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/entry.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'arch/blackfin/include/asm/entry.h') diff --git a/arch/blackfin/include/asm/entry.h b/arch/blackfin/include/asm/entry.h index c4f721e..d94e4f5 100644 --- a/arch/blackfin/include/asm/entry.h +++ b/arch/blackfin/include/asm/entry.h @@ -53,9 +53,11 @@ /* This one pushes RETI without using CLI. Interrupts are enabled. */ #define SAVE_CONTEXT_SYSCALL save_context_syscall #define SAVE_CONTEXT save_context_with_interrupts +#define SAVE_CONTEXT_CPLB save_context_cplb #define RESTORE_ALL_SYS restore_context_no_interrupts #define RESTORE_CONTEXT restore_context_with_interrupts +#define RESTORE_CONTEXT_CPLB restore_context_cplb #endif /* __ASSEMBLY__ */ #endif /* __BFIN_ENTRY_H */ -- cgit v1.1