projects / linux-2.6-block.git / blame
| Commit | Line | Data |
|---|---|---|
| ebb5e78c AS |
1 | /* |
| 2 | * Copyright (C) 2015 Imagination Technologies | |
| 3 | * Author: Alex Smith <alex.smith@imgtec.com> | |
| 4 | * | |
| 5 | * This program is free software; you can redistribute it and/or modify it | |
| 6 | * under the terms of the GNU General Public License as published by the | |
| 7 | * Free Software Foundation; either version 2 of the License, or (at your | |
| 8 | * option) any later version. | |
| 9 | */ | |
| 10 | ||
| 11 | #include <asm/sgidefs.h> | |
| 12 | ||
| 13 | #if _MIPS_SIM != _MIPS_SIM_ABI64 && defined(CONFIG_64BIT) | |
| 14 | ||
| 15 | /* Building 32-bit VDSO for the 64-bit kernel. Fake a 32-bit Kconfig. */ | |
| 16 | #undef CONFIG_64BIT | |
| 17 | #define CONFIG_32BIT 1 | |
| 18 | #ifndef __ASSEMBLY__ | |
| 19 | #include <asm-generic/atomic64.h> | |
| 20 | #endif | |
| 21 | #endif | |
| 22 | ||
| 23 | #ifndef __ASSEMBLY__ | |
| 24 | ||
| 25 | #include <asm/asm.h> | |
| 26 | #include <asm/page.h> | |
| 27 | #include <asm/vdso.h> | |
| 28 | ||
| 29 | static inline unsigned long get_vdso_base(void) | |
| 30 | { | |
| 31 | unsigned long addr; | |
| 32 | ||
| 33 | /* | |
| 34 | * We can't use cpu_has_mips_r6 since it needs the cpu_data[] | |
| 35 | * kernel symbol. | |
| 36 | */ | |
| 37 | #ifdef CONFIG_CPU_MIPSR6 | |
| 38 | /* | |
| 39 | * lapc <symbol> is an alias to addiupc reg, <symbol> - . | |
| 40 | * | |
| 41 | * We can't use addiupc because there is no label-label | |
| 42 | * support for the addiupc reloc | |
| 43 | */ | |
| 44 | __asm__("lapc %0, _start \n" | |
| 45 | : "=r" (addr) : :); | |
| 46 | #else | |
| 47 | /* | |
| 48 | * Get the base load address of the VDSO. We have to avoid generating | |
| 49 | * relocations and references to the GOT because ld.so does not peform | |
| 50 | * relocations on the VDSO. We use the current offset from the VDSO base | |
| 51 | * and perform a PC-relative branch which gives the absolute address in | |
| 52 | * ra, and take the difference. The assembler chokes on | |
| 53 | * "li %0, _start - .", so embed the offset as a word and branch over | |
| 54 | * it. | |
| 55 | * | |
| 56 | */ | |
| 57 | ||
| 58 | __asm__( | |
| 59 | " .set push \n" | |
| 60 | " .set noreorder \n" | |
| 61 | " bal 1f \n" | |
| 62 | " nop \n" | |
| 63 | " .word _start - . \n" | |
| 64 | "1: lw %0, 0($31) \n" | |
| 65 | " " STR(PTR_ADDU) " %0, $31, %0 \n" | |
| 66 | " .set pop \n" | |
| 67 | : "=r" (addr) | |
| 68 | : | |
| 69 | : "$31"); | |
| 70 | #endif /* CONFIG_CPU_MIPSR6 */ | |
| 71 | ||
| 72 | return addr; | |
| 73 | } | |
| 74 | ||
| 75 | static inline const union mips_vdso_data *get_vdso_data(void) | |
| 76 | { | |
| 77 | return (const union mips_vdso_data *)(get_vdso_base() - PAGE_SIZE); | |
| 78 | } | |
| 79 | ||
| a7f4df4e AS |
80 | #ifdef CONFIG_CLKSRC_MIPS_GIC |
| 81 | ||
| 82 | static inline void __iomem *get_gic(const union mips_vdso_data *data) | |
| 83 | { | |
| 84 | return (void __iomem *)data - PAGE_SIZE; | |
| 85 | } | |
| 86 | ||
| 87 | #endif /* CONFIG_CLKSRC_MIPS_GIC */ | |
| 88 | ||
| ebb5e78c | 89 | #endif /* __ASSEMBLY__ */ |