From: Guo Ren <ren_guo@xxxxxxxxx>
Current arch_get_unmapped_area() of abiv1 doesn't use standard kernel
api. After referring to the implementation of arch/arm, we implement
it with vm_unmapped_area() from linux/mm.h.
Signed-off-by: Guo Ren <ren_guo@xxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
---
arch/csky/abiv1/inc/abi/page.h | 5 +--
arch/csky/abiv1/mmap.c | 75 ++++++++++++++++++++++--------------------
2 files changed, 43 insertions(+), 37 deletions(-)
diff --git a/arch/csky/abiv1/inc/abi/page.h b/arch/csky/abiv1/inc/abi/page.h
index 6336e92..c864519 100644
--- a/arch/csky/abiv1/inc/abi/page.h
+++ b/arch/csky/abiv1/inc/abi/page.h
@@ -1,13 +1,14 @@
/* SPDX-License-Identifier: GPL-2.0 */
// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
-extern unsigned long shm_align_mask;
+#include <asm/shmparam.h>
+
extern void flush_dcache_page(struct page *page);
static inline unsigned long pages_do_alias(unsigned long addr1,
unsigned long addr2)
{
- return (addr1 ^ addr2) & shm_align_mask;
+ return (addr1 ^ addr2) & (SHMLBA-1);
}
static inline void clear_user_page(void *addr, unsigned long vaddr,
diff --git a/arch/csky/abiv1/mmap.c b/arch/csky/abiv1/mmap.c
index b462fd5..6792aca 100644
--- a/arch/csky/abiv1/mmap.c
+++ b/arch/csky/abiv1/mmap.c
@@ -9,58 +9,63 @@
#include <linux/random.h>
#include <linux/io.h>
-unsigned long shm_align_mask = (0x4000 >> 1) - 1; /* Sane caches */
+#define COLOUR_ALIGN(addr,pgoff) \
+ ((((addr)+SHMLBA-1)&~(SHMLBA-1)) + \
+ (((pgoff)<<PAGE_SHIFT) & (SHMLBA-1)))
-#define COLOUR_ALIGN(addr, pgoff) \
- ((((addr) + shm_align_mask) & ~shm_align_mask) + \
- (((pgoff) << PAGE_SHIFT) & shm_align_mask))
-
-unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
+/*
+ * 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.
+ */
+unsigned long
+arch_get_unmapped_area(struct file *filp, unsigned long addr,
unsigned long len, unsigned long pgoff, unsigned long flags)
{
- struct vm_area_struct *vmm;
- int do_color_align;
+ struct mm_struct *mm = current->mm;
+ struct vm_area_struct *vma;
+ int do_align = 0;
+ struct vm_unmapped_area_info info;
+
+ /*
+ * We only need to do colour alignment if either the I or D
+ * caches alias.
+ */
+ do_align = filp || (flags & MAP_SHARED);
+ /*
+ * We enforce the MAP_FIXED case.
+ */
if (flags & MAP_FIXED) {
- /*
- * We do not accept a shared mapping if it would violate
- * cache aliasing constraints.
- */
- if ((flags & MAP_SHARED) &&
- ((addr - (pgoff << PAGE_SHIFT)) & shm_align_mask))
+ if (flags & MAP_SHARED &&
+ (addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1))
return -EINVAL;
return addr;
}
if (len > TASK_SIZE)
return -ENOMEM;
- do_color_align = 0;
- if (filp || (flags & MAP_SHARED))
- do_color_align = 1;
+
if (addr) {
- if (do_color_align)
+ if (do_align)
addr = COLOUR_ALIGN(addr, pgoff);
else
addr = PAGE_ALIGN(addr);
- vmm = find_vma(current->mm, addr);
+
+ vma = find_vma(mm, addr);
if (TASK_SIZE - len >= addr &&
- (!vmm || addr + len <= vmm->vm_start))
+ (!vma || addr + len <= vm_start_gap(vma)))
return addr;
}
- addr = TASK_UNMAPPED_BASE;
- if (do_color_align)
- addr = COLOUR_ALIGN(addr, pgoff);
- else
- addr = PAGE_ALIGN(addr);
- for (vmm = find_vma(current->mm, addr); ; vmm = vmm->vm_next) {
- /* At this point: (!vmm || addr < vmm->vm_end). */
- if (TASK_SIZE - len < addr)
- return -ENOMEM;
- if (!vmm || addr + len <= vmm->vm_start)
- return addr;
- addr = vmm->vm_end;
- if (do_color_align)
- addr = COLOUR_ALIGN(addr, pgoff);
- }
+ 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);
}
--
2.7.4
