Commit graph

53 commits

Author SHA1 Message Date
Michal Simek
7574349cee microblaze: Fix _reset function
If soft reset falls through with no hardware assisted reset, the best
we can do is jump to the reset vector and see what the bootloader left
for us.

Signed-off-by: Michal Simek <monstr@monstr.eu>
Signed-off-by: John Williams <john.williams@petalogix.com>
2011-03-15 10:58:44 +01:00
Michal Simek
626afa35c1 microblaze: Fix microblaze init vectors
Microblaze vector table stores several vectors (reset, user exception,
interrupt, debug exception and hardware exception).
All these functions can be below address 0x10000. If they are, wrong
vector table is genarated because jump is not setup from two instructions
(imm upper 16bit and brai lower 16bit).
Adding specific offset prevent problem if address is below 0x10000.
For this case only brai instruction is used.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2011-03-15 10:58:34 +01:00
Michal Simek
cd3415779b microblaze: Do not use "la" pseudo instruction - use addik instead
"la" pseudo instruction is only translation to "addik".
Use directly "addik" which is described in the MB reference guide.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2011-03-09 08:09:54 +01:00
Michal Simek
6e83557c38 microblaze: Remove r0_ram pointer and PTO alignment
r0_ram pool was used for saving/restoring register
content if hw exception happen. This poll was replaced by
pt_pool_space with PT_SIZE size.
Based on this change SAVE_STATE_ARG_SPACE was removed which
caused that PTO offset is zero that's why is also removed.

r0_ram space was used as scratchpad by v850. In early
Microblaze Linux developing phase was this part of code
blindly copied.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2011-03-09 08:09:54 +01:00
Michal Simek
d8748e73e8 microblaze: Do not use r0_ram space for syscall debugging
Remove syscall counting space from r0_ram. Use special
syscall_debug_table pool for syscall statistic.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2011-03-09 08:09:54 +01:00
Michal Simek
9da6345885 Revert "microblaze: Simplify syscall rutine"
This reverts commit 0e41c90908.

Break jffs2 rootfs because the patch removes syscall calling
from kernel space.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-11-18 13:13:52 +01:00
Michal Simek
600eb6110a microblaze: Fix r16 and r17 reg saving
r16 and r17 should be saved across interrupt and exception handling.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-10-21 15:51:33 +10:00
Michal Simek
7d4320956f microblaze: Clear return value in pt_regs
Signal code uses r3 value which saved in restore_sigcontext to
rt_sigframe but it require to be zeroed. If is not zero rt_sigframe
contains wrong values.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-10-21 15:51:29 +10:00
Michal Simek
791d0a169b microblaze: Fix sys_rt_sigreturn_wrapper
Do not save return registers before rt_sigreturn is called.
_user_exception(syscall handler) already setup return address
that's why it is removed from rt_sigreturn_wrapper.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-10-21 15:51:27 +10:00
Michal Simek
2d5973cb5a microblaze: Add KGDB support
Kgdb uses brki r16, 0x18 instruction to call
low level _debug_exception function which save
current state to pt_regs and call microblaze_kgdb_break
function. _debug_exception should be called only from
the kernel space. User space calling is not supported
because user application debugging uses different handling.

pt_regs_to_gdb_regs loads additional special registers
which can't be changed

 * Enable KGDB in Kconfig
 * Remove ancient not-tested KGDB support
 * Remove ancient _debug_exception code from entry.S

Only MMU KGDB support is supported.

Signed-off-by: Michal Simek <monstr@monstr.eu>
CC: Jason Wessel <jason.wessel@windriver.com>
CC: John Williams <john.williams@petalogix.com>
CC: Edgar E. Iglesias <edgar.iglesias@petalogix.com>
CC: linux-kernel@vger.kernel.org
Acked-by: Jason Wessel <jason.wessel@windriver.com>
2010-08-04 10:45:17 +02:00
Michal Simek
751f1605e0 microblaze: Support brki rX, 0x18 for user application debugging
This is the first patch which add support for
user application debugging through brki rX, 0x18 vector.

This patch has side effect which also remove security issue
to use brki rX, 0x18 to freeze kernel.

Support for old gdb support via priviledged exception
(brk r0, r0) is still there. It will be remove in future.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-08-04 10:45:16 +02:00
Michal Simek
958063e67b microblaze: Remove nop after MSRCLR/SET, MTS, MFS instructions
We need to save instruction and the latest Microblaze shouldn't
have any problem with it.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-08-04 10:45:16 +02:00
Michal Simek
0e41c90908 microblaze: Simplify syscall rutine
Syscall can be called only from userspace that's why
we don't need to check which space kernel come from.

