diff options
Diffstat (limited to 'arch/blackfin/kernel/cplb-nompu/cplbmgr.S')
| -rw-r--r-- | arch/blackfin/kernel/cplb-nompu/cplbmgr.S | 646 |
1 files changed, 646 insertions, 0 deletions
diff --git a/arch/blackfin/kernel/cplb-nompu/cplbmgr.S b/arch/blackfin/kernel/cplb-nompu/cplbmgr.S new file mode 100644 index 00000000000..f5cf3accef3 --- /dev/null +++ b/arch/blackfin/kernel/cplb-nompu/cplbmgr.S @@ -0,0 +1,646 @@ +/* + * File: arch/blackfin/mach-common/cplbmgtr.S + * Based on: + * Author: LG Soft India + * + * Created: ? + * Description: CPLB replacement routine for CPLB mismatch + * + * Modified: + * Copyright 2004-2006 Analog Devices Inc. + * + * Bugs: Enter bugs at http://blackfin.uclinux.org/ + * + * 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 2 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 the file COPYING, or write + * to the Free Software Foundation, Inc., + * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + */ + +/* 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 is + * presumably misbehaving. + * CPLB_PROT_VIOL => The address being accessed, that triggered the + * 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. + */ + +#include <linux/linkage.h> +#include <asm/blackfin.h> +#include <asm/cplb.h> + +#ifdef CONFIG_EXCPT_IRQ_SYSC_L1 +.section .l1.text +#else +.text +#endif + +.align 2; +ENTRY(_cplb_mgr) + + [--SP]=( R7:4,P5:3 ); + + CC = R0 == 2; + IF CC JUMP .Ldcplb_write; + + CC = R0 == 0; + IF !CC JUMP .Ldcplb_miss_compare; + + /* ICPLB Miss Exception. We need to choose one of the + * currently-installed CPLBs, and replace it with one + * from the configuration table. + */ + + /* A multi-word instruction can cross a page boundary. This means the + * first part of the instruction can be in a valid page, but the + * second part is not, and hence generates the instruction miss. + * However, the fault address is for the start of the instruction, + * not the part that's in the bad page. Therefore, we have to check + * whether the fault address applies to a page that is already present + * in the table. + */ + + P4.L = LO(ICPLB_FAULT_ADDR); + P4.H = HI(ICPLB_FAULT_ADDR); + + P1 = 16; + P5.L = _page_size_table; + P5.H = _page_size_table; + + P0.L = LO(ICPLB_DATA0); + P0.H = HI(ICPLB_DATA0); + 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, two bits at posn 16 */ + + R5 = 0; +.Lisearch: + + R1 = [P0-0x100]; /* Address for this CPLB */ + + R0 = [P0++]; /* Info for this CPLB*/ + CC = BITTST(R0,0); /* Is the CPLB valid?*/ + IF !CC JUMP .Lnomatch; /* Skip it, if not.*/ + CC = R4 < R1(IU); /* If fault address less than page start*/ + IF CC JUMP .Lnomatch; /* 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 .Lisearch_done; +.Lnomatch: + /* Go around again*/ + R5 += 1; + CC = BITTST(R5, 4); /* i.e CC = R5 >= 16*/ + IF !CC JUMP .Lisearch; + +.Lisearch_done: + I0 = R4; /* Fault address we'll search for*/ + + /* set up pointers */ + P0.L = LO(ICPLB_DATA0); + P0.H = HI(ICPLB_DATA0); + + /* The replacement procedure for ICPLBs */ + + P4.L = LO(IMEM_CONTROL); + P4.H = HI(IMEM_CONTROL); + + /* Turn off CPLBs while we work, necessary according to HRM before + * modifying CPLB descriptors + */ + 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 */ +.Licheck_lock: + R0 = [P0++]; + R3 = R3 + R1; + CC = R3 == R1; + IF CC JUMP .Lall_locked; + CC = BITTST(R0, 0); /* an invalid entry is good */ + IF !CC JUMP .Lifound_victim; + CC = BITTST(R0,1); /* but a locked entry isn't */ + IF CC JUMP .Licheck_lock; + +.Lifound_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; +.Licount: + R2 = [P2]; /* address from config table */ + P2 += 8; + P3 += 8; + CC = R2==-1; + IF CC JUMP .Licount_done; + CC = R7==R2; + IF !CC JUMP .Licount; + R7 = [P3]; + R7 += 1; + [P3] = R7; + CSYNC; +.Licount_done: +#endif + LC0=R3; + LSETUP(.Lis_move,.Lie_move) LC0; +.Lis_move: + R0 = [P0]; + [P0 - 4] = R0; + R0 = [P0 - 0x100]; + [P0-0x104] = R0; +.Lie_move: + P0+=4; + + /* Clear ICPLB_DATA15, in case we don't find a replacement + * otherwise, we would have a duplicate entry, and will crash + */ + R0 = 0; + [P0 - 4] = R0; + + /* 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); +.Linext: 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 .Lno_page_in_table; + + /* See if failed address > start address */ + CC = R4 <= R0(IU); + IF !CC JUMP .Linext; + + /* 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 .Linext; + + /* 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 = LO(ICPLB_DATA15); /* ICPLB_DATA15 */ + P1.H = HI(ICPLB_DATA15); + [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; + + ( R7:4,P5:3 ) = [SP++]; + R0 = CPLB_RELOADED; + RTS; + +/* FAILED CASES*/ +.Lno_page_in_table: + R0 = CPLB_NO_ADDR_MATCH; + JUMP .Lfail_ret; + +.Lall_locked: + R0 = CPLB_NO_UNLOCKED; + JUMP .Lfail_ret; + +.Lprot_violation: + R0 = CPLB_PROT_VIOL; + +.Lfail_ret: + /* Make sure we turn protection/cache back on, even in the failing case */ + BITSET(R5,ENICPLB_P); + CLI R2; + SSYNC; /* SSYNC required before writing to IMEM_CONTROL. */ + .align 8; + [P4] = R5; + SSYNC; + STI R2; + + ( R7:4,P5:3 ) = [SP++]; + RTS; + +.Ldcplb_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 = LO(DCPLB_STATUS); + P4.H = HI(DCPLB_STATUS); + P3.L = LO(DCPLB_DATA0); + P3.H = HI(DCPLB_DATA0); + 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 .Lprot_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 .Lprot_violation; + CC = BITTST(R3, 7); /* 0 == clean, 1 == dirty*/ + IF CC JUMP .Lprot_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 .Lprot_violation; + + /* It's a genuine write-to-clean-page.*/ + + BITSET(R3, 7); /* mark as dirty*/ + [P3] = R3; /* and write back.*/ + NOP; + CSYNC; + ( R7:4,P5:3 ) = [SP++]; + R0 = CPLB_RELOADED; + RTS; + +.Ldcplb_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 = LO(DCPLB_DATA15); + P1.H = HI(DCPLB_DATA15); + + P4.L = LO(DCPLB_FAULT_ADDR); + P4.H = HI(DCPLB_FAULT_ADDR); + R4 = [P4]; + I0 = R4; + + /* The replacement procedure for DCPLBs*/ + + R6 = R1; /* Save for later*/ + + /* Turn off CPLBs while we work.*/ + P4.L = LO(DMEM_CONTROL); + P4.H = HI(DMEM_CONTROL); + 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 = LO(DCPLB_DATA0); + I1.H = HI(DCPLB_DATA0); + P1 = 2; + P2 = 16; + I2.L = _dcplb_preference; + I2.H = _dcplb_preference; + LSETUP(.Lsdsearch1, .Ledsearch1) LC0 = P1; +.Lsdsearch1: + R0 = [I2++]; /* Get the bits we're interested in*/ + P0 = I1; /* Go back to start of table*/ + LSETUP (.Lsdsearch2, .Ledsearch2) LC1 = P2; +.Lsdsearch2: + 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 .Lskip_stack_check; + + R2 = [P0 - 0x104]; /* R2 - PageStart */ + P3.L = _page_size_table; /* retrieve end address */ + P3.H = _page_size_table; /* retrieve end address */ + R3 = 0x1002; /* 16th - position, 2 bits -length */ +#if ANOMALY_05000209 + nop; /* Anomaly 05000209 */ +#endif + R7 = EXTRACT(R1,R3.l); + R7 = R7 << 2; /* Page size index offset */ + P5 = R7; + P3 = P3 + P5; + R7 = [P3]; /* page size in bytes */ + + R7 = R2 + R7; /* R7 - PageEnd */ + R4 = SP; /* Test SP is in range */ + + CC = R7 < R4; /* if PageEnd < SP */ + IF CC JUMP .Ldfound_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 .Ldfound_victim; +.Lskip_stack_check: + +.Ledsearch2: NOP; +.Ledsearch1: NOP; + + /* If we got here, we didn't find a DCPLB we considered + * replacable, which means all of them were locked. + */ + + JUMP .Lall_locked; +.Ldfound_victim: + +#ifdef CONFIG_CPLB_INFO + R7 = [P0 - 0x104]; + P2.L = _dpdt_table; + P2.H = _dpdt_table; + P3.L = _dpdt_swapcount_table; + P3.H = _dpdt_swapcount_table; + P3 += -4; +.Ldicount: + R2 = [P2]; + P2 += 8; + P3 += 8; + CC = R2==-1; + IF CC JUMP .Ldicount_done; + CC = R7==R2; + IF !CC JUMP .Ldicount; + R7 = [P3]; + R7 += 1; + [P3] = R7; +.Ldicount_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). + */ + +.LDdoverwrite: + + /* [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 = LO(DCPLB_DATA16); /* DCPLB_DATA15 + 4 */ + R1.H = HI(DCPLB_DATA16); + R0 = P0; + + /* If the victim happens to be in DCPLB15, + * we don't need to move anything. + */ + + CC = R1 == R0; + IF CC JUMP .Lde_moved; + R1 = R1 - R0; + R1 >>= 2; + P1 = R1; + LSETUP(.Lds_move, .Lde_move) LC0=P1; +.Lds_move: + R0 = [P0++]; /* move data */ + [P0 - 8] = R0; + R0 = [P0-0x104] /* move address */ +.Lde_move: + [P0-0x108] = R0; + +.Lde_moved: + NOP; + + /* Clear DCPLB_DATA15, in case we don't find a replacement + * otherwise, we would have a duplicate entry, and will crash + */ + R0 = 0; + [P0 - 0x4] = 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. + */ + + 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; +.Ldnext: R4 = [P2++]; /* address */ + R2 = [P2++]; /* data */ +#ifdef CONFIG_CPLB_INFO + P3 += 8; +#endif + + CC = R4 == -1; + IF CC JUMP .Lno_page_in_table; + + /* See if failed address > start address */ + CC = R4 <= R0(IU); + IF !CC JUMP .Ldnext; + + /* 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 .Ldnext; + + /* We've found the CPLB that should be installed, so + * write it into CPLB15, masking off any caching bits + * if necessary. + */ + + P1.L = LO(DCPLB_DATA15); + P1.H = HI(DCPLB_DATA15); + + /* 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_BFIN_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; + + ( R7:4,P5:3 ) = [SP++]; + R0 = CPLB_RELOADED; + RTS; +ENDPROC(_cplb_mgr) + +.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 0x00000002; /* lock bit */ |