Blackfin arch: Faster C implementation of no-MPU CPLB handler

This is a mixture ofcMichael McTernan's patch and the existing cplb-mpu code.

We ditch the old cplb-nompu implementation, which is a good example of
why a good algorithm in a HLL is preferrable to a bad algorithm written in
assembly.  Rather than try to construct a table of all posible CPLBs and
search it, we just create a (smaller) table of memory regions and
their attributes.  Some of the data structures are now unified for both
the mpu and nompu cases.  A lot of needless complexity in cplbinit.c is
removed.

Further optimizations:
  * compile cplbmgr.c with a lot of -ffixed-reg options, and omit saving
    these registers on the stack when entering a CPLB exception.
  * lose cli/nop/nop/sti sequences for some workarounds - these don't
  * make
    sense in an exception context

Additional code unification should be possible after this.

[Mike Frysinger <vapier.adi@gmail.com>:
 - convert CPP if statements to C if statements
 - remove redundant statements
 - use a do...while loop rather than a for loop to get slightly better
   optimization and to avoid gcc "may be used uninitialized" warnings ...
   we know that the [id]cplb_nr_bounds variables will never be 0, so this
   is OK
 - the no-mpu code was the last user of MAX_MEM_SIZE and with that rewritten,
   we can punt it
 - add some BUG_ON() checks to make sure we dont overflow the small
   cplb_bounds array
 - add i/d cplb entries for the bootrom because there is functions/data in
   there we want to access
 - we do not need a NULL trailing entry as any time we access the bounds
   arrays, we use the nr_bounds variable
]

Signed-off-by: Michael McTernan <mmcternan@airvana.com>
Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Bernd Schmidt <bernds_cb1@t-online.de>
Signed-off-by: Bryan Wu <cooloney@kernel.org>

1 files changed, 0 insertions, 130 deletions

diff --git a/arch/blackfin/kernel/cplb-nompu/cplbhdlr.S b/arch/blackfin/kernel/cplb-nompu/cplbhdlr.S
deleted file mode 100644
index ecbabc0a1fed..000000000000
--- a/arch/blackfin/kernel/cplb-nompu/cplbhdlr.S
+++ /dev/null
@@ -1,130 +0,0 @@
-/*
- * File:         arch/blackfin/mach-common/cplbhdlr.S
- * Based on:
- * Author:       LG Soft India
- *
- * Created:      ?
- * Description:  CPLB exception handler
- *
- * 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
- */
-
-#include <linux/linkage.h>
-#include <asm/cplb.h>
-#include <asm/entry.h>
-
-#ifdef CONFIG_EXCPT_IRQ_SYSC_L1
-.section .l1.text
-#else
-.text
-#endif
-
-.type _cplb_mgr, STT_FUNC;
-.type _panic_cplb_error, STT_FUNC;
-
-.align 2
-
-ENTRY(__cplb_hdr)
-	R2 = SEQSTAT;
-
-	/* Mask the contents of SEQSTAT and leave only EXCAUSE in R2 */
-	R2 <<= 26;
-	R2 >>= 26;
-
-	R1 = 0x23; /* Data access CPLB protection violation */
-	CC = R2 == R1;
-	IF !CC JUMP .Lnot_data_write;
-	R0 = 2;		/* is a write to data space*/
-	JUMP .Lis_icplb_miss;
-
-.Lnot_data_write:
-	R1 = 0x2C; /* CPLB miss on an instruction fetch */
-	CC = R2 == R1;
-	R0 = 0;		/* is_data_miss == False*/
-	IF CC JUMP .Lis_icplb_miss;
-
-	R1 = 0x26;
-	CC = R2 == R1;
-	IF !CC JUMP .Lunknown;
-
-	R0 = 1;		/* is_data_miss == True*/
-
-.Lis_icplb_miss:
-
-#if defined(CONFIG_BFIN_ICACHE) || defined(CONFIG_BFIN_DCACHE)
-# if defined(CONFIG_BFIN_ICACHE) && !defined(CONFIG_BFIN_DCACHE)
-	R1 = CPLB_ENABLE_ICACHE;
-# endif
-# if !defined(CONFIG_BFIN_ICACHE) && defined(CONFIG_BFIN_DCACHE)
-	R1 = CPLB_ENABLE_DCACHE;
-# endif
-# if defined(CONFIG_BFIN_ICACHE) && defined(CONFIG_BFIN_DCACHE)
-	R1 = CPLB_ENABLE_DCACHE | CPLB_ENABLE_ICACHE;
-# endif
-#else
-	R1 = 0;
-#endif
-
-	[--SP] = RETS;
-	CALL _cplb_mgr;
-	RETS = [SP++];
-	CC = R0 == 0;
-	IF !CC JUMP .Lnot_replaced;
-	RTS;
-
-/*
- * Diagnostic exception handlers
- */
-.Lunknown:
-	R0 = CPLB_UNKNOWN_ERR;
-	JUMP .Lcplb_error;
-
-.Lnot_replaced:
-	CC = R0 == CPLB_NO_UNLOCKED;
-	IF !CC JUMP .Lnext_check;
-	R0 = CPLB_NO_UNLOCKED;
-	JUMP .Lcplb_error;
-
-.Lnext_check:
-	CC = R0 == CPLB_NO_ADDR_MATCH;
-	IF !CC JUMP .Lnext_check2;
-	R0 = CPLB_NO_ADDR_MATCH;
-	JUMP .Lcplb_error;
-
-.Lnext_check2:
-	CC = R0 == CPLB_PROT_VIOL;
-	IF !CC JUMP .Lstrange_return_from_cplb_mgr;
-	R0 = CPLB_PROT_VIOL;
-	JUMP .Lcplb_error;
-
-.Lstrange_return_from_cplb_mgr:
-	IDLE;
-	CSYNC;
-	JUMP .Lstrange_return_from_cplb_mgr;
-
-.Lcplb_error:
-	R1 = sp;
-	SP += -12;
-	call _panic_cplb_error;
-	SP += 12;
-	JUMP.L _handle_bad_cplb;
-
-ENDPROC(__cplb_hdr)