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https://github.com/edk2-porting/linux-next.git
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59f35d53fd
Use a wrapper for copy_to/from_user to chose the best usercopy method. The mvcos instruction is better for sizes greater than 256 bytes, if mvcos is not available a page table walk is better for sizes greater than 1024 bytes. Also removed the redundant copy_to/from_user_std_small functions. Signed-off-by: Gerald Schaefer <geraldsc@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
182 lines
4.9 KiB
C
182 lines
4.9 KiB
C
/*
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* arch/s390/lib/uaccess_mvcos.c
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*
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* Optimized user space space access functions based on mvcos.
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*
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* Copyright (C) IBM Corp. 2006
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* Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
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* Gerald Schaefer (gerald.schaefer@de.ibm.com)
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*/
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#include <linux/errno.h>
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#include <linux/mm.h>
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#include <asm/uaccess.h>
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#include <asm/futex.h>
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#ifndef __s390x__
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#define AHI "ahi"
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#define ALR "alr"
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#define CLR "clr"
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#define LHI "lhi"
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#define SLR "slr"
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#else
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#define AHI "aghi"
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#define ALR "algr"
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#define CLR "clgr"
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#define LHI "lghi"
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#define SLR "slgr"
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#endif
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extern size_t copy_from_user_std(size_t, const void __user *, void *);
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extern size_t copy_to_user_std(size_t, void __user *, const void *);
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size_t copy_from_user_mvcos(size_t size, const void __user *ptr, void *x)
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{
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register unsigned long reg0 asm("0") = 0x81UL;
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unsigned long tmp1, tmp2;
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tmp1 = -4096UL;
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asm volatile(
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"0: .insn ss,0xc80000000000,0(%0,%2),0(%1),0\n"
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" jz 7f\n"
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"1:"ALR" %0,%3\n"
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" "SLR" %1,%3\n"
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" "SLR" %2,%3\n"
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" j 0b\n"
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"2: la %4,4095(%1)\n"/* %4 = ptr + 4095 */
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" nr %4,%3\n" /* %4 = (ptr + 4095) & -4096 */
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" "SLR" %4,%1\n"
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" "CLR" %0,%4\n" /* copy crosses next page boundary? */
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" jnh 4f\n"
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"3: .insn ss,0xc80000000000,0(%4,%2),0(%1),0\n"
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" "SLR" %0,%4\n"
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" "ALR" %2,%4\n"
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"4:"LHI" %4,-1\n"
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" "ALR" %4,%0\n" /* copy remaining size, subtract 1 */
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" bras %3,6f\n" /* memset loop */
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" xc 0(1,%2),0(%2)\n"
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"5: xc 0(256,%2),0(%2)\n"
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" la %2,256(%2)\n"
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"6:"AHI" %4,-256\n"
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" jnm 5b\n"
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" ex %4,0(%3)\n"
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" j 8f\n"
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"7:"SLR" %0,%0\n"
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"8: \n"
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EX_TABLE(0b,2b) EX_TABLE(3b,4b)
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: "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
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: "d" (reg0) : "cc", "memory");
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return size;
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}
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size_t copy_from_user_mvcos_check(size_t size, const void __user *ptr, void *x)
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{
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if (size <= 256)
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return copy_from_user_std(size, ptr, x);
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return copy_from_user_mvcos(size, ptr, x);
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}
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size_t copy_to_user_mvcos(size_t size, void __user *ptr, const void *x)
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{
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register unsigned long reg0 asm("0") = 0x810000UL;
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unsigned long tmp1, tmp2;
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tmp1 = -4096UL;
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asm volatile(
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"0: .insn ss,0xc80000000000,0(%0,%1),0(%2),0\n"
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" jz 4f\n"
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"1:"ALR" %0,%3\n"
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" "SLR" %1,%3\n"
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" "SLR" %2,%3\n"
