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Diffstat (limited to 'cpu/bf533/cplbmgr.S')
| -rw-r--r-- | cpu/bf533/cplbmgr.S | 601 |
1 files changed, 601 insertions, 0 deletions
diff --git a/cpu/bf533/cplbmgr.S b/cpu/bf533/cplbmgr.S new file mode 100644 index 0000000..7a0b048 --- /dev/null +++ b/cpu/bf533/cplbmgr.S @@ -0,0 +1,601 @@ +/*This file is subject to the terms and conditions of the GNU General Public + * License. + * + * Blackfin BF533/2.6 support : LG Soft India + * Modification: Dec 07 2004 + * 1. Correction in icheck_lock. Valid lock entries were + * geting victimized, for instruction cplb replacement. + * 2. Setup loop's are modified as now toolchain support's P Indexed + * addressing + * :LG Soft India + * + */ + +/* Usage: int _cplb_mgr(is_data_miss,int enable_cache) + * is_data_miss==2 => Mark as Dirty, write to the clean data page + * is_data_miss==1 => Replace a data CPLB. + * is_data_miss==0 => Replace an instruction CPLB. + * + * Returns: + * CPLB_RELOADED => Successfully updated CPLB table. + * CPLB_NO_UNLOCKED => All CPLBs are locked, so cannot be evicted.This indicates + * that the CPLBs in the configuration tablei are badly + * configured, as this should never occur. + * CPLB_NO_ADDR_MATCH => The address being accessed, that triggered the exception, + * is not covered by any of the CPLBs in the configuration + * table. The application isi presumably misbehaving. + * CPLB_PROT_VIOL => The address being accessed, that triggered thei exception, + * was not a first-write to a clean Write Back Data page, + * and so presumably is a genuine violation of the page's + * protection attributes. The application is misbehaving. + */ +#define ASSEMBLY + +#include <asm-blackfin/linkage.h> +#include <asm-blackfin/blackfin.h> +#include <asm-blackfin/cplbtab.h> +#include <asm-blackfin/cplb.h> + +.text + +.align 2; +ENTRY(_cplb_mgr) + + [--SP]=( R7:0,P5:0 ); + + CC = R0 == 2; + IF CC JUMP dcplb_write; + + CC = R0 == 0; + IF !CC JUMP dcplb_miss_compare; + + /* ICPLB Miss Exception. We need to choose one of the + * currently-installed CPLBs, and replace it with one + * from the configuration table. + */ + + P4.L = (ICPLB_FAULT_ADDR & 0xFFFF); + P4.H = (ICPLB_FAULT_ADDR >> 16); + + P1 = 16; + P5.L = page_size_table; + P5.H = page_size_table; + + P0.L = (ICPLB_DATA0 & 0xFFFF); + P0.H = (ICPLB_DATA0 >> 16); + R4 = [P4]; /* Get faulting address*/ + R6 = 64; /* Advance past the fault address, which*/ + R6 = R6 + R4; /* we'll use if we find a match*/ + R3 = ((16 << 8) | 2); /* Extract mask, bits 16 and 17.*/ + + R5 = 0; +isearch: + + R1 = [P0-0x100]; /* Address for this CPLB */ + + R0 = [P0++]; /* Info for this CPLB*/ + CC = BITTST(R0,0); /* Is the CPLB valid?*/ + IF !CC JUMP nomatch; /* Skip it, if not.*/ + CC = R4 < R1(IU); /* If fault address less than page start*/ + IF CC JUMP nomatch; /* then skip this one.*/ + R2 = EXTRACT(R0,R3.L) (Z); /* Get page size*/ + P1 = R2; + P1 = P5 + (P1<<2); /* index into page-size table*/ + R2 = [P1]; /* Get the page size*/ + R1 = R1 + R2; /* and add to page start, to get page end*/ + CC = R4 < R1(IU); /* and see whether fault addr is in page.