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s390/zcore: simplify memcpy_hsa

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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: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Martin Schwidefsky 2015-10-12 10:51:54 +02:00
parent df9694c797
commit 019d6bec6d
1 changed files with 39 additions and 74 deletions
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113
drivers/s390/char/zcore.c
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@ -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 {
@ -56,86 +54,36 @@ static struct dentry *zcore_reipl_file;
static struct dentry *zcore_hsa_file;
static struct ipl_parameter_block *ipl_block;
/*
* Copy memory from HSA to kernel or 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
* @mode: Either TO_KERNEL or TO_USER
*/
static int memcpy_hsa(void *dest, unsigned long src, size_t count, int mode)
{
int offs, blk_num;
static char buf[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE)));
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)) {
TRACE("sclp_sdias_copy() failed\n");
return -EIO;
}
if (mode == TO_USER) {
if (copy_to_user((__force __user void*) dest + offs,
buf, PAGE_SIZE))
return -EFAULT;
} else
memcpy(dest + offs, buf, PAGE_SIZE);
}
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;
}
static char hsa_buf[PAGE_SIZE] __aligned(PAGE_SIZE);
/*
* 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
*/
int memcpy_hsa_user(void __user *dest, unsigned long src, size_t count)
{
return memcpy_hsa((void __force *) dest, src, count, TO_USER);
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);
if (copy_to_user(dest, hsa_buf + offset, bytes))
return -EFAULT;
src += bytes;
dest += bytes;
count -= bytes;
}
return 0;
}
/*
@ -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)