From bab247ff5f669216e3ed2f9a4034c540187e874c Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Tue, 10 May 2016 16:28:28 +0200 Subject: [PATCH] s390/vmem: simplify vmem code for read-only mappings For the kernel identity mapping map everything read-writeable and subsequently call set_memory_ro() to make the ro section read-only. This simplifies the code a lot. Signed-off-by: Heiko Carstens Acked-by: Martin Schwidefsky Signed-off-by: Martin Schwidefsky --- arch/s390/mm/vmem.c | 37 +++++++++---------------------------- 1 file changed, 9 insertions(+), 28 deletions(-) diff --git a/arch/s390/mm/vmem.c b/arch/s390/mm/vmem.c index 0a7b034..b200f97 100644 --- a/arch/s390/mm/vmem.c +++ b/arch/s390/mm/vmem.c @@ -11,6 +11,7 @@ #include #include #include +#include #include #include #include @@ -77,7 +78,7 @@ pte_t __ref *vmem_pte_alloc(void) /* * Add a physical memory range to the 1:1 mapping. */ -static int vmem_add_mem(unsigned long start, unsigned long size, int ro) +static int vmem_add_mem(unsigned long start, unsigned long size) { unsigned long end = start + size; unsigned long address = start; @@ -99,8 +100,7 @@ static int vmem_add_mem(unsigned long start, unsigned long size, int ro) if (MACHINE_HAS_EDAT2 && pud_none(*pu_dir) && address && !(address & ~PUD_MASK) && (address + PUD_SIZE <= end) && !debug_pagealloc_enabled()) { - pud_val(*pu_dir) = address | - pgprot_val(ro ? REGION3_KERNEL_RO : REGION3_KERNEL); + pud_val(*pu_dir) = address | pgprot_val(REGION3_KERNEL); address += PUD_SIZE; continue; } @@ -114,8 +114,7 @@ static int vmem_add_mem(unsigned long start, unsigned long size, int ro) if (MACHINE_HAS_EDAT1 && pmd_none(*pm_dir) && address && !(address & ~PMD_MASK) && (address + PMD_SIZE <= end) && !debug_pagealloc_enabled()) { - pmd_val(*pm_dir) = address | - pgprot_val(ro ? SEGMENT_KERNEL_RO : SEGMENT_KERNEL); + pmd_val(*pm_dir) = address | pgprot_val(SEGMENT_KERNEL); address += PMD_SIZE; continue; } @@ -127,8 +126,7 @@ static int vmem_add_mem(unsigned long start, unsigned long size, int ro) } pt_dir = pte_offset_kernel(pm_dir, address); - pte_val(*pt_dir) = address | - pgprot_val(ro ? PAGE_KERNEL_RO : PAGE_KERNEL); + pte_val(*pt_dir) = address | pgprot_val(PAGE_KERNEL); address += PAGE_SIZE; } ret = 0; @@ -338,7 +336,7 @@ int vmem_add_mapping(unsigned long start, unsigned long size) if (ret) goto out_free; - ret = vmem_add_mem(start, size, 0); + ret = vmem_add_mem(start, size); if (ret) goto out_remove; goto out; @@ -361,29 +359,12 @@ void __init vmem_map_init(void) { unsigned long ro_start, ro_end; struct memblock_region *reg; - phys_addr_t start, end; + for_each_memblock(memory, reg) + vmem_add_mem(reg->base, reg->size); ro_start = PFN_ALIGN((unsigned long)&_stext); ro_end = (unsigned long)&_eshared & PAGE_MASK; - for_each_memblock(memory, reg) { - start = reg->base; - end = reg->base + reg->size; - if (start >= ro_end || end <= ro_start) - vmem_add_mem(start, end - start, 0); - else if (start >= ro_start && end <= ro_end) - vmem_add_mem(start, end - start, 1); - else if (start >= ro_start) { - vmem_add_mem(start, ro_end - start, 1); - vmem_add_mem(ro_end, end - ro_end, 0); - } else if (end < ro_end) { - vmem_add_mem(start, ro_start - start, 0); - vmem_add_mem(ro_start, end - ro_start, 1); - } else { - vmem_add_mem(start, ro_start - start, 0); - vmem_add_mem(ro_start, ro_end - ro_start, 1); - vmem_add_mem(ro_end, end - ro_end, 0); - } - } + set_memory_ro(ro_start, (ro_end - ro_start) >> PAGE_SHIFT); } /* -- 2.7.4