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Diffstat (limited to 'include/asm-xtensa/xtensa/cacheattrasm.h')
| -rw-r--r-- | include/asm-xtensa/xtensa/cacheattrasm.h | 432 |
1 files changed, 432 insertions, 0 deletions
diff --git a/include/asm-xtensa/xtensa/cacheattrasm.h b/include/asm-xtensa/xtensa/cacheattrasm.h new file mode 100644 index 0000000..1c3e117 --- /dev/null +++ b/include/asm-xtensa/xtensa/cacheattrasm.h @@ -0,0 +1,432 @@ +#ifndef XTENSA_CACHEATTRASM_H +#define XTENSA_CACHEATTRASM_H + +/* + * THIS FILE IS GENERATED -- DO NOT MODIFY BY HAND + * + * include/asm-xtensa/xtensa/cacheattrasm.h -- assembler-specific + * CACHEATTR register related definitions that depend on CORE + * configuration. + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 2002 Tensilica Inc. + */ + + +#include <xtensa/coreasm.h> + + +/* + * This header file defines assembler macros of the form: + * <x>cacheattr_<func> + * where: + * <x> is 'i', 'd' or absent for instruction, data + * or both caches; and + * <func> indicates the function of the macro. + * + * The following functions are defined: + * + * icacheattr_get + * Reads I-cache CACHEATTR into a2 (clobbers a3-a5). + * + * dcacheattr_get + * Reads D-cache CACHEATTR into a2 (clobbers a3-a5). + * (Note: for configs with a real CACHEATTR register, the + * above two macros are identical.) + * + * cacheattr_set + * Writes both I-cache and D-cache CACHEATTRs from a2 (a3-a8 clobbered). + * Works even when changing one's own code's attributes. + * + * icacheattr_is_enabled label + * Branches to \label if I-cache appears to have been enabled + * (eg. if CACHEATTR contains a cache-enabled attribute). + * (clobbers a2-a5,SAR) + * + * dcacheattr_is_enabled label + * Branches to \label if D-cache appears to have been enabled + * (eg. if CACHEATTR contains a cache-enabled attribute). + * (clobbers a2-a5,SAR) + * + * cacheattr_is_enabled label + * Branches to \label if either I-cache or D-cache appears to have been enabled + * (eg. if CACHEATTR contains a cache-enabled attribute). + * (clobbers a2-a5,SAR) + * + * The following macros are only defined under certain conditions: + * + * icacheattr_set (if XCHAL_HAVE_MIMIC_CACHEATTR || XCHAL_HAVE_XLT_CACHEATTR) + * Writes I-cache CACHEATTR from a2 (a3-a8 clobbered). + * + * dcacheattr_set (if XCHAL_HAVE_MIMIC_CACHEATTR || XCHAL_HAVE_XLT_CACHEATTR) + * Writes D-cache CACHEATTR from a2 (a3-a8 clobbered). + */ + + + +/*************************** GENERIC -- ALL CACHES ***************************/ + +/* + * _cacheattr_get + * + * (Internal macro.) + * Returns value of CACHEATTR register (or closest equivalent) in a2. + * + * Entry: + * (none) + * Exit: + * a2 value read from CACHEATTR + * a3-a5 clobbered (temporaries) + */ + .macro _cacheattr_get tlb +#if XCHAL_HAVE_CACHEATTR + rsr a2, CACHEATTR +#elif XCHAL_HAVE_MIMIC_CACHEATTR || XCHAL_HAVE_XLT_CACHEATTR + // We have a config that "mimics" CACHEATTR using a simplified + // "MMU" composed of a single statically-mapped way. + // DTLB and ITLB are independent, so there's no single + // cache attribute that can describe both. So for now + // just return the DTLB state. + movi a5, 0xE0000000 + movi a2, 0 + movi a3, 0 +1: add a3, a3, a5 // next segment + r&tlb&1 a4, a3 // get PPN+CA of segment at 0xE0000000, 0xC0000000, ..., 0 + dsync // interlock??? + slli a2, a2, 4 + extui a4, a4, 