linux-stable.git/arch/arc/kernel, branch v6.6.26 Linux kernel stable tree ARC: fix smatch warning 2024-01-20T10:51:44+00:00 Vineet Gupta vgupta@kernel.org 2023-12-09T00:25:23+00:00 544ce65cb52a668c442e4756711909a2a878054f [ Upstream commit 4eb69d00fe967699b9d93f7e74a990fe813e8d2b ] Reported-by: kernel test robot <lkp@intel.com> Reported-by: Dan Carpenter <error27@gmail.com> Closes: https://lore.kernel.org/r/202311280906.VAIwEAfT-lkp@intel.com/ Signed-off-by: Vineet Gupta <vgupta@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 4eb69d00fe967699b9d93f7e74a990fe813e8d2b ]

Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <error27@gmail.com>
Closes: https://lore.kernel.org/r/202311280906.VAIwEAfT-lkp@intel.com/
Signed-off-by: Vineet Gupta <vgupta@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
ARC: fix spare error 2024-01-20T10:51:44+00:00 Vineet Gupta vgupta@kernel.org 2023-12-08T23:57:07+00:00 358bca0bb1b4a3f479cba48ee8454dc0d6344ef3 [ Upstream commit aca02d933f63ba8bc84258bf35f9ffaf6b664336 ] Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202312082320.VDN5A9hb-lkp@intel.com/ Signed-off-by: Vineet Gupta <vgupta@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit aca02d933f63ba8bc84258bf35f9ffaf6b664336 ]

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202312082320.VDN5A9hb-lkp@intel.com/
Signed-off-by: Vineet Gupta <vgupta@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
ARC: boot log: fix warning 2023-08-24T05:36:19+00:00 Vineet Gupta vgupta@kernel.org 2023-08-23T23:02:33+00:00 c40cad3b0aa47d6d0995637178fb6607ac3d45c1 Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202308221549.XKufWEWp-lkp@intel.com/ Signed-off-by: Vineet Gupta <vgupta@kernel.org> 
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202308221549.XKufWEWp-lkp@intel.com/
Signed-off-by: Vineet Gupta <vgupta@kernel.org>
ARC: pt_regs: create seperate type for ecr 2023-08-18T17:30:47+00:00 Vineet Gupta vgupta@kernel.org 2020-05-22T00:44:32+00:00 58d9ceb7d9f56bd74b8e904e26511d27a4220827 Reduces duplication in each ISA specific pt_regs Tested-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202308151342.ROQ9Urvv-lkp@intel.com Signed-off-by: Vineet Gupta <vgupta@kernel.org> 
Reduces duplication in each ISA specific pt_regs

Tested-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202308151342.ROQ9Urvv-lkp@intel.com
Signed-off-by: Vineet Gupta <vgupta@kernel.org>
ARCv2: entry: rearrange pt_regs slightly 2023-08-18T17:30:47+00:00 Vineet Gupta vgupta@kernel.org 2020-05-22T23:24:53+00:00 d4624bf6a6c9d9ff084eb2cba6d3cf6aeda9f974 Instead of r26,fp,sp,r12,r30 order as fp,r30,r12,r26,sp - keeps SP at well known position (right abive hardware autosave) - r26,r12 saved specifically for ARCv2 (and not in ARCv3) kept closer for easy ifdef'ry later Signed-off-by: Vineet Gupta <vgupta@kernel.org> 
Instead of r26,fp,sp,r12,r30 order as fp,r30,r12,r26,sp

 - keeps SP at well known position (right abive hardware autosave)
 - r26,r12 saved specifically for ARCv2 (and not in ARCv3) kept
   closer for easy ifdef'ry later

Signed-off-by: Vineet Gupta <vgupta@kernel.org>
ARC: entry: Add more common chores to EXCEPTION_PROLOGUE 2023-08-18T17:30:07+00:00 Vineet Gupta vgupta@kernel.org 2020-05-20T07:39:09+00:00 13347c10396055c4c6c38a54d10bc6ed5024fbe9 THe high level structure of most ARC exception handlers is 1. save regfile with EXCEPTION_PROLOGUE 2. setup r0: EFA (not part of pt_regs) 3. setup r1: pointer to pt_regs (SP) 4. drop down to pure kernel mode (from exception) 5. call the Linux "C" handler Remove the boiler plate code by moving #2, #3, #4 into #1. The exceptions to most exceptions are syscall Trap and Machine check which don't do some of above for various reasons, so call a newly introduced variant EXCEPTION_PROLOGUE_KEEP_AE (same as original EXCEPTION_PROLOGUE) Tested-by: Pavel Kozlov <Pavel.Kozlov@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@kernel.org> 
THe high level structure of most ARC exception handlers is
 1. save regfile with EXCEPTION_PROLOGUE
 2. setup r0: EFA (not part of pt_regs)
 3. setup r1: pointer to pt_regs (SP)
 4. drop down to pure kernel mode (from exception)
 5. call the Linux "C" handler

Remove the boiler plate code by moving #2, #3, #4 into #1.