*/ + IF !CC R4 = R6; /* If so, advance the address and finish loop.*/ + IF !CC JUMP isearch_done; +nomatch: + /* Go around again*/ + R5 += 1; + CC = BITTST(R5, 4); /* i.e CC = R5 >= 16*/ + IF !CC JUMP isearch; + +isearch_done: + I0 = R4; /* Fault address we'll search for*/ + + /* set up pointers */ + P0.L = (ICPLB_DATA0 & 0xFFFF); + P0.H = (ICPLB_DATA0 >> 16); + + /* The replacement procedure for ICPLBs */ + + P4.L = (IMEM_CONTROL & 0xFFFF); + P4.H = (IMEM_CONTROL >> 16); + + /* disable cplbs */ + R5 = [P4]; /* Control Register*/ + BITCLR(R5,ENICPLB_P); + CLI R1; + SSYNC; /* SSYNC required before writing to IMEM_CONTROL. */ + .align 8; + [P4] = R5; + SSYNC; + STI R1; + + R1 = -1; /* end point comparison */ + R3 = 16; /* counter */ + + /* Search through CPLBs for first non-locked entry */ + /* Overwrite it by moving everyone else up by 1 */ +icheck_lock: + R0 = [P0++]; + R3 = R3 + R1; + CC = R3 == R1; + IF CC JUMP all_locked; + CC = BITTST(R0, 0); /* an invalid entry is good */ + IF !CC JUMP ifound_victim; + CC = BITTST(R0,1); /* but a locked entry isn't */ + IF CC JUMP icheck_lock; + +ifound_victim: +#ifdef CONFIG_CPLB_INFO + R7 = [P0 - 0x104]; + P2.L = ipdt_table; + P2.H = ipdt_table; + P3.L = ipdt_swapcount_table; + P3.H = ipdt_swapcount_table; + P3 += -4; +icount: + R2 = [P2]; /* address from config table */ + P2 += 8; + P3 += 8; + CC = R2==-1; + IF CC JUMP icount_done; + CC = R7==R2; + IF !CC JUMP icount; + R7 = [P3]; + R7 += 1; + [P3] = R7; + CSYNC; +icount_done: +#endif + LC0=R3; + LSETUP(is_move,ie_move) LC0; +is_move: + R0 = [P0]; + [P0 - 4] = R0; + R0 = [P0 - 0x100]; + [P0-0x104] = R0; +ie_move:P0+=4; + + /* We've made space in the ICPLB table, so that ICPLB15 + * is now free to be overwritten. Next, we have to determine + * which CPLB we need to install, from the configuration + * table. This is a matter of getting the start-of-page + * addresses and page-lengths from the config table, and + * determining whether the fault address falls within that + * range. + */ + + P2.L = ipdt_table; + P2.H = ipdt_table; +#ifdef CONFIG_CPLB_INFO + P3.L = ipdt_swapcount_table; + P3.H = ipdt_swapcount_table; + P3 += -8; +#endif + P0.L = page_size_table; + P0.H = page_size_table; + + /* Retrieve our fault address (which may have been advanced + * because the faulting instruction crossed a page boundary). + */ + + R0 = I0; + + /* An extraction pattern, to get the page-size bits from + * the CPLB data entry. Bits 16-17, so two bits at posn 16. + */ + + R1 = ((16<<8)|2); +inext: R4 = [P2++]; /* address from config table */ + R2 = [P2++]; /* data from config table */ +#ifdef CONFIG_CPLB_INFO + P3 += 8; +#endif + + CC = R4 == -1; /* End of config table*/ + IF CC JUMP no_page_in_table; + + /* See if failed address > start address */ + CC = R4 <= R0(IU); + IF !CC JUMP inext; + + /* extract page size (17:16)*/ + R3 = EXTRACT(R2, R1.L) (Z); + + /* add page size to addr to get range */ + + P5 = R3; + P5 = P0 + (P5 << 2); /* scaled, for int access*/ + R3 = [P5]; + R3 = R3 + R4; + + /* See if failed address < (start address + page size) */ + CC = R0 < R3(IU); + IF !CC JUMP inext; + + /* We've found a CPLB