Commit graph

62 commits

Author SHA1 Message Date
Wayne Ren
84cdfa271d arch : arc: clean up of assembly codes
* update comments to match latest codes
* add extra comments for some assembly, macros
* use macro to replace duplcated codes
* remove unused codes, lables, symobols

Signed-off-by: Wayne Ren <wei.ren@synopsys.com>
2020-03-12 13:02:17 -04:00
Wayne Ren
3f88ddd549 arch: arc: overhaul the thread switch code in epilogue of irq and exception
overhaul the thread switch code in epilogue of irq and
exception handling:
* add z_arch_get_next_switch_handle to call z_get_next_switch_handle,
  let the scheduler to decide the switch thread. This will also cover
  the case of SMP.

* put lots of common codes in macros for thread switch to improve
  the maintainablity, readability.

* clean up of some lables to make codes easier to understand

Signed-off-by: Wayne Ren <wei.ren@synopsys.com>
2020-03-12 13:02:17 -04:00
Wayne Ren
0d7769f3b8 arch: arc: fix the bug that idle thread blocks other threads
* for COOP_SCHED case, i.e., PREEMPT_ENABLED is not enabled, the
  idle thread will block other threads which is not correct.

* remove the check of PREEMPT_ENABLED in the epilogue of irq and
  exception handling. Let the scheduler (should_preempt()) decide
  whether the thread should be preempted.

Signed-off-by: Wayne Ren <wei.ren@synopsys.com>
2020-02-13 09:39:25 -08:00
Wayne Ren
05a669c568 arch: arc: fix the bug where regular irq comes out in user mode
if USERSPACE is configured, it needs to record the user/kernel mode
of interrupted thread, because the switch of aux_sec_k_sp/aux_user_sp
depends on the aux_irq_act's U bit.

Signed-off-by: Wayne Ren <wei.ren@synopsys.com>
2020-02-05 08:49:10 -08:00
Andrew Boie
4f77c2ad53 kernel: rename z_arch_ to arch_
Promote the private z_arch_* namespace, which specifies
the interface between the core kernel and the
architecture code, to a new top-level namespace named
arch_*.

This allows our documentation generation to create
online documentation for this set of interfaces,
and this set of interfaces is worth treating in a
more formal way anyway.

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
2019-11-07 15:21:46 -08:00
Andrew Boie
3f1cf02e05 arc: rename some arc-specific functions
These are not part of the generic kernel to
architecture interface, rename appropriately to
reflect they are ARC-specific.

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
2019-11-07 15:21:46 -08:00
Stephanos Ioannidis
2d7460482d headers: Refactor kernel and arch headers.
This commit refactors kernel and arch headers to establish a boundary
between private and public interface headers.

The refactoring strategy used in this commit is detailed in the issue

This commit introduces the following major changes:

1. Establish a clear boundary between private and public headers by
  removing "kernel/include" and "arch/*/include" from the global
  include paths. Ideally, only kernel/ and arch/*/ source files should
  reference the headers in these directories. If these headers must be
  used by a component, these include paths shall be manually added to
  the CMakeLists.txt file of the component. This is intended to
  discourage applications from including private kernel and arch
  headers either knowingly and unknowingly.

  - kernel/include/ (PRIVATE)
    This directory contains the private headers that provide private
   kernel definitions which should not be visible outside the kernel
   and arch source code. All public kernel definitions must be added
   to an appropriate header located under include/.

  - arch/*/include/ (PRIVATE)
    This directory contains the private headers that provide private
   architecture-specific definitions which should not be visible
   outside the arch and kernel source code. All public architecture-
   specific definitions must be added to an appropriate header located
   under include/arch/*/.

  - include/ AND include/sys/ (PUBLIC)
    This directory contains the public headers that provide public
   kernel definitions which can be referenced by both kernel and
   application code.

  - include/arch/*/ (PUBLIC)
    This directory contains the public headers that provide public
   architecture-specific definitions which can be referenced by both
   kernel and application code.

2. Split arch_interface.h into "kernel-to-arch interface" and "public
  arch interface" divisions.

  - kernel/include/kernel_arch_interface.h
    * provides private "kernel-to-arch interface" definition.
    * includes arch/*/include/kernel_arch_func.h to ensure that the
     interface function implementations are always available.
    * includes sys/arch_interface.h so that public arch interface
     definitions are automatically included when including this file.

