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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /arch/nds32/mm/mmap.c | |
parent | Initial commit. (diff) | |
download | linux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.tar.xz linux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.zip |
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/nds32/mm/mmap.c')
-rw-r--r-- | arch/nds32/mm/mmap.c | 73 |
1 files changed, 73 insertions, 0 deletions
diff --git a/arch/nds32/mm/mmap.c b/arch/nds32/mm/mmap.c new file mode 100644 index 000000000..1bdf5e7d1 --- /dev/null +++ b/arch/nds32/mm/mmap.c @@ -0,0 +1,73 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (C) 2005-2017 Andes Technology Corporation + +#include <linux/sched.h> +#include <linux/mman.h> +#include <linux/shm.h> + +#define COLOUR_ALIGN(addr,pgoff) \ + ((((addr)+SHMLBA-1)&~(SHMLBA-1)) + \ + (((pgoff)<<PAGE_SHIFT) & (SHMLBA-1))) + +/* + * We need to ensure that shared mappings are correctly aligned to + * avoid aliasing issues with VIPT caches. We need to ensure that + * a specific page of an object is always mapped at a multiple of + * SHMLBA bytes. + * + * We unconditionally provide this function for all cases, however + * in the VIVT case, we optimise out the alignment rules. + */ +unsigned long +arch_get_unmapped_area(struct file *filp, unsigned long addr, + unsigned long len, unsigned long pgoff, + unsigned long flags) +{ + struct mm_struct *mm = current->mm; + struct vm_area_struct *vma; + int do_align = 0; + struct vm_unmapped_area_info info; + int aliasing = 0; + if(IS_ENABLED(CONFIG_CPU_CACHE_ALIASING)) + aliasing = 1; + + /* + * We only need to do colour alignment if either the I or D + * caches alias. + */ + if (aliasing) + do_align = filp || (flags & MAP_SHARED); + + /* + * We enforce the MAP_FIXED case. + */ + if (flags & MAP_FIXED) { + if (aliasing && flags & MAP_SHARED && + (addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1)) + return -EINVAL; + return addr; + } + + if (len > TASK_SIZE) + return -ENOMEM; + + if (addr) { + if (do_align) + addr = COLOUR_ALIGN(addr, pgoff); + else + addr = PAGE_ALIGN(addr); + + vma = find_vma(mm, addr); + if (TASK_SIZE - len >= addr && + (!vma || addr + len <= vm_start_gap(vma))) + return addr; + } + + info.flags = 0; + info.length = len; + info.low_limit = mm->mmap_base; + info.high_limit = TASK_SIZE; + info.align_mask = do_align ? (PAGE_MASK & (SHMLBA - 1)) : 0; + info.align_offset = pgoff << PAGE_SHIFT; + return vm_unmapped_area(&info); +} |