in the config table that covers + * the faulting address, so install this CPLB into the + * last entry of the table. + */ + + P1.L = (ICPLB_DATA15 & 0xFFFF); /*ICPLB_DATA15*/ + P1.H = (ICPLB_DATA15 >> 16); + [P1] = R2; + [P1-0x100] = R4; +#ifdef CONFIG_CPLB_INFO + R3 = [P3]; + R3 += 1; + [P3] = R3; +#endif + + /* P4 points to IMEM_CONTROL, and R5 contains its old + * value, after we disabled ICPLBS. Re-enable them. + */ + + BITSET(R5,ENICPLB_P); + CLI R2; + SSYNC; /* SSYNC required before writing to IMEM_CONTROL. */ + .align 8; + [P4] = R5; + SSYNC; + STI R2; + + ( R7:0,P5:0 ) = [SP++]; + R0 = CPLB_RELOADED; + RTS; + +/* FAILED CASES*/ +no_page_in_table: + ( R7:0,P5:0 ) = [SP++]; + R0 = CPLB_NO_ADDR_MATCH; + RTS; +all_locked: + ( R7:0,P5:0 ) = [SP++]; + R0 = CPLB_NO_UNLOCKED; + RTS; +prot_violation: + ( R7:0,P5:0 ) = [SP++]; + R0 = CPLB_PROT_VIOL; + RTS; + +dcplb_write: + + /* if a DCPLB is marked as write-back (CPLB_WT==0), and + * it is clean (CPLB_DIRTY==0), then a write to the + * CPLB's page triggers a protection violation. We have to + * mark the CPLB as dirty, to indicate that there are + * pending writes associated with the CPLB. + */ + + P4.L = (DCPLB_STATUS & 0xFFFF); + P4.H = (DCPLB_STATUS >> 16); + P3.L = (DCPLB_DATA0 & 0xFFFF); + P3.H = (DCPLB_DATA0 >> 16); + R5 = [P4]; + + /* A protection violation can be caused by more than just writes + * to a clean WB page, so we have to ensure that: + * - It's a write + * - to a clean WB page + * - and is allowed in the mode the access occurred. + */ + + CC = BITTST(R5, 16); /* ensure it was a write*/ + IF !CC JUMP prot_violation; + + /* to check the rest, we have to retrieve the DCPLB.*/ + + /* The low half of DCPLB_STATUS is a bit mask*/ + + R2 = R5.L (Z); /* indicating which CPLB triggered the event.*/ + R3 = 30; /* so we can use this to determine the offset*/ + R2.L = SIGNBITS R2; + R2 = R2.L (Z); /* into the DCPLB table.*/ + R3 = R3 - R2; + P4 = R3; + P3 = P3 + (P4<<2); + R3 = [P3]; /* Retrieve the CPLB*/ + + /* Now we can check whether it's a clean WB page*/ + + CC = BITTST(R3, 14); /* 0==WB, 1==WT*/ + IF CC JUMP prot_violation; + CC = BITTST(R3, 7); /* 0 == clean, 1 == dirty*/ + IF CC JUMP prot_violation; + + /* Check whether the write is allowed in the mode that was active.*/ + + R2 = 1<<3; /* checking write in user mode*/ + CC = BITTST(R5, 17); /* 0==was user, 1==was super*/ + R5 = CC; + R2 <<= R5; /* if was super, check write in super mode*/ + R2 = R3 & R2; + CC = R2 == 0; + IF CC JUMP prot_violation; + + /* It's a genuine write-to-clean-page.*/ + + BITSET(R3, 7); /* mark as dirty*/ + [P3] = R3; /* and write back.*/ + CSYNC; + ( R7:0,P5:0 ) = [SP++]; + R0 = CPLB_RELOADED; + RTS; + +dcplb_miss_compare: + + /* Data CPLB Miss event. We need to choose a CPLB to + * evict, and then locate a new CPLB to install from the + * config table, that covers the faulting address. + */ + + P1.L = (DCPLB_DATA15 & 0xFFFF); + P1.H = (DCPLB_DATA15 >> 16); + + P4.L = (DCPLB_FAULT_ADDR & 0xFFFF); + P4.H = (DCPLB_FAULT_ADDR >> 16); + R4 = [P4]; + I0 = R4; + + /* The replacement procedure for DCPLBs*/ + + R6 = R1; /* Save for later*/ + + /* Turn off CPLBs while we work.