0, 4 // extract CA + or a2, a2, a4 + bnez a3, 1b +#else + // This macro isn't applicable to arbitrary MMU configurations. + // Just return zero. + movi a2, 0 +#endif + .endm + + .macro icacheattr_get + _cacheattr_get itlb + .endm + + .macro dcacheattr_get + _cacheattr_get dtlb + .endm + + +#define XCHAL_CACHEATTR_ALL_BYPASS 0x22222222 /* default (powerup/reset) value of CACHEATTR, all BYPASS + mode (ie. disabled/bypassed caches) */ + +#if XCHAL_HAVE_CACHEATTR || XCHAL_HAVE_MIMIC_CACHEATTR || XCHAL_HAVE_XLT_CACHEATTR + +#define XCHAL_FCA_ENAMASK 0x001A /* bitmap of fetch attributes that require enabled icache */ +#define XCHAL_LCA_ENAMASK 0x0003 /* bitmap of load attributes that require enabled dcache */ +#define XCHAL_SCA_ENAMASK 0x0003 /* bitmap of store attributes that require enabled dcache */ +#define XCHAL_LSCA_ENAMASK (XCHAL_LCA_ENAMASK|XCHAL_SCA_ENAMASK) /* l/s attrs requiring enabled dcache */ +#define XCHAL_ALLCA_ENAMASK (XCHAL_FCA_ENAMASK|XCHAL_LSCA_ENAMASK) /* all attrs requiring enabled caches */ + +/* + * _cacheattr_is_enabled + * + * (Internal macro.) + * Branches to \label if CACHEATTR in a2 indicates an enabled + * cache, using mask in a3. + * + * Parameters: + * label where to branch to if cache is enabled + * Entry: + * a2 contains CACHEATTR value used to determine whether + * caches are enabled + * a3 16-bit constant where each bit correspond to + * one of the 16 possible CA values (in a CACHEATTR mask); + * CA values that indicate the cache is enabled + * have their corresponding bit set in this mask + * (eg. use XCHAL_xCA_ENAMASK , above) + * Exit: + * a2,a4,a5 clobbered + * SAR clobbered + */ + .macro _cacheattr_is_enabled label + movi a4, 8 // loop 8 times +.Lcaife\@: + extui a5, a2, 0, 4 // get CA nibble + ssr a5 // index into mask according to CA... + srl a5, a3 // ...and get CA's mask bit in a5 bit 0 + bbsi.l a5, 0, \label // if CA indicates cache enabled, jump to label + srli a2, a2, 4 // next nibble + addi a4, a4, -1 + bnez a4, .Lcaife\@ // loop for each nibble + .endm + +#else /* XCHAL_HAVE_CACHEATTR || XCHAL_HAVE_MIMIC_CACHEATTR || XCHAL_HAVE_XLT_CACHEATTR */ + .macro _cacheattr_is_enabled label + j \label // macro not applicable, assume caches always enabled + .endm +#endif /* XCHAL_HAVE_CACHEATTR || XCHAL_HAVE_MIMIC_CACHEATTR || XCHAL_HAVE_XLT_CACHEATTR */ + + + +/* + * icacheattr_is_enabled + * + * Branches to \label if I-cache is enabled. + * + * Parameters: + * label where to branch to if icache is enabled + * Entry: + * (none) + * Exit: + * a2-a5, SAR clobbered (temporaries) + */ + .macro icacheattr_is_enabled label +#if XCHAL_HAVE_CACHEATTR || XCHAL_HAVE_MIMIC_CACHEATTR || XCHAL_HAVE_XLT_CACHEATTR + icacheattr_get + movi a3, XCHAL_FCA_ENAMASK +#endif + _cacheattr_is_enabled \label + .endm + +/* + * dcacheattr_is_enabled + * + * Branches to \label if D-cache is enabled. + * + * Parameters: + * label where to branch to if dcache is enabled + * Entry: + * (none) + * Exit: + * a2-a5, SAR clobbered (temporaries) + */ + .macro dcacheattr_is_enabled label +#if XCHAL_HAVE_CACHEATTR || XCHAL_HAVE_MIMIC_CACHEATTR || XCHAL_HAVE_XLT_CACHEATTR + dcacheattr_get + movi a3, XCHAL_LSCA_ENAMASK +#endif + _cacheattr_is_enabled \label + .endm + +/* + * cacheattr_is_enabled + * + * Branches to \label if either I-cache or D-cache is enabled. + * + * Parameters: + * label where to branch