  - arch/*/include/kernel_arch_func.h
    * provides architecture-specific "kernel-to-arch interface"
     implementation.
    * only the functions that will be used in kernel and arch source
     files are defined here.

  - include/sys/arch_interface.h
    * provides "public arch interface" definition.
    * includes include/arch/arch_inlines.h to ensure that the
     architecture-specific public inline interface function
     implementations are always available.

  - include/arch/arch_inlines.h
    * includes architecture-specific arch_inlines.h in
     include/arch/*/arch_inline.h.

  - include/arch/*/arch_inline.h
    * provides architecture-specific "public arch interface" inline
     function implementation.
    * supersedes include/sys/arch_inline.h.

3. Refactor kernel and the existing architecture implementations.

  - Remove circular dependency of kernel and arch headers. The
   following general rules should be observed:

    * Never include any private headers from public headers
    * Never include kernel_internal.h in kernel_arch_data.h
    * Always include kernel_arch_data.h from kernel_arch_func.h
    * Never include kernel.h from kernel_struct.h either directly or
     indirectly. Only add the kernel structures that must be referenced
     from public arch headers in this file.

  - Relocate syscall_handler.h to include/ so it can be used in the
   public code. This is necessary because many user-mode public codes
   reference the functions defined in this header.

  - Relocate kernel_arch_thread.h to include/arch/*/thread.h. This is
   necessary to provide architecture-specific thread definition for
   'struct k_thread' in kernel.h.

  - Remove any private header dependencies from public headers using
   the following methods:

    * If dependency is not required, simply omit
    * If dependency is required,
      - Relocate a portion of the required dependencies from the
       private header to an appropriate public header OR
      - Relocate the required private header to make it public.

This commit supersedes #20047, addresses #19666, and fixes #3056.

Signed-off-by: Stephanos Ioannidis <root@stephanos.io>
2019-11-06 16:07:32 -08:00
Wayne Ren
a75b0014fb arc: replace 32-bit instructions with possible 16-bit instructions
replace 32-bit instructions with possible 16-bit instructions to
get better code density

Signed-off-by: Wayne Ren <wei.ren@synopsys.com>
2019-09-08 12:36:02 +02:00
Alexey Brodkin
9a3ee641b6 arc: interrupts: Explain return from interrupt to cooperative thread
The code in question is very non-trivial so without good explanation
it takes a lot of time to realize what's done there and why
it still works in the end.

Here I'm trying to save a couple of man-days for the next developers
who's going to touch that piece of code.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
2019-08-30 20:10:14 +02:00
Alexey Brodkin
4449ad52da arch: arc: _rirq_exit: Comment clean-up
We manage IRQs in a quite a different way now since
commit f8d061faf7 ("arch: arc: add nested interrupt support")
so that comment not only makes no sense but also may fool a reader
as disabling of interrupts happens in the very beginning of
_rirq_exit() but not here.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
2019-08-28 11:53:32 +02:00
Wayne Ren
44c917e6b2 arch: arc: fix the bug that interrupt stack is not switched
For the old codes, if nest interrupts come out after _isr_wrapper
and before _check_nest_int_by_irq_act, then multi-bits in irq_act
will be set, this will result irq stack will not be switched in
correctly

As a fix, it's still need to use nest interrupt counter to do
interrupt stack switch as before

The difference is in the past exc_nest_count is used, but here
_kernel.nested/_kernel.cpus[cpu_id].nested is used.

Signed-off-by: Wayne Ren <wei.ren@synopsys.com>
2019-08-28 08:22:14 +02:00
Wayne Ren
5a73bf3966 arch: arc: fix and optimize the handling of SECT_STAT.IRM
For arc processor equiped with secureshield, SEC_STAT.IRM
bit should be recorded, it determins which mode irq should
return

Signed-off-by: Wayne Ren <wei.ren@synopsys.com>
2019-08-28 08:22:14 +02:00
Wayne Ren
cca39204c2 arch: arc: add initial support of ARC TEE
* it's based on ARC SecureShield
* add basic secure service in arch/arc/core/secureshield
* necesssary changes in arch level
   * thread switch
   * irq/exception handling
   * initialization
* add secure time support