*/ + P4.L = (DMEM_CONTROL & 0xFFFF); + P4.H = (DMEM_CONTROL >> 16); + R5 = [P4]; + BITCLR(R5,ENDCPLB_P); + CLI R0; + SSYNC; /* SSYNC required before writing to DMEM_CONTROL. */ + .align 8; + [P4] = R5; + SSYNC; + STI R0; + + /* Start looking for a CPLB to evict. Our order of preference + * is: invalid CPLBs, clean CPLBs, dirty CPLBs. Locked CPLBs + * are no good. + */ + + I1.L = (DCPLB_DATA0 & 0xFFFF); + I1.H = (DCPLB_DATA0 >> 16); + P1 = 3; + P2 = 16; + I2.L = dcplb_preference; + I2.H = dcplb_preference; + LSETUP(sdsearch1, edsearch1) LC0 = P1; +sdsearch1: + R0 = [I2++]; /* Get the bits we're interested in*/ + P0 = I1; /* Go back to start of table*/ + LSETUP (sdsearch2, edsearch2) LC1 = P2; +sdsearch2: + R1 = [P0++]; /* Fetch each installed CPLB in turn*/ + R2 = R1 & R0; /* and test for interesting bits.*/ + CC = R2 == 0; /* If none are set, it'll do.*/ + IF !CC JUMP skip_stack_check; + + R2 = [P0 - 0x104]; /* R2 - PageStart */ + P3.L = page_size_table; /* retrive end address */ + P3.H = page_size_table; /* retrive end address */ + R3 = 0x2; /* 0th - position, 2 bits -length */ + nop; /*Anamoly 05000209*/ + R7 = EXTRACT(R1,R3.l); + R7 = R7 << 2; /* Page size index offset */ + P5 = R7; + P3 = P3 + P5; + R7 = [P3]; /* page size in 1K bytes */ + + R7 = R7 << 0xA; /* in bytes * 1024*/ + R7 = R2 + R7; /* R7 - PageEnd */ + R4 = SP; /* Test SP is in range */ + + CC = R7 < R4; /* if PageEnd < SP */ + IF CC JUMP dfound_victim; + R3 = 0x284; /* stack length from start of trap till the point */ + /* 20 stack locations for future modifications */ + R4 = R4 + R3; + CC = R4 < R2; /* if SP + stacklen < PageStart */ + IF CC JUMP dfound_victim; +skip_stack_check: + +edsearch2: NOP; +edsearch1: NOP; + + /* If we got here, we didn't find a DCPLB we considered + * replacable, which means all of them were locked. + */ + + JUMP all_locked; +dfound_victim: + +#ifdef CONFIG_CPLB_INFO + R1 = [P0 - 0x104]; + P2.L = dpdt_table; + P2.H = dpdt_table; + P3.L = dpdt_swapcount_table; + P3.H = dpdt_swapcount_table; + P3 += -4; +dicount: + R2 = [P2]; + P2 += 8; + P3 += 8; + CC = R2==-1; + IF CC JUMP dicount_done; + CC = R1==R2; + IF !CC JUMP dicount; + R1 = [P3]; + R1 += 1; + [P3] = R1; + CSYNC; +dicount_done: +#endif + + /* Clean down the hardware loops*/ + R2 = 0; + LC1 = R2; + LC0 = R2; + + /* There's a suitable victim in [P0-4] (because we've + * advanced already). If it's a valid dirty write-back + * CPLB, we need to flush the pending writes first. + */ + + CC = BITTST(R1, 0); /* Is it valid?*/ + IF !CC JUMP Ddoverwrite;/* nope.*/ + CC = BITTST(R1, 7); /* Is it dirty?*/ + IF !CC JUMP Ddoverwrite (BP); /* Nope.*/ + CC = BITTST(R1, 14); /* Is it Write-Through?