From 5f03d4f286b8506912083f90cd448852543fc990 Mon Sep 17 00:00:00 2001 From: Alexandre Ghiti Date: Wed, 8 Nov 2023 08:59:29 +0100 Subject: [PATCH] riscv: Don't use PGD entries for the linear mapping [ Upstream commit 629db01c64ff6cea08fc61b52426362689ef8618 ] Propagating changes at this level is cumbersome as we need to go through all the page tables when that happens (either when changing the permissions or when splitting the mapping). Note that this prevents the use of 4MB mapping for sv32 and 1GB mapping for sv39 in the linear mapping. Signed-off-by: Alexandre Ghiti Link: https://lore.kernel.org/r/20231108075930.7157-2-alexghiti@rivosinc.com Signed-off-by: Palmer Dabbelt Stable-dep-of: c67ddf59ac44 ("riscv: force PAGE_SIZE linear mapping if debug_pagealloc is enabled") Signed-off-by: Sasha Levin --- arch/riscv/mm/init.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c index 83ac1eb8e7e6..4d62f54698b9 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -668,16 +668,16 @@ void __init create_pgd_mapping(pgd_t *pgdp, static uintptr_t __init best_map_size(phys_addr_t pa, uintptr_t va, phys_addr_t size) { - if (!(pa & (PGDIR_SIZE - 1)) && !(va & (PGDIR_SIZE - 1)) && size >= PGDIR_SIZE) - return PGDIR_SIZE; - - if (!(pa & (P4D_SIZE - 1)) && !(va & (P4D_SIZE - 1)) && size >= P4D_SIZE) + if (pgtable_l5_enabled && + !(pa & (P4D_SIZE - 1)) && !(va & (P4D_SIZE - 1)) && size >= P4D_SIZE) return P4D_SIZE; - if (!(pa & (PUD_SIZE - 1)) && !(va & (PUD_SIZE - 1)) && size >= PUD_SIZE) + if (pgtable_l4_enabled && + !(pa & (PUD_SIZE - 1)) && !(va & (PUD_SIZE - 1)) && size >= PUD_SIZE) return PUD_SIZE; - if (!(pa & (PMD_SIZE - 1)) && !(va & (PMD_SIZE - 1)) && size >= PMD_SIZE) + if (IS_ENABLED(CONFIG_64BIT) && + !(pa & (PMD_SIZE - 1)) && !(va & (PMD_SIZE - 1)) && size >= PMD_SIZE) return PMD_SIZE; return PAGE_SIZE;