The misaligned load emulation does not sign-extend values correctly
due to missing sign typecast in value passed to the SET_RD() macro.
A very easy way to reproduce this issue is to load 16-bit value
0xff1e from a byte aligned address using LH instruction on hardware
lacking misaligned load/store.
This patch fixes sbi_misaligned_load_handler() for above issue.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
If MTINST[0:0] bit is 1 then we have transformed instruction encoding
in MTINST CSR. For transformed instructions, if the MTINST[1:1] bit
is Zero then original trapped instruction was a 16bit instruction
which was converted to 32bit instruction at time of taking trap.
We should use MTINST[1:1] bit to determine correct instruction length
of transformed instruction.
This patch updates misaligned load/store emulation as-per above.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
We remove mcause, scratch and hartid parameters from various functions
for misaligned load/store handling because we can always get current
HART id and current scratch pointer using just one CSR access.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
The scratch parameter of sbi_trap_redirect() is not used hence we
remove it.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
The scratch parameter of unpriv load/store functions is now redundant
hence we remove it.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
Compile time checks of __riscv_compressed can only check if OpenSBI is
being compiled using compressed instructions or not. Checking this macro
does not indicate if an instruction that generated a misaligned trap is
a compressed instruction or not.
Since the misaligned trap handling code inspects instructions _C_ bits
to detect compressed instructions, we can remove all static checks on
__riscv_compressed and dissociate hanlding of misaligned traps and
OpenSBI compilation.
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
We should use MTINST CSR in misaligned load/store emulation whenever
possible to avoid unpriv read in getting trapped instruction. This will
improve preformance on HW having proper implementation of MTINST CSR.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
The hypervisor v0.5 spec introduces two new CSRs for both M-mode
and HS-mode which need to be considered when redirecting traps
hence this patch.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
The unpriv APIs can be useful to external firmware and out-of-tree
platform support code.
This patch adds "sbi_" prefix to unpriv load/store APIs and rename
struct riscv_unpriv to struct sbi_trap_info everywhere. We also
place struct sbi_trap_info in sbi/sbi_trap.h so that we can use
it for sbi_trap_redirect() as well.
Overall, this patch will make naming of unpriv APIs consistent
with other OpenSBI APIs.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
We don't need to set VSSTATUS.MXR bit in get_insn() for
unpriv instruction read because MSTATUS.MXR bit applies
to both "Stage1" and "Stage2" page tables.
This also allows us to remove the "virt" parameter of
get_insn() function.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
Current implementation of get_insn() is not suitable for reading
instruction from VS/VU mode because we have to set SSTATUS_MXR bit
in VSSTATUS CSR for reading instruction from VS/VU mode.
This patch extends get_insn() to read instruction from VS/VU mode.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
We can get a page/access trap when doing unpriv load/store in
get_insn() function because on a SMP system Linux swapper running
on HART A can unmap pages from page table used by HART B.
To tackle this we extend get_insn() implementation so that if
we get trap in get_insn() then we redirect it to S-mode as fetch
page/access fault.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Currently, we mandate 'F' and 'D' extension in riscv_fp.h so that
misaligned load/store emulation has access to FP registers.
The above is too restrictive and we should certainly allow compilation
for soft-FP toolchains and explicit PLATFORM_RISCV_ISA not having 'F'
and 'D' extensions.
This patch extends riscv_fp.h and misaligned load/store emulation to
allow compiling OpenSBI without FP support.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
