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author | Bernd Schmidt <bernds_cb1@t-online.de> | 2009-01-07 16:14:38 +0100 |
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committer | Bryan Wu <cooloney@kernel.org> | 2009-01-07 16:14:38 +0100 |
commit | dbdf20db537a5369c65330f878ad4905020a8bfa (patch) | |
tree | c7fa553755e2d75a6e98d3f32fbe41fab9f72609 /arch/blackfin/mach-common/entry.S | |
parent | Blackfin arch: update anomaly headers to match latest sheets (diff) | |
download | linux-dbdf20db537a5369c65330f878ad4905020a8bfa.tar.xz linux-dbdf20db537a5369c65330f878ad4905020a8bfa.zip |
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/mach-common/entry.S')
-rw-r--r-- | arch/blackfin/mach-common/entry.S | 21 |
1 files changed, 9 insertions, 12 deletions
diff --git a/arch/blackfin/mach-common/entry.S b/arch/blackfin/mach-common/entry.S index 0efd5f5b7ba0..fae774651374 100644 --- a/arch/blackfin/mach-common/entry.S +++ b/arch/blackfin/mach-common/entry.S @@ -112,24 +112,21 @@ ENTRY(_ex_dcplb_viol) ENTRY(_ex_dcplb_miss) ENTRY(_ex_icplb_miss) (R7:6,P5:4) = [sp++]; - ASTAT = [sp++]; - SAVE_ALL_SYS -#ifdef CONFIG_MPU + /* We leave the previously pushed ASTAT on the stack. */ + SAVE_CONTEXT_CPLB + /* We must load R1 here, _before_ DEBUG_HWTRACE_SAVE, since that * will change the stack pointer. */ R0 = SEQSTAT; R1 = SP; -#endif + DEBUG_HWTRACE_SAVE(p5, r7) -#ifdef CONFIG_MPU + sp += -12; call _cplb_hdr; sp += 12; CC = R0 == 0; IF !CC JUMP _handle_bad_cplb; -#else - call __cplb_hdr; -#endif #ifdef CONFIG_DEBUG_DOUBLEFAULT /* While we were processing this, did we double fault? */ @@ -143,7 +140,8 @@ ENTRY(_ex_icplb_miss) #endif DEBUG_HWTRACE_RESTORE(p5, r7) - RESTORE_ALL_SYS + RESTORE_CONTEXT_CPLB + ASTAT = [SP++]; SP = EX_SCRATCH_REG; rtx; ENDPROC(_ex_icplb_miss) @@ -298,9 +296,8 @@ ENTRY(_handle_bad_cplb) * the stack to get ready so, we can fall through - we * need to make a CPLB exception look like a normal exception */ - - RESTORE_ALL_SYS - [--sp] = ASTAT; + RESTORE_CONTEXT_CPLB + /* ASTAT is still on the stack, where it is needed. */ [--sp] = (R7:6,P5:4); ENTRY(_ex_replaceable) |