Kernel syscall calling is not check and shouldn't come
throught this part of code.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-08-04 10:45:15 +02:00
Michal Simek
0a6b08fda6 microblaze: Move PT_MODE saving to delay slot
We can save one more instruction if PT_MODE is saved in delay slot

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-08-04 10:45:14 +02:00
Michal Simek
80c5ff6b9b microblaze: Fix _interrupt function
Save instructions by using delay slot and
clear UMS only if kernel comes from user space.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-08-04 10:45:13 +02:00
Michal Simek
25f6e59657 microblaze: Fix _user_exception function
Saving some instructions. Clear VMS bit if kernel comes
from kernel space.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-08-04 10:45:12 +02:00
Michal Simek
287503fabd microblaze: Put together addik instructions
Saving instructions by adding 2/3 addik instructions to one.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-08-04 10:44:56 +02:00
Michal Simek
9814cc11e5 microblaze: Use delay slot in syscall macros
Saving instruction with delay slot usage.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-08-04 10:32:22 +02:00
Michal Simek
da23355280 microblaze: Save kernel mode in delay slot
This change save one instruction if kernel comes from kernel
space.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-08-04 10:32:21 +02:00
Michal Simek
e7741075b3 microblaze: Do not mix register saving and mode setting
Separate reg saving and mode setting.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-08-04 10:32:20 +02:00
Michal Simek
e5d2af2b96 microblaze: Move SAVE_STATE upward
SAVE_STATE macro could be used by other rutines too.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-08-04 10:31:09 +02:00
Michal Simek
66f7de8634 microblaze: entry.S: Macro optimization
We are not working with values from MSR that's why
we can discard it and use r11 for different purpose without
saving/restoring.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-08-04 10:30:07 +02:00
Michal Simek
c318d483b3 microblaze: Optimize hw exception rutine
Remove set_vms because UMS is cleared and VMS is already setup.
Optimize function calling which save one additional instruction.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-08-04 10:30:06 +02:00
Michal Simek
b318067e2c microblaze: Implement clear_ums macro and fix SAVE_STATE macro
VMS is always setup because VM mode was before
exception/syscall/interrupt. Kernel continues in kernel mode
that's why we have to clear UMS bit if kernel comes from
user space.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-08-04 10:29:44 +02:00
Michal Simek
77f6d22605 microblaze: Remove additional setup for kernel_mode
PT_MODE stores information if kernel comes from user
or kernel space. If come from user space, PT_MODE
contains 0. If come from kernel store, PT_MODE contains
non zero value. We don't need to save value 1. I am using
r1 register which contains non zero value.
This change save one additional instruction.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-08-04 10:22:53 +02:00
Michal Simek
06a54604a3 microblaze: Optimize SAVE_STATE macro
SAVE_STATE macro could be used for user_exception
or interrupt functions.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-08-04 10:22:52 +02:00
Michal Simek
40eb0dc456 microblaze: Remove additional loading
We don't need to save r0 to PT_R0. It could be additional
operation.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-08-04 10:22:51 +02:00
Michal Simek
653e447e11 microblaze: Completely remove working with R11 register
We don't need to save R11 register. There is easy way
to use only R1 which is saved and restore later.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-08-04 10:22:50 +02:00
Michal Simek
0388107dd5 microblaze: Do not setup BIP in _debug_exception
BIP is already setup.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-08-04 10:22:50 +02:00
Michal Simek
06b2864038 microblaze: Simplify _debug_exception function
Keep together all arguments for send_sig function.
Move returning address to delay slot which is executed.
Remove additional send_sig loading. I am using IMM part of
rtbd instruction with r0.

old solution:
addik r11, r0, send_sig
rtbd r11, 0
nop

new solution:
rtbd r0, send_sig
nop

There is one instruction saving.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-08-04 10:22:48 +02:00
Michal Simek
8b110d157c microblaze: Optimize SAVE_STATE macro
It is necessary to setup BIP and EE and clear EIP
only for unaligned exception handler. The rest of
hw exception handlers don't require it.
HW exception occured and we are not in virtual mode.
That's why we can do operations protected by EIP.
Interrupt, next hw exception or syscall can't occur.

EIP is cleared by rted.

This change speedup page_fault hw exception handler
which is critical path.

There is also necessary to save R11 content before
flag setup for unaligned exception.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-08-04 10:22:48 +02:00
Michal Simek
b9ea77e2d3 microblaze: trivial: Use la insted of addik
la is translated to addik by toolchain.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-08-04 10:22:47 +02:00
Michal Simek
be304350dd microblaze: remove enable_irq from SAVE_STATE macro
SAVE_STATE macro is used in hw exceptions high level handling
functions. Hw exception doesn't disable IRQ that's why we don't
need to reenable it.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-08-04 10:22:46 +02:00
Michal Simek
63708f635c microblaze: Move stack backup to SAVE_STATE macro
Remove code duplicity and move it to SAVE_STATE macro.
There is no impact on performance.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-08-04 10:22:45 +02:00
Michal Simek
96014cc39b microblaze: Move BIP setup to the end of ret_from_trap/ret_from_exc
We don't need to protect by BIP whole ret_from_trap/ret_from_exc code.
Only restoring from user/hw exception should be covered.
If BIP is setup, IRQ can't occur.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-08-04 10:22:45 +02:00
Michal Simek
5c0d72b1b3 microblaze: Remove PER_CPU(KM) variable
There is a way howto remove Kernel Mode variable. It is easier
to parse UMS bit in MSR to find out if I come from kernel or user
space. Loading MSR content should be in one cycle and loading
PER_CPU variable depends on memory state.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-08-04 10:22:44 +02:00
Michal Simek
3fbd93e58e microblaze: Optimize clear_vms_ums macro
We can save two instruction when MSR_VMS and MSR_UMS
are setup in one instruction.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-08-04 10:22:43 +02:00
Michal Simek
36f6095419 microblaze: Save and restore r3/r4 in SAVE/RESTORE_REGS macros
Save and restore R3/R4 registers in macros. This change
help to cleanup entry.S.

