We improve HPM CSR read/write emulation as follows:
1. Fail for unimplemented counters so that trap is redirected
to S-mode which can further help debugging S-mode software.
2. Check permissions in both MCOUNTEREN and SCOUNTEREN for
HS-mode and U-mode.
3. Don't check permissions for TIME CSR because we emulate
TIME CSR for both Host (HS/U-mode) and Guest (VS/VU-mode).
Also, faster TIME CSR read is very helpful for good
performance of S-mode software.
4. Don't emulate S-mode CSR read/write to M-mode HPM CSRs
because these should not be accessible to S-mode software.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
A RISC-V platform can leave unimplemented MHPM counters hard-wired
to zero. We extend hart_detect_features() to detect MHPM counters
which are accessible and not hard-wired to zero. We also print
number of available MHPM counters as part of boot prints.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
As-per latest RISC-V privilege spec up to 64 PMP entries are supported.
Implementations may implement zero, 16, or 64 PMP CSRs. All PMP CSR
fields are WARL and may be hardwired to zero.
This patch improves PMP CSR detection and progamming considering
above facts.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
The SBI_HART_HAS_PMP feature is redundant because we already
have number of PMP regions returned by sbi_hart_pmp_count().
Checking whether PMP is supported for a HART can be simply done
by checking non-zero value returned by sbi_hart_pmp_count().
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
The Kendryte K210 follows RISC-V v1.9 spec so MTVAL has instruction
address (instead of instruction encoding) on illegal instruction trap.
To handle above case, we fix sbi_illegal_insn_handler() without any
impact on RISC-V v1.10 (or higher) systems. This achieved by exploiting
the fact that program counter (and instruction address) is always 2-byte
aligned in RISC-V world.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Tested-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Bin Meng <bin.meng@windriver.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
We can have thundering hurd problem with coldboot_lock where the
boot HART can potentially starve trying to acquire coldboot_lock
because some of the non-boot HARTs are continuously acquiring and
releasing coldboot_lock. This can happen if MIP.MSIP bit is already
set for some of the non-boot HARTs.
To avoid thundering hurd problem for coldboot_lock, we use the
__smp_load_acquire() and __smp_store_release() for coldboot_done
flag and use coldboot_lock only for coldboot_wait_hmask.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Tested-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Bin Meng <bin.meng@windriver.com>
When redirecting from VS/VU-mode to HS-mode, hstatus.SPVP was set
to the value of mstatus.SPP, as according to the specification both
flags should be set to the same value.
However, the assignment of SPVP takes place before SPP itself is
updated, which results in SPVP having an outdated value.
Signed-off-by: Georg Kotheimer <georg.kotheimer@tu-dresden.de>
Reviewed-by: Anup Patel <anup.patel@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 should only return valid error codes from SBI ecalls as
defined by the RISC-V SBI spec.
To achieve this:
1. We use SBI_Exxxx defines for OpenSBI internal errors with
error values starting from -1000
2. We use SBI_ERR_xxxx defines for errors defined by SBI spec
3. We map some of the SBI_Exxxx defines to SBI_ERR_xxxx defines
which are semantically same
4. We throw a error print and force return error code to
SBI_ERR_FAILED in sbi_ecall_handler() if we see an invalid
error code being returned to S-mode
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
On RV64,"unsigned long" is 64bit and "unsigned int" is 32bit. So in
function "pmp_get" and "pmp_set", if "pmpcfg_shift >= 32", "0xff << pmpcfg_shift"
will go beyond "unsigned int" width. This patch tries to fix this issue.
In function 'pmp_get':
cfgmask = (0xff << pmpcfg_shift);
-->
cfgmask = (0xffUL << pmpcfg_shift);
In function 'pmp_set':
cfgmask = ~(0xff << pmpcfg_shift);
-->
cfgmask = ~(0xffUL << pmpcfg_shift);
Signed-off-by: Liush <liush.damon@gmail.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
The arguments/parameters of __sbi_hfence_gvma_vmid_gpa() and
__sbi_hfence_vvma_asid_va() functions are swapped so we fix it.
Currently, we did not face any issues because QEMU does a full
TLB flush for all HFENCE instructions.
We also improve documentation of HFENCE.GVMA and HFENCE.VVMA
instruction encoding.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
To support RISC-V hypervisor v0.6.1, we:
1. Don't need to explicitly forward WFI traps from VS/VU-mode
2. Have to delegate virtual instruction trap to HS-mode
3. Have to update trap redirection for changes in HSTATUS CSR
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
It is not mandatory for a RISC-V systems to implement all PMP
regions so we have to check all PMPADDRx CSRs to determine excat
number of supported PMP regions.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
This patch does few cosmetic improvements to HART feature detection:
1. Remove sbi_ perfix from HART feature detection functions
because all local/static functions in sbi_hart.c don't have
sbi_ prefix
2. Remove sbi_hart_set_feature() because it's quite small and
local/static in sbi_hart.c
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
It makes more sense to have scratch pointer as parameter in
HART feature APIs because:
1. We already have scratch pointer at places where these APIs
are used.