*/ + IF CC JUMP Ddoverwrite; /* Yep*/ + + /* This is a dirty page, so we need to flush all writes + * that are pending on the page. + */ + + /* Retrieve the page start address*/ + R0 = [P0 - 0x104]; + [--sp] = rets; + CALL dcplb_flush; /* R0==CPLB addr, R1==CPLB data*/ + rets = [sp++]; +Ddoverwrite: + + /* [P0-4] is a suitable victim CPLB, so we want to + * overwrite it by moving all the following CPLBs + * one space closer to the start. + */ + + R1.L = ((DCPLB_DATA15+4) & 0xFFFF); /*DCPLB_DATA15+4*/ + R1.H = ((DCPLB_DATA15+4) >> 16); + R0 = P0; + + /* If the victim happens to be in DCPLB15, + * we don't need to move anything. + */ + + CC = R1 == R0; + IF CC JUMP de_moved; + R1 = R1 - R0; + R1 >>= 2; + P1 = R1; + LSETUP(ds_move, de_move) LC0=P1; +ds_move: + R0 = [P0++]; /* move data */ + [P0 - 8] = R0; + R0 = [P0-0x104] /* move address */ +de_move: [P0-0x108] = R0; + + /* We've now made space in DCPLB15 for the new CPLB to be + * installed. The next stage is to locate a CPLB in the + * config table that covers the faulting address. + */ + +de_moved:NOP; + R0 = I0; /* Our faulting address */ + + P2.L = dpdt_table; + P2.H = dpdt_table; +#ifdef CONFIG_CPLB_INFO + P3.L = dpdt_swapcount_table; + P3.H = dpdt_swapcount_table; + P3 += -8; +#endif + + P1.L = page_size_table; + P1.H = page_size_table; + + /* An extraction pattern, to retrieve bits 17:16.*/ + + R1 = (16<<8)|2; +dnext: R4 = [P2++]; /* address */ + R2 = [P2++]; /* data */ +#ifdef CONFIG_CPLB_INFO + P3 += 8; +#endif + + CC = R4 == -1; + IF CC JUMP no_page_in_table; + + /* See if failed address > start address */ + CC = R4 <= R0(IU); + IF !CC JUMP dnext; + + /* extract page size (17:16)*/ + R3 = EXTRACT(R2, R1.L) (Z); + + /* add page size to addr to get range */ + + P5 = R3; + P5 = P1 + (P5 << 2); + R3 = [P5]; + R3 = R3 + R4; + + /* See if failed address < (start address + page size) */ + CC = R0 < R3(IU); + IF !CC JUMP dnext; + + /* We've found the CPLB that should be installed, so + * write it into CPLB15, masking off any caching bits + * if necessary. + */ + + P1.L = (DCPLB_DATA15 & 0xFFFF); + P1.H = (DCPLB_DATA15 >> 16); + + /* If the DCPLB has cache bits set, but caching hasn't + * been enabled, then we want to mask off the cache-in-L1 + * bit before installing. Moreover, if caching is off, we + * also want to ensure that the DCPLB has WT mode set, rather + * than WB, since WB pages still trigger first-write exceptions + * even when not caching is off, and the page isn't marked as + * cachable. Finally, we could mark the page as clean, not dirty, + * but we choose to leave that decision to the user; if the user + * chooses to have a CPLB pre-defined as dirty, then they always + * pay the cost of flushing during eviction, but don't pay the + * cost of first-write exceptions to mark the page as dirty. + */ + +#ifdef CONFIG_BLKFIN_WT + BITSET(R6, 14); /* Set WT*/ +#endif + + [P1] = R2; + [P1-0x100] = R4; +#ifdef CONFIG_CPLB_INFO + R3 = [P3]; + R3 += 1; + [P3] = R3; +#endif + + /* We've installed the CPLB, so re-enable CPLBs. P4 + * points to DMEM_CONTROL, and R5 is the value we + * last wrote to it, when we were disabling CPLBs. + */ + + BITSET(R5,ENDCPLB_P); + CLI R2; + .align 8; + [P4] = R5; + SSYNC; + STI R2; + + ( R7:0,P5:0 ) = [SP++]; + R0 = CPLB_RELOADED; + RTS; + +.data +.align 4; +page_size_table: +.byte4 0x00000400; /* 1K */ +.byte4 0x00001000; /* 4K */ +.byte4 0x00100000; /* 1M */ +.byte4 0x00400000; /* 4M */ + +.align 4; +dcplb_preference: +.byte4 0x00000001; /* valid bit */ +.byte4 0x00000082; /* dirty+lock bits */ +.byte4 0x00000002; /* lock bit */ |