Signed-off-by: Wayne Ren <wei.ren@synopsys.com>
2019-08-10 17:45:22 +02:00
Wayne Ren
e11be42558 arch: arc: add initial support of SMP
* modify the reset flow for SMP
* add smp related initialization
* implement ipi related functions
* implement thread switch in isr/exception

Signed-off-by: Wayne Ren <wei.ren@synopsys.com>
2019-08-07 12:21:00 +02:00
Wayne Ren
733c11b11b arch: arc: use IRQ_ACT to check nest interrupt
* use IRQ_ACT to check nest interrupt
* implement an asm macro for nest interrupt check
* no need to use exc_nest_count, remove it

Signed-off-by: Wayne Ren <wei.ren@synopsys.com>
2019-07-30 10:16:38 -07:00
Wayne Ren
4f2e873454 arch: arc: fix the bug caused by hardware sp switch in interrupt
* if thread switchs in interrupt, the target sp must be in
thread's kernel stack, no need to do hardware sp switch

Signed-off-by: Wayne Ren <wei.ren@synopsys.com>
2019-07-02 19:42:14 -07:00
Andrew Boie
1ee017050b arc: use different load instruction
If the offset within the thread struct to the
ARC arch-specific 'relinquish_cause' member is too
large, ld_s instructions referencing it will not
compile. This happens easily if CONFIG_THREAD_NAME
reserves a name buffer within the thread struct, since
all the arch-specific members come last.

Use the regular 'ld' instruction instead.

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
2019-07-01 16:29:45 -07:00
Wayne Ren
890b9ebab7 arch: arc: implement z_arch_switch to replace swap
* here use new style z_arch_switch,i.e. CONFIG_USE_SWITCH
to replace old swap mechnism.

* it's also required by SMP support

Signed-off-by: Wayne Ren <wei.ren@synopsys.com>
2019-06-28 09:56:03 -04:00
Wayne Ren
1f0fc6d712 arch: arc: fix the bug of nest interrupt handling in int exit
* it's not reliable to use exc_nest_count to decide nest interrupt.
  A better option is to use IRQ_ACT

* ext_nest_count is just used to switch interrupt stack

Signed-off-by: Wayne Ren <wei.ren@synopsys.com>
2019-04-09 15:35:17 -04:00
Patrik Flykt
4344e27c26 all: Update reserved function names
Update reserved function names starting with one underscore, replacing
them as follows:
   '_k_' with 'z_'
   '_K_' with 'Z_'
   '_handler_' with 'z_handl_'
   '_Cstart' with 'z_cstart'
   '_Swap' with 'z_swap'

This renaming is done on both global and those static function names
in kernel/include and include/. Other static function names in kernel/
are renamed by removing the leading underscore. Other function names
not starting with any prefix listed above are renamed starting with
a 'z_' or 'Z_' prefix.

Function names starting with two or three leading underscores are not
automatcally renamed since these names will collide with the variants
with two or three leading underscores.

Various generator scripts have also been updated as well as perf,
linker and usb files. These are
   drivers/serial/uart_handlers.c
   include/linker/kobject-text.ld
   kernel/include/syscall_handler.h
   scripts/gen_kobject_list.py
   scripts/gen_syscall_header.py

Signed-off-by: Patrik Flykt <patrik.flykt@intel.com>
2019-03-11 13:48:42 -04:00
Ruud Derwig
fd0a4372b9 arc: Fix zero-overhead loop in fake stackframe
Fixes incorrect PR #12480
lp_count set to zero doesn't reset zero overhead loops,
it encodes a maximum loopcount.

Signed-off-by: Ruud Derwig <Ruud.Derwig@synopsys.com>
2019-02-05 09:43:36 -05:00
Wayne Ren
8f47802d73 arc: fix the pollution of lp_xxx regs in _rirq_return_from_coop
in the _rirq_return_from_coop, a fake irq stack frame is created.
But the value of lp_start, lp_end, lp_count are not set correctly.
When rtie is executed, the zero-overhead loop will be enabled, if
the pc crosses the value of lp_end and lp_count is not zero. The pc
will jump to lp_start. This will break down the system.

This commit fixs this bug and set the correct value of lp_start, lp_end
and lp_count(only need to set lp_count).

Signed-off-by: Wayne Ren <wei.ren@synopsys.com>
2019-01-17 07:45:01 -05:00
Wayne Ren
d68c016793 arch: arc: enable stack check when arc is in secure mode
when arc is in secure mode, SSC bit of sec_stat,
not SC bit of status32,is used to enable stack check.

