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Commit 019d6bec authored by Martin Schwidefsky's avatar Martin Schwidefsky
Browse files

s390/zcore: simplify memcpy_hsa 



Replace the three part copy logic int memcpy_hsa with a single loop
around sclp_sdias_copy with appropriate offset and size calculations,
and inline memcpy_hsa into memcpy_hsa_user and memcpy_hsa_kernel.

Acked-by: default avatarMichael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent df9694c7

drivers/s390/char/zcore.c

+33 −68
Original line number Diff line number Diff line
@@ -34,8 +34,6 @@ 


#define TRACE(x...) debug_sprintf_event(zcore_dbf, 1, x)



#define TO_USER		1

#define TO_KERNEL	0

#define CHUNK_INFO_SIZE	34 /* 2 16-byte char, each followed by blank */



enum arch_id {
@@ -56,88 +54,38 @@ static struct dentry *zcore_reipl_file; 
static struct dentry *zcore_hsa_file;

static struct ipl_parameter_block *ipl_block;



static char hsa_buf[PAGE_SIZE] __aligned(PAGE_SIZE);



/*

 * Copy memory from HSA to kernel or user memory (not reentrant):

 * Copy memory from HSA to user memory (not reentrant):

 *

 * @dest:  Kernel or user buffer where memory should be copied to

 * @dest:  User buffer where memory should be copied to

 * @src:   Start address within HSA where data should be copied

 * @count: Size of buffer, which should be copied

 * @mode:  Either TO_KERNEL or TO_USER

 */

static int memcpy_hsa(void *dest, unsigned long src, size_t count, int mode)

int memcpy_hsa_user(void __user *dest, unsigned long src, size_t count)

{

	int offs, blk_num;

	static char buf[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE)));

	unsigned long offset, bytes;



	if (!hsa_available)

		return -ENODATA;

	if (count == 0)

		return 0;



	/* copy first block */

	offs = 0;

	if ((src % PAGE_SIZE) != 0) {

		blk_num = src / PAGE_SIZE + 2;

		if (sclp_sdias_copy(buf, blk_num, 1)) {

			TRACE("sclp_sdias_copy() failed\n");

			return -EIO;

		}

		offs = min((PAGE_SIZE - (src % PAGE_SIZE)), count);

		if (mode == TO_USER) {

			if (copy_to_user((__force __user void*) dest,

					 buf + (src % PAGE_SIZE), offs))

				return -EFAULT;

		} else

			memcpy(dest, buf + (src % PAGE_SIZE), offs);

	}

	if (offs == count)

		goto out;



	/* copy middle */

	for (; (offs + PAGE_SIZE) <= count; offs += PAGE_SIZE) {

		blk_num = (src + offs) / PAGE_SIZE + 2;

		if (sclp_sdias_copy(buf, blk_num, 1)) {

	while (count) {

		if (sclp_sdias_copy(hsa_buf, src / PAGE_SIZE + 2, 1)) {

			TRACE("sclp_sdias_copy() failed\n");

			return -EIO;

		}

		if (mode == TO_USER) {

			if (copy_to_user((__force __user void*) dest + offs,

					 buf, PAGE_SIZE))

		offset = src % PAGE_SIZE;

		bytes = min(PAGE_SIZE - offset, count);

		if (copy_to_user(dest, hsa_buf + offset, bytes))

			return -EFAULT;

		} else

			memcpy(dest + offs, buf, PAGE_SIZE);

		src += bytes;

		dest += bytes;

		count -= bytes;

	}

	if (offs == count)

		goto out;



	/* copy last block */

	blk_num = (src + offs) / PAGE_SIZE + 2;

	if (sclp_sdias_copy(buf, blk_num, 1)) {

		TRACE("sclp_sdias_copy() failed\n");

		return -EIO;

	}

	if (mode == TO_USER) {

		if (copy_to_user((__force __user void*) dest + offs, buf,

				 count - offs))

			return -EFAULT;

	} else

		memcpy(dest + offs, buf, count - offs);

out:

	return 0;

}



/*

 * Copy memory from HSA to user memory (not reentrant):

 *

 * @dest:  Kernel or user buffer where memory should be copied to

 * @src:   Start address within HSA where data should be copied

 * @count: Size of buffer, which should be copied

 */

int memcpy_hsa_user(void __user *dest, unsigned long src, size_t count)

{

	return memcpy_hsa((void __force *) dest, src, count, TO_USER);

}



/*

 * Copy memory from HSA to kernel memory (not reentrant):

 *
@@ -147,7 +95,24 @@ int memcpy_hsa_user(void __user *dest, unsigned long src, size_t count) 
 */

int memcpy_hsa_kernel(void *dest, unsigned long src, size_t count)

{

	return memcpy_hsa(dest, src, count, TO_KERNEL);

	unsigned long offset, bytes;



	if (!hsa_available)

		return -ENODATA;



	while (count) {

		if (sclp_sdias_copy(hsa_buf, src / PAGE_SIZE + 2, 1)) {

			TRACE("sclp_sdias_copy() failed\n");

			return -EIO;

		}

		offset = src % PAGE_SIZE;

		bytes = min(PAGE_SIZE - offset, count);

		memcpy(dest, hsa_buf + offset, bytes);

		src += bytes;

		dest += bytes;

		count -= bytes;

	}

	return 0;

}



static int __init init_cpu_info(void)