2. This is consistent with lot of other APIs in sbi_hart.h
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
On platforms with continuous HART ids starting from zero:
0 <= boot HART id < platform HART count
The above co-relation of boot HART id and platform HART count
is true for most RISC-V platfors so it's better to print platform
HART count just before boot HART id.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
We do following improvements for get_feature_str():
1. We should return "none" from get_feature_str() no features
available instead of sbi_boot_prints() explicitly handling
failure.
2. We don't need to return failure (just like misa_xlen())
because we are returning "none" for no features and we are
truncating output when space is not available.
3. Based on 1 and 2, the sbi_boot_prints() can be further
simplified.
4. No need for two char[] in sbi_boot_prints()
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
We should detect HART features in sbi_hart_init() before
mstatus_init(), delegate_traps() and pmp_init().
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
Currently, unprivileged access functions uses few additional instructions
which are redundant. It also uses specific registers which are not necessary.
Remove those additional instructions and let the compiler choose the
registers.
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
We have now clear distinction between platform and hart features.
Modify the boot print messages to print hart specific features in
a string format.
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Tested-by: Jonathan Balkind <jbalkind@cs.princeton.edu>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
We have now clear distinction between platform and hart features.
Modify the boot print messages to print platform features in a string
format. In the process, this patch moved relatively larger functions
to its own file from platform.h header file.
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Tested-by: Jonathan Balkind <jbalkind@cs.princeton.edu>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
As per the RISC-V specification, time value can be obtained from a time
CSR implemented in hardware or a MMIO based IP block. Qemu virt machine
already supports timer csr while CLINT provides the timer for other
platforms.
Implement a hart specific timer feature that can be detected at runtime.
As CSR based timer implementation are faster than MMIO address based, it
is always preferred over MMIO based one.
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Tested-by: Jonathan Balkind <jbalkind@cs.princeton.edu>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
PMP & performance counters belong to a hart rather than a platform.
In addition to that, these features enable reading/writing from a
particular csr. Thus, they can be detected and set at runtime rather
than compile time.
Move PMP/MCOUNTEREN/SCOUNTEREN features to hart and detect them at runtime.
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Tested-by: Jonathan Balkind <jbalkind@cs.princeton.edu>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
There may be some features which are hart specific rather than a platform
specific feature. Add a framework to support that.
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Tested-by: Jonathan Balkind <jbalkind@cs.princeton.edu>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
There may be few common mathematics helper functions which can be used
anywhere in OpenSBI project.
Add a separate math helper function file to add these functions.
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
Unprivileged trap handler can be reused for any cases where the executing
code expects a trap.
Rename it to "expected" trap handler as it will be used in other cases in
future.
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Tested-by: Jonathan Balkind <jbalkind@cs.princeton.edu>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
The RISC-V ISA string does not follow alphabetical order. Instead,
we have a RISC-V specific ordering of extensions in the RISC-V ISA
string. This patch improves misa_string() implementation to return
a valid RISC-V ISA string.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
The HFENCE VVMA instructions flushes TLB based on the VMID
present in HGATP CSR. To handle this, we get the current
VMID for SBI HFENCE VVMA call and we use this current VMID
to do remote TLB HFENCE VVMA on desired set of HARTs.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
Now that we have generic platform which detects hart count from
DTB, we should print platform hart count at boot time.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
We can achieve shutdown, cold reboot, and warm reboot using just
one sbi_platform callback so we combine system_reboot() and
system_shutdown() callbacks into one system_reset() callback.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
The default (usually last) PMP region provides S-mode access to
complete memory range not covered by other PMP regions.
Currently, the default PMP region is described as platform specific
PMP region which is not appropriate because all platforms need it
and default PMP region should be part of generic library.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Ideally, the SBI implementation ID for OpenSBI should always be
0x1 (as mentioned in SBI v0.2 spec) but external firmware (such
as EDK2) which use OpenSBI as library might want to override the
SBI implementation ID with their custom implementation ID.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
Enable vector context in mstatus by updating the corresponding bits
in mstatus if vector extension is supported by the hart.
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
This patch removes scratch parameter from sbi_dprintf() function
because sbi_dprintf() can use sbi_scratch_thishart_ptr() to get
current HART scratch space.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
The sbi_ipi_send_many() should get current HART scratch pointer
on it's own using eventually hence removing scratch parameter from
sbi_tlb_request().
Signed-off-by: Anup Patel <anup.patel@wdc.com>
The patch adds sbi_scratch_last_hartid() API which returns
last HART id having a scratch space. We can use this new API
to optimize places where we iterate over HART id from 0 to
SBI_HARTMASK_MAX_BITS.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
We should remove the "arch_" prefix from atomic xchg() and cmpxchg()
function names to have consistent naming of all atomic functions.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
The priv parameter in hart_start() platform callback is redundant hence
we remove it.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
This patch simplify sbi_trap_handler() API as follows:
1. Remove current hartid local variable because sbi_trap_handler()
itself does not need it.
2. Remove scratch parameter because none of the functions directly
called by sbi_trap_handler() require it.
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 ecall 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>
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>
We remove mcause, scratch and hartid parameters from various
functions for illegal instruction 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>
We remove scratch and hartid parameter from various functions
for CSR emulation 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>