Signed-off-by: Wayne Ren <wei.ren@synopsys.com>
2018-08-22 07:57:11 -07:00
Wayne Ren
b829bc78c1 arch: arc: refactor the arc stack check support
* the original stack check codes have no consideration
  for userspace case. This will wrong cause possible stack
  check exception.
* this commit refactors the arc stack check support to
  support the usperspace.

* this commit fixes #7885. All the failed tests in #7885
  are run again to verify this commit. The test results are ok

Signed-off-by: Wayne Ren <wei.ren@synopsys.com>
2018-06-04 13:31:43 -04:00
Andy Ross
3a0cb2d35d kernel: Remove legacy preemption checking
The metairq feature exposed the fact that all of our arch code (and a
few mistaken spots in the scheduler too) was trying to interpret
"preemptible" threads independently.

As of the scheduler rewrite, that logic is entirely within sched.c and
doing it externally is redundant.  And now that "cooperative" threads
can be preempted, it's wrong and produces test failures when used with
metairq threads.

Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
2018-05-25 09:40:55 -07:00
Wayne Ren
adf6f48e0d arch: arc: add the support of STACK_SENTINEL
* call the _check_stack_sentinel in unnested isr
return.

* for firq, _check_stack_sentinel is called in kernel
  isr stack because the limitation of banked register

* for normal irq, _check_stak_sentinel is called in
  the interruptted thread stack

Signed-off-by: Wayne Ren <wei.ren@synopsys.com>
2018-04-17 10:50:12 -07:00
Wayne Ren
2c577ff90e arch: arc: fix the bug of context switch in interrupt
* the bug comes out when a context switch happens in interrupt
* the bug only affects the em7d in emsk 2.3
* the bug is caused by
  * wrong operations of stack
  * wrong setting of SEC_STAT's IRM bit

Signed-off-by: Wayne Ren <wei.ren@synopsys.com>
2018-03-08 11:01:11 +01:00
Wayne Ren
f81dee0b2b arch: arc: add user space support for arc
* add the implementation of syscall
  * based on 'trap_s' intruction, id = 3
* add the privilege stack
  * the privilege stack is allocted with thread stack
  * for the kernel thread, the privilege stack is also a
    part of thread stack, the start of stack can be configured
    as stack guard
  * for the user thread, no stack guard, when the user stack is
    overflow, it will fall into kernel memory area which requires
    kernel privilege, privilege violation will be raised
* modify the linker template and add MPU_ADDR_ALIGN
* add user space corresponding codes in mpu
* the user sp aux reg will be part of thread context
* When user thread is interruptted for the 1st time, the context is
  saved in user stack (U bit of IRQ_CTLR is set to 1). When nest
  interrupt comes, the context is saved in thread's privilege stack
* the arc_mpu_regions.c is moved to board folder, as it's board
  specific
* the above codes have been tested through tests/kernel/mem_protect/
  userspace for MPU version 2

Signed-off-by: Wayne Ren <wei.ren@synopsys.com>
2018-02-16 12:20:16 +01:00
Wayne Ren
9a40bf6b7e arch: arc: Add the intial support of memory domain
Refering the ARM's implementation, the initial support of memory
domain in ARC is added:
* changes in MPU drivers
* changes in Kconfig
* codes to configure memory domain during thread swap
* changes in linker script template
* memory domain related macro definitions

the commited codes are simply tested through
samples/mpu/mem_domain_apis_test.

Signed-off-by: Wayne Ren <wei.ren@synopsys.com>
2018-01-18 11:50:59 -08:00
Wayne Ren
528c960ae7 arch: arc: Add the support of secure mode for em
In ARC's SecureShield, a new secure mode (currently only em) is added.
The secure/normal mode is orthogonal to kernel/user mode. The
differences between secure mode and normal mode are following:

* different irq stack frame. so need to change the definition of
  _irq_stack_frame, assembly code.

* new aux regs, e.g, secure status(SEC_STAT), secure vector base
  (VECT_BASE_S)

* interrupts and exceptions, secure mode has its own vector base;
  interrupt can be configured as secure or normal through the
  interrupt priority aux reg.

