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>
This commit is contained in:
Helge Deller
Родитель
fc79168a7c
Коммит
06bff6b9d7
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@ -40,14 +40,10 @@ static inline long access_ok(int type, const void __user * addr,
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#define get_user __get_user
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#if !defined(CONFIG_64BIT)
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#define LDD_KERNEL(ptr) BUILD_BUG()
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#define LDD_USER(ptr) BUILD_BUG()
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#define STD_KERNEL(x, ptr) __put_kernel_asm64(x, ptr)
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#define STD_USER(x, ptr) __put_user_asm64(x, ptr)
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#else
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#define LDD_KERNEL(ptr) __get_kernel_asm("ldd", ptr)
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#define LDD_USER(ptr) __get_user_asm("ldd", ptr)
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#define STD_KERNEL(x, ptr) __put_kernel_asm("std", x, ptr)
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#define STD_USER(x, ptr) __put_user_asm("std", x, ptr)
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#endif
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@ -80,43 +76,39 @@ struct exception_data {
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unsigned long fault_addr;
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};
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/*
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* load_sr2() preloads the space register %%sr2 - based on the value of
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* get_fs() - with either a value of 0 to access kernel space (KERNEL_DS which
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* is 0), or with the current value of %%sr3 to access user space (USER_DS)
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* memory. The following __get_user_asm() and __put_user_asm() functions have
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* %%sr2 hard-coded to access the requested memory.
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*/
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#define load_sr2() \
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__asm__(" or,= %0,%%r0,%%r0\n\t" \
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" mfsp %%sr3,%0\n\t" \
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" mtsp %0,%%sr2\n\t" \
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: : "r"(get_fs()) : )
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#define __get_user(x, ptr) \
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({ \
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register long __gu_err __asm__ ("r8") = 0; \
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register long __gu_val __asm__ ("r9") = 0; \
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\
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if (segment_eq(get_fs(), KERNEL_DS)) { \
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switch (sizeof(*(ptr))) { \
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case 1: __get_kernel_asm("ldb", ptr); break; \
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case 2: __get_kernel_asm("ldh", ptr); break; \
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case 4: __get_kernel_asm("ldw", ptr); break; \
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case 8: LDD_KERNEL(ptr); break; \
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default: BUILD_BUG(); break; \
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} \
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} \
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else { \
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switch (sizeof(*(ptr))) { \
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load_sr2(); \
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switch (sizeof(*(ptr))) { \
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case 1: __get_user_asm("ldb", ptr); break; \
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case 2: __get_user_asm("ldh", ptr); break; \
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case 4: __get_user_asm("ldw", ptr); break; \
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case 8: LDD_USER(ptr); break; \
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default: BUILD_BUG(); break; \
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} \
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} \
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\
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(x) = (__force __typeof__(*(ptr))) __gu_val; \
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__gu_err; \
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})
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#define __get_kernel_asm(ldx, ptr) \
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__asm__("\n1:\t" ldx "\t0(%2),%0\n\t" \
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ASM_EXCEPTIONTABLE_ENTRY(1b, fixup_get_user_skip_1)\
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: "=r"(__gu_val), "=r"(__gu_err) \
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: "r"(ptr), "1"(__gu_err) \
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: "r1");
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#define __get_user_asm(ldx, ptr) \
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__asm__("\n1:\t" ldx "\t0(%%sr3,%2),%0\n\t" \
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__asm__("\n1:\t" ldx "\t0(%%sr2,%2),%0\n\t" \
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ASM_EXCEPTIONTABLE_ENTRY(1b, fixup_get_user_skip_1)\
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: "=r"(__gu_val), "=r"(__gu_err) \
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: "r"(ptr), "1"(__gu_err) \
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@ -127,23 +119,13 @@ struct exception_data {
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register long __pu_err __asm__ ("r8") = 0; \
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__typeof__(*(ptr)) __x = (__typeof__(*(ptr)))(x); \
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\
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if (segment_eq(get_fs(), KERNEL_DS)) { \
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switch (sizeof(*(ptr))) { \
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case 1: __put_kernel_asm("stb", __x, ptr); break; \
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case 2: __put_kernel_asm("sth", __x, ptr); break; \
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case 4: __put_kernel_asm("stw", __x, ptr); break; \
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case 8: STD_KERNEL(__x, ptr); break; \
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default: BUILD_BUG(); break; \
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} \
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} \
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else { \
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switch (sizeof(*(ptr))) { \
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load_sr2(); \
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switch (sizeof(*(ptr))) { \
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case 1: __put_user_asm("stb", __x, ptr); break; \
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case 2: __put_user_asm("sth", __x, ptr); break; \
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case 4: __put_user_asm("stw", __x, ptr); break; \
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case 8: STD_USER(__x, ptr); break; \
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default: BUILD_BUG(); break; \
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} \
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} \
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\
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__pu_err; \
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@ -159,17 +141,9 @@ struct exception_data {
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* r8/r9 are already listed as err/val.
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*/
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#define __put_kernel_asm(stx, x, ptr) \
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__asm__ __volatile__ ( \
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"\n1:\t" stx "\t%2,0(%1)\n\t" \
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ASM_EXCEPTIONTABLE_ENTRY(1b, fixup_put_user_skip_1)\
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: "=r"(__pu_err) \
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: "r"(ptr), "r"(x), "0"(__pu_err) \
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: "r1")
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#define __put_user_asm(stx, x, ptr) \
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__asm__ __volatile__ ( \
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"\n1:\t" stx "\t%2,0(%%sr3,%1)\n\t" \
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"\n1:\t" stx "\t%2,0(%%sr2,%1)\n\t" \
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ASM_EXCEPTIONTABLE_ENTRY(1b, fixup_put_user_skip_1)\
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: "=r"(__pu_err) \
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: "r"(ptr), "r"(x), "0"(__pu_err) \
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@ -178,21 +152,10 @@ struct exception_data {
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#if !defined(CONFIG_64BIT)
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#define __put_kernel_asm64(__val, ptr) do { \
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__asm__ __volatile__ ( \
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"\n1:\tstw %2,0(%1)" \
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"\n2:\tstw %R2,4(%1)\n\t" \
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ASM_EXCEPTIONTABLE_ENTRY(1b, fixup_put_user_skip_2)\
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ASM_EXCEPTIONTABLE_ENTRY(2b, fixup_put_user_skip_1)\
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: "=r"(__pu_err) \
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: "r"(ptr), "r"(__val), "0"(__pu_err) \
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: "r1"); \
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} while (0)
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#define __put_user_asm64(__val, ptr) do { \
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__asm__ __volatile__ ( \
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"\n1:\tstw %2,0(%%sr3,%1)" \
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"\n2:\tstw %R2,4(%%sr3,%1)\n\t" \
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"\n1:\tstw %2,0(%%sr2,%1)" \
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"\n2:\tstw %R2,4(%%sr2,%1)\n\t" \
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ASM_EXCEPTIONTABLE_ENTRY(1b, fixup_put_user_skip_2)\
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ASM_EXCEPTIONTABLE_ENTRY(2b, fixup_put_user_skip_1)\
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: "=r"(__pu_err) \
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