Original interrupt context save/restore routine saves to/restore from
per-cpu stack. This commit modifies it to support saving to/restoring
from address pointed to by sscratch register.
When sscratch is 0, the assembly is functionally equivalent to the
old version (save to/restore from per-cpu stack)
When sscratch is not 0, the assembly saves to/restores from the place
that sscratch points to.
hstatus is also added to the trap frame as this affects the virtual
mode the trap returns to.
Tracked-On: #8841
Signed-off-by: Yifan Liu <yifan1.liu@intel.com>
Signed-off-by: Haicheng Li <haicheng.li@intel.com>
Acked-by: Wang Yu1 <yu1.wang@intel.com>
The RISC-V calling convention defines a full descending stack, where 'sp'
points to the last used stack address. The current implementation of
cpu_ctx_save() subtracts only CPU_REGS_OFFSET_SCRATCH from 'sp', which
allocates 8 bytes too few and may overwrite the caller's stack contents.
Fix this by adjusting CPU_REGS_OFFSET_LAST to include the last slot,
ensuring the full context save/restore area is properly reserved.
Fixes: 6276763cd (hv: riscv: implement cpu_ctx_save and cpu_ctx_restore)
Tracked-On: #8827
Signed-off-by: Shiqing Gao <shiqing.gao@intel.com>
Acked-by: Wang, Yu1 <yu1.wang@intel.com>
