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authorHelge Deller <deller@gmx.de>2016-04-09 02:26:14 -0400
committerHelge Deller <deller@gmx.de>2016-05-22 15:38:56 -0400
commit06bff6b9d7d50566a9320f64b0624957798cb08b (patch)
tree62aae1924b900d7ef2415f1cf8e4c8a270c11fc9 /arch/parisc/include
parentfc79168a7c75423047d60a033dc4844955ccae0b (diff)
parisc: Simplify and speed up get_user() and put_user()
This patch simplifies the code for get_user() and put_user() a lot. Instead of accessing kernel memory (%sr0) and userspace memory (%sr3) hard-coded in the assembler instruction, we now preload %sr2 with either %sr0 (for accessing KERNEL_DS) or with sr3 (to access USER_DS) and use %sr2 in the load directly. The generated code avoids a branch and speeds up execution by generating less assembler instructions. Signed-off-by: Helge Deller <deller@gmx.de> Tested-by: Rolf Eike Beer <eike-kernel@sf-tec.de>
Diffstat (limited to 'arch/parisc/include')
-rw-r--r--arch/parisc/include/asm/uaccess.h79
1 files changed, 21 insertions, 58 deletions
diff --git a/arch/parisc/include/asm/uaccess.h b/arch/parisc/include/asm/uaccess.h
index 7955e43f3f3f..56b7208da9a4 100644
--- a/arch/parisc/include/asm/uaccess.h
+++ b/arch/parisc/include/asm/uaccess.h
@@ -40,14 +40,10 @@ static inline long access_ok(int type, const void __user * addr,
40#define get_user __get_user 40#define get_user __get_user
41 41
42#if !defined(CONFIG_64BIT) 42#if !defined(CONFIG_64BIT)
43#define LDD_KERNEL(ptr) BUILD_BUG()
44#define LDD_USER(ptr) BUILD_BUG() 43#define LDD_USER(ptr) BUILD_BUG()
45#define STD_KERNEL(x, ptr) __put_kernel_asm64(x, ptr)
46#define STD_USER(x, ptr) __put_user_asm64(x, ptr) 44#define STD_USER(x, ptr) __put_user_asm64(x, ptr)
47#else 45#else
48#define LDD_KERNEL(ptr) __get_kernel_asm("ldd", ptr)
49#define LDD_USER(ptr) __get_user_asm("ldd", ptr) 46#define LDD_USER(ptr) __get_user_asm("ldd", ptr)
50#define STD_KERNEL(x, ptr) __put_kernel_asm("std", x, ptr)
51#define STD_USER(x, ptr) __put_user_asm("std", x, ptr) 47#define STD_USER(x, ptr) __put_user_asm("std", x, ptr)
52#endif 48#endif
53 49
@@ -80,43 +76,39 @@ struct exception_data {
80 unsigned long fault_addr; 76 unsigned long fault_addr;
81}; 77};
82 78
79/*
80 * load_sr2() preloads the space register %%sr2 - based on the value of
81 * get_fs() - with either a value of 0 to access kernel space (KERNEL_DS which
82 * is 0), or with the current value of %%sr3 to access user space (USER_DS)
83 * memory. The following __get_user_asm() and __put_user_asm() functions have
84 * %%sr2 hard-coded to access the requested memory.
