d097c4cd4 (x86/pti: Filter at vma->vm_page_prot population) which give a choice for arch custom implementation. Signed-off-by: Heiko Stuebner <heiko@...>
Patch-Comment
arch/riscv/Kconfig | 4 ++++ arch/riscv/mm/init.c | 22 ++++++++++++++++++++++ mm/mmap.c | 4 ++++ 3 files changed, 30 insertions(+)
Statistics
- 30 lines added
- 0 lines removed
Changes
------------------------------ arch/riscv/Kconfig ------------------------------
index 821252b65f89..07543b9add8e 100644
@@ -23,6 +23,7 @@ config RISCV
select ARCH_HAS_GIGANTIC_PAGE
select ARCH_HAS_KCOV
select ARCH_HAS_MMIOWB
+ select ARCH_HAS_PROTECTION_MAP_INIT
select ARCH_HAS_PTE_SPECIAL
select ARCH_HAS_SET_DIRECT_MAP if MMU
select ARCH_HAS_SET_MEMORY if MMU
@@ -210,6 +211,9 @@ config GENERIC_HWEIGHT
config FIX_EARLYCON_MEM
def_bool MMU
+config ARCH_HAS_PROTECTION_MAP_INIT
+ def_bool y
+
config PGTABLE_LEVELS
int
default 3 if 64BIT
----------------------------- arch/riscv/mm/init.c -----------------------------
index 24b2b8044602..60a1b26a956c 100644
@@ -588,6 +588,26 @@ static void __init create_fdt_early_page_table(pgd_t *pgdir, uintptr_t dtb_pa)
dtb_early_pa = dtb_pa;
}
+static void __init setup_protection_map(void)
+{
+ protection_map[0] = __P000;
+ protection_map[1] = __P001;
+ protection_map[2] = __P010;
+ protection_map[3] = __P011;
+ protection_map[4] = __P100;
+ protection_map[5] = __P101;
+ protection_map[6] = __P110;
+ protection_map[7] = __P111;
+ protection_map[8] = __S000;
+ protection_map[9] = __S001;
+ protection_map[10] = __S010;
+ protection_map[11] = __S011;
+ protection_map[12] = __S100;
+ protection_map[13] = __S101;
+ protection_map[14] = __S110;
+ protection_map[15] = __S111;
+}
+
asmlinkage void __init setup_vm(uintptr_t dtb_pa)
{
pmd_t __maybe_unused fix_bmap_spmd, fix_bmap_epmd;
@@ -624,6 +644,8 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa)
BUG_ON((kernel_map.virt_addr + kernel_map.size) > ADDRESS_SPACE_END - SZ_4K);
#endif
+ setup_protection_map();
+
pt_ops.alloc_pte = alloc_pte_early;
pt_ops.get_pte_virt = get_pte_virt_early;
#ifndef __PAGETABLE_PMD_FOLDED
---------------------------------- mm/mmap.c -----------------------------------
index bfb0ea164a90..33f4a5936ac9 100644
@@ -100,10 +100,14 @@ static void unmap_region(struct mm_struct *mm,
* w: (no) no
* x: (yes) yes
*/
+#ifdef CONFIG_ARCH_HAS_PROTECTION_MAP_INIT
+pgprot_t protection_map[16] __ro_after_init;
+#else
pgprot_t protection_map[16] __ro_after_init = {
__P000, __P001, __P010, __P011, __P100, __P101, __P110, __P111,
__S000, __S001, __S010, __S011, __S100, __S101, __S110, __S111
};
+#endif
#ifndef CONFIG_ARCH_HAS_FILTER_PGPROT
static inline pgprot_t arch_filter_pgprot(pgprot_t prot)