History log of /arch/microblaze/kernel/hw_exception_handler.S
Revision Date Author Comments
e02db0aa3e1976ae4e23a66077d252a2f3ba74c7 08-Feb-2010 Michal Simek <monstr@monstr.eu> microblaze: Handle TLB skip size dynamically

This patch fix the problem with rootfs on JFFS2 with early printk
console turned on.

The origin version used TLB63 for temporary early printk mapping.
The code expect that kernel is not able to use all 64 TLB entries
till early printk console is remapped by ioremap. After that
temporary mapping on TLB63 is silently lost.
This expectation give the opportunity to have early console pretty
early.

Microblaze systems with JFFS2 rootfs with early printk console turned on
used more than 64 TLB entries before kernel can remap early console.
Based on that kernel does access to bad area because early printk mapping
is rewritten.

This patch introduces tlb_skip variable which dynamically stores number
of skipped TLB entries from the TLB0. skip_tlb=2 means that TLB0 and TLB1
should be skipped.

MICROBLAZE_TLB_SKIP defines how many TLB is skipped at the kernel start.
They can be used for user purpose.

TLB 63 is used for temporary LMB mapping (MICROBLAZE_LMB_TLB_ID).

Also clean TLBLO when kernel starts.

For specific kernel sizes kernel can use just one TLB. Detect this case
and use the second TLB for general purpose.

Change _tlbia function to flush TLB entries from tlb_skip to TLB_SIZE.

Export tlb_skip size through debugfs.

Signed-off-by: Michal Simek <monstr@monstr.eu>
1451d1d88b9aa32ac9ee54180239e9b34b6f9e86 04-Apr-2011 Michal Simek <monstr@monstr.eu> microblaze: Introduce TLB skip size

TLB skip size direct how many TLBs is skipped.
Currently TLB0 and TLB1 are used for Linux kernel mapping
that's why their are skipped.

Signed-off-by: Michal Simek <monstr@monstr.eu>
c11389406f19e4bddc7b347e5259aebda02b23f1 20-May-2011 Michal Simek <monstr@monstr.eu> microblaze: Fix unaligned value saving to the stack for system with MMU

Several registers weren't saved correctly to the stack.

Unaligned expection for system with MMU stores
value in ex_tmp_data_loc_X address which is load to registers r3.
The next step is to move this value from r3 to a destination
register which caused unaligned exception. For several registers
this value was directly moved to the register.

For example for r28:
by "or r28, r0, r3"

but register r28 was rewritten when kernel returns from exception
handler by value saved on stack.

This patch changed r3 saving to the correct address on the stack.
For example for r28:
by "swi r3, r1, 4 * 28"

When kernel returns from the exception handler, correct value is restored.

Signed-off-by: Michal Simek <monstr@monstr.eu>
cd3415779bdb13e3daaf13965c89d286a0cf0480 01-Feb-2011 Michal Simek <monstr@monstr.eu> 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>
6e83557c38b40d6e9d1c82ad0ae59d8e5db9c50c 31-Jan-2011 Michal Simek <monstr@monstr.eu> 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>
c06b3a068223cb885d85ac4f6c31e870ca2b5aac 31-Jan-2011 Michal Simek <monstr@monstr.eu> microblaze: Do not use r0_ram space for hw exception debugging

Remove hw exception counting space from r0_ram. Use special
exception_debug_table poll for exception statistic.

Signed-off-by: Michal Simek <monstr@monstr.eu>
9c749e177ccc0b3ee9589425c7255079e7a726fc 28-Jan-2011 Michal Simek <monstr@monstr.eu> microblaze: Fix unaligned issue on MMU system with BS=0 DIV=1

Unaligned code use shift for finding register operand.
There is used BSRLI(r8,r8,2) macro which is expand for BS=0, DIV=1
by
ori rD, r0, (1 << imm); \
idivu rD, rD, rA

but if rD is equal rA then ori instruction rewrite value which
should be devide.

The patch remove this macro which use idivu instruction because
idivu takes 32/34 cycles. The highest shifting is 20 which takes
20 cycles.