85 */
86#define load_sr2() \
87 __asm__(" or,= %0,%%r0,%%r0\n\t" \
88 " mfsp %%sr3,%0\n\t" \
89 " mtsp %0,%%sr2\n\t" \
90 : : "r"(get_fs()) : )
91
83#define __get_user(x, ptr) \ 92#define __get_user(x, ptr) \
84({ \ 93({ \
85 register long __gu_err __asm__ ("r8") = 0; \ 94 register long __gu_err __asm__ ("r8") = 0; \
86 register long __gu_val __asm__ ("r9") = 0; \ 95 register long __gu_val __asm__ ("r9") = 0; \
87 \ 96 \
88 if (segment_eq(get_fs(), KERNEL_DS)) { \ 97 load_sr2(); \
89 switch (sizeof(*(ptr))) { \ 98 switch (sizeof(*(ptr))) { \
90 case 1: __get_kernel_asm("ldb", ptr); break; \
91 case 2: __get_kernel_asm("ldh", ptr); break; \
92 case 4: __get_kernel_asm("ldw", ptr); break; \
93 case 8: LDD_KERNEL(ptr); break; \
94 default: BUILD_BUG(); break; \
95 } \
96 } \
97 else { \
98 switch (sizeof(*(ptr))) { \
99 case 1: __get_user_asm("ldb", ptr); break; \ 99 case 1: __get_user_asm("ldb", ptr); break; \
100 case 2: __get_user_asm("ldh", ptr); break; \ 100 case 2: __get_user_asm("ldh", ptr); break; \
101 case 4: __get_user_asm("ldw", ptr); break; \ 101 case 4: __get_user_asm("ldw", ptr); break; \
102 case 8: LDD_USER(ptr); break; \ 102 case 8: LDD_USER(ptr); break; \
103 default: BUILD_BUG(); break; \ 103 default: BUILD_BUG(); break; \
104 } \
105 } \ 104 } \
106 \ 105 \
107 (x) = (__force __typeof__(*(ptr))) __gu_val; \ 106 (x) = (__force __typeof__(*(ptr))) __gu_val; \
108 __gu_err; \ 107 __gu_err; \
109}) 108})
110 109
111#define __get_kernel_asm(ldx, ptr) \
112 __asm__("\n1:\t" ldx "\t0(%2),%0\n\t" \
113 ASM_EXCEPTIONTABLE_ENTRY(1b, fixup_get_user_skip_1)\
114 : "=r"(__gu_val), "=r"(__gu_err) \
115 : "r"(ptr), "1"(__gu_err) \
116 : "r1");
117
118#define __get_user_asm(ldx, ptr) \ 110#define __get_user_asm(ldx, ptr) \
119 __asm__("\n1:\t" ldx "\t0(%%sr3,%2),%0\n\t" \ 111 __asm__("\n1:\t" ldx "\t0(%%sr2,%2),%0\n\t" \
120 ASM_EXCEPTIONTABLE_ENTRY(1b, fixup_get_user_skip_1)\ 112 ASM_EXCEPTIONTABLE_ENTRY(1b, fixup_get_user_skip_1)\
121 : "=r"(__gu_val), "=r"(__gu_err) \ 113 : "=r"(__gu_val), "=r"(__gu_err) \
122 : "r"(ptr), "1"(__gu_err) \ 114 : "r"(ptr), "1"(__gu_err) \
@@ -127,23 +119,13 @@ struct exception_data {
127 register long __pu_err __asm__ ("r8") = 0; \ 119 register long __pu_err __asm__ ("r8") = 0; \
128 __typeof__(*(ptr)) __x = (__typeof__(*(ptr)))(x); \ 120 __typeof__(*(ptr)) __x = (__typeof__(*(ptr)))(x); \
129 \ 121 \
130 if (segment_eq(get_fs(), KERNEL_DS)) { \ 122 load_sr2(); \
131 switch (sizeof(*(ptr))) { \ 123 switch (sizeof(*(ptr))) { \
132 case 1: __put_kernel_asm("stb", __x, ptr); break; \
133 case 2: __put_kernel_asm("sth", __x, ptr); break; \
134 case 4: __put_kernel_asm("stw", __x, ptr); break; \
135 case 8: STD_KERNEL(__x, ptr); break; \
136 default: BUILD_BUG(); break; \
137 } \
138 } \
139 else { \
140 switch (sizeof(*(ptr))) { \
141 case 1: __put_user_asm("stb", __x, ptr); break; \ 124 case 1: __put_user_asm("stb", __x, ptr); break; \
142 case 2: __put_user_asm("sth", __x, ptr); break; \ 125 case 2: __put_user_asm("sth", __x, ptr); break; \
143 case 4: __put_user_asm("stw", __x, ptr); break; \ 126 case 4: __put_user_asm("stw", __x, ptr); break; \
144 case 8: STD_USER(__x, ptr); break; \ 127 case 8: STD_USER(__x, ptr); break; \
145 default: BUILD_BUG(); break; \ 128 default: BUILD_BUG(); break; \
146 } \
147 } \ 129 } \
148 \ 130 \
149 __pu_err; \ 131 __pu_err; \
@@ -159,17 +141,9 @@ struct exception_data {
159 * r8/r9 are already listed as err/val. 141 * r8/r9 are already listed as err/val.
