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author | Greg Ungerer <gerg@linux-m68k.org> | 2020-09-09 04:27:27 +0300 |
---|---|---|
committer | Greg Ungerer <gerg@linux-m68k.org> | 2020-10-05 14:51:31 +0300 |
commit | a27bc11f4b7c54a95a977a8e8b15c84dac804bd4 (patch) | |
tree | 5f33c52bfe54812bd1bcad330135b2311ccb3ac6 /arch/m68k/include/asm/uaccess.h | |
parent | 549738f15da0e5a00275977623be199fbbf7df50 (diff) | |
download | linux-a27bc11f4b7c54a95a977a8e8b15c84dac804bd4.tar.xz |
m68knommu: switch to using asm-generic/uaccess.h
Switch to using the asm-generic/uaccess functions for non-MMU builds.
Remove all the m68knommu local specific uaccess defines and macros.
There is nothing so special about the m68knommu targets that they cannot
use all of the asm-generic uaccess support. Using the asm-generic
uaccess definitions also resolves some of the existing problems with
missing __user annotations in the m68knommu specific functions.
The elimination of all of the contents of uaccess_no.h means we can fold
the uaccess_mm.h back into uaccess.h - and just have the single file
now.
The resulting generated code ends up being slightly smaller (by a few
hundred bytes) due to the compilers ability to better optimize load
and stores without forcing its hand with asm statements.
Specifically trivial cases like this contrived example:
get_user(x, ptr);
x++;
put_user(x, ptr);
end up now being optimized to a single instruction on m68k. More
generally the compiler can avoid using a temporary register in many
cases as well.
Reported-by: kernel test robot <lkp@intel.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Greg Ungerer <gerg@linux-m68k.org>
Diffstat (limited to 'arch/m68k/include/asm/uaccess.h')
-rw-r--r-- | arch/m68k/include/asm/uaccess.h | 398 |
1 files changed, 394 insertions, 4 deletions
diff --git a/arch/m68k/include/asm/uaccess.h b/arch/m68k/include/asm/uaccess.h index e896466a41a4..f98208ccbbcd 100644 --- a/arch/m68k/include/asm/uaccess.h +++ b/arch/m68k/include/asm/uaccess.h @@ -1,7 +1,397 @@ /* SPDX-License-Identifier: GPL-2.0 */ -#ifdef __uClinux__ -#include <asm/uaccess_no.h> +#ifndef __M68K_UACCESS_H +#define __M68K_UACCESS_H + +#ifdef CONFIG_MMU + +/* + * User space memory access functions + */ +#include <linux/compiler.h> +#include <linux/types.h> +#include <asm/segment.h> +#include <asm/extable.h> + +/* We let the MMU do all checking */ +static inline int access_ok(const void __user *addr, + unsigned long size) +{ + return 1; +} + +/* + * Not all varients of the 68k family support the notion of address spaces. + * The traditional 680x0 parts do, and they use the sfc/dfc registers and + * the "moves" instruction to access user space from kernel space. Other + * family members like ColdFire don't support this, and only have a single + * address space, and use the usual "move" instruction for user space access. + * + * Outside of this difference the user space access functions are the same. + * So lets keep the code simple and just define in what we need to use. + */ +#ifdef CONFIG_CPU_HAS_ADDRESS_SPACES +#define MOVES "moves" #else -#include <asm/uaccess_mm.h> +#define MOVES "move" #endif -#include <asm/extable.h> + +extern int __put_user_bad(void); +extern int __get_user_bad(void); + +#define __put_user_asm(res, x, ptr, bwl, reg, err) \ +asm volatile ("\n" \ + "1: "MOVES"."