MIPS: Disable pte_special() for MIPS32 with RiXi

Commit 61cbfff4b1 ("MIPS: pte_special()/pte_mkspecial() support")
added a _PAGE_SPECIAL bit to the pgprot bits of our PTEs. Unfortunately
for MIPS32 configurations with RiXi support this pushed the number of
pgprot bits to 13. Since the PFN field in EntryLo begins at bit 12 this
results in us shifting the most significant bit of the physical address
beyond the end of the PTE, leading any mapped access to a physical
address above 2GB to incorrectly access an address 2GB lower than
intended.

For now, disable the pte_special() support for MIPS32 configurations
that support RiXi.

Fixes: 61cbfff4b1 ("MIPS: pte_special()/pte_mkspecial() support")
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: Dmitry Korotin <dkorotin@wavecomp.com>
Cc: linux-mips@vger.kernel.org
This commit is contained in:
Paul Burton 2019-09-18 22:03:27 +00:00
parent c4d48cf5e2
commit d1af2ab36d
No known key found for this signature in database
GPG Key ID: 3EA79FACB57500DD
2 changed files with 14 additions and 2 deletions

View File

@ -84,7 +84,7 @@ config MIPS
select RTC_LIB
select SYSCTL_EXCEPTION_TRACE
select VIRT_TO_BUS
select ARCH_HAS_PTE_SPECIAL
select ARCH_HAS_PTE_SPECIAL if !(32BIT && CPU_HAS_RIXI)
menu "Machine selection"

View File

@ -52,7 +52,9 @@ enum pgtable_bits {
_PAGE_WRITE_SHIFT,
_PAGE_ACCESSED_SHIFT,
_PAGE_MODIFIED_SHIFT,
#if defined(CONFIG_ARCH_HAS_PTE_SPECIAL)
_PAGE_SPECIAL_SHIFT,
#endif
};
/*
@ -79,7 +81,9 @@ enum pgtable_bits {
_PAGE_WRITE_SHIFT,
_PAGE_ACCESSED_SHIFT,
_PAGE_MODIFIED_SHIFT,
#if defined(CONFIG_ARCH_HAS_PTE_SPECIAL)
_PAGE_SPECIAL_SHIFT,
#endif
};
#elif defined(CONFIG_CPU_R3K_TLB)
@ -92,7 +96,9 @@ enum pgtable_bits {
_PAGE_WRITE_SHIFT,
_PAGE_ACCESSED_SHIFT,
_PAGE_MODIFIED_SHIFT,
#if defined(CONFIG_ARCH_HAS_PTE_SPECIAL)
_PAGE_SPECIAL_SHIFT,
#endif
/* Used by TLB hardware (placed in EntryLo) */
_PAGE_GLOBAL_SHIFT = 8,
@ -116,7 +122,9 @@ enum pgtable_bits {
#if defined(CONFIG_MIPS_HUGE_TLB_SUPPORT)
_PAGE_HUGE_SHIFT,
#endif
#if defined(CONFIG_ARCH_HAS_PTE_SPECIAL)
_PAGE_SPECIAL_SHIFT,
#endif
/* Used by TLB hardware (placed in EntryLo*) */
#if defined(CONFIG_CPU_HAS_RIXI)
@ -139,7 +147,11 @@ enum pgtable_bits {
#if defined(CONFIG_MIPS_HUGE_TLB_SUPPORT)
# define _PAGE_HUGE (1 << _PAGE_HUGE_SHIFT)
#endif
#define _PAGE_SPECIAL (1 << _PAGE_SPECIAL_SHIFT)
#if defined(CONFIG_ARCH_HAS_PTE_SPECIAL)
# define _PAGE_SPECIAL (1 << _PAGE_SPECIAL_SHIFT)
#else
# define _PAGE_SPECIAL 0
#endif
/* Used by TLB hardware (placed in EntryLo*) */
#if defined(CONFIG_XPA)