* secure timers. Two secure timers (secure timer 0 and timer 1) are
  added.Here, for simplicity and backwards compatibility original
  internal timers (timer 0 and timer1) are used as sys clock of zephyr

* on reset, the processor is in secure mode and secure vector base is
  used.

Note: the mix of secure and normal mode is not supported, i.e. it's
assumed that the processor is always in secure mode.

Signed-off-by: Wayne Ren <wei.ren@synopsys.com>
2017-12-13 12:05:33 -05:00
Wayne Ren
12cc6598b0 arch: arc: Add mpu support
* add arc mpu driver
* modify the corresponding kconfig and kbuild
* currently only em_starterkit 2.2's em7d configuration
  has mpu feature (mpu version 2)
* as the minimum region size of arc mpu version 2 is 2048 bytes and
  region size should be power of 2, the stack size of threads
  (including main thread and idle thread) should be at least
  2048 bytes and power of 2
* for mpu stack guard feature, a stack guard region of 2048 bytes
  is generated. This brings more memory footprint
* For arc mpu version 3, the minimum region size is 32 bytes.
* the codes are tested by the mpu_stack_guard_test and stackprot

Signed-off-by: Wayne Ren <wei.ren@synopsys.com>
2017-08-16 16:09:45 -04:00
Wayne Ren
f8d061faf7 arch: arc: add nested interrupt support
* add nested interrupt support for interrupts
   + use a varibale exc_nest_count to trace nest interrupt and exception
   + regular interrupts can be nested by regular interrupts and fast
interrupts
   + fast interrupt's priority is the highest, cannot be nested
* remove the firq stack and exception stack
   + remove the coressponding kconfig option
   + all interrupts (normal and fast) and exceptions will be handled
     in the same stack (_interrupt stack)
   + the pros are, smaller memory footprint (no firq stack), simpler
     stack management, simpler codes, etc.. The cons are, possible
     10-15 instructions overhead for the case where fast irq nests
     regular irq
* add the case of ARC in test/kernel/gen_isr_table

Signed-off-by: Wayne Ren <wei.ren@synopsys.com>
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
2017-08-10 12:47:15 -04:00
Huaqi Fang
9bc69a46fa boards: Update arc em_starterkit support from 2.2 to 2.3
Here are the main changes:
* board: Update EMSK onboard resources such as Button, Switch and LEDs
  + update soc.h for em7d, em9d, em11d
  + update board.h for em_starterkit board
* arc: Add floating point support and code density support
  + add kconfig configuration
  + add compiler options
  + add register definitions, marcos, assembly codes
  + fixes in existing codes and configurations.
* arc: Update detailed board configurations for cores of emsk 2.3
* script: Provide arc_debugger.sh for debugging em_starterkit board
  + make BOARD=em_starterkit debug
    This will start openocd server for emsk, and arc gdb will connect
    to this debug server, user can run `continue` command if user just
    want to run the application, or other commands if debugging needed.
  + make BOARD=em_starterkit debugserver
    This will start an openocd debugger server for emsk, and user can
    connect to this debugserver using arc gdb and do what they want to.
  + make BOARD=em_starterkit flash
    This will download the zephyr application elf file to emsk,
    and run it.

Signed-off-by: Huaqi Fang <huaqi.fang@synopsys.com>
2017-05-19 15:58:41 +02:00
Andrew Boie
9175d20ceb arc: fix CONFIG_ARC_STACK_CHECKING
- There's no clear need to disable frame pointers if this feature is
used, remove this directive.
- The 'top' and 'base' terms are reversed. The 'base' is the high
address of the stack. The top is the lowest address, where we cannot
push further down. Fixup member and offset names to correspond to how
these terms are used in hardware documentation.
- Use correct pointers for stack top location
- Fatal exceptions now go through _NanoFatalErrorHandler to report the
faulting ip and thread.

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
2017-05-13 15:14:41 -04:00
Benjamin Walsh
ee659ae1a1 build: add _ASMLANGUAGE to all asm files
This avoids asm files from having to explicitly define the _ASMLANGUAGE
symbol themselves.

Change-Id: I71f5a169f75d7443a58a0365a41c55b20dae3029
Signed-off-by: Benjamin Walsh <walsh.benj@gmail.com>
2017-01-24 13:34:51 +00:00
David B. Kinder
ac74d8b652 license: Replace Apache boilerplate with SPDX tag
Replace the existing Apache 2.0 boilerplate header with an SPDX tag
throughout the zephyr code tree. This patch was generated via a
script run over the master branch.

