u-boot/cpu/blackfin/flush.S
Mike Frysinger 9171fc8172 Blackfin: unify cpu and boot modes
All of the duplicated code for Blackfin processors and boot modes have been
unified.  After all, the core is the same for all processors, just the
peripheral set differs (which gets handled in the drivers).

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
2008-03-30 15:50:19 -04:00

230 lines
5.9 KiB
ArmAsm

/* flush.S - low level cache flushing routines
* Copyright (C) 2003-2007 Analog Devices Inc.
* Licensed under the GPL-2 or later.
*/
#include <config.h>
#include <asm/blackfin.h>
#include <asm/cplb.h>
#include <asm/mach-common/bits/mpu.h>
.text
/* This is an external function being called by the user
* application through __flush_cache_all. Currently this function
* serves the purpose of flushing all the pending writes in
* in the data cache.
*/
ENTRY(_flush_data_cache)
[--SP] = ( R7:6, P5:4 );
LINK 12;
SP += -12;
P5.H = HI(DCPLB_ADDR0);
P5.L = LO(DCPLB_ADDR0);
P4.H = HI(DCPLB_DATA0);
P4.L = LO(DCPLB_DATA0);
R7 = CPLB_VALID | CPLB_L1_CHBL | CPLB_DIRTY (Z);
R6 = 16;
.Lnext: R0 = [P5++];
R1 = [P4++];
CC = BITTST(R1, 14); /* Is it write-through?*/
IF CC JUMP .Lskip; /* If so, ignore it.*/
R2 = R1 & R7; /* Is it a dirty, cached page?*/
CC = R2;
IF !CC JUMP .Lskip; /* If not, ignore it.*/
[--SP] = RETS;
CALL _dcplb_flush; /* R0 = page, R1 = data*/
RETS = [SP++];
.Lskip: R6 += -1;
CC = R6;
IF CC JUMP .Lnext;
SSYNC;
SP += 12;
UNLINK;
( R7:6, P5:4 ) = [SP++];
RTS;
ENDPROC(_flush_data_cache)
/* This is an internal function to flush all pending
* writes in the cache associated with a particular DCPLB.
*
* R0 - page's start address
* R1 - CPLB's data field.
*/
.align 2
ENTRY(_dcplb_flush)
[--SP] = ( R7:0, P5:0 );
[--SP] = LC0;
[--SP] = LT0;
[--SP] = LB0;
[--SP] = LC1;
[--SP] = LT1;
[--SP] = LB1;
/* If it's a 1K or 4K page, then it's quickest to
* just systematically flush all the addresses in
* the page, regardless of whether they're in the
* cache, or dirty. If it's a 1M or 4M page, there
* are too many addresses, and we have to search the
* cache for lines corresponding to the page.
*/
CC = BITTST(R1, 17); /* 1MB or 4MB */
IF !CC JUMP .Ldflush_whole_page;
/* We're only interested in the page's size, so extract
* this from the CPLB (bits 17:16), and scale to give an
* offset into the page_size and page_prefix tables.
*/
R1 <<= 14;
R1 >>= 30;
R1 <<= 2;
/* The page could be mapped into Bank A or Bank B, depending
* on (a) whether both banks are configured as cache, and
* (b) on whether address bit A[x] is set. x is determined
* by DCBS in DMEM_CONTROL
*/
R2 = 0; /* Default to Bank A (Bank B would be 1)*/
P0.L = LO(DMEM_CONTROL);
P0.H = HI(DMEM_CONTROL);
R3 = [P0]; /* If Bank B is not enabled as cache*/
CC = BITTST(R3, 2); /* then Bank A is our only option.*/
IF CC JUMP .Lbank_chosen;
R4 = 1<<14; /* If DCBS==0, use A[14].*/
R5 = R4 << 7; /* If DCBS==1, use A[23];*/
CC = BITTST(R3, 4);
IF CC R4 = R5; /* R4 now has either bit 14 or bit 23 set.*/
R5 = R0 & R4; /* Use it to test the Page address*/
CC = R5; /* and if that bit is set, we use Bank B,*/
