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Commit be819aa6 authored by Guo Ren's avatar Guo Ren
Browse files

csky: Fixup arch_get_unmapped_area() implementation 



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: default avatarGuo Ren <ren_guo@c-sky.com>
Cc: Arnd Bergmann <arnd@arndb.de>
parent 5336c179

arch/csky/abiv1/inc/abi/page.h

+3 −2
Original line number Diff line number Diff line 
/* 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,

arch/csky/abiv1/mmap.c

+40 −35
Original line number Diff line number Diff line
@@ -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) + shm_align_mask) & ~shm_align_mask) + \

	 (((pgoff) << PAGE_SHIFT) & shm_align_mask))

	((((addr)+SHMLBA-1)&~(SHMLBA-1)) +	\

	 (((pgoff)<<PAGE_SHIFT) & (SHMLBA-1)))



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;



	if (flags & MAP_FIXED) {

	/*

		 * We do not accept a shared mapping if it would violate

		 * cache aliasing constraints.

	 * We only need to do colour alignment if either the I or D

	 * caches alias.

	 */

		if ((flags & MAP_SHARED) &&

			((addr - (pgoff << PAGE_SHIFT)) & shm_align_mask))

	do_align = filp || (flags & MAP_SHARED);



	/*

	 * We enforce the MAP_FIXED case.

	 */

	if (flags & MAP_FIXED) {

		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);

}