Signed-off-by: Michal Simek <monstr@monstr.eu>
e3288f310111f7d18c323d95ae998765dee8c825 29-Dec-2010 Michal Simek <monstr@monstr.eu> microblaze: Fix unaligned exception for little endian platform

Half word unaligned accesses need to be fixed.

Signed-off-by: Michal Simek <monstr@monstr.eu>
ce3266c047389443d5f433d605c769e878cbe46e 27-Apr-2010 Steven J. Magnani <steve@digidescorp.com> 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>
3765d6958dfff34a15588e23c5d1274e1f6ba200 22-Mar-2010 Michal Simek <monstr@monstr.eu> microblaze: Use instruction with delay slot

Sync labels.

Signed-off-by: Michal Simek <monstr@monstr.eu>
bd1637d63e82aaf732ffbe907ba887fa12e82df4 19-Mar-2010 Michal Simek <monstr@monstr.eu> microblaze: Remove additional resr and rear loading

RESR and REAR uses the same regs in whole file.

Signed-off-by: Michal Simek <monstr@monstr.eu>
b175bcfe31cba846d8bfa35a3a4820667f7af383 19-Mar-2010 Michal Simek <monstr@monstr.eu> microblaze: Change register usage for ESR and EAR

This change synchronize register usage in code.
ESR = R4
EAR = R3

Signed-off-by: Michal Simek <monstr@monstr.eu>
7a6bbdc9304b45cc759e03623cbe63d81aff7337 22-Mar-2010 Michal Simek <monstr@monstr.eu> microblaze: Prepare work for optimization in exception code

Any sync branch must follow mts instructions not mfs.

Signed-off-by: Michal Simek <monstr@monstr.eu>
708e7153d6fc4d2e5fe15c6ccc5d2907fe8a9c8d 18-Mar-2010 Michal Simek <monstr@monstr.eu> microblaze: Add DEBUG option

Disable debug option in asm code.

Signed-off-by: Michal Simek <monstr@monstr.eu>
131e4e97bfee809dc64febe8accef2f042a92722 28-Sep-2009 Michal Simek <monstr@monstr.eu> 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>
71b23d547b5a06f49acacaf742ebf1a85673f8d1 14-Sep-2009 John Williams <john.williams@petalogix.com> microblaze: Clear sticky FSR register after generating exception signals

FSR is sticky, so after the userspace exception/signal generation, clear
it ready for next time.

Signed-off-by: John Williams <john.williams@petalogix.com>
ac854ff1fc779101ff1989c3a20c1f238a2b5f3a 17-Sep-2009 Michal Simek <monstr@monstr.eu> microblaze: Save and restore msr in hw exception

I thought that this part of code could be removed because just
save and restore MSR but any code can't change it. But seems to
that any part of code works with this information.

This patch solved problem with allocation.

Signed-off-by: Michal Simek <monstr@monstr.eu>
3863dbceac7e69642b95f43de1c12c6236fdbe5b 21-Jul-2009 Michal Simek <monstr@monstr.eu> microblaze: Support unaligned address for put/get_user macros

This patch add support for cases where load/store instruction
in put/get_user macro gets unaligned pointer to data and this
address is not valid. I prevent all cases which can failed.
I had to disable first stage of unaligned handler which is used
only for noMMU kernel and the whole work is done when interrupt
is enabled.
You have enable HW support for detect unaligned access in Microblaze.

This patch fixed three LTP tests:
getpeername01, getsockname01, socketpair01

Signed-off-by: Michal Simek <monstr@monstr.eu>
7db29dde731db02143418cfa008b7b77ccb2fa57 26-May-2009 Michal Simek <monstr@monstr.eu> microblaze_mmu_v2: Update exception handling - MMU exception

Signed-off-by: Michal Simek <monstr@monstr.eu>
c4df4bc155bbe18fb91800bb9d29499a4fb211ad 27-Mar-2009 Michal Simek <monstr@monstr.eu> microblaze_v8: exception handling

Reviewed-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Stephen Neuendorffer <stephen.neuendorffer@xilinx.com>
Acked-by: John Linn <john.linn@xilinx.com>
Acked-by: John Williams <john.williams@petalogix.com>
Signed-off-by: Michal Simek <monstr@monstr.eu>