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/*
* User address space access functions.
*
* Copyright 1997 Andi Kleen <ak@muc.de>
* Copyright 1997 Linus Torvalds
* Copyright 2002 Andi Kleen <ak@suse.de>
*/
#include <xen/lib.h>
#include <xen/sched.h>
#include <asm/uaccess.h>
#ifndef GUARD
# define GUARD UA_KEEP
#endif
unsigned int copy_to_guest_ll(void __user *to, const void *from, unsigned int n)
{
unsigned dummy;
stac();
asm volatile (
GUARD(
" guest_access_mask_ptr %[to], %q[scratch1], %q[scratch2]\n"
)
" cmp $"STR(2*BYTES_PER_LONG-1)", %[cnt]\n"
" jbe 1f\n"
" mov %k[to], %[cnt]\n"
" neg %[cnt]\n"
" and $"STR(BYTES_PER_LONG-1)", %[cnt]\n"
" sub %[cnt], %[aux]\n"
"4: rep movsb\n" /* make 'to' address aligned */
" mov %[aux], %[cnt]\n"
" shr $"STR(LONG_BYTEORDER)", %[cnt]\n"
" and $"STR(BYTES_PER_LONG-1)", %[aux]\n"
" .align 2,0x90\n"
"0: rep movs"__OS"\n" /* as many words as possible... */
" mov %[aux],%[cnt]\n"
"1: rep movsb\n" /* ...remainder copied as bytes */
"2:\n"
".section .fixup,\"ax\"\n"
"5: add %[aux], %[cnt]\n"
" jmp 2b\n"
"3: lea (%q[aux], %q[cnt], "STR(BYTES_PER_LONG)"), %[cnt]\n"
" jmp 2b\n"
".previous\n"
_ASM_EXTABLE(4b, 5b)
_ASM_EXTABLE(0b, 3b)
_ASM_EXTABLE(1b, 2b)
: [cnt] "+c" (n), [to] "+D" (to), [from] "+S" (from),
[aux] "=&r" (dummy)
GUARD(, [scratch1] "=&r" (dummy), [scratch2] "=&r" (dummy))
: "[aux]" (n)
: "memory" );
clac();
return n;
}
unsigned int copy_from_guest_ll(void *to, const void __user *from, unsigned int n)
{
unsigned dummy;
stac();
asm volatile (
GUARD(
" guest_access_mask_ptr %[from], %q[scratch1], %q[scratch2]\n"
)
" cmp $"STR(2*BYTES_PER_LONG-1)", %[cnt]\n"
" jbe 1f\n"
" mov %k[to], %[cnt]\n"
" neg %[cnt]\n"
" and $"STR(BYTES_PER_LONG-1)", %[cnt]\n"
" sub %[cnt], %[aux]\n"
"4: rep movsb\n" /* make 'to' address aligned */
" mov %[aux],%[cnt]\n"
" shr $"STR(LONG_BYTEORDER)", %[cnt]\n"
" and $"STR(BYTES_PER_LONG-1)", %[aux]\n"
" .align 2,0x90\n"
"0: rep movs"__OS"\n" /* as many words as possible... */
" mov %[aux], %[cnt]\n"
"1: rep movsb\n" /* ...remainder copied as bytes */
"2:\n"
".section .fixup,\"ax\"\n"
"5: add %[aux], %[cnt]\n"
" jmp 6f\n"
"3: lea (%q[aux], %q[cnt], "STR(BYTES_PER_LONG)"), %[cnt]\n"
"6: mov %[cnt], %k[from]\n"
" xchg %%eax, %[aux]\n"
" xor %%eax, %%eax\n"
" rep stosb\n"
" xchg %[aux], %%eax\n"
" mov %k[from], %[cnt]\n"
" jmp 2b\n"
".previous\n"
_ASM_EXTABLE(4b, 5b)
_ASM_EXTABLE(0b, 3b)
_ASM_EXTABLE(1b, 6b)
: [cnt] "+c" (n), [to] "+D" (to), [from] "+S" (from),
[aux] "=&r" (dummy)
GUARD(, [scratch1] "=&r" (dummy), [scratch2] "=&r" (dummy))
: "[aux]" (n)
: "memory" );
clac();
return n;
}
#if GUARD(1) + 0
/**
* copy_to_guest_pv: - Copy a block of data into PV guest space.
* @to: Destination address, in PV guest space.
* @from: Source address, in hypervisor space.
* @n: Number of bytes to copy.
*
* Copy data from hypervisor space to PV guest space.
*
* Returns number of bytes that could not be copied.
* On success, this will be zero.
*/
unsigned int copy_to_guest_pv(void __user *to, const void *from, unsigned int n)
{
if ( access_ok(to, n) )
n = __copy_to_guest_pv(to, from, n);
return n;
}
/**
* clear_guest_pv: - Zero a block of memory in PV guest space.
* @to: Destination address, in PV guest space.
* @n: Number of bytes to zero.
*
* Zero a block of memory in PV guest space.
*
* Returns number of bytes that could not be cleared.
* On success, this will be zero.
*/
unsigned int clear_guest_pv(void __user *to, unsigned int n)
{
if ( access_ok(to, n) )
{
long dummy;
stac();
asm volatile (
" guest_access_mask_ptr %[to], %[scratch1], %[scratch2]\n"
"0: rep stos"__OS"\n"
" mov %[bytes], %[cnt]\n"
"1: rep stosb\n"
"2:\n"
".section .fixup,\"ax\"\n"
"3: lea (%q[bytes], %q[longs], "STR(BYTES_PER_LONG)"), %[cnt]\n"
" jmp 2b\n"
".previous\n"
_ASM_EXTABLE(0b,3b)
_ASM_EXTABLE(1b,2b)
: [cnt] "=&c" (n), [to] "+D" (to), [scratch1] "=&r" (dummy),
[scratch2] "=&r" (dummy)
: [bytes] "r" (n & (BYTES_PER_LONG - 1)),
[longs] "0" (n / BYTES_PER_LONG), "a" (0) );
clac();
}
return n;
}
/**
* copy_from_guest_pv: - Copy a block of data from PV guest space.
* @to: Destination address, in hypervisor space.
* @from: Source address, in PV guest space.
* @n: Number of bytes to copy.
*
* Copy data from PV guest space to hypervisor space.
*
* Returns number of bytes that could not be copied.
* On success, this will be zero.
*
* If some data could not be copied, this function will pad the copied
* data to the requested size using zero bytes.
*/
unsigned int copy_from_guest_pv(void *to, const void __user *from,
unsigned int n)
{
if ( access_ok(from, n) )
n = __copy_from_guest_pv(to, from, n);
else
memset(to, 0, n);
return n;
}
# undef GUARD
# define GUARD UA_DROP
# define copy_to_guest_ll copy_to_unsafe_ll
# define copy_from_guest_ll copy_from_unsafe_ll
# undef __user
# define __user
# include __FILE__
#endif /* GUARD(1) */
/*
* Local variables:
* mode: C
* c-file-style: "BSD"
* c-basic-offset: 4
* tab-width: 4
* indent-tabs-mode: nil
* End:
*/
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