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>
diff --git a/arch/blackfin/include/asm/context.S b/arch/blackfin/include/asm/context.S
index 9ce21f6..16561ab 100644
--- a/arch/blackfin/include/asm/context.S
+++ b/arch/blackfin/include/asm/context.S
@@ -357,3 +357,42 @@
SYSCFG = [sp++];
csync;
.endm
+
+.macro save_context_cplb
+ [--sp] = (R7:0, P5:0);
+ [--sp] = fp;
+
+ [--sp] = a0.x;
+ [--sp] = a0.w;
+ [--sp] = a1.x;
+ [--sp] = a1.w;
+
+ [--sp] = LC0;
+ [--sp] = LC1;
+ [--sp] = LT0;
+ [--sp] = LT1;
+ [--sp] = LB0;
+ [--sp] = LB1;
+
+ [--sp] = RETS;
+.endm
+
+.macro restore_context_cplb
+ RETS = [sp++];
+
+ LB1 = [sp++];
+ LB0 = [sp++];
+ LT1 = [sp++];
+ LT0 = [sp++];
+ LC1 = [sp++];
+ LC0 = [sp++];
+
+ a1.w = [sp++];
+ a1.x = [sp++];
+ a0.w = [sp++];
+ a0.x = [sp++];
+
+ fp = [sp++];
+
+ (R7:0, P5:0) = [SP++];
+.endm