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authorBernd Schmidt <bernds_cb1@t-online.de>2009-01-07 23:14:38 +0800
committerBryan Wu <cooloney@kernel.org>2009-01-07 23:14:38 +0800
commitdbdf20db537a5369c65330f878ad4905020a8bfa (patch)
treec7fa553755e2d75a6e98d3f32fbe41fab9f72609 /arch/blackfin/kernel/cplb-mpu
parent6651ece9e257302ee695ee76e69a4427f7033235 (diff)
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>
Diffstat (limited to 'arch/blackfin/kernel/cplb-mpu')
-rw-r--r--arch/blackfin/kernel/cplb-mpu/Makefile5
-rw-r--r--arch/blackfin/kernel/cplb-mpu/cplbinit.c4
-rw-r--r--arch/blackfin/kernel/cplb-mpu/cplbmgr.c9
3 files changed, 16 insertions, 2 deletions
diff --git a/arch/blackfin/kernel/cplb-mpu/Makefile b/arch/blackfin/kernel/cplb-mpu/Makefile
index bd92301a704..7d70d3bf321 100644
--- a/arch/blackfin/kernel/cplb-mpu/Makefile
+++ b/arch/blackfin/kernel/cplb-mpu/Makefile
@@ -3,3 +3,8 @@
#
obj-y := cplbinit.o cacheinit.o cplbmgr.o
+
+CFLAGS_cplbmgr.o := -ffixed-I0 -ffixed-I1 -ffixed-I2 -ffixed-I3 \
+ -ffixed-L0 -ffixed-L1 -ffixed-L2 -ffixed-L3 \
+ -ffixed-M0 -ffixed-M1 -ffixed-M2 -ffixed-M3 \
+ -ffixed-B0 -ffixed-B1 -ffixed-B2 -ffixed-B3
diff --git a/arch/blackfin/kernel/cplb-mpu/cplbinit.c b/arch/blackfin/kernel/cplb-mpu/cplbinit.c
index 1ea7c18435a..bdb958486e7 100644
--- a/arch/blackfin/kernel/cplb-mpu/cplbinit.c
+++ b/arch/blackfin/kernel/cplb-mpu/cplbinit.c
@@ -107,3 +107,7 @@ void __init generate_cplb_tables_cpu(unsigned int cpu)
while (i_i < MAX_CPLBS)
icplb_tbl[cpu][i_i++].data = 0;
}
+
+void generate_cplb_tables_all(void)
+{
+}
diff --git a/arch/blackfin/kernel/cplb-mpu/cplbmgr.c b/arch/blackfin/kernel/cplb-mpu/cplbmgr.c
index 76bd99177de..5ef5d1a787f 100644
--- a/arch/blackfin/kernel/cplb-mpu/cplbmgr.c
+++ b/arch/blackfin/kernel/cplb-mpu/cplbmgr.c
@@ -25,8 +25,13 @@
#include <asm/cplbinit.h>
#include <asm/mmu_context.h>
-#define FAULT_RW (1 << 16)
-#define FAULT_USERSUPV (1 << 17)
+/*
+ * WARNING
+ *
+ * This file is compiled with certain -ffixed-reg options. We have to
+ * make sure not to call any functions here that could clobber these
+ * registers.
+ */
int page_mask_nelts;
int page_mask_order;