Also updated doc/porting/application.rst that had a dependency on
line numbers in a literal include.

Manually updated subsys/logging/sys_log.c that had a malformed
header in the original file.  Also cleanup several cases that already
had a SPDX tag and we either got a duplicate or missed updating.

Jira: ZEP-1457

Change-Id: I6131a1d4ee0e58f5b938300c2d2fc77d2e69572c
Signed-off-by: David B. Kinder <david.b.kinder@intel.com>
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
2017-01-19 03:50:58 +00:00
Benjamin Walsh
168695c7ef kernel/arch: inspect prio/sched_locked together for preemptibility
These two fields in the thread structure control the preemptibility of a
thread.

sched_locked is decremented when the scheduler gets locked, which means
that the scheduler is locked for values 0xff to 0x01, since it can be
locked recursively. A thread is coop if its priority is negative, thus
if the prio field value is 0x80 to 0xff when looked at as an unsigned
value.

By putting them end-to-end, this means that a thread is non-preemptible
if the bundled value is greater than or equal to 0x0080. This is the
only thing the interrupt exit code has to check to decide to try a
reschedule or not.

Change-Id: I902d36c14859d0d7a951a6aa1bea164613821aca
Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
2017-01-09 20:52:25 +00:00
Benjamin Walsh
f955476559 kernel/arch: optimize memory use of some thread fields
Some thread fields were 32-bit wide, when they are not even close to
using that full range of values. They are instead changed to 8-bit fields.

- prio can fit in one byte, limiting the priorities range to -128 to 127

- recursive scheduler locking can be limited to 255; a rollover results
  most probably from a logic error

- flags are split into execution flags and thread states; 8 bits is
  enough for each of them currently, with at worst two states and four
  flags to spare (on x86, on other archs, there are six flags to spare)

Doing this saves 8 bytes per stack. It also sets up an incoming
enhancement when checking if the current thread is preemptible on
interrupt exit.

Change-Id: Ieb5321a5b99f99173b0605dd4a193c3bc7ddabf4
Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
2017-01-09 20:52:24 +00:00
Benjamin Walsh
e6a69cae54 kernel/arch: reverse polarity on sched_locked
This will allow for an enhancement when checking if the thread is
preemptible when exiting an interrupt.

Change-Id: If93ccd1916eacb5e02a4d15b259fb74f9800d6f4
Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
2017-01-06 17:32:24 +00:00
Benjamin Walsh
8e4a534ea1 kernel: enable and optimize coop-only configurations
Some kernel operations, like scheduler locking can be optmized out,
since coop threads lock the scheduler by their very nature. Also, the
interrupt exit path for all architecture does not have to do any
rescheduling, again by the nature of non-preemptible threads.

Change-Id: I270e926df3ce46e11d77270330f2f4b463971763
Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
2016-12-15 16:17:38 -05:00
Benjamin Walsh
88b3691415 kernel/arch: enhance the "ready thread" cache
The way the ready thread cache was implemented caused it to not always
be "hot", i.e. there could be some misses, which happened when the
cached thread was taken out of the ready queue. When that happened, it
was not replaced immediately, since doing so could mean that the
replacement might not run because the flow could be interrupted and
another thread could take its place. This was the more conservative
approach that insured that moving a thread to the cache would never be
wasted.

However, this caused two problems:

1. The cache could not be refilled until another thread context-switched
in, since there was no thread in the cache to compare priorities
against.

2. Interrupt exit code would always have to call into C to find what
thread to run when the current thread was not coop and did not have the
scheduler locked. Furthermore, it was possible for this code path to
encounter a cold cache and then it had to find out what thread to run
the long way.

To fix this, filling the cache is now more aggressive, i.e. the next
thread to put in the cache is found even in the case the current cached
thread is context-switched out. This ensures the interrupt exit code is
much faster on the slow path. In addition, since finding the next thread
to run is now always "get it from the cache", which is a simple fetch
from memory (_kernel.ready_q.cache), there is no need to call the more
complex C code.

