Commit Graph

4 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 a50c433012 riscv: exception code mega simplification and optimization
Complete revamp of the exception entry code, including syscall handling.
Proper syscall frame exception trigger. Many correctness fixes, hacks
removal, etc. etc.

I tried to make this into several commits, but this stuff is all
inter-related and a pain to split.

The diffstat summary:

 14 files changed, 250 insertions(+), 802 deletions(-)

Binary size (before):

   text	   data	    bss	    dec	    hex	filename
   1104	      0	      0	   1104	    450	isr.S.obj
     64	      0	      0	     64	     40	userspace.S.obj

Binary size (after):

   text	   data	    bss	    dec	    hex	filename
    600	      0	      0	    600	    258	isr.S.obj
     36	      0	      0	     36	     24	userspace.S.obj

Run of samples/userspace/syscall_perf (before):

*** Booting Zephyr OS build zephyr-v3.0.0-325-g3748accae018  ***
Main Thread started; qemu_riscv32
Supervisor thread started
User thread started
Supervisor thread(0x80010048):       384 cycles	     509 instructions
User thread(0x80010140):           77312 cycles	   77437 instructions

Run of samples/userspace/syscall_perf (after):

*** Booting Zephyr OS build zephyr-v3.0.0-326-g4c877a2753b3  ***
Main Thread started; qemu_riscv32
Supervisor thread started
User thread started
Supervisor thread(0x80010048):       384 cycles	     509 instructions
User thread(0x80010138):            7040 cycles     7165 instructions

Yes, that's more than a 10x speed-up!

Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
2022-03-21 07:28:05 -04:00
Nicolas Pitre 1fd79b3ef4 riscv: better abstraction for register-wide load/store opcodes
Those are prominent enough that having RV_OP_LOADREG and RV_OP_STOREREG
shouting at you all over the place is rather unpleasant and bad taste.

Let's create pseudo-instructions of our own with assembler macros
rather than preprocessor defines and only in assembly scope.
This makes the asm code way more uniform and readable.

Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
2022-03-21 07:28:05 -04:00
Alexandre Mergnat 542a7fa25d arch: riscv: add memory protection support
The IRQ handler has had a major changes to manage syscall, reschedule
and interrupt from user thread and stack guard.

Add userspace support:
- Use a global variable to know if the current execution is user or
  machine. The location of this variable is read only for all user
  thread and read/write for kernel thread.
- Memory shared is supported.
- Use dynamic allocation to optimize PMP slot usage. If the area size
  is a power of 2, only one PMP slot is used, else 2 are used.

Add stack guard support:
- Use MPRV bit to force PMP rules to machine mode execution.
- IRQ stack have a locked stack guard to avoid re-write PMP
  configuration registers for each interruption and then win some
  cycle.
- The IRQ stack is used as "temporary" stack at the beginning of IRQ
  handler to save current ESF. That avoid to trigger write fault on
  thread stack during store ESF which that call IRQ handler to
  infinity.
- A stack guard is also setup for privileged stack of a user thread.

Thread:
- A PMP setup is specific to each thread. PMP setup are saved in each
  thread structure to improve reschedule performance.

Signed-off-by: Alexandre Mergnat <amergnat@baylibre.com>
Reviewed-by: Nicolas Royer <nroyer@baylibre.com>
2020-11-09 15:37:11 -05:00