C-Class is a member of the SHAKTI family of processors from Indian
Institute of Technology - Madras(IIT-M).
It is an extremely configurable and commercial-grade 5-stage in-order
core supporting the standard RV64GCSUN ISA extensions.

https://gitlab.com/shaktiproject/cores/c-class/blob/master/README.md



We add OpenSBI support for Shakti C-class SoC.

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

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

If the platform doesn't support S-Mode don't print the delegation
registers.

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

Changes are made to support our FPGA evaluation board,
it has DDR memory(0xA0000000-0xB0000000).

* Adapt the config.mk to match FPGA evaluation board DDR memory address
* Since the RISC-V CPU core frequency of FPGA might change, so we use the
  fixed TIMER frequency to measure the real CPU core frequency.
* And the UART baudrate has to set to 57600bps for Nuclei FPGA evaluation
  board when CPU core frequency is about 8MHz, otherwise the UART input
  will not work correctly.

Signed-off-by: Huaqi Fang <578567190@qq.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>

This is achieved by removing the 'no-map' property from the
'reserved-memory' node when PMP is present, otherwise we keep it as it
offers a small protection if the OS does not map this region at all.
A new callback in platform_override is introduced and allows to fixup the
device-tree. It is used here to override this new default behaviour on
SiFive Fu540 platforms that has an erratum that prevents S-mode software
to access a PMP protected region using 1GB page table mapping.

If PMP is present, telling the OS not to map the reserved regions does not
add much protection since it only avoids access to regions that are already
protected by PMP. But by not allowing the OS to map those regions, it
creates holes in the OS system memory map and prevents the use of
hugepages which would generate, among other benefits, less TLB miss.

Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
Reviewed-by: Atish Patra <atish.patra@wdc.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>

This patch contains the following AE350 specific SBIs:

- get mcache_ctl status
- get mmisc_ctl status
- set mcache_ctl status
- set mmisc_ctl status
- I-cache operation
- D-cache operation
- enable/disable L1-I-cache prefetch
- enable/disable L1-D-cache prefetch
- enable/disable non-blocking load store
- enable/disable write-around

Signed-off-by: Nylon Chen <nylon7@andestech.com>
Reviewed-by: Anup Patel <Anup.Patel@wdc.com>
Reviewed-by: Atish Patra <Atish.Patra@wdc.com>

We add AE350 platform specific SBI handler to implement
AE350 specific SBI calls.

Signed-off-by: Nylon Chen <nylon7@andestech.com>
Reviewed-by: Anup Patel <Anup.Patel@wdc.com>
Reviewed-by: Atish Patra <Atish.Patra@wdc.com>

U-Boot now supports loading Linux kernel image via network and storage
media. Thus, we don't need to use a combined payload containing both
U-Boot & Linux kernel image to boot Linux from U-Boot prompt.

Remove the old documentation.

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

The doxygen config option "USE_MDFILE_AS_MAINPAGE" can be used to set
the main page in doxygen generated pdf. This allows us to remove the
"#mainpage" from the README file which markdown doesn't parse.

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

Now that no platform is using FW_PAYLOAD_FDT mechanism, we
remove related code from Makefile and related documentation.

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

We update kendryte/k210 to use new mechanism of having builtin DTB
where we convert k210.dts to C source and further compile-n-link it
with libplatsbi.a.

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

Currently, we can only include one DTB as builtin for a platform
using FDT_PAYLOAD_DTB make variable in platform config.mk.

This patch adds new mechanism using which we can convert any DTS
file to C source and futher compile-n-link it with libplatsbi.a.

The generated C source will have the DTB contents as an array
"const char <varprefix>_start[]" where <varprefix> is specified
in platform objects.mk makefile.

Example1
--------
If we have built-in k210.dts and desired <varprefix> is
"dt_k210" then specify following in platform objects.mk:
platform-objs-y += k210.o
platform-varprefix-k210.o = dt_k210

Example2
--------
If we have built-in abc/k210.dts and desired <varprefix> is
"dt_abc_k210" then specify following in platform objects.mk:
platform-objs-y += abc/k210.o
platform-varprefix-abc-k210.o = dt_abc_k210

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

In order to use GCC style defines and macros in DTS, we should
preporcess builtin DTS before converting it to DTB.

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

Currently, the fw_platform_init() does not return anything but we can
further improve by allowing fw_platform_init() to return updated FDT
location.

It is certainly not mandatory for fw_platform_init() to return a new
location of FDT (or modify FDT). In fact, the fw_platform_init() can
always return the original FDT location (i.e. 'arg1') unmodified.

This new capability of fw_platform_init() will allow platforms to:
1. Have multiple built-in FDTs and select one
2. Modify FDT before using based on platform specific straps or OTP

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

Currently, we are ORing FW_OPTIONS with the options passed by
previous booting stage to fw_dynamic. This causes confusion
because compiling fw_dynamic with FW_OPTIONS=0x2 does not force
enable boot prints as the U-Boot SPL passes options=0x1 in
fw_dyanmic_info.

The best thing to do is always prefer FW_OPTIONS when available.
This is intuitive for OpenSBI users and easy in debugging.

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

Currently, fw_prev_arg1() is called after fw_platform_init() which
caused builtin DTB to be not available to fw_platform_init().

To allow builtin DTB available to fw_platform_init(), we should
call fw_save_info() and fw_prev_arg1() before fw_platform_init().

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

The make rule for builtin DTB compilation does not consider
out-of-tree platforms so this patch fixes it.

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

We can have multiple matching DT nodes of the same FDT timer driver
so in this case we should call cold_init() for all matching DT nodes
instead of just first matching DT node.

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

We can have multiple matching DT nodes of the same FDT ipi driver
so in this case we should call cold_init() for all matching DT nodes
instead of just first matching DT node.

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

We add fdt_parse_clint_node() function which will be used by
fdt_ipi_clint and fdt_timer_clint drivers to parse CLINT details
from DT node.

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

We extend CLINT cold init function to have a "struct clint_data *"
parameter pointing to CLINT details. This allows platforms to use
CLINT functions for multiple CLINT instances.

When multiple CLINTs are present, the platform can also provide
one of the CLINT as reference CLINT for other CLINTs. This will
help CLINTs to sync their time value with reference CLINT using
a time_delta computed in warm init function.

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

We can have multiple matching DT nodes of the same FDT irqchip
driver so in this case we should call cold_init() for all matching
DT nodes instead of just first matching DT node.

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

We extend fdt_find_match() implementation by adding node offset
parameter which represents the first node to match from.

The improved fdt_find_match() can be used to find multiple
match nodes.

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

We extend all PLIC functions to have a "struct plic_data *"
parameter pointing to PLIC details. This allows platforms to
use these functions for multiple PLIC instances.

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

The "target_hart" and "hart_count" parameters of PLIC cold and
warm init functions are only used for sanity checks and not
required in PLIC initialization.

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

Cc: Abner Chang <abner.chang@hpe.com>
Signed-off-by: Daniel Schaefer <git@danielschaefer.me>
Reviewed-by: Anup Patel <anup.patel@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 remove extra spaces from boot time prints.

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>

Signed-off-by: Daniel Schaefer <git@danielschaefer.me>
Reviewed-by: Anup Patel <anup.patel@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>