R2 = CC; /* else we use Bank A.*/
R2 <<= 23; /* The Bank selection's at posn 23.*/
.Lbank_chosen:
/* We can also determine the sub-bank used, because this is
* taken from bits 13:12 of the address.
*/
R3 = ((12<<8)|2); /* Extraction pattern */
nop; /*Anamoly 05000209*/
R4 = EXTRACT(R0, R3.L) (Z); /* Extract bits*/
/* Save in extraction pattern for later deposit.*/
R3.H = R4.L << 0;
/* So:
* R0 = Page start
* R1 = Page length (actually, offset into size/prefix tables)
* R2 = Bank select mask
* R3 = sub-bank deposit values
*
* The cache has 2 Ways, and 64 sets, so we iterate through
* the sets, accessing the tag for each Way, for our Bank and
* sub-bank, looking for dirty, valid tags that match our
* address prefix.
*/
P5.L = LO(DTEST_COMMAND);
P5.H = HI(DTEST_COMMAND);
P4.L = LO(DTEST_DATA0);
P4.H = HI(DTEST_DATA0);
P0.L = page_prefix_table;
P0.H = page_prefix_table;
P1 = R1;
R5 = 0; /* Set counter*/
P0 = P1 + P0;
R4 = [P0]; /* This is the address prefix*/
/* We're reading (bit 1==0) the tag (bit 2==0), and we
* don't care about which double-word, since we're only
* fetching tags, so we only have to set Set, Bank,
* Sub-bank and Way.
*/
P2 = 2;
LSETUP (.Lfs1, .Lfe1) LC1 = P2;
.Lfs1: P0 = 64; /* iterate over all sets*/
LSETUP (.Lfs0, .Lfe0) LC0 = P0;
.Lfs0: R6 = R5 << 5; /* Combine set*/
R6.H = R3.H << 0 ; /* and sub-bank*/
R6 = R6 | R2; /* and Bank. Leave Way==0 at first.*/
BITSET(R6,14);
[P5] = R6; /* Issue Command*/
SSYNC;
R7 = [P4]; /* and read Tag.*/
CC = BITTST(R7, 0); /* Check if valid*/
IF !CC JUMP .Lfskip; /* and skip if not.*/
CC = BITTST(R7, 1); /* Check if dirty*/
IF !CC JUMP .Lfskip; /* and skip if not.*/
/* Compare against the page address. First, plant bits 13:12
* into the tag, since those aren't part of the returned data.
*/
R7 = DEPOSIT(R7, R3); /* set 13:12*/
R1 = R7 & R4; /* Mask off lower bits*/
CC = R1 == R0; /* Compare against page start.*/
IF !CC JUMP .Lfskip; /* Skip it if it doesn't match.*/
/* Tag address matches against page, so this is an entry
* we must flush.
*/
R7 >>= 10; /* Mask off the non-address bits*/
R7 <<= 10;
P3 = R7;
SSYNC;
FLUSHINV [P3]; /* And flush the entry*/
.Lfskip:
.Lfe0: R5 += 1; /* Advance to next Set*/
.Lfe1: BITSET(R2, 26); /* Go to next Way.*/
.Ldfinished:
SSYNC; /* Ensure the data gets out to mem.*/
/*Finished. Restore context.*/
LB1 = [SP++];
LT1 = [SP++];
LC1 = [SP++];
LB0 = [SP++];
LT0 = [SP++];
LC0 = [SP++];
( R7:0, P5:0 ) = [SP++];
RTS;
.Ldflush_whole_page:
/* It's a 1K or 4K page, so quicker to just flush the
* entire page.
*/
P1 = 32; /* For 1K pages*/
P2 = P1 << 2; /* For 4K pages*/
P0 = R0; /* Start of page*/
CC = BITTST(R1, 16); /* Whether 1K or 4K*/
IF CC P1 = P2;
P1 += -1; /* Unroll one iteration*/
SSYNC;
FLUSHINV [P0++]; /* because CSYNC can't end loops.*/
LSETUP (.Leall, .Leall) LC0 = P1;
.Leall: FLUSHINV [P0++];
SSYNC;
JUMP .Ldfinished;
ENDPROC(_dcplb_flush)
.align 4;
page_prefix_table:
.byte4 0xFFFFFC00; /* 1K */
.byte4 0xFFFFF000; /* 4K */
.byte4 0xFFF00000; /* 1M */
.byte4 0xFFC00000; /* 4M */
.page_prefix_table.end: