asm/vdso/timebase.h

0001 /* SPDX-License-Identifier: GPL-2.0-or-later */
0002 /*
0003  * Common timebase prototypes and such for all ppc machines.
0004  */
0005
0006 #ifndef _ASM_POWERPC_VDSO_TIMEBASE_H
0007 #define _ASM_POWERPC_VDSO_TIMEBASE_H
0008
0009 #include <asm/reg.h>
0010
0011 /*
0012  * We use __powerpc64__ here because we want the compat VDSO to use the 32-bit
0013  * version below in the else case of the ifdef.
0014  */
0015 #if defined(__powerpc64__) && (defined(CONFIG_PPC_CELL) || defined(CONFIG_E500))
0016 #define mftb()      ({unsigned long rval;               \
0017             asm volatile(                   \
0018                 "90:    mfspr %0, %2;\n"        \
0019                 ASM_FTR_IFSET(              \
0020                     "97:    cmpwi %0,0;\n"      \
0021                     "   beq- 90b;\n", "", %1)   \
0022             : "=r" (rval) \
0023             : "i" (CPU_FTR_CELL_TB_BUG), "i" (SPRN_TBRL) : "cr0"); \
0024             rval;})
0025 #elif defined(CONFIG_PPC_8xx)
0026 #define mftb()      ({unsigned long rval;   \
0027             asm volatile("mftbl %0" : "=r" (rval)); rval;})
0028 #else
0029 #define mftb()      ({unsigned long rval;   \
0030             asm volatile("mfspr %0, %1" : \
0031                      "=r" (rval) : "i" (SPRN_TBRL)); rval;})
0032 #endif /* !CONFIG_PPC_CELL */
0033
0034 #if defined(CONFIG_PPC_8xx)
0035 #define mftbu()     ({unsigned long rval;   \
0036             asm volatile("mftbu %0" : "=r" (rval)); rval;})
0037 #else
0038 #define mftbu()     ({unsigned long rval;   \
0039             asm volatile("mfspr %0, %1" : "=r" (rval) : \
0040                 "i" (SPRN_TBRU)); rval;})
0041 #endif
0042
0043 #define mttbl(v)    asm volatile("mttbl %0":: "r"(v))
0044 #define mttbu(v)    asm volatile("mttbu %0":: "r"(v))
0045
0046 static __always_inline u64 get_tb(void)
0047 {
0048     unsigned int tbhi, tblo, tbhi2;
0049
0050     /*
0051      * We use __powerpc64__ here not CONFIG_PPC64 because we want the compat
0052      * VDSO to use the 32-bit compatible version in the while loop below.
0053      */
0054     if (__is_defined(__powerpc64__))
0055         return mftb();
0056
0057     do {
0058         tbhi = mftbu();
0059         tblo = mftb();
0060         tbhi2 = mftbu();
0061     } while (tbhi != tbhi2);
0062
0063     return ((u64)tbhi << 32) | tblo;
0064 }
0065
0066 static inline void set_tb(unsigned int upper, unsigned int lower)
0067 {
0068     mtspr(SPRN_TBWL, 0);
0069     mtspr(SPRN_TBWU, upper);
0070     mtspr(SPRN_TBWL, lower);
0071 }
0072
0073 #endif /* _ASM_POWERPC_VDSO_TIMEBASE_H */