From: Christophe Leroy christophe.leroy@csgroup.eu
commit 37eb7ca91b692e8e49e7dd50158349a6c8fb5b09 upstream.
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 christophe.leroy@csgroup.eu Signed-off-by: Michael Ellerman mpe@ellerman.id.au Link: https://lore.kernel.org/r/ab58b296832b0ec650e2203200e060adbcb2677d.163793042... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/powerpc/mm/book3s32/mmu.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-)
--- a/arch/powerpc/mm/book3s32/mmu.c +++ b/arch/powerpc/mm/book3s32/mmu.c @@ -201,18 +201,17 @@ 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)