The exceptions to most exceptions are syscall Trap and Machine check
which don't do some of above for various reasons, so call a newly
introduced variant EXCEPTION_PROLOGUE_KEEP_AE (same as original
EXCEPTION_PROLOGUE)

Tested-by: Pavel Kozlov <Pavel.Kozlov@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@kernel.org>
ARC: entry: EV_MachineCheck dont re-read ECR 2023-08-18T03:31:59+00:00 Vineet Gupta vgupta@kernel.org 2020-05-20T07:52:45+00:00 0e93ecaeebd5d0f189d1fa50a614ac0816a8c703 Signed-off-by: Vineet Gupta <vgupta@kernel.org> 
Signed-off-by: Vineet Gupta <vgupta@kernel.org>
ARC: entry: ARcompact EV_ProtV to use r10 directly 2023-08-18T03:31:59+00:00 Vineet Gupta vgupta@kernel.org 2020-05-20T07:47:20+00:00 6b606c8d6625aeda0b526cb687367f72bb98cd30 Signed-off-by: Vineet Gupta <vgupta@kernel.org> 
Signed-off-by: Vineet Gupta <vgupta@kernel.org>
ARC: entry: rework (non-functional) 2023-08-18T03:31:59+00:00 Vineet Gupta vgupta@kernel.org 2020-05-19T23:01:52+00:00 c505b0da76a67139e073a5a5c4a1986b1cf168d3 - comments update - rename syscall_trace_entry - use PT_xxx in entry code Signed-off-by: Vineet Gupta <vgupta@kernel.org> 
 - comments update
 - rename syscall_trace_entry
 - use PT_xxx in entry code

Signed-off-by: Vineet Gupta <vgupta@kernel.org>
ARC: __switch_to: move ksp to thread_info from thread_struct 2023-08-18T03:31:59+00:00 Vineet Gupta vgupta@kernel.org 2020-05-14T07:51:26+00:00 fd476197c63dd3aae85e286dab7da23b159562b9 task's arch specific bits are carried in 2 places - embedded thread_struct in task_struct - associated thread_info (hoisted in task's stack page) and syntactically: (thread_info *)(task_struct->stack) ksp (dynamic kernel stack top) currently lives in thread_struct but given its deep location in task struct likely to cache miss when accessed from __switch_to(). Moving it to thread_info would be more efficient given proximity to frequently accessed items such as preempt_count thus very likely to be in cache, specially in schedular code. Note however that currently tsk.thread.ksp takes 1 memory access (off of tsk pointer) while new code tsk->stack.ksp would take 2, but likely to be in cache. Moreover if task is current the 2nd reference can be elided and instead derived from SP as (SP & ~(THREAD_SIZE - 1)) All of this also makes __switch_to() code simpler and we can see the 2 ways of retirving ksp (descrobed above) in new code. Signed-off-by: Vineet Gupta <vgupta@kernel.org> 
task's arch specific bits are carried in 2 places
 - embedded thread_struct in task_struct
 - associated thread_info (hoisted in task's stack page) and
   syntactically: (thread_info *)(task_struct->stack)

ksp (dynamic kernel stack top) currently lives in thread_struct but
given its deep location in task struct likely to cache miss when
accessed from  __switch_to(). Moving it to thread_info would be more
efficient given proximity to frequently accessed items such as
preempt_count thus very likely to be in cache, specially in schedular
code.

Note however that currently tsk.thread.ksp takes 1 memory access (off
of tsk pointer) while new code tsk->stack.ksp would take 2, but likely
to be in cache. Moreover if task is current the 2nd reference can be
elided and instead derived from SP as (SP & ~(THREAD_SIZE - 1))

All of this also makes __switch_to() code simpler and we can see the 2
ways of retirving ksp (descrobed above) in new code.

Signed-off-by: Vineet Gupta <vgupta@kernel.org>