In ret_from_trap function we are saving returning value from
syscall to pt_regs on stack that's why we don't need to save and
restore these values before kernel functions (schedule, do_signal).

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-08-04 10:22:42 +02:00
Michal Simek
a4a94dbf20 microblaze: Fix VM_ON and VM_OFF macros
Jump behind macro. We don't want to execute nop instruction again.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-08-04 10:22:42 +02:00
Steven J. Magnani
ce3266c047 microblaze: Add stack unwinder
Implement intelligent backtracing by searching for stack frame creation,
and emitting only return addresses. Use print_hex_dump() to display the
entire binary kernel stack.

Limitation: MMU kernels are not currently able to trace beyond a system trap
(interrupt, syscall, etc.). It is the intent of this patch to provide
infrastructure that can be extended to add this capability later.

Changes from V1:
* Removed checks in find_frame_creation() that prevented location of the frame
  creation instruction in heavily optimized code
* Various formatting/commenting/file location tweaks per review comments
* Dropped Kconfig option to enable STACKTRACE as something logically separate

Signed-off-by: Steven J. Magnani <steve@digidescorp.com>
2010-08-04 10:22:35 +02:00
Michal Simek
570e3e236e microblaze: Fix sys_clone syscall
sys_clone syscall ignored args which this patch mapped to args
which are passing from glibc.

Here is the origin problem description.

"I ran the static libgcc tests (very few of them are there, they are
mostly dynamically linked) and some of  them fail with an assertion in
fork() system call (tid != pid), I looked at the microblaze/entry.S
file and it looks suspicious (ignores arguments 3-5)"

Arg mapping should be:
glibc ARCH_FORK(...) -> do_fork(...)
r5 -> r5   (clone_flags)
r6  -> r6 (stack_start, use parent->stack if NULL)
pt_regs -> r7 (pt_regs)
r7 -> r8 (stack_size)
r8 -> r9 (parent_tidptr)
r9 -> r10 (child_tidptr)

Signed-off-by: John Williams <john.williams@petalogix.com>
Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-08-04 10:22:32 +02:00
Michal Simek
841d6e8c4e microblaze: entry.S use delay slot for return handlers
Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-03-11 14:26:13 +01:00
Michal Simek
8633bebc63 microblaze: Save current task directly
Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-03-11 14:25:54 +01:00
Michal Simek
b1d70c62ff microblaze: Simplify entry.S - save/restore r3/r4 - ret_from_trap
There is possible to save r3/r4 at the beggining of user part
before calling handlers and at the end restore it.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-03-11 14:25:30 +01:00
Michal Simek
7775379057 microblaze: Add support from PREEMPT
This patch add core PREEMPT support for Microblaze.
I tried to trace it via tracers and I was able to see any output.

I also added low level debug functions to see if that code is called.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-03-11 14:07:32 +01:00
Michal Simek
571202f50f microblaze: Remove rt_sigsuspend wrapper
Generic rt_sigsuspend syscalls doesn't need any asm wrapper.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2009-12-14 08:45:12 +01:00
Michal Simek
11d5136043 microblaze: Do not count system calls in default
There is not necessary to count system calls that's why
I added DEBUG macro

Signed-off-by: Michal Simek <monstr@monstr.eu>
2009-12-14 08:45:08 +01:00
Michal Simek
f7816e284b microblaze: Remove saving and restoring before calling signal code
Saving is done in SAVE_STATE macros that's why another save discard
previous saved value.

This change has no effect to normal programs because they ends in any exception
and they are killed. On the other side has effect on debugging.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2009-12-14 08:44:55 +01:00
Michal Simek
131e4e97bf microblaze: Clear sticky FSR register after saving it to func parametr
Previous patch d63678d607d0e37ec7abe5ceb545d7e8aab956a4 clear
it for noMMU kernel. This one do it for MMU.

Correct noMMU version

Signed-off-by: Michal Simek <monstr@monstr.eu>
2009-10-05 11:37:47 +02:00
Michal Simek
235754834b microblaze: Support ptrace syscall tracing.
Signed-off-by: Edgar E. Iglesias <edgar.iglesias@gmail.com>
Signed-off-by: Michal Simek <monstr@monstr.eu>
2009-09-22 10:00:45 +02:00