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" j 0b\n"
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"2: la %4,4095(%1)\n"/* %4 = ptr + 4095 */
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" nr %4,%3\n" /* %4 = (ptr + 4095) & -4096 */
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" "SLR" %4,%1\n"
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" "CLR" %0,%4\n" /* copy crosses next page boundary? */
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" jnh 5f\n"
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"3: .insn ss,0xc80000000000,0(%4,%1),0(%2),0\n"
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" "SLR" %0,%4\n"
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" j 5f\n"
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"4:"SLR" %0,%0\n"
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"5: \n"
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EX_TABLE(0b,2b) EX_TABLE(3b,5b)
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: "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
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: "d" (reg0) : "cc", "memory");
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return size;
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}
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size_t copy_to_user_mvcos_check(size_t size, void __user *ptr, const void *x)
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{
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if (size <= 256)
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return copy_to_user_std(size, ptr, x);
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return copy_to_user_mvcos(size, ptr, x);
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}
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size_t copy_in_user_mvcos(size_t size, void __user *to, const void __user *from)
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{
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register unsigned long reg0 asm("0") = 0x810081UL;
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unsigned long tmp1, tmp2;
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tmp1 = -4096UL;
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/* FIXME: copy with reduced length. */
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asm volatile(
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"0: .insn ss,0xc80000000000,0(%0,%1),0(%2),0\n"
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" jz 2f\n"
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"1:"ALR" %0,%3\n"
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" "SLR" %1,%3\n"
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" "SLR" %2,%3\n"
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" j 0b\n"
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"2:"SLR" %0,%0\n"
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"3: \n"
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EX_TABLE(0b,3b)
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: "+a" (size), "+a" (to), "+a" (from), "+a" (tmp1), "=a" (tmp2)
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: "d" (reg0) : "cc", "memory");
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return size;
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}
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size_t clear_user_mvcos(size_t size, void __user *to)
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{
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register unsigned long reg0 asm("0") = 0x810000UL;
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unsigned long tmp1, tmp2;
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tmp1 = -4096UL;
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asm volatile(
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"0: .insn ss,0xc80000000000,0(%0,%1),0(%4),0\n"
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" jz 4f\n"
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"1:"ALR" %0,%2\n"
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" "SLR" %1,%2\n"
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" j 0b\n"
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"2: la %3,4095(%1)\n"/* %4 = to + 4095 */
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" nr %3,%2\n" /* %4 = (to + 4095) & -4096 */
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" "SLR" %3,%1\n"
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" "CLR" %0,%3\n" /* copy crosses next page boundary? */
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" jnh 5f\n"
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"3: .insn ss,0xc80000000000,0(%3,%1),0(%4),0\n"
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" "SLR" %0,%3\n"
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" j 5f\n"
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"4:"SLR" %0,%0\n"
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"5: \n"
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EX_TABLE(0b,2b) EX_TABLE(3b,5b)
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: "+a" (size), "+a" (to), "+a" (tmp1), "=a" (tmp2)
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: "a" (empty_zero_page), "d" (reg0) : "cc", "memory");
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return size;
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}
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extern size_t strnlen_user_std(size_t, const char __user *);
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extern size_t strncpy_from_user_std(size_t, const char __user *, char *);
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extern int futex_atomic_op(int, int __user *, int, int *);
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extern int futex_atomic_cmpxchg(int __user *, int, int);
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struct uaccess_ops uaccess_mvcos = {
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.copy_from_user = copy_from_user_mvcos_check,
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.copy_from_user_small = copy_from_user_std,
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.copy_to_user = copy_to_user_mvcos_check,
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.copy_to_user_small = copy_to_user_std,
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.copy_in_user = copy_in_user_mvcos,
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.clear_user = clear_user_mvcos,
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.strnlen_user = strnlen_user_std,
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.strncpy_from_user = strncpy_from_user_std,
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.futex_atomic_op = futex_atomic_op,
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.futex_atomic_cmpxchg = futex_atomic_cmpxchg,
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};
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