We make the the root domain instance global variable so that
platform support and drivers can iterate over the root domain
regions.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Xiang W <wxjstz@126.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>

The CLINT memory should not be accessed by the supervisor-mode
software so let's protect it by adding CLINT memregion to the
root domain.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Xiang W <wxjstz@126.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>

We should allow platform support to add more root memory regions
before domains are finalized. This will help platform support to
protect critical M-mode only resources.

This patch adds sbi_domain_root_add_memregion() API for above
described purpose.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Xiang W <wxjstz@126.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>

This patch adds sbi_domain_memregion_init() helper API which can
be used by platform support to initialize a domain memory region
before adding it to the root domain.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Xiang W <wxjstz@126.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>

The domains are boot-time system-level partitions so we should
allow platform support to register domains only before hart
domain assignments are finalized.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Xiang W <wxjstz@126.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>

Updates link in platforms documentation to point to the correct
OpenPiton document.

Signed-off-by: hasheddan <georgedanielmangum@gmail.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>

The unsigned length may be 4 bytes or 8 bytes, amoadd.w only applies
to 4 bytes hence this patch.

Signed-off-by: Xiang W <wxjstz@126.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>

Replace the test-and-set spinlock implementation with ticket locks
in order to get fairness (in form of FIFO order).

The implementation uses a 32-bit wide struct, which consists of
two 16-bit counters (owner and next). This is inspired by similar
spinlock implementations on other architectures.
This allows that the code works for both, RV32 and RV64.

Signed-off-by: Christoph Muellner <cmuellner@linux.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Xiang W <wxjstz@126.com>

The current implementation of SPIN_LOCK_INIT() provides the spinlock
to be initialized as reference. This does not allow a direct
initialization of the spinlock object at the creation site.

Let's pass the spinlock directly instead (like Linux does as well)
and adjust all users of the macro (in fact there is only one user).

Signed-off-by: Christoph Muellner <cmuellner@linux.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>

The __aligned(x) macro is a common wrapper around compiler's
aligned attribute, which allow to define the minimum alignement
of a data type. Let's add this macro.

Signed-off-by: Christoph Muellner <cmuellner@linux.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>

The "add sp, a0, zero" instruction in the trap restore path is redundant
and can be avoided if TRAP_RESTORE_xyz() assembly macros use a0 as the
base register instead of sp.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Xiang W <wxjstz@126.com>

csr_read_allowed/csr_read_allowed requires trap.case to detect the results,
but if no exception occurs, the value of trap.case will remain unchanged,
which makes the detection results unreliable. Add code to initialize
trap.case to 0.

Signed-off-by: Xiang W <wxjstz@126.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>

There are two copies of the same abnormal exit code, this patch deletes one

Signed-off-by: Xiang W <wxjstz@126.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>

Current fdt_plic_fixup() only does necessary fix-up against the legacy
"riscv,plic0" node. The upstream Linux kernel defines its official DT
bindings which uses "sifive,plic-1.0.0" as the compatible string and
we should check that first, and if not present fall back to legacy.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>

At present fdt_plic_fixup() accepts a 'compat' parameter for PLIC
compatible string. In preparation to support the new DT bindings,
drop this and use "riscv,plic0" directly in fdt_plic_fixup().

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>

Linux kernel commit a2770b57d083 ("dt-bindings: timer: Add CLINT bindings")
adds the official DT bindings for CLINT, which uses "sifive,clint0"
as the compatible string. "riscv,clint0" is now legacy and has to
be kept for backward compatibility of legacy systems.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>

GCC has already a predefined macro __ASSEMBLER__ therefore, it can be
used without the need to define a new flag with -D__ASSEMBLY__.
This is useful when adding the library to projects having a build
system such one can build without the need to make changes.
THe build system does not use the Makefile in the sources tree.

Signed-off-by: Marouene Boubakri <marouene.boubakri@nxp.com>
Signed-off-by: Anup Patel <anup.patel@wdc.com>

The trap handler sbi_emulate_csr_read() invokes hpm_allowed() which reads
CSR 0x306 (mcounteren). The K210 does not support CSR 0x306. While trying
to handle a trap occurring in S-mode code this creates an additional trap
in M-mode. This results in failure to redirect to S-mode and the system
hanging in sbi_hart_hang().

In hart_detect_features() we have already determined if CSR 0x306 is
available and stored that information in the scratch area. We can use this
information to decide if CSR 0x306 shall be accessed in hpm_allowed() and
thus avoid the M-mode trap.

Likewise if CSR scounteren is not available we have to avoid reading CSR
0x106.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Anup Patel <anup.patel@wdc.com>

Enable OpenSBI to support position independent execution. Because the
position independent code will cause an additional GOT reference when
accessing the global variables, it will reduce performance a bit. Therefore,
the position independent execution is disabled by default. Users can
through specifying "FW_PIC=y" on the make command to enable this feature.

In theory, after enabling position-independent execution, the OpenSBI
can run at arbitrary address with appropriate alignment. Therefore, the
original relocation mechanism will be skipped. In other words, OpenSBI will
directly run at the load address without any code movement.

