Commit Graph

14 Commits

Author SHA1 Message Date
Gerard Marull-Paretas
4b91c2d79f asm: update files with <zephyr/...> include prefix
Assembler files were not migrated with the new <zephyr/...> prefix.
Note that the conversion has been scripted, refer to #45388 for more
details.

Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no>
2022-05-09 12:45:29 -04:00
Nicolas Pitre
563a8d11a4 arm64: refer to the link register as "lr" rather than "x30"
In ARM parlance, the subroutine call return address is stored in the
"link register" or simply lr. Refer to it as lr which is clearer than
the anonymous x30 designation.

Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
2022-04-07 16:31:30 -05:00
Nicolas Pitre
47e4a4487f arm64: simplify the code around the call to z_get_next_switch_handle()
Remove the special SMP workaround and the extra wrapper.

Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
2022-03-18 13:32:49 -04:00
Nicolas Pitre
8affac64a7 arm64: improved arch_switch() implementation
Make it optimal without the need for an SVC/exception  roundtrip on
every context switch. Performance numbers from tests/benchmarks/sched:

Before:
unpend   85 ready   58 switch  258 pend  231 tot  632 (avg  699)

After:
unpend   85 ready   59 switch  115 pend  138 tot  397 (avg  478)

Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
2022-03-15 22:24:22 -04:00
Nicolas Pitre
bd941bcc68 arm64: implement CONFIG_IRQ_OFFLOAD_NESTED
It can easily be done now, so why not. Suffice to increment the nested
count like with actual IRQs.

Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
2022-03-14 22:03:05 -04:00
Nicolas Pitre
90fcef4254 arm64: irq_offload: simpler implementation
Get rid of all those global variables and scheduler locking.
Use the reguler IRQ exit path to let tests properly validate preemption.

Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
2022-03-14 22:03:05 -04:00
Nicolas Pitre
34d425fbe5 arm64: switch to the IRQ stack during ISR execution
Avoid executing ISRs using the thread stack as it might not be sized
for that. Plus, we do have IRQ stacks already set up for us.

The non-nested IRQ context is still (and has to be) saved on the thread
stack as the thread could be preempted.

The irq_offload case is never nested and always invoked with the
sched_lock held so it can be simplified a bit.

Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
2022-02-21 21:53:23 -05:00
Nicolas Pitre
6381ee7391 arm64: update _current_cpu->nested properly
This is an uint32_t so the proper register width must be used, otherwise
the adjacent structure member will be overwritten (didn't happen in
practice because of struct member alignment but still). This makes the
inc_nest_counter and dec_nest_counter macros rather unwieldy, especially
with upcoming changes, so let's just remove them.

Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
2022-02-21 21:53:23 -05:00
Jaxson Han
d282d86d7e arm64: Create common mmu and mpu interfaces
Include the new introduced include/arch/arm64/mm.h instead of the
arm_mmu.h or arm_mpu.h.

Unify function names z_arm64_thread_pt_init/z_arm64_swap_ptables with
z_arm64_thread_mem_domains_init/z_arm64_swap_mem_domains for mmu and
mpu, because:
1. mmu and mpu have almost the same logic.
2. mpu doesn't have ptables.
3. using the function names help reducing "#if define" macros.

Similarly, change z_arm64_ptable_ipi to z_arm64_domain_sync_ipi

And fix a log bug in arm_mmu.c.

Signed-off-by: Jaxson Han <jaxson.han@arm.com>
2021-09-28 20:06:06 -04:00
Nicolas Pitre
76494f8589 arm64: optimize offsets in z_arm64_context_switch
We can use build-time offsets from a struct k_thread pointer directly
to struct _callee_saved members. No need to compute that at run time.

Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
2021-05-04 22:41:32 -04:00
Nicolas Pitre
f1f63dda17 arm64: FPU context switching support
This adds FPU sharing support with a lazy context switching algorithm.

Every thread is allowed to use FPU/SIMD registers. In fact, the compiler
may insert FPU reg accesses in anycontext to optimize even non-FP code
unless the -mgeneral-regs-only compiler flag is used, but Zephyr
currently doesn't support such a build.

It is therefore possible to do FP access in IRS as well with this patch
although IRQs are then disabled to prevent nested IRQs in such cases.

Because the thread object grows in size, some tests have to be adjusted.

Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
2021-05-03 11:56:50 +02:00
Nicolas Pitre
a82fff04ff arm64: implement exception depth count
Add the exception depth count to tpidrro_el0 and make it available
through the arch_exception_depth() accessor.

The IN_EL0 flag is now updated unconditionally even if userspace is
not configured. Doing otherwise made the code rather hairy and
I doubt the overhead is measurable.

Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
2021-05-03 11:56:50 +02:00
Carlo Caione
256ca55476 arm64: Rework stack usage
The ARM64 port is currently using SP_EL0 for everything: kernel threads,
user threads and exceptions. In addition when taking an exception the
exception code is still using the thread SP without relying on any
interrupt stack.

If from one hand this makes the context switch really quick because the
thread context is already on the thread stack so we have only to save
one register (SP) for the whole context, on the other hand the major
limitation introduced by this choice is that if for some reason the
thread SP is corrupted or pointing to some unaccessible location (for
example in case of stack overflow), the exception code is unable to
recover or even deal with it.

The usual way of dealing with this kind of problems is to use a
dedicated interrupt stack on SP_EL1 when servicing the exceptions. The
real drawback of this is that, in case of context switch, all the
context must be copied from the shared interrupt stack into a
thread-specific stack or structure, so it is really slow.

We use here an hybrid approach, sacrificing a bit of stack space for a
quicker context switch. While nothing really changes for kernel threads,
for user threads we now use the privileged stack (already present to
service syscalls) as interrupt stack.

When an exception arrives the code now switches to use SP_EL1 that for
user threads is always pointing inside the privileged portion of the
stack of the current running thread. This achieves two things: (1)
isolate exceptions and syscall code to use a stack that is isolated,
privileged and not accessible to user threads and (2) the thread SP is
not touched at all during exceptions, so it can be invalid or corrupted
without any direct consequence.

Signed-off-by: Carlo Caione <ccaione@baylibre.com>
2021-04-23 06:32:20 -04:00
Carlo Caione
3539c2fbb3 arm/arm64: Make ARM64 a standalone architecture
Split ARM and ARM64 architectures.

Details:

- CONFIG_ARM64 is decoupled from CONFIG_ARM (not a subset anymore)
- Arch and include AArch64 files are in a dedicated directory
  (arch/arm64 and include/arch/arm64)
- AArch64 boards and SoC are moved to soc/arm64 and boards/arm64
- AArch64-specific DTS files are moved to dts/arm64
- The A72 support for the bcm_vk/viper board is moved in the
  boards/bcm_vk/viper directory

Signed-off-by: Carlo Caione <ccaione@baylibre.com>
2021-03-31 10:34:33 -05:00