Commit 221302d3 authored by Bixuan Cui's avatar Bixuan Cui Committed by Yang Yingliang
Browse files

svm: add support for allocing memory which is within 4G physical address in svm_mmap 



ascend inclusion
category: feature
bugzilla: NA
CVE: NA

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

Add alloc and release memory functions in svm. And the physical address
of the memory is within 4GB.

For example:
    /* alloc */
    fd = open("dev/svm0",);
    mmap(0, ALLOC_SIZE,, MAP_PA32BIT, fd, 0);

    /* free */
    ioctl(fd, SVM_IOCTL_RELEASE_PHYS32,);
    close(fd);

Signed-off-by: default avatarBixuan Cui <cuibixuan@huawei.com>
Reviewed-by: default avatarZefan Li <lizefan@huawei.com>
Reviewed-by: default avatarHanjun Guo <guohanjun@huawei.com>
Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
parent ae336d6f

drivers/char/svm.c

+82 −16
Original line number Diff line number Diff line
@@ -48,6 +48,9 @@ 


#define SVM_REMAP_MEM_LEN_MAX		(16 * 1024 * 1024)



#define SVM_IOCTL_RELEASE_PHYS32	0xfff3

#define MMAP_PHY32_MAX (16 * 1024 * 1024)



#define CORE_SID		0

static int probe_index;

static LIST_HEAD(child_list);
@@ -146,6 +149,8 @@ static char *svm_cmd_to_string(unsigned int cmd) 
		return "remap proc";

	case SVM_IOCTL_LOAD_FLAG:

		return "load flag";

	case SVM_IOCTL_RELEASE_PHYS32:

		return "release phys";

	default:

		return "unsupported";

	}
@@ -1483,12 +1488,6 @@ static unsigned long svm_get_unmapped_area(struct file *file, 
	if (!acpi_disabled)

		return -EPERM;



	if (len != sdev->l2size) {

		dev_err(sdev->dev, "Just map the size of L2BUFF %ld\n",

			sdev->l2size);

		return -EINVAL; //lint !e570

	}



	if (flags & MAP_FIXED) {

		if (IS_ALIGNED(addr, len))

			return addr;
@@ -1544,23 +1543,87 @@ static int svm_mmap(struct file *file, struct vm_area_struct *vma) 
	if (!acpi_disabled)

		return -EPERM;



	if (vma->vm_flags & VM_PA32BIT) {

		unsigned long vm_size = vma->vm_end - vma->vm_start;

		struct page *page = NULL;



		if ((vma->vm_end < vma->vm_start) || (vm_size > MMAP_PHY32_MAX))

			return -EINVAL;



		page = alloc_pages(GFP_KERNEL | GFP_DMA32, get_order(vm_size));

		if (!page) {

			dev_err(sdev->dev, "fail to alloc page\n");

			return -ENOMEM;

		}



		err = remap_pfn_range(vma,

				vma->vm_start,

				page_to_pfn(page),

				vm_size, vma->vm_page_prot);

		if (err)

			dev_err(sdev->dev,

				"fail to remap 0x%pK err=%d\n",

				(void *)vma->vm_start, err);

	} else {

		if ((vma->vm_end < vma->vm_start) ||

		    ((vma->vm_end - vma->vm_start) > sdev->l2size))

			return -EINVAL;



	vma->vm_page_prot = __pgprot((~PTE_SHARED) & vma->vm_page_prot.pgprot);

		vma->vm_page_prot = __pgprot((~PTE_SHARED) &

				    vma->vm_page_prot.pgprot);



	err = remap_pfn_range(vma, vma->vm_start, sdev->l2buff >> PAGE_SHIFT,

		err = remap_pfn_range(vma,

				vma->vm_start,

				sdev->l2buff >> PAGE_SHIFT,

				vma->vm_end - vma->vm_start,

				__pgprot(vma->vm_page_prot.pgprot | PTE_DIRTY));



		if (err)

		dev_err(sdev->dev, "fail to remap 0x%pK err = %d\n",

			dev_err(sdev->dev,

				"fail to remap 0x%pK err=%d\n",

				(void *)vma->vm_start, err);

	}



	return err;

}



static int svm_release_phys32(unsigned long __user *arg)

{

	struct mm_struct *mm = current->mm;

	struct vm_area_struct *vma = NULL;

	struct page *page = NULL;

	pte_t *pte = NULL;

	unsigned long phys, addr, offset;

	unsigned int len = 0;



	if (arg == NULL)

		return -EINVAL;



	if (get_user(addr, arg))

		return -EFAULT;



	pte = svm_walk_pt(addr, NULL, &offset);

	if (pte && pte_present(*pte))

		phys = PFN_PHYS(pte_pfn(*pte)) + offset;

	else

		return -EINVAL;



	down_read(&mm->mmap_sem);

	vma = find_vma(mm, addr);

	if (!vma) {

		up_read(&mm->mmap_sem);

		return -EFAULT;

	}



	page = phys_to_page(phys);

	len = vma->vm_end - vma->vm_start;



	__free_pages(page, get_order(len));



	up_read(&mm->mmap_sem);



	return 0;

}



/*svm ioctl will include some case for HI1980 and HI1910*/

static long svm_ioctl(struct file *file, unsigned int cmd,

			 unsigned long arg)
@@ -1630,6 +1693,9 @@ static long svm_ioctl(struct file *file, unsigned int cmd, 
	case SVM_IOCTL_LOAD_FLAG:

		err = svm_proc_load_flag((int __user *)arg);

		break;

	case SVM_IOCTL_RELEASE_PHYS32:

		err = svm_release_phys32((unsigned long __user *)arg);

		break;

	default:

			err = -EINVAL;

		}

include/linux/mm.h

+1 −0
Original line number Diff line number Diff line
@@ -219,6 +219,7 @@ extern unsigned int kobjsize(const void *objp); 
#define VM_HUGEPAGE	0x20000000	/* MADV_HUGEPAGE marked this vma */

#define VM_NOHUGEPAGE	0x40000000	/* MADV_NOHUGEPAGE marked this vma */

#define VM_MERGEABLE	0x80000000	/* KSM may merge identical pages */

#define VM_PA32BIT	0x400000000	/* Physical address is within 4G */



#ifdef CONFIG_COHERENT_DEVICE

#define VM_CDM		0x100000000	/* Contains coherent device memory */

include/uapi/asm-generic/mman.h

+1 −0
Original line number Diff line number Diff line
@@ -14,6 +14,7 @@ 
#define MAP_STACK	0x20000		/* give out an address that is best suited for process/thread stacks */

#define MAP_HUGETLB	0x40000		/* create a huge page mapping */

#define MAP_SYNC	0x80000		/* perform synchronous page faults for the mapping */

#define MAP_PA32BIT	0x400000	/* physical address is within 4G */



/* Bits [26:31] are reserved, see mman-common.h for MAP_HUGETLB usage */

mm/mmap.c

+4 −0
Original line number Diff line number Diff line
@@ -1415,6 +1415,10 @@ unsigned long do_mmap(struct file *file, unsigned long addr, 
			pkey = 0;

	}



	/* Physical address is within 4G */

	if (flags & MAP_PA32BIT)

		vm_flags |= VM_PA32BIT;



	/* Do simple checking here so the lower-level routines won't have

	 * to. we assume access permissions have been handled by the open

	 * of the memory object, so we don't do any here.