to if a cache is enabled + * Entry: + * (none) + * Exit: + * a2-a5, SAR clobbered (temporaries) + */ + .macro cacheattr_is_enabled label +#if XCHAL_HAVE_CACHEATTR + rsr a2, CACHEATTR + movi a3, XCHAL_ALLCA_ENAMASK +#elif XCHAL_HAVE_MIMIC_CACHEATTR || XCHAL_HAVE_XLT_CACHEATTR + icacheattr_get + movi a3, XCHAL_FCA_ENAMASK + _cacheattr_is_enabled \label + dcacheattr_get + movi a3, XCHAL_LSCA_ENAMASK +#endif + _cacheattr_is_enabled \label + .endm + + + +/* + * The ISA does not have a defined way to change the + * instruction cache attributes of the running code, + * ie. of the memory area that encloses the current PC. + * However, each micro-architecture (or class of + * configurations within a micro-architecture) + * provides a way to deal with this issue. + * + * Here are a few macros used to implement the relevant + * approach taken. + */ + +#if XCHAL_HAVE_MIMIC_CACHEATTR || XCHAL_HAVE_XLT_CACHEATTR + // We have a config that "mimics" CACHEATTR using a simplified + // "MMU" composed of a single statically-mapped way. + +/* + * icacheattr_set + * + * Entry: + * a2 cacheattr value to set + * Exit: + * a2 unchanged + * a3-a8 clobbered (temporaries) + */ + .macro icacheattr_set + + movi a5, 0xE0000000 // mask of upper 3 bits + movi a6, 3f // PC where ITLB is set + movi a3, 0 // start at region 0 (0 .. 7) + and a6, a6, a5 // upper 3 bits of local PC area + mov a7, a2 // copy a2 so it doesn't get clobbered + j 3f + +# if XCHAL_HAVE_XLT_CACHEATTR + // Can do translations, use generic method: +1: sub a6, a3, a5 // address of some other segment + ritlb1 a8, a6 // save its PPN+CA + dsync // interlock?? + witlb a4, a6 // make it translate to this code area + movi a6, 5f // where to jump into it + isync + sub a6, a6, a5 // adjust jump address within that other segment + jx a6 + + // Note that in the following code snippet, which runs at a different virtual + // address than it is assembled for, we avoid using literals (eg. via movi/l32r) + // just in case literals end up in a different 512 MB segment, and we avoid + // instructions that rely on the current PC being what is expected. + // + .align 4 + _j 6f // this is at label '5' minus 4 bytes + .align 4 +5: witlb a4, a3 // we're in other segment, now can write previous segment's CA + isync + add a6, a6, a5 // back to previous segment + addi a6, a6, -4 // next jump label + jx a6 + +6: sub a6, a3, a5 // address of some other segment + witlb a8, a6 // restore PPN+CA of other segment + mov a6, a3 // restore a6 + isync +# else /* XCHAL_HAVE_XLT_CACHEATTR */ + // Use micro-architecture specific method. + // The following 4-instruction sequence is aligned such that + // it all fits within a single I-cache line. Sixteen byte + // alignment is sufficient for this (using XCHAL_ICACHE_LINESIZE + // actually causes problems because that can be greater than + // the alignment of the reset vector, where this macro is often + // invoked, which would cause the linker to align the reset + // vector code away from the reset vector!!). + .align 16 /*XCHAL_ICACHE_LINESIZE*/ +1: _witlb a4, a3 // write wired PTE (CA, no PPN) of 512MB segment to ITLB + _isync + nop + nop +# endif /* XCHAL_HAVE_XLT_CACHEATTR */ + beq a3, a5, 4f // done? + + // Note that in the WITLB loop, we don't do any load/stores + // (may not be an issue here, but it is important in the DTLB case). +2: srli a7, a7, 