Commit eaafc4a2 authored by Wang Wensheng's avatar Wang Wensheng
Browse files

mm/sharepool: Implement mg_sp_unshare_kva 

ascend inclusion
category: Feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I8LNGH



---------------------------------------------

This is reversed to sp_make_share_u2k that unmaps the vmalloc area from
u2k.

Signed-off-by: default avatarWang Wensheng <wangwensheng4@huawei.com>
parent 549b1f40

mm/share_pool.c

+95 −1
Original line number Diff line number Diff line
@@ -1098,6 +1098,36 @@ void *mg_sp_alloc(unsigned long size, unsigned long sp_flags, int spg_id) 
}

EXPORT_SYMBOL_GPL(mg_sp_alloc);



/**

 * is_vmap_hugepage() - Check if a kernel address belongs to vmalloc family.

 * @addr: the kernel space address to be checked.

 *

 * Return:

 * * >0		- a vmalloc hugepage addr.

 * * =0		- a normal vmalloc addr.

 * * -errno	- failure.

 */

static int is_vmap_hugepage(unsigned long addr)

{

	struct vm_struct *area;



	if (unlikely(!addr)) {

		pr_err_ratelimited("null vmap addr pointer\n");

		return -EINVAL;

	}



	area = find_vm_area((void *)addr);

	if (unlikely(!area)) {

		pr_debug("can't find vm area(%lx)\n", addr);

		return -EINVAL;

	}



	if (area->flags & VM_HUGE_PAGES)

		return 1;

	else

		return 0;

}



/**

 * mg_sp_make_share_k2u() - Share kernel memory to current process or an sp_group.

 * @kva: the VA of shared kernel memory.
@@ -1428,6 +1458,50 @@ void *mg_sp_make_share_u2k(unsigned long uva, unsigned long size, int tgid) 
}

EXPORT_SYMBOL_GPL(mg_sp_make_share_u2k);



/* No possible concurrent protection, take care when use */

static int sp_unshare_kva(unsigned long kva, unsigned long size)

{

	unsigned long addr, kva_aligned;

	struct page *page;

	unsigned long size_aligned;

	unsigned long step;

	bool is_hugepage = true;

	int ret;



	ret = is_vmap_hugepage(kva);

	if (ret > 0) {

		kva_aligned = ALIGN_DOWN(kva, PMD_SIZE);

		size_aligned = ALIGN(kva + size, PMD_SIZE) - kva_aligned;

		step = PMD_SIZE;

	} else if (ret == 0) {

		kva_aligned = ALIGN_DOWN(kva, PAGE_SIZE);

		size_aligned = ALIGN(kva + size, PAGE_SIZE) - kva_aligned;

		step = PAGE_SIZE;

		is_hugepage = false;

	} else {

		pr_err_ratelimited("check vmap hugepage failed %d\n", ret);

		return -EINVAL;

	}



	if (kva_aligned + size_aligned < kva_aligned) {

		pr_err_ratelimited("overflow happened in unshare kva\n");

		return -EINVAL;

	}



	for (addr = kva_aligned; addr < (kva_aligned + size_aligned); addr += step) {

		page = vmalloc_to_page((void *)addr);

		if (page)

			put_page(page);

		else

			WARN(1, "vmalloc %pK to page/hugepage failed\n",

			       (void *)addr);

	}



	vunmap((void *)kva_aligned);



	return 0;

}



/**

 * mg_sp_unshare() - Unshare the kernel or user memory which shared by calling

 *                sp_make_share_{k2u,u2k}().
@@ -1440,7 +1514,27 @@ EXPORT_SYMBOL_GPL(mg_sp_make_share_u2k); 
 */

int mg_sp_unshare(unsigned long va, unsigned long size, int spg_id)

{

	int ret = 0;



	if (!sp_is_enabled())

		return -EOPNOTSUPP;



	check_interrupt_context();



	if (current->flags & PF_KTHREAD)

		return -EINVAL;



	if (va < TASK_SIZE) {

	} else if (va >= PAGE_OFFSET) {

		/* kernel address */

		ret = sp_unshare_kva(va, size);

	} else {

		/* regard user and kernel address ranges as bad address */

		pr_debug("unshare addr %lx is not a user or kernel addr\n", (unsigned long)va);

		ret = -EFAULT;

	}



	return ret;

}

EXPORT_SYMBOL_GPL(mg_sp_unshare);