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| author | Heiko Carstens <hca@linux.ibm.com> | 2022-09-05 14:18:27 +0200 |
|---|---|---|
| committer | Vasily Gorbik <gor@linux.ibm.com> | 2022-09-07 14:04:52 +0200 |
| commit | b193d2d4d01ecf211c935bcb7409a69768851c6e (patch) | |
| tree | 25ec55cc8b818a73a81af925236f299564899660 | |
| parent | s390/mm: remove unused access parameter from do_fault_error() (diff) | |
| download | linux-b193d2d4d01ecf211c935bcb7409a69768851c6e.tar.xz linux-b193d2d4d01ecf211c935bcb7409a69768851c6e.zip | |
s390/mm: split lowcore pages with set_memory_4k()
Use set_memory_4k() to split lowcore pages within the kernel mapping
instead of using the quite subtle !addr check within modify_pmd_table()
and modify_pud_table() to prevent large pages for address zero.
With this lowcore might be mapped with 1MB / 2GB frames and only later
will be split. This way this mapping is handled like every other.
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
| -rw-r--r-- | arch/s390/mm/vmem.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/arch/s390/mm/vmem.c b/arch/s390/mm/vmem.c index c2583f921ca8..1c86de9dd87f 100644 --- a/arch/s390/mm/vmem.c +++ b/arch/s390/mm/vmem.c @@ -240,7 +240,7 @@ static int __ref modify_pmd_table(pud_t *pud, unsigned long addr, } else if (pmd_none(*pmd)) { if (IS_ALIGNED(addr, PMD_SIZE) && IS_ALIGNED(next, PMD_SIZE) && - MACHINE_HAS_EDAT1 && addr && direct && + MACHINE_HAS_EDAT1 && direct && !debug_pagealloc_enabled()) { set_pmd(pmd, __pmd(__pa(addr) | prot)); pages++; @@ -336,7 +336,7 @@ static int modify_pud_table(p4d_t *p4d, unsigned long addr, unsigned long end, } else if (pud_none(*pud)) { if (IS_ALIGNED(addr, PUD_SIZE) && IS_ALIGNED(next, PUD_SIZE) && - MACHINE_HAS_EDAT2 && addr && direct && + MACHINE_HAS_EDAT2 && direct && !debug_pagealloc_enabled()) { set_pud(pud, __pud(__pa(addr) | prot)); pages++; @@ -584,6 +584,9 @@ void __init vmem_map_init(void) __set_memory(__stext_amode31, (__etext_amode31 - __stext_amode31) >> PAGE_SHIFT, SET_MEMORY_RO | SET_MEMORY_X); + /* lowcore requires 4k mapping for real addresses / prefixing */ + set_memory_4k(0, LC_PAGES); + /* lowcore must be executable for LPSWE */ if (!static_key_enabled(&cpu_has_bear)) set_memory_x(0, 1); |