From dbdf20db537a5369c65330f878ad4905020a8bfa Mon Sep 17 00:00:00 2001 From: Bernd Schmidt Date: Wed, 7 Jan 2009 23:14:38 +0800 Subject: 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 : - 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 Signed-off-by: Mike Frysinger Signed-off-by: Bernd Schmidt Signed-off-by: Bryan Wu --- arch/blackfin/include/asm/context.S | 39 +++++++++++++++++++++++++++++++++++++ 1 file changed, 39 insertions(+) (limited to 'arch/blackfin/include/asm/context.S') diff --git a/arch/blackfin/include/asm/context.S b/arch/blackfin/include/asm/context.S index 9ce21f68e914..16561ab18b38 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 -- cgit v1.2.3