4 // next CA + sub a3, a3, a5 // next segment (add 0x20000000) +3: +# if XCHAL_HAVE_XLT_CACHEATTR /* if have translation, preserve it */ + ritlb1 a8, a3 // get current PPN+CA of segment + dsync // interlock??? + extui a4, a7, 0, 4 // extract CA to set + srli a8, a8, 4 // clear CA but keep PPN ... + slli a8, a8, 4 // ... + add a4, a4, a8 // combine new CA with PPN to preserve +# else + extui a4, a7, 0, 4 // extract CA +# endif + beq a3, a6, 1b // current PC's region? if so, do it in a safe way + witlb a4, a3 // write wired PTE (CA [+PPN]) of 512MB segment to ITLB + bne a3, a5, 2b + isync // make sure all ifetch changes take effect +4: + .endm // icacheattr_set + + +/* + * dcacheattr_set + * + * Entry: + * a2 cacheattr value to set + * Exit: + * a2 unchanged + * a3-a8 clobbered (temporaries) + */ + + .macro dcacheattr_set + + movi a5, 0xE0000000 // mask of upper 3 bits + movi a3, 0 // start at region 0 (0 .. 7) + mov a7, a2 // copy a2 so it doesn't get clobbered + j 3f + // Note that in the WDTLB loop, we don't do any load/stores + // (including implicit l32r via movi) because it isn't safe. +2: srli a7, a7, 4 // next CA + sub a3, a3, a5 // next segment (add 0x20000000) +3: +# if XCHAL_HAVE_XLT_CACHEATTR /* if have translation, preserve it */ + rdtlb1 a8, a3 // get current PPN+CA of segment + dsync // interlock??? + extui a4, a7, 0, 4 // extract CA to set + srli a8, a8, 4 // clear CA but keep PPN ... + slli a8, a8, 4 // ... + add a4, a4, a8 // combine new CA with PPN to preserve +# else + extui a4, a7, 0, 4 // extract CA to set +# endif + wdtlb a4, a3 // write wired PTE (CA [+PPN]) of 512MB segment to DTLB + bne a3, a5, 2b + dsync // make sure all data path changes take effect + .endm // dcacheattr_set + +#endif /* XCHAL_HAVE_MIMIC_CACHEATTR || XCHAL_HAVE_XLT_CACHEATTR */ + + + +/* + * cacheattr_set + * + * Macro that sets the current CACHEATTR safely + * (both i and d) according to the current contents of a2. + * It works even when changing the cache attributes of + * the currently running code. + * + * Entry: + * a2 cacheattr value to set + * Exit: + * a2 unchanged + * a3-a8 clobbered (temporaries) + */ + .macro cacheattr_set + +#if XCHAL_HAVE_CACHEATTR +# if XCHAL_ICACHE_LINESIZE < 4 + // No i-cache, so can always safely write to CACHEATTR: + wsr a2, CACHEATTR +# else + // The Athens micro-architecture, when using the old + // exception architecture option (ie. with the CACHEATTR register) + // allows changing the cache attributes of the running code + // using the following exact sequence aligned to be within + // an instruction cache line. (NOTE: using XCHAL_ICACHE_LINESIZE + // alignment actually causes problems because that can be greater + // than the alignment of the reset vector, where this macro is often + // invoked, which would cause the linker to align the reset + // vector code away from the reset vector!!). + j 1f + .align 16 /*XCHAL_ICACHE_LINESIZE*/ // align to within an I-cache line +1: _wsr a2, CACHEATTR + _isync + nop + nop +# endif +#elif XCHAL_HAVE_MIMIC_CACHEATTR || XCHAL_HAVE_XLT_CACHEATTR + // DTLB and ITLB are independent, but to keep semantics + // of this macro we simply write to both. + icacheattr_set + dcacheattr_set +#else + // This macro isn't applicable to arbitrary MMU configurations. + // Do nothing in this case. +#endif + .endm + + +#endif /*XTENSA_CACHEATTRASM_H*/ + |