#bwl" %2,%1\n" \ + "2:\n" \ + " .section .fixup,\"ax\"\n" \ + " .even\n" \ + "10: moveq.l %3,%0\n" \ + " jra 2b\n" \ + " .previous\n" \ + "\n" \ + " .section __ex_table,\"a\"\n" \ + " .align 4\n" \ + " .long 1b,10b\n" \ + " .long 2b,10b\n" \ + " .previous" \ + : "+d" (res), "=m" (*(ptr)) \ + : #reg (x), "i" (err)) + +/* + * These are the main single-value transfer routines. They automatically + * use the right size if we just have the right pointer type. + */ + +#define __put_user(x, ptr) \ +({ \ + typeof(*(ptr)) __pu_val = (x); \ + int __pu_err = 0; \ + __chk_user_ptr(ptr); \ + switch (sizeof (*(ptr))) { \ + case 1: \ + __put_user_asm(__pu_err, __pu_val, ptr, b, d, -EFAULT); \ + break; \ + case 2: \ + __put_user_asm(__pu_err, __pu_val, ptr, w, r, -EFAULT); \ + break; \ + case 4: \ + __put_user_asm(__pu_err, __pu_val, ptr, l, r, -EFAULT); \ + break; \ + case 8: \ + { \ + const void __user *__pu_ptr = (ptr); \ + asm volatile ("\n" \ + "1: "MOVES".l %2,(%1)+\n" \ + "2: "MOVES".l %R2,(%1)\n" \ + "3:\n" \ + " .section .fixup,\"ax\"\n" \ + " .even\n" \ + "10: movel %3,%0\n" \ + " jra 3b\n" \ + " .previous\n" \ + "\n" \ + " .section __ex_table,\"a\"\n" \ + " .align 4\n" \ + " .long 1b,10b\n" \ + " .long 2b,10b\n" \ + " .long 3b,10b\n" \ + " .previous" \ + : "+d" (__pu_err), "+a" (__pu_ptr) \ + : "r" (__pu_val), "i" (-EFAULT) \ + : "memory"); \ + break; \ + } \ + default: \ + __pu_err = __put_user_bad(); \ + break; \ + } \ + __pu_err; \ +}) +#define put_user(x, ptr) __put_user(x, ptr) + + +#define __get_user_asm(res, x, ptr, type, bwl, reg, err) ({ \ + type __gu_val; \ + asm volatile ("\n" \ + "1: "MOVES"."#bwl" %2,%1\n" \ + "2:\n" \ + " .section .fixup,\"ax\"\n" \ + " .even\n" \ + "10: move.l %3,%0\n" \ + " sub.l %1,%1\n" \ + " jra 2b\n" \ + " .previous\n" \ + "\n" \ + " .section __ex_table,\"a\"\n" \ + " .align 4\n" \ + " .long 1b,10b\n" \ + " .previous" \ + : "+d" (res), "=&" #reg (__gu_val) \ + : "m" (*(ptr)), "i" (err)); \ + (x) = (__force typeof(*(ptr)))(__force unsigned long)__gu_val; \ +}) + +#define __get_user(x, ptr) \ +({ \ + int __gu_err = 0; \ + __chk_user_ptr(ptr); \ + switch (sizeof(*(ptr))) { \ + case 1: \ + __get_user_asm(__gu_err, x, ptr, u8, b, d, -EFAULT); \ + break; \ + case 2: \ + __get_user_asm(__gu_err, x, ptr, u16, w, r, -EFAULT); \ + break; \ + case 4: \ + __get_user_asm(__gu_err, x, ptr, u32, l, r, -EFAULT); \ + break; \ + case 8: { \ + const void __user *__gu_ptr = (ptr); \ + union { \ + u64 l; \ + __typeof__(*(ptr)) t; \ + } __gu_val; \ + asm volatile ("\n" \ + "1: "MOVES".l (%2)+,%1\n" \ + "2: "MOVES".l (%2),%R1\n" \ + "3:\n" \ + " .section .fixup,\"ax\"\n" \ + " .even\n" \ + "10: move.l %3,%0\n" \ + " sub.l %1,%1\n" \ + " sub.l %R1,%R1\n" \ + " jra 3b\n" \ + " .previous\n" \ + "\n" \ + " .section __ex_table,\"a\"\n" \ + " .align 4\n" \ + " .long 1b,10b\n" \ + " .long 2b,10b\n" \ + " .previous" \ + : "+d" (__gu_err), "=&r" (__gu_val.l), \ + "+a" (__gu_ptr) \ + : "i" (-EFAULT) \ + : "memory"); \ + (x) = __gu_val.t; \ + break; \ + } \ + default: \ + __gu_err = __get_user_bad(); \ + break; \ + } \ + __gu_err; \ +}) +#define get_user(x, ptr) __get_user(x, ptr) + +unsigned long __generic_copy_from_user(void *to, const void __user *from, unsigned long n); +unsigned long __generic_copy_to_user(void __user *to, const void *from, unsigned long n); + +#define __suffix0 +#define __suffix1 b +#define __suffix2 w +#define __suffix4 l + +#define ____constant_copy_from_user_asm(res, to, from, tmp, n1, n2, n3, s1, s2, s3)\ + asm volatile ("\n" \ + "1: "MOVES"."#s1" (%2)+,%3\n" \ + " move."#s1" %3,(%1)+\n" \ + " .ifnc \""#s2"\",\"\"\n" \ + "2: "MOVES"."#s2" (%2)+,%3\n" \ + " move."#s2" %3,(%1)+\n" \ + " .ifnc \""#s3"\",\"\"\n" \ + "3: "MOVES"."#s3" (%2)+,%3\n" \ + " move."#s3" %3,(%1)+\n" \ + " .endif\n" \ + " .endif\n" \ + "4:\n" \ + " .section __ex_table,\"a\"\n" \ + " .align 4\n" \ + " .long 1b,10f\n" \ + " .ifnc \""#s2"\",\"\"\n" \ + " .long 2b,20f\n" \ + " .ifnc \""#s3"\",\"\"\n" \ + " .long 3b,30f\n" \ + " .endif\n" \ + " .endif\n" \ + " .previous\n" \ + "\n" \ + " .section .fixup,\"ax\"\n" \ + " .even\n" \ + "10: addq.l #"#n1",%0\n" \ + " .ifnc \""#s2"\",\"\"\n" \ + "20: addq.l #"#n2",%0\n" \ + " .ifnc \""#s3"\",\"\"\n" \ + "30: addq.l #"#n3",%0\n" \ + " .endif\n" \ + " .endif\n" \ + " jra 4b\n" \ + " .previous\n" \ + : "+d" (res), "+&a" (to), "+a" (from), "=&d" (tmp) \ + : : "memory") + +#define ___constant_copy_from_user_asm(res, to, from, tmp, n1, n2, n3, s1, s2, s3)\ + ____constant_copy_from_user_asm(res, to, from, tmp, n1, n2, n3, s1, s2, s3) +#define __constant_copy_from_user_asm(res, to, from, tmp, n1, n2, n3) \ + ___constant_copy_from_user_asm(res, to, from, tmp, n1, n2, n3, \ + __suffix##n1, __suffix##n2, __suffix##n3) + +static __always_inline unsigned long +__constant_copy_from_user(void *to, const void __user *from, unsigned long n) +{ + unsigned long res = 0, tmp; + + switch (n) { + case 1: + __constant_copy_from_user_asm(res, to, from, tmp, 1, 0, 0); + break; + case 2: + __constant_copy_from_user_asm(res, to, from, tmp, 2, 0, 0); + break; + case 3: + __constant_copy_from_user_asm(res, to, from, tmp, 2, 1, 0); + break; + case 4: + __constant_copy_from_user_asm(res, to, from, tmp, 4, 0, 0); + break; + case 5: + __constant_copy_from_user_asm(res, to, from, tmp, 4, 1, 0); + break; + case 6: + __constant_copy_from_user_asm(res, to, from, tmp, 4, 2, 0); + break; + case 7: + __constant_copy_from_user_asm(res, to, from, tmp, 4, 2, 1); + break; + case 8: + __constant_copy_from_user_asm(res, to, from, tmp, 4, 4, 0); + break; + case 9: + __constant_copy_from_user_asm(res, to, from, tmp, 4, 4, 1); + break; + case 10: + __constant_copy_from_user_asm(res, to, from, tmp, 4, 4, 2); + break; + case 12: + __constant_copy_from_user_asm(res, to, from, tmp, 4, 4, 4); + break; + default: + /* we limit the inlined version to 3 moves */ + return __generic_copy_from_user(to, from, n); + } + + return res; +} + +#define __constant_copy_to_user_asm(res, to, from, tmp, n, s1, s2, s3) \ + asm volatile ("\n" \ + " move."