From: Huacai Chen chenhc@lemote.com
commit d191aaffe3687d1e73e644c185f5f0550ec242b5 upstream.
LDDIR/LDPTE is Loongson-3's acceleration for Page Table Walking. If BD (Base Directory, the 4th page directory) is not enabled, then GDOffset is biased by BadVAddr[63:62]. So, if GDOffset (aka. BadVAddr[47:36] for Loongson-3) is big enough, "0b11(BadVAddr[63:62])|BadVAddr[47:36]|...." can far beyond pg_swapper_dir. This means the pg_swapper_dir may NOT be accessed by LDDIR correctly, so fix it by set PWDirExt in CP0_PWCtl.
Cc: stable@vger.kernel.org Signed-off-by: Pei Huang huangpei@loongson.cn Signed-off-by: Huacai Chen chenhc@lemote.com Signed-off-by: Thomas Bogendoerfer tsbogend@alpha.franken.de Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/mips/mm/tlbex.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
--- a/arch/mips/mm/tlbex.c +++ b/arch/mips/mm/tlbex.c @@ -1480,6 +1480,7 @@ static void build_r4000_tlb_refill_handl
static void setup_pw(void) { + unsigned int pwctl; unsigned long pgd_i, pgd_w; #ifndef __PAGETABLE_PMD_FOLDED unsigned long pmd_i, pmd_w; @@ -1506,6 +1507,7 @@ static void setup_pw(void)
pte_i = ilog2(_PAGE_GLOBAL); pte_w = 0; + pwctl = 1 << 30; /* Set PWDirExt */
#ifndef __PAGETABLE_PMD_FOLDED write_c0_pwfield(pgd_i << 24 | pmd_i << 12 | pt_i << 6 | pte_i); @@ -1516,8 +1518,9 @@ static void setup_pw(void) #endif
#ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT - write_c0_pwctl(1 << 6 | psn); + pwctl |= (1 << 6 | psn); #endif + write_c0_pwctl(pwctl); write_c0_kpgd((long)swapper_pg_dir); kscratch_used_mask |= (1 << 7); /* KScratch6 is used for KPGD */ }