160 */ 142 */
161 143
162#define __put_kernel_asm(stx, x, ptr) \
163 __asm__ __volatile__ ( \
164 "\n1:\t" stx "\t%2,0(%1)\n\t" \
165 ASM_EXCEPTIONTABLE_ENTRY(1b, fixup_put_user_skip_1)\
166 : "=r"(__pu_err) \
167 : "r"(ptr), "r"(x), "0"(__pu_err) \
168 : "r1")
169
170#define __put_user_asm(stx, x, ptr) \ 144#define __put_user_asm(stx, x, ptr) \
171 __asm__ __volatile__ ( \ 145 __asm__ __volatile__ ( \
172 "\n1:\t" stx "\t%2,0(%%sr3,%1)\n\t" \ 146 "\n1:\t" stx "\t%2,0(%%sr2,%1)\n\t" \
173 ASM_EXCEPTIONTABLE_ENTRY(1b, fixup_put_user_skip_1)\ 147 ASM_EXCEPTIONTABLE_ENTRY(1b, fixup_put_user_skip_1)\
174 : "=r"(__pu_err) \ 148 : "=r"(__pu_err) \
175 : "r"(ptr), "r"(x), "0"(__pu_err) \ 149 : "r"(ptr), "r"(x), "0"(__pu_err) \
@@ -178,21 +152,10 @@ struct exception_data {
178 152
179#if !defined(CONFIG_64BIT) 153#if !defined(CONFIG_64BIT)
180 154
181#define __put_kernel_asm64(__val, ptr) do { \
182 __asm__ __volatile__ ( \
183 "\n1:\tstw %2,0(%1)" \
184 "\n2:\tstw %R2,4(%1)\n\t" \
185 ASM_EXCEPTIONTABLE_ENTRY(1b, fixup_put_user_skip_2)\
186 ASM_EXCEPTIONTABLE_ENTRY(2b, fixup_put_user_skip_1)\
187 : "=r"(__pu_err) \
188 : "r"(ptr), "r"(__val), "0"(__pu_err) \
189 : "r1"); \
190} while (0)
191
192#define __put_user_asm64(__val, ptr) do { \ 155#define __put_user_asm64(__val, ptr) do { \
193 __asm__ __volatile__ ( \ 156 __asm__ __volatile__ ( \
194 "\n1:\tstw %2,0(%%sr3,%1)" \ 157 "\n1:\tstw %2,0(%%sr2,%1)" \
195 "\n2:\tstw %R2,4(%%sr3,%1)\n\t" \ 158 "\n2:\tstw %R2,4(%%sr2,%1)\n\t" \
196 ASM_EXCEPTIONTABLE_ENTRY(1b, fixup_put_user_skip_2)\ 159 ASM_EXCEPTIONTABLE_ENTRY(1b, fixup_put_user_skip_2)\
197 ASM_EXCEPTIONTABLE_ENTRY(2b, fixup_put_user_skip_1)\ 160 ASM_EXCEPTIONTABLE_ENTRY(2b, fixup_put_user_skip_1)\
198 : "=r"(__pu_err) \ 161 : "=r"(__pu_err) \
generated by cgit v1.2.2 (git 2.25.0) at 2026-04-28 02:04:08 -0400