[ Upstream commit d5be446948 ]
For 32BIT platform _PAGE_PROTNONE is 0, so set a VMA to be VM_NONE or
VM_SHARED will make pages non-present, then cause Oops with kernel page
fault.
Fix it by set correct protection_map[] for VM_NONE/VM_SHARED, replacing
_PAGE_PROTNONE with _PAGE_PRESENT.
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Both shm_align_mask and SHMLBA want to avoid cache alias. But they are
inconsistent: shm_align_mask is (PAGE_SIZE - 1) while SHMLBA is SZ_64K,
but PAGE_SIZE is not always equal to SZ_64K.
This may cause problems when shmat() twice. Fix this problem by removing
shm_align_mask and using SHMLBA (strictly SHMLBA - 1) instead.
Reported-by: Jiantao Shan <shanjiantao@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Current cache probe and flush methods have some drawbacks:
1, Assume there are 3 cache levels and only 3 levels;
2, Assume L1 = I + D, L2 = V, L3 = S, V is exclusive, S is inclusive.
However, the fact is I + D, I + D + V, I + D + S and I + D + V + S are
all valid. So, refactor the cache probe and flush methods to adapt more
types of cache hierarchy.
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Add memory management support for LoongArch, including: cache and tlb
management, page fault handling and ioremap/mmap support.
Reviewed-by: WANG Xuerui <git@xen0n.name>
Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Huacai Chen
Anshuman Khandual