From 37eb7ca91b692e8e49e7dd50158349a6c8fb5b09 Mon Sep 17 00:00:00 2001 From: Christophe Leroy Date: Fri, 26 Nov 2021 13:40:35 +0100 Subject: [PATCH] powerpc/32s: Allocate one 256k IBAT instead of two consecutives 128k IBATs Today we have the following IBATs allocated: ---[ Instruction Block Address Translation ]--- 0: 0xc0000000-0xc03fffff 0x00000000 4M Kernel x m 1: 0xc0400000-0xc05fffff 0x00400000 2M Kernel x m 2: 0xc0600000-0xc06fffff 0x00600000 1M Kernel x m 3: 0xc0700000-0xc077ffff 0x00700000 512K Kernel x m 4: 0xc0780000-0xc079ffff 0x00780000 128K Kernel x m 5: 0xc07a0000-0xc07bffff 0x007a0000 128K Kernel x m 6: - 7: - The two 128K should be a single 256K instead. When _etext is not aligned to 128Kbytes, the system will allocate all necessary BATs to the lower 128Kbytes boundary, then allocate an additional 128Kbytes BAT for the remaining block. Instead, align the top to 128Kbytes so that the function directly allocates a 256Kbytes last block: ---[ Instruction Block Address Translation ]--- 0: 0xc0000000-0xc03fffff 0x00000000 4M Kernel x m 1: 0xc0400000-0xc05fffff 0x00400000 2M Kernel x m 2: 0xc0600000-0xc06fffff 0x00600000 1M Kernel x m 3: 0xc0700000-0xc077ffff 0x00700000 512K Kernel x m 4: 0xc0780000-0xc07bffff 0x00780000 256K Kernel x m 5: - 6: - 7: - Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/ab58b296832b0ec650e2203200e060adbcb2677d.1637930421.git.christophe.leroy@csgroup.eu --- arch/powerpc/mm/book3s32/mmu.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/arch/powerpc/mm/book3s32/mmu.c b/arch/powerpc/mm/book3s32/mmu.c index 27061583a010..33ab63d56435 100644 --- a/arch/powerpc/mm/book3s32/mmu.c +++ b/arch/powerpc/mm/book3s32/mmu.c @@ -196,18 +196,17 @@ void mmu_mark_initmem_nx(void) int nb = mmu_has_feature(MMU_FTR_USE_HIGH_BATS) ? 8 : 4; int i; unsigned long base = (unsigned long)_stext - PAGE_OFFSET; - unsigned long top = (unsigned long)_etext - PAGE_OFFSET; + unsigned long top = ALIGN((unsigned long)_etext - PAGE_OFFSET, SZ_128K); unsigned long border = (unsigned long)__init_begin - PAGE_OFFSET; unsigned long size; - for (i = 0; i < nb - 1 && base < top && top - base > (128 << 10);) { + for (i = 0; i < nb - 1 && base < top;) { size = block_size(base, top); setibat(i++, PAGE_OFFSET + base, base, size, PAGE_KERNEL_TEXT); base += size; } if (base < top) { size = block_size(base, top); - size = max(size, 128UL << 10); if ((top - base) > size) { size <<= 1; if (strict_kernel_rwx_enabled() && base + size > border) -- 2.34.1