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[/] [openrisc/] [trunk/] [or1ksim/] [cache/] [icache-model.c] - Rev 179
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/* icache-model.c -- instruction cache simulation Copyright (C) 1999 Damjan Lampret, lampret@opencores.org Copyright (C) 2008 Embecosm Limited Contributor Jeremy Bennett <jeremy.bennett@embecosm.com> This file is part of OpenRISC 1000 Architectural Simulator. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see <http://www.gnu.org/licenses/>. */ /* This program is commented throughout in a fashion suitable for processing with Doxygen. */ /* Cache functions. At the moment this functions only simulate functionality of instruction caches and do not influence on fetche/decode/execute stages and timings. They are here only to verify performance of various cache configurations. */ /* Autoconf and/or portability configuration */ #include "config.h" #include "port.h" /* System includes */ #include <stdlib.h> /* Package includes */ #include "icache-model.h" #include "execute.h" #include "spr-defs.h" #include "abstract.h" #include "misc.h" #include "stats.h" #include "sim-cmd.h" #define MAX_IC_SETS 1024 #define MAX_IC_WAYS 32 #define MIN_IC_BLOCK_SIZE 16 #define MAX_IC_BLOCK_SIZE 32 struct ic *ic_state = NULL; static void ic_info (void *dat) { struct ic *ic = dat; if (!(cpu_state.sprs[SPR_UPR] & SPR_UPR_ICP)) { PRINTF ("ICache not implemented. Set UPR[ICP].\n"); return; } PRINTF ("Instruction cache %dKB: ", ic->nsets * ic->blocksize * ic->nways / 1024); PRINTF ("%d ways, %d sets, block size %d bytes\n", ic->nways, ic->nsets, ic->blocksize); } /* First check if instruction is already in the cache and if it is: - increment IC read hit stats, - set 'lru' at this way to ic->ustates - 1 and decrement 'lru' of other ways unless they have reached 0, - read insn from the cache line and if not: - increment IC read miss stats - find lru way and entry and replace old tag with tag of the 'fetchaddr' - set 'lru' with ic->ustates - 1 and decrement 'lru' of other ways unless they have reached 0 - refill cache line */ uint32_t ic_simulate_fetch (oraddr_t fetchaddr, oraddr_t virt_addr) { oraddr_t set; oraddr_t way; oraddr_t lru_way; oraddr_t tagaddr; uint32_t tmp; oraddr_t reload_addr; oraddr_t reload_end; unsigned int minlru; struct ic *ic = ic_state; /* ICache simulation enabled/disabled. */ if (!(cpu_state.sprs[SPR_UPR] & SPR_UPR_ICP) || !(cpu_state.sprs[SPR_SR] & SPR_SR_ICE) || insn_ci) { tmp = evalsim_mem32 (fetchaddr, virt_addr); if (cur_area && cur_area->log) fprintf (cur_area->log, "[%" PRIxADDR "] -> read %08" PRIx32 "\n", fetchaddr, tmp); return tmp; } /* Which set to check out? */ set = (fetchaddr & ic->set_mask) >> ic->blocksize_log2; tagaddr = fetchaddr & ic->tagaddr_mask; /* Scan all ways and try to find a matching way. */ for (way = set; way < ic->last_way; way += ic->nsets) { if (ic->tags[way] == tagaddr) { ic_stats.readhit++; for (lru_way = set; lru_way < ic->last_way; lru_way += ic->nsets) if (ic->lrus[lru_way] > ic->lrus[way]) ic->lrus[lru_way]--; ic->lrus[way] = ic->ustates_reload; runtime.sim.mem_cycles += ic->hitdelay; way <<= ic->blocksize_log2; return *(uint32_t *) & ic-> mem[way | (fetchaddr & ic->block_offset_mask)]; } } minlru = ic->ustates_reload; way = set; ic_stats.readmiss++; for (lru_way = set; lru_way < ic->last_way; lru_way += ic->nsets) { if (ic->lrus[lru_way] < minlru) { way = lru_way; minlru = ic->lrus[lru_way]; } } ic->tags[way] = tagaddr; for (lru_way = set; lru_way < ic->last_way; lru_way += ic->nsets) if (ic->lrus[lru_way]) ic->lrus[lru_way]--; ic->lrus[way] = ic->ustates_reload; reload_addr = fetchaddr & ic->block_offset_mask; reload_end = reload_addr + ic->blocksize; fetchaddr &= ic->block_mask; way <<= ic->blocksize_log2; for (; reload_addr < reload_end; reload_addr += 4) { tmp = *(uint32_t *) & ic->mem[way | (reload_addr & ic->block_offset_mask)] = /* FIXME: What is the virtual address meant to be? (ie. What happens if * we read out of memory while refilling a cache line?) */ evalsim_mem32 (fetchaddr | (reload_addr & ic->block_offset_mask), 0); if (!cur_area) { ic->tags[way >> ic->blocksize_log2] = -1; ic->lrus[way >> ic->blocksize_log2] = 0; return 0; } else if (cur_area->log) fprintf (cur_area->log, "[%" PRIxADDR "] -> read %08" PRIx32 "\n", fetchaddr, tmp); } runtime.sim.mem_cycles += ic->missdelay; return *(uint32_t *) & ic->mem[way | (reload_addr & ic->block_offset_mask)]; } /* First check if data is already in the cache and if it is: - invalidate block if way isn't locked otherwise don't do anything. */ void ic_inv (oraddr_t dataaddr) { oraddr_t set; oraddr_t way; oraddr_t tagaddr; struct ic *ic = ic_state; if (!(cpu_state.sprs[SPR_UPR] & SPR_UPR_ICP)) return; /* Which set to check out? */ set = (dataaddr & ic->set_mask) >> ic->blocksize_log2; if (!(cpu_state.sprs[SPR_SR] & SPR_SR_ICE)) { for (way = set; way < ic->last_way; way += ic->nsets) { ic->tags[way] = -1; ic->lrus[way] = 0; } return; } tagaddr = dataaddr & ic->tagaddr_mask; /* Scan all ways and try to find a matching way. */ for (way = set; way < ic->last_way; way += ic->nsets) { if (ic->tags[way] == tagaddr) { ic->tags[way] = -1; ic->lrus[way] = 0; } } } /*-----------------------------------------------------[ IC configuration ]---*/ /*---------------------------------------------------------------------------*/ /*!Enable or disable the instruction cache Set the corresponding fields in the UPR @param[in] val The value to use @param[in] dat The config data structure */ /*---------------------------------------------------------------------------*/ static void ic_enabled (union param_val val, void *dat) { struct ic *ic = dat; ic->enabled = val.int_val; if (val.int_val) { cpu_state.sprs[SPR_UPR] |= SPR_UPR_ICP; } else { cpu_state.sprs[SPR_UPR] &= ~SPR_UPR_ICP; } } /* ic_enabled() */ /*---------------------------------------------------------------------------*/ /*!Set the number of instruction cache sets Set the corresponding field in the UPR @param[in] val The value to use @param[in] dat The config data structure */ /*---------------------------------------------------------------------------*/ static void ic_nsets (union param_val val, void *dat) { struct ic *ic = dat; if (is_power2 (val.int_val) && (val.int_val <= MAX_IC_SETS)) { int set_bits = log2_int (val.int_val); ic->nsets = val.int_val; cpu_state.sprs[SPR_ICCFGR] &= ~SPR_ICCFGR_NCS; cpu_state.sprs[SPR_ICCFGR] |= set_bits << SPR_ICCFGR_NCS_OFF; } else { fprintf (stderr, "Warning: instruction cache nsets not a power of " "2 <= %d: ignored\n", MAX_IC_SETS); } } /* ic_nsets() */ /*---------------------------------------------------------------------------*/ /*!Set the number of instruction cache ways Set the corresponding field in the UPR @param[in] val The value to use @param[in] dat The config data structure */ /*---------------------------------------------------------------------------*/ static void ic_nways (union param_val val, void *dat) { struct ic *ic = dat; if (is_power2 (val.int_val) && (val.int_val <= MAX_IC_WAYS)) { int way_bits = log2_int (val.int_val); ic->nways = val.int_val; cpu_state.sprs[SPR_ICCFGR] &= ~SPR_ICCFGR_NCW; cpu_state.sprs[SPR_ICCFGR] |= way_bits << SPR_ICCFGR_NCW_OFF; } else { fprintf (stderr, "Warning: instruction cache nways not a power of " "2 <= %d: ignored\n", MAX_IC_WAYS); } } /* ic_nways() */ /*---------------------------------------------------------------------------*/ /*!Set the instruction cache block size Value must be either MIN_IC_BLOCK_SIZE or MAX_IC_BLOCK_SIZE. If not issue a warning and ignore. Set the relevant field in the data cache config register @param[in] val The value to use @param[in] dat The config data structure */ /*---------------------------------------------------------------------------*/ static void ic_blocksize (union param_val val, void *dat) { struct ic *ic = dat; switch (val.int_val) { case MIN_IC_BLOCK_SIZE: ic->blocksize = val.int_val; cpu_state.sprs[SPR_ICCFGR] &= ~SPR_ICCFGR_CBS; break; case MAX_IC_BLOCK_SIZE: ic->blocksize = val.int_val; cpu_state.sprs[SPR_ICCFGR] |= SPR_ICCFGR_CBS; break; default: fprintf (stderr, "Warning: instruction cache block size not %d or %d: " "ignored\n", MIN_IC_BLOCK_SIZE, MAX_IC_BLOCK_SIZE); break; } } /* ic_blocksize() */ /*---------------------------------------------------------------------------*/ /*!Set the number of instruction cache usage states Value must be 2, 3 or 4. If not issue a warning and ignore. @param[in] val The value to use @param[in] dat The config data structure */ /*---------------------------------------------------------------------------*/ static void ic_ustates (union param_val val, void *dat) { struct ic *ic = dat; if ((val.int_val >= 2) && (val.int_val <= 4)) { ic->ustates = val.int_val; } else { fprintf (stderr, "Warning number of instruction cache usage states " "must be 2, 3 or 4: ignored\n"); } } /* ic_ustates() */ static void ic_hitdelay (union param_val val, void *dat) { struct ic *ic = dat; ic->hitdelay = val.int_val; } static void ic_missdelay (union param_val val, void *dat) { struct ic *ic = dat; ic->missdelay = val.int_val; } /*---------------------------------------------------------------------------*/ /*!Initialize a new instruction cache configuration ALL parameters are set explicitly to default values. Corresponding SPR flags are set as appropriate. @return The new memory configuration data structure */ /*---------------------------------------------------------------------------*/ static void * ic_start_sec () { struct ic *ic; int set_bits; int way_bits; if (NULL == (ic = malloc (sizeof (struct ic)))) { fprintf (stderr, "OOM\n"); exit (1); } ic->enabled = 0; ic->nsets = 1; ic->nways = 1; ic->blocksize = MIN_IC_BLOCK_SIZE; ic->ustates = 2; ic->hitdelay = 1; ic->missdelay = 1; ic->mem = NULL; /* Internal configuration */ ic->lrus = NULL; ic->tags = NULL; /* Set SPRs as appropriate */ if (ic->enabled) { cpu_state.sprs[SPR_UPR] |= SPR_UPR_ICP; } else { cpu_state.sprs[SPR_UPR] &= ~SPR_UPR_ICP; } set_bits = log2_int (ic->nsets); cpu_state.sprs[SPR_ICCFGR] &= ~SPR_ICCFGR_NCS; cpu_state.sprs[SPR_ICCFGR] |= set_bits << SPR_ICCFGR_NCS_OFF; way_bits = log2_int (ic->nways); cpu_state.sprs[SPR_ICCFGR] &= ~SPR_ICCFGR_NCW; cpu_state.sprs[SPR_ICCFGR] |= way_bits << SPR_ICCFGR_NCW_OFF; if (MIN_IC_BLOCK_SIZE == ic->blocksize) { cpu_state.sprs[SPR_ICCFGR] &= ~SPR_ICCFGR_CBS; } else { cpu_state.sprs[SPR_ICCFGR] |= SPR_ICCFGR_CBS; } ic_state = ic; return ic; } /* ic_start_sec() */ static void ic_end_sec (void *dat) { struct ic *ic = dat; unsigned int size = ic->nways * ic->nsets * ic->blocksize; if (size) { if (!(ic->mem = malloc (size))) { fprintf (stderr, "OOM\n"); exit (1); } if (! (ic->lrus = malloc (ic->nsets * ic->nways * sizeof (unsigned int)))) { fprintf (stderr, "OOM\n"); exit (1); } if (!(ic->tags = malloc (ic->nsets * ic->nways * sizeof (oraddr_t)))) { fprintf (stderr, "OOM\n"); exit (1); } /* Clear the cache data. John Alfredo's fix for using 0 (which is a valid tag), so we now use -1 */ memset (ic->mem, 0, size); memset (ic->lrus, 0, ic->nsets * ic->nways * sizeof (unsigned int)); memset (ic->tags, -1, ic->nsets * ic->nways * sizeof (oraddr_t)); } else { ic->enabled = 0; } ic->blocksize_log2 = log2_int (ic->blocksize); ic->set_mask = (ic->nsets - 1) << ic->blocksize_log2; ic->tagaddr_mask = ~((ic->nsets * ic->blocksize) - 1); ic->last_way = ic->nsets * ic->nways; ic->block_offset_mask = ic->blocksize - 1; ic->block_mask = ~ic->block_offset_mask; ic->ustates_reload = ic->ustates - 1; if (ic->enabled) reg_sim_stat (ic_info, dat); } void reg_ic_sec (void) { struct config_section *sec = reg_config_sec ("ic", ic_start_sec, ic_end_sec); reg_config_param (sec, "enabled", paramt_int, ic_enabled); reg_config_param (sec, "nsets", paramt_int, ic_nsets); reg_config_param (sec, "nways", paramt_int, ic_nways); reg_config_param (sec, "blocksize", paramt_int, ic_blocksize); reg_config_param (sec, "ustates", paramt_int, ic_ustates); reg_config_param (sec, "missdelay", paramt_int, ic_missdelay); reg_config_param (sec, "hitdelay", paramt_int, ic_hitdelay); }
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