Signed-off-by: Vincent Chen <vincent.chen@sifive.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>

When OpenSBI is compiled as fPIE mode, the assembler will translate "la"
to GOT reference pattern. It will cause to cost an additional load
instruction when obtaining the symbol address. However, if the symbol
locates within the positive or negative 2GB region, we can use "lla"
instead of "la" to avoid unneeded GOT references. This patch assumes that
the OpenSBI image excluding the payload does not exceed 2GB. Based on
this assumption, all "la" instructions are replaced by "lla" to avoid
performance degradation when compiling as fPIE mode.

Signed-off-by: Vincent Chen <vincent.chen@sifive.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>

The SBI function IDs for RFENCE extension must match the SBI specification.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Atish Patra <atish.patra@wdc.com>

The sbi_platform_ipi_clear() called from wait_for_coldboot() and
sbi_hsm_hart_wait() is redundant because IPI will be automatically
cleared by sbi_platform_ipi_init() called from sbi_ipi_init().

Further, wait_for_coldboot() is common for warm startup and warm
resume path so the sbi_platform_ipi_clear() called in warm resume
path cause resuming HART to miss an IPI injected other HART to
wakeup the HART.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>

The OpenSBI SBI implementation is now compliant with latest draft
SBI v0.3 specification so let's upgrade SBI implementation version.

This will also help HSM suspend function detection in S-mode because
HSM suspend function is only present when HSM extension is present
and SBI implementation version is 0.3 (or higher).

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>

This patch implements the SBI HSM suspend function. Using this
new SBI call, the S-mode software can put calling HART in platform
specific suspend (i.e. low-power) state. For a successful retentive
suspend, the SBI call will return without errors upon resuming
whereas for a successful non-retentive suspend, the SBI call will
resume from a user provided resume address.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>

We add hart_suspend() callback in platform operations which will
be used by HSM implementation to enter retentive or non-retentive
suspend state.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>

We add sbi_hart_reinit() function which will re-initialize HART CSRs
assuming HART features are already detected. This new function will
be useful in re-initializing HART after it resumes from HSM SUSPENDED
state.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>

This patch adds SBI HSM suspend related defines to ecall interface
header.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>

The sbi_hsm_hart_start() and sbi_hsm_hart_stop() functions should
only return error codes as defined by the SBI specification.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>

The sbi_hsm_hart_started() function is only used by sbi_hsm_hart_stop()
for checking state of calling HART and current domain assignment.

The atomic_cmpxchg() called by sbi_hsm_hart_stop() will check state of
calling hart anyway and domain assignment can be checked by other domain
function such as sbi_domain_is_assigned_hart().

This means sbi_hsm_hart_started() is redundant and can be removed.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>

A hart can take interrupt in the new HSM states introduced by the
SBI HSM suspend function (such as SUSPENDED state) so we rename
sbi_hsm_hart_started_mask() to something more generic such as
sbi_hsm_hart_interruptible_mask().

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>

We replace the use of SBI_STATE_xyz defines with SBI_HSM_STATE_xyz
defines because the HSM state defines are complete enough to implement
HSM state machine in OpenSBI. As a result of this, we can now remove
sbi_hsm_hart_state_to_status() function because it is now redundant
and sbi_hsm_hart_get_state() can directly return HSM state or error.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>

We simplify HSM state define names so that these defines can directly
replace SBI_HART_xyz defines used by SBI HSM implementation.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>

Implement rebooting the K210 via the system reset extension.

All reset types are treated in the same way.
A request for shutdown results in a reboot.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>

This patch updates OpenSBI version to 0.9 as part of
release preparation.

Signed-off-by: Anup Patel <anup.patel@wdc.com>

This clint driver init functions were incorrectly used in
template platform which resulted in compile error. This patch
fixes clint driver function usage in template platform.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>

We don't need to pack struct sbi_platform and sbi_platform_operations
because GCC ensures member offsets match member data type irrespective
to the target system (RV32 or RV64). This also allows GCC to generate
more optimized instruction sequence when accessing members of struct
sbi_platform and struct sbi_platform_operations.

Reported-by: Paul Campbell <taniwha@gmail.com>
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>

All members in struct sbi_scrach are of machine word size so no need
to pack this structure. This also allows GCC to generate more optimized
instruction sequence when accessing members of struct sbi_scratch.

Reported-by: Paul Campbell <taniwha@gmail.com>
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>

All members in struct sbi_trap_regs are of machine word size so
no need to pack this structure. This also allows GCC to generate
more optimized instruction sequence when accessing members of
struct sbi_trap_regs.

Reported-by: Paul Campbell <taniwha@gmail.com>
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>

Currently, the root domain memory regions are fixed in generic
code but some of the platforms may want to explicitly define
memory regions for the root domain.

This patch adds optional domains_root_regions() platform callback
which platforms can use to provide platform specific root domain
memory regions. Due to this changes, the root domain should also
undergo all sanity checks (just like regular domain) so we use
sbi_domain_register() to register root domain.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>

Fix uart_putc implementation.
Due to a bug in the IP, this went unnoticed.
Use macros instead of magic numbers to make the code
more readable.

Signed-off-by: Vijai Kumar K <vijai@behindbytes.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>