u-boot/cpu/bf533/cplbmgr.S
2006-03-12 02:12:27 +01:00

601 lines
15 KiB
ArmAsm

/*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 */