The SiFive SMC0 controls the clock and power domain of the core complex
on the SiFive platform. The core complex enters the low power state
after the secondary cores enter the tile power gating and last core
execute the `CEASE` instruction with the corresponding SMC0
configurations. The devices that inside both tile power domain and core
complex power domain will be off, including caches and timer. Therefore
we need to flush the last level cache before entering the core complex
power gating and update the timer after waking up.
Reviewed-by: Cyan Yang <cyan.yang@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Nick Hu <nick.hu@sifive.com>
Link: https://lore.kernel.org/r/20251020-cache-upstream-v7-12-69a132447d8a@sifive.com
Signed-off-by: Anup Patel <anup@brainfault.org>
If we hotplug a core and then perform a suspend-to-RAM operation on a
multi-core platform, the hotplugged CPU may be woken up along with the rest
of the system, particularly on platforms that wake all cores from the
deepest sleep state. When this happens, the hotplugged CPU enters the
sbi_hsm_wait WFI wait loop instead of transitioning into a
platform-specific low-power state. To address this, we add a HSM stop call
within the wait loop. This allows platforms that support HSM stop to enter
a low-power state when the CPU is unexpectedly woken up.
Signed-off-by: Nick Hu <nick.hu@sifive.com>
Reviewed-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/20250418064506.15771-1-nick.hu@sifive.com
Signed-off-by: Anup Patel <anup@brainfault.org>
The hotplug cpu should clear the fwft config's SBI_FWFT_SET_FLAG_LOCK
in the warm boot flow otherwise the cpu can't set the menvcfg.sse by
SBI_EXT_FWFT_SET sbi call and cause the illegal instruction when
accessing the CSR_SSP in kernel.
Signed-off-by: Nick Hu <nick.hu@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Current interruptible hart mask doesn't include the hart which HSM state
is SBI_HSM_STATE_RESUME_PENDING. So when there is a request to send an
IPI to the hart which is in the resume process, this hart would miss the
IPI forever. Put the SBI_HSM_STATE_RESUME_PENDING hart in the
interruptible hart mask to fix the issue.
Signed-off-by: Nick Hu <nick.hu@sifive.com>
Reviewed-by: Xiang W <wxjstz@126.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
If we use the csr_write to restore the MIP, we may clear the SEIP.
In generic behavior of QEMU, if the pending bits of PLIC are set and we
clear the SEIP, the QEMU may not set it back immediately. It may cause
the interrupts won't be handled anymore until the new interrupts arrived
and QEMU set the bits back.
Signed-off-by: Nick Hu <nick.hu@sifive.com>
Signed-off-by: Jim Shu <jim.shu@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
In generic behavior of QEMU, if the pending bits of PLIC are still set and
we clear the SEIP, the QEMU may not set the SEIP back immediately and the
interrupt may not be handled anymore until the new interrupts arrived and
QEMU set the SEIP back which is a generic behavior in QEMU.
Signed-off-by: Nick Hu <nick.hu@sifive.com>
Signed-off-by: Jim Shu <jim.shu@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