On the ARM FRDM K64F board, this improvement is seen:

Before:

1- Measure time to switch from ISR back to interrupted task

   switching time is 215 tcs = 1791 nsec

2- Measure time from ISR to executing a different task (rescheduled)

   switch time is 315 tcs = 2625 nsec

After:

1- Measure time to switch from ISR back to interrupted task

   switching time is 130 tcs = 1083 nsec

2- Measure time from ISR to executing a different task (rescheduled)

   switch time is 225 tcs = 1875 nsec

These are the most dramatic improvements, but most of the numbers
generated by the latency_measure test are improved.

Fixes ZEP-1401.

Change-Id: I2eaac147048b1ec71a93bd0a285e743a39533973
Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
2016-12-15 15:50:02 -05:00
Julien Delayen
176d184fb8 power: Add ARC core suspend and resume support
When going into DEEP_SLEEP mode, the ARC core now saves
its context. This includes:
- All core registers
- Stack pointer
- Program counter (restored by jumping to the restore code)

The arc reset code now checks if the GPS0 bit 2 is set.
This is similar to the behavior of the x86 core done by
the QMSI bootloader which is setting GPS0 bit 1 in order
to call the restore path instead of cold boot path.

The sample has been adapted in order to support the ARC.

Jira: ZEP-1222

Change-Id: I375f03b16b8a5fd1f07ead55cf7e4947d6290c9f
Signed-off-by: Julien Delayen <julien.delayen@intel.com>
2016-12-15 12:49:33 +00:00
Chuck Jordan
cd198764ba arc: branch too far when STACK_CHECKING enabled.
A build error was resulting if CONFIG_ARC_STACK_CHECKING is enabled.
There is a breq that was too far. Adding conditional code to
re-arrange the branching so that it can be done.

See ZEP-1116.

Change-Id: Idea85817b2e05617bbaa4450437aa74c5737e213
Signed-off-by: Chuck Jordan <cjordan@synopsys.com>
2016-12-02 22:57:14 +00:00
Benjamin Walsh
f6ca7de09c kernel/arch: consolidate tTCS and TNANO definitions
There was a lot of duplication between architectures for the definition
of threads and the "nanokernel" guts. These have been consolidated.

Now, a common file kernel/unified/include/kernel_structs.h holds the
common definitions. Architectures provide two files to complement it:
kernel_arch_data.h and kernel_arch_func.h. The first one contains at
least the struct _thread_arch and struct _kernel_arch data structures,
as well as the struct _callee_saved and struct _caller_saved register
layouts. The second file contains anything that needs what is provided
by the common stuff in kernel_structs.h. Those two files are only meant
to be included in kernel_structs.h in very specific locations.

The thread data structure has been separated into three major parts:
common struct _thread_base and struct k_thread, and arch-specific struct
_thread_arch. The first and third ones are included in the second.

The struct s_NANO data structure has been split into two: common struct
_kernel and arch-specific struct _kernel_arch. The latter is included in
the former.

Offsets files have also changed: nano_offsets.h has been renamed
kernel_offsets.h and is still included by the arch-specific offsets.c.
Also, since the thread and kernel data structures are now made of
sub-structures, offsets have to be added to make up the full offset.
Some of these additions have been consolidated in shorter symbols,
available from kernel/unified/include/offsets_short.h, which includes an
arch-specific offsets_arch_short.h. Most of the code include
offsets_short.h now instead of offsets.h.

Change-Id: I084645cb7e6db8db69aeaaf162963fe157045d5a
Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
2016-11-12 07:04:52 -05:00
Benjamin Walsh
5986ec040b arc: fix race condition when returning from interrupt
A race condition would happend if a FIRQ interrupted a
return-from-interrupt from a RIRQ at the wrong moment: if a decision was
already taken which thread to context switch in and the FIRQ woke up
another thread of higher priority, the ready queue would be corrupted.

The solution is to lock interrupts at the moment the interrupt return
code starts looking at the kernel queues. Interrupts do not need to be
unlocked before exiting: the return-from-interrupt (rtie) instruction
will restore the correct interrupt locking state for the thread being
context switched in.

Change-Id: I777665c2faeca7b1f2a77ddd9ee2a520080bae88
Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
2016-11-08 22:50:14 +00:00
Andrew Boie
8871cf0994 arc: remove support for legacy kernels
Change-Id: Id3d8285dc39428752758ee47fb1b826f05b1f3e0
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
2016-11-04 11:45:14 -07:00
Chuck Jordan
8b1958a36a arc: Don't need CONFIG_NUM_REGULAR_IRQ_PRIO_LEVELS
We can derive NUM_REGULAR_IRQ_PRIO_LEVELS by subtracting 1
from CONFIG_IRQ_PRIO_LEVELS if FIRQ is present (which is currently
always the case). If FIRQ is not present, the value will be equal
to CONFIG_IRQ_PRIO_LEVELS since all interrupts will be regular.