#s1" (%2)+,%3\n" \ + "11: "MOVES"."#s1" %3,(%1)+\n" \ + "12: move."#s2" (%2)+,%3\n" \ + "21: "MOVES"."#s2" %3,(%1)+\n" \ + "22:\n" \ + " .ifnc \""#s3"\",\"\"\n" \ + " move."#s3" (%2)+,%3\n" \ + "31: "MOVES"."#s3" %3,(%1)+\n" \ + "32:\n" \ + " .endif\n" \ + "4:\n" \ + "\n" \ + " .section __ex_table,\"a\"\n" \ + " .align 4\n" \ + " .long 11b,5f\n" \ + " .long 12b,5f\n" \ + " .long 21b,5f\n" \ + " .long 22b,5f\n" \ + " .ifnc \""#s3"\",\"\"\n" \ + " .long 31b,5f\n" \ + " .long 32b,5f\n" \ + " .endif\n" \ + " .previous\n" \ + "\n" \ + " .section .fixup,\"ax\"\n" \ + " .even\n" \ + "5: moveq.l #"#n",%0\n" \ + " jra 4b\n" \ + " .previous\n" \ + : "+d" (res), "+a" (to), "+a" (from), "=&d" (tmp) \ + : : "memory") + +static __always_inline unsigned long +__constant_copy_to_user(void __user *to, const void *from, unsigned long n) +{ + unsigned long res = 0, tmp; + + switch (n) { + case 1: + __put_user_asm(res, *(u8 *)from, (u8 __user *)to, b, d, 1); + break; + case 2: + __put_user_asm(res, *(u16 *)from, (u16 __user *)to, w, r, 2); + break; + case 3: + __constant_copy_to_user_asm(res, to, from, tmp, 3, w, b,); + break; + case 4: + __put_user_asm(res, *(u32 *)from, (u32 __user *)to, l, r, 4); + break; + case 5: + __constant_copy_to_user_asm(res, to, from, tmp, 5, l, b,); + break; + case 6: + __constant_copy_to_user_asm(res, to, from, tmp, 6, l, w,); + break; + case 7: + __constant_copy_to_user_asm(res, to, from, tmp, 7, l, w, b); + break; + case 8: + __constant_copy_to_user_asm(res, to, from, tmp, 8, l, l,); + break; + case 9: + __constant_copy_to_user_asm(res, to, from, tmp, 9, l, l, b); + break; + case 10: + __constant_copy_to_user_asm(res, to, from, tmp, 10, l, l, w); + break; + case 12: + __constant_copy_to_user_asm(res, to, from, tmp, 12, l, l, l); + break; + default: + /* limit the inlined version to 3 moves */ + return __generic_copy_to_user(to, from, n); + } + + return res; +} + +static inline unsigned long +raw_copy_from_user(void *to, const void __user *from, unsigned long n) +{ + if (__builtin_constant_p(n)) + return __constant_copy_from_user(to, from, n); + return __generic_copy_from_user(to, from, n); +} + +static inline unsigned long +raw_copy_to_user(void __user *to, const void *from, unsigned long n) +{ + if (__builtin_constant_p(n)) + return __constant_copy_to_user(to, from, n); + return __generic_copy_to_user(to, from, n); +} +#define INLINE_COPY_FROM_USER +#define INLINE_COPY_TO_USER + +#define user_addr_max() \ + (uaccess_kernel() ? ~0UL : TASK_SIZE) + +extern long strncpy_from_user(char *dst, const char __user *src, long count); +extern __must_check long strnlen_user(const char __user *str, long n); + +unsigned long __clear_user(void __user *to, unsigned long n); + +#define clear_user __clear_user + +#else /* !CONFIG_MMU */ +#include <asm-generic/uaccess.h> +#endif + +#endif /* _M68K_UACCESS_H */ |