When a hart implements Smepmp, S-mode and U-mode cannot reach either
device unless its region is shared explicitly. Suspend and resume then
take an access violation as soon as the supervisor touches the SMU or
the LLC.
Share both regions, and take their sizes from the DT nodes rather than
ignoring them.
Signed-off-by: Ben Zong-You Xie <ben717@andestech.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/20260728081041.2724668-3-ben717@andestech.com
Signed-off-by: Anup Patel <anup@brainfault.org>
Implement a system-wide suspend driver for the Andes AE350 platform.
This driver supports Andes-specific deep sleep (suspend to RAM) and
light sleep (suspend to standby) functionalities via the ATCSMU.
The major differences between deep sleep and light sleep are:
- Power Domain and Resume Path: Deep sleep powers down the core domain.
Consequently, harts waking from deep sleep resume from the reset
vector. Light sleep utilizes clock gating to the core domain; harts
maintain state and resume execution at the instruction immediately
following the WFI instruction.
- Primary Hart Wakeup: In both modes, the primary hart is woken by
UART or RTC alarm interrupts. In deep sleep, the primary hart is
additionally responsible for re-enabling the Last Level Cache (LLC)
and restoring Andes-specific CSRs.
- Secondary Hart Wakeup: In light sleep, secondary harts are woken
by an IPI sent from the primary hart. In deep sleep, they are
woken by an ATCSMU hardware wake-up command. Furthermore,
secondary harts must restore Andes-specific CSRs when returning
from deep sleep.
Signed-off-by: Ben Zong-You Xie <ben717@andestech.com>
Signed-off-by: Leo Yu-Chi Liang <ycliang@andestech.com>
Link: https://lore.kernel.org/r/20251229071914.1451587-6-ben717@andestech.com
Signed-off-by: Anup Patel <anup@brainfault.org>
Refactor ATCSMU (System Management Unit) support by moving it from a
system utility into a dedicated FDT-based HSM driver.
Key changes include:
- Moving the functions in lib/utils/sys/atcsmu.c into the new HSM driver
- Moving hart start and stop operations on AE350 platform into the new
HSM driver
- Converting the assembly-based functions in sleep.S to C code for the
readability
- Updating the ATCWDT200 driver
Signed-off-by: Ben Zong-You Xie <ben717@andestech.com>
Signed-off-by: Leo Yu-Chi Liang <ycliang@andestech.com>
Link: https://lore.kernel.org/r/20251229071914.1451587-2-ben717@andestech.com
Signed-off-by: Anup Patel <anup@brainfault.org>
Ben Zong-You Xie