Change-Id: Ibefc939e3771bf0adf712127db0d36cb49bf732b
Signed-off-by: Chuck Jordan <cjordan@synopsys.com>
2016-10-31 23:56:56 +00:00
Dmitriy Korovkin
3c7dda3897 unified/arc: Fix scheduler algorithm bug
Fix the error in thread rescheduling:

Fix Fast IRQ exit routine error when it reschedules threads if
(prio >= 0) || (sched_locked == 0) || (next_thread == _current),
while the correct condition for thread rescheduling is:
(prio >= 0) && (sched_locked == 0) && (next_thread != _current),

Fix regular IRQ error when the regular IRQ exit routine rescheduled
threads when (next_thread == _current) instead of
(next_thread != current).

Increased IDLE_STACK_SIZE for ARC architecture, to hold saved
registers.

Change-Id: I1d87a968e231e13822844b7564567e6ca310cde2
Signed-off-by: Dmitriy Korovkin <dmitriy.korovkin@windriver.com>
2016-10-28 17:46:54 +00:00
Dmitriy Korovkin
909bfffda9 unified/arc: add unified kernel support for ARC arch
- the interrupt (both regular and fast) now does not do rescheduling
  if the current thread is a coop thread or if the scheduler is not locked

- the _nanokernel.flags cache of _current.flags is not used anymore
  (could be a source of bugs) and is not needed in the scheduling algo

- there is no 'task' field in the _nanokernel anymore: scheduling routines
  call _get_next_ready_thread instead

- the _nanokernel.fiber field is replaced by a more sophisticated
  ready_q, based on the microkernel's priority-bitmap-based one

- thread initialization initializes new fields in the tcs, and does not
  initialize obsolete ones

- nano_private includes nano_internal.h from the unified directory

- The FIBER, TASK and PREEMPTIBLE flags do not exist anymore: the thread
  priority drives the behaviour

- the tcs uses a dlist for queuing in both ready and wait queues instead
  of a custom singly-linked list

- other new fields in the tcs include a schedule-lock count, a
  back-pointer to init data (when the task is static) and a pointer to
  swap data, needed when a thread pending on _Swap() must be passed more
  then just one value (e.g. k_stack_pop() needs an error code and data)

- the 'fiber' and 'task' fields of _nanokernel are replaced with an O(1)
  ready queue (taken from the microkernel)

- fiberRtnValueSet() is aliased to _set_thread_return_value since it
  also operates on preempt threads now

- _set_thread_return_value_with_data() sets the swap_data field in
  addition to a return value from _Swap()

- convenience aliases are created for shorter names:

  - _current is defined as _nanokernel.current
  - _ready_q is defined as _nanokernel.ready_q

- _Swap() sets the threads's return code to -EAGAIN before swapping out
  to prevent timeouts to have to set it (solves hard issues in some
  kernel objects).

Change-Id: Ib9690173cbc36c36a9ec67e65590b40d758673de
Signed-off-by: Dmitriy Korovkin <dmitriy.korovkin@windriver.com>
2016-10-22 01:27:00 +00:00
Chuck Jordan
0ca24cedda arc: trap handler, used by irq_offload, now handles thread switch
It was found that the test latency_measure, when compiled
for microkernel, would fail on the ARC. This because the
trap handler, used by irq_offload, wasn't supporting thread switching.
This submission adds the code to do that, and the code size is
bigger only when CONFIG_MICROKERNEL is defined.

To keep code a bit smaller, there is a trick exploited here where
the AE bit is cleared in the STATUS32 register and in AUX_IRQ_ACT,
bit 1 is set, to make it appear as if the machine has interrupted
at priority 1 level. It then can jump into some common interrupt
exit code for regular interrupts and perform an RTIE instruction
to switch into the new thread.

test/latency_measure/microkernel now passes.

Change-Id: I1872a80bb09a259814540567f51721203201679a
Signed-off-by: Chuck Jordan <cjordan@synopsys.com>
2016-05-27 21:11:24 +00:00