428 Commits

Author SHA1 Message Date
Anup Patel
ff4769bf08 lib: utils: Add simple FDT based HSM driver framework
The generic platform can have multiple HSM drivers so add a simple
FDT based HSM driver framework.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
2024-12-06 09:26:40 +05:30
Anup Patel
9d760b810e lib: utils/fdt: Allow dynamic registration of FDT fixup callbacks
It should possible to fixup FDT from any part of OpenSBI so add
fdt_register_general_fixup() which allows dynamic registration of
FDT fixup callbacks.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
2024-12-06 09:26:38 +05:30
Subrahmanya Lingappa
13f55f33a1 lib: utils/suspend: Add RPMI system suspend driver
Add RPMI based system suspend driver.

To test this, execute the follwoing in Linux:
 $ echo mem > /sys/power/state

To wake up, execute the following command on qemu monitor terminal:
 (qemu) system_wakeup

Signed-off-by: Subrahmanya Lingappa <slingappa@ventanamicro.com>
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
2024-12-06 09:26:32 +05:30
Anup Patel
3676324b0e lib: utils: Add simple FDT based system suspend driver framework
The generic platform can have multiple system suspend drivers so add a
simple FDT based system suspend driver framework.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
2024-12-06 09:26:29 +05:30
Rahul Pathak
6a26726e08 lib/utils: reset: Add RPMI System Reset driver
Add RPMI based driver for system reset and enable it in the generic
platform defconfig

Signed-off-by: Rahul Pathak <rpathak@ventanamicro.com>
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
2024-12-06 09:26:27 +05:30
Rahul Pathak
91f46fb47e lib/utils: Add RPMI messaging protocol and shared memory transport support
The RISC-V Platform Management Interface (RPMI) defines a messaging protocol
and shared memory based transport for bi-directional communication with an
on-chip or external microcontroller.

To support RPMI in OpenSBI, add:
1) The RPMI messaging protocol defines and helper macros
2) A FDT mailbox driver for the RPMI shared memory transport

Signed-off-by: Rahul Pathak <rpathak@ventanamicro.com>
Co-developed-by: Subrahmanya Lingappa <slingappa@ventanamicro.com>
Signed-off-by: Subrahmanya Lingappa <slingappa@ventanamicro.com>
Co-developed-by: Anup Patel <apatel@ventanamicro.com>
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
2024-12-06 09:26:21 +05:30
Anup Patel
2244a34f0d lib: utils/mailbox: Add simple FDT based mailbox framework
Add a simple FDT based mailbox framework which is built on top of the generic
mailbox library. The phandle of FDT mailbox DT node is treated as the unique
mailbox controller ID which is required by the generic mailbox library. The
FDT based mailbox drivers will be probed on-demand from fdt_mailbox_request_chan()
called by the mailbox client drivers.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
2024-12-06 09:26:19 +05:30
Anup Patel
ad846a7cb8 lib: utils/mailbox: Add generic mailbox library
Add generic mailbox library which is independent of hardware description
format. The OpenSBI platform support or mailbox drivers can register
mailbox controller instances which can be discovered and used by different
mailbox client drivers. Each mailbox controller instance has a unique ID
which can be used by mailbox client drivers for find the mailbox controller
instance. The mailbox client drivers will typically request a mailbox channel
from the mailbox controller and use it to do data transfer with the remote
end of mailbox channel.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
2024-12-06 09:26:13 +05:30
Samuel Holland
a387a8dff0 lib: utils/timer: Use fdt_driver for initialization
The timer driver subsystem does not need any extra data, so it can use
`struct fdt_driver` directly. The generic fdt_timer_init() performs a
best-effort initialization of all matching DT nodes.

Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2024-11-28 17:57:20 +05:30
Samuel Holland
a524f0a507 lib: utils/serial: Use fdt_driver for initialization
The serial driver subsystem does not need any extra data, so it can use
`struct fdt_driver` directly. The generic fdt_serial_init() first
attempts to match the chosen stdout device, and upon failure matches the
first available serial device in the DT. It is a fatal error if no such
device is found. This matches the behavior of fdt_driver_init_one().

Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2024-11-28 17:52:58 +05:30
Samuel Holland
6d9ad492db lib: utils/reset: Use fdt_driver for initialization
The reset driver subsystem does not need any extra data, so it can use
`struct fdt_driver` directly. The generic fdt_reset_init() performs a
best-effort initialization of all matching DT nodes. Platform-specific
logic expects exactly one DT node to match a single driver. This is
accomplished by using fdt_driver_init_one() with a local list containing
that one driver.

Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2024-11-28 17:48:17 +05:30
Samuel Holland
1f8db2f18f lib: utils/regmap: Use fdt_driver for initialization
The regmap driver subsystem does not need any extra data, so it can use
`struct fdt_driver` directly. It always initializes the driver for a
specific DT node.

Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2024-11-28 17:45:29 +05:30
Samuel Holland
5fa510c5f6 lib: utils/ipi: Use fdt_driver for initialization
The ipi driver subsystem does not need any extra data, so it can use
`struct fdt_driver` directly. The generic fdt_ipi_init() performs a
best-effort initialization of all matching DT nodes.

Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2024-11-28 17:42:05 +05:30
Samuel Holland
333133edaa lib: utils/i2c: Use fdt_driver for initialization
The i2c driver subsystem does not need any extra data, so it can use
`struct fdt_driver` directly. It always initializes the driver for a
specific DT node.

Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2024-11-28 17:38:05 +05:30
Samuel Holland
bef8f9b806 lib: utils/gpio: Use fdt_driver for initialization
FDT gpio drivers have an extra .xlate operation, so they need to embed
the `struct fdt_driver` inside the subsystem-specific type. The gpio
subsystem always initializes the driver for a specific DT node.

Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2024-11-28 17:29:12 +05:30
Samuel Holland
1ccc52c427 lib: utils/fdt: Add helpers for generic driver initialization
Currently, each driver subsystem contains its own code for matching
drivers against the platform's devicetree blob. This bloats firmware
size because the several FDT scanning loops are almost exact copies of
each other, and is confusing because the loops do have some subtle
differences. Furthermore, the existing match algorithm is inefficient:
it scans the FDT structure separately for each driver in the list. A
faster algorithm scans the FDT blob only once, matching all drivers in
the list for each `compatible` property seen.

Add new helpers implementing this faster algorithm. Since they must
iterate through the list of drivers, the driver structure cannot be
opaque. However, since the driver list is an array of pointers, the
`struct fdt_driver` can be embedded in a subsystem-specific driver
structure if needed. These three helpers cover all existing use cases
for driver initialization within OpenSBI.

An additional benefit of centralized driver initialization is the
consistent use of fdt_node_is_enabled().

Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2024-11-28 17:13:05 +05:30
Samuel Holland
df1c100001 treewide: Make carray arrays const and NULL-terminated
This allows the compiler to generate significantly better code, because
it does not have to maintain either the loop counter or loop limit. Plus
there are half as many symbols to relocate. This also simplifies passing
carray arrays to helper functions.

Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2024-11-28 17:09:17 +05:30
Samuel Holland
111772353f lib: sbi_irqchip: Set the IRQ handler when registering a chip
In addition to saving some code size, this moves the decision about
setting the top-level external interrupt handler to the irqchip core,
not the specific driver, which would be needed to support chained
interrupt handlers.

Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2024-11-28 11:51:56 +05:30
Samuel Holland
678f5909a3 platform: Drop irqchip warm init and exit hooks
Now that driver lifecycle is managed from within the SBI irqchip core,
platforms need only to initialize the driver once during cold init.
Remove the remaining platform hooks that are no longer used.

Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2024-11-28 11:46:36 +05:30
Samuel Holland
2dd6eaf680 lib: sbi_irqchip: Call driver warm_init from SBI core
Currently, each platform keeps track of which irqchip driver is in use
and calls its warm init function. Since the generic platform may use
multiple irqchip drivers, it has logic to track an array of drivers.

The code is simplified and made common across platforms by treating warm
init and exit as properties of the driver, not the platform. Then the
platform's only role is to select and prepare a driver during cold boot.

For now, only add a .warm_init hook, since none of the existing drivers
need an .exit hook. It could be added in the future if needed.

Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2024-11-28 11:40:17 +05:30
Samuel Holland
e3e5686ef9 lib: sbi_irqchip: Register devices during cold init
Have the SBI irqchip core keep track of registered irqchip devices. This
is useful for any callbacks the irqchip driver may have, such as for
warm initialization, the external interrupt handler function, and any
future support for handling external interrupts (beyond IPIs) in M-mode.

This improves on the tracking done in fdt_irqchip.c, as it tracks device
instances, not just drivers, so callbacks can target a specific device.

Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2024-11-28 11:37:25 +05:30
Samuel Holland
56fddce83f lib: utils/irqchip: Move per-hart data from fdt_plic to plic
The per-hart PLIC pointer is not really specific to FDT platforms. Move
it into the main driver and drop the extra wrapper functions.

Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2024-11-28 11:35:01 +05:30
Samuel Holland
c6c22f00f4 lib: utils/irqchip: plic: Common PM save/restore
Move the PLIC save/restore functions inside the driver, so they can be
reused on any platform that needs them. The memory needed to store the
PLIC context is also allocated by the driver. The PM data cannot be
completely encapsulated, as some platforms (including Allwinner D1) need
to program the IRQ enable status to a sideband interrupt controller for
wakeup capability.

Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2024-11-28 11:28:38 +05:30
Samuel Holland
69448a0790 lib: utils/irqchip: plic: Provide a hartindex to context map
This removes platform-specific arguments to plic_warm_irqchip_init(),
which makes the driver independent from the platform after cold init,
and allows for further refactoring.

Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2024-11-28 09:36:46 +05:30
Samuel Holland
c26e3fd2ed lib: utils/irqchip: plic: Move delegation to base PLIC driver
This needs to be in the base PLIC driver as part of the power management
save/restore flow.

This is also in preparation for moving the PLIC information in the
scratch area to the base PLIC driver. After that change, the FDT PLIC
layer will be unable to look up the `struct plic_data` after cold boot.

Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2024-11-28 09:35:11 +05:30
Samuel Holland
a786aed08d lib: utils/irqchip: plic: Allow enabling IRQs by default
Unlike other platforms, Ariane and OpenPiton enable all IRQs by default.
This was described in commit b44e844880 ("Add support for Ariane FPGA
SoC") as "due to some issue of the design." Add this workaround behind a
flag in plic_warm_irqchip_init(), so every platform can use the same
warm init function.

Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2024-11-28 09:35:10 +05:30
Samuel Holland
86d2c1797a platform: Drop IPI warm init and exit hooks
Now that the SBI IPI core clears IPIs at warm boot in a generic way,
none of the drivers or platforms use these hooks, and we can remove
them. Platforms need only to initialize the driver once during cold
init. If other hooks are needed in the future, they can be added to
struct sbi_ipi_device.

Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2024-11-11 18:21:04 +05:30
Samuel Holland
693afc818f lib: sbi_ipi: Move initial IPI clear to sbi_ipi_init()
sbi_ipi_init() expects the platform warm init function to clear IPIs
on the local hart, but there is already a generic function to do this.
After this change, none of the existing drivers need a warm init
callback.

Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2024-11-11 18:18:35 +05:30
Samuel Holland
be9752a071 lib: sbi_ipi: Make .ipi_clear always target the current hart
All existing users of this operation target the current hart, and it
seems unlikely that a future user will need to clear the pending IPI
status of a remote hart. Simplify the logic by changing .ipi_clear (and
its wrapper sbi_ipi_raw_clear()) to always operate on the current hart.

This incidentally fixes a bug introduced in commit 78c667b6fc ("lib:
sbi: Prefer hartindex over hartid in IPI framework"), which changed the
.ipi_clear parameter from a hartid to a hart index, but failed to update
the warm_init functions to match.

Fixes: 78c667b6fc ("lib: sbi: Prefer hartindex over hartid in IPI framework")
Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2024-11-11 18:17:15 +05:30
Samuel Holland
9782b8847d lib: utils/regmap: Use FDT node offset as regmap ID
Since the FDT is not modified during driver initialization, node offsets
are just as suitable as phandles for use as identifiers: they are stable
and unique. With this change, it is no longer necessary to pass the
phandle to the driver init functions, so these init functions now use
the same prototype as other kinds of drivers.

This matches what is already done for I2C adapters.

Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2024-11-05 17:54:41 +05:30
Samuel Holland
d71150ee70 lib: utils/gpio: Use FDT node offset as GPIO chip ID
Since the FDT is not modified during driver initialization, node offsets
are just as suitable as phandles for use as identifiers: they are stable
and unique. With this change, it is no longer necessary to pass the
phandle to the driver init functions, so these init functions now use
the same prototype as other kinds of drivers.

This matches what is already done for I2C adapters.

Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2024-11-05 17:54:39 +05:30
Samuel Holland
598cf961d8 lib: utils/gpio: Remove fdt_gpio_driver() function
This function looks up a chip's driver by matching known drivers against
chip->driver, but that is equivalent to using chip->driver directly.

Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2024-11-05 17:54:37 +05:30
Samuel Holland
99b01ab610 platform: Drop timer warm init and exit hooks
Now that driver lifecycle is managed from within the SBI timer core,
platforms need only to initialize the driver once during cold init.
Remove the remaining platform hooks that are no longer used.

Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2024-11-05 17:39:31 +05:30
Samuel Holland
4500828743 lib: sbi_timer: Call driver warm_init from SBI core
Currently, the platform's timer device is tracked in two places: the
core SBI implementation has `timer_dev`, and the FDT timer layer has
`current_driver`. The latter is used for warm initialization of the
timer device. However, this warm init is not specific to FDT-based
platforms; other platforms call exactly the same functions from the
same point in the boot sequence.

The code is simplified and made common across platforms by treating warm
init and exit as properties of the driver, not the platform. Then the
platform's only role is to select and prepare a driver during cold boot.

For now, only add a .warm_init hook, since none of the existing drivers
need an .exit hook. It could be added in the future if needed.

Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2024-11-05 17:29:13 +05:30
Samuel Holland
3e0c170397 lib: utils/gpio: designware: Allocate chips on the heap
This reduces firmware size for SoCs which do not use this driver.

Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2024-10-28 10:40:25 +05:30
Anup Patel
2d517fce9b lib: utils/fdt: Use sbi_domain_memregion_init() when parsing domains
Use sbi_domain_memregion_init() at the time of parsing domains from
FDT so that sbi_domain_memregion_init() is always used for setting
up all memregions.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Samuel Holland <samuel.holland@sifive.com>
2024-10-25 23:00:02 +05:30
Anup Patel
dc5d747af8 lib: utils/irqchip: Use sbi_domain_root_add_memrange() for APLIC
The sbi_domain_root_add_memrange() should be preferred for creating
multiple memregions over a range. Update APLIC driver to use
sbi_domain_root_add_memrange() instead of explicitly registering
memregions.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Samuel Holland <samuel.holland@sifive.com>
2024-10-25 22:59:58 +05:30
Anup Patel
abc68e881d lib: utils/irqchip: Use sbi_domain_root_add_memrange() for IMSIC
The sbi_domain_root_add_memrange() should be preferred for creating
multiple memregions over a range. Update IMSIC driver to use
sbi_domain_root_add_memrange() instead of explicitly registering
memregions.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Samuel Holland <samuel.holland@sifive.com>
2024-10-25 22:59:56 +05:30
Anup Patel
8576ca4234 lib: utils/ipi: Use sbi_domain_root_add_memrange() for ACLINT mswi
The sbi_domain_root_add_memrange() should be preferred for creating
multiple memregions over a range. Update ACLINT mswi driver to use
sbi_domain_root_add_memrange() instead of explicitly registering
memregions.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Samuel Holland <samuel.holland@sifive.com>
2024-10-25 22:59:54 +05:30
Samuel Holland
cae230c935 lib: utils/ipi: Fix hartid wrongly used as hart index
Since commit 78c667b6fc ("lib: sbi: Prefer hartindex over hartid in
IPI framework"), The .ipi_clear callback functions take a hart index,
not a hartid. However, these warm_init functions were never updated.

Fixes: 78c667b6fc ("lib: sbi: Prefer hartindex over hartid in IPI framework")
Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2024-09-27 10:42:24 +05:30
Samuel Holland
9f86524b58 lib: sbi: Update sbi_domain_is_assigned_hart() to take a hart index
This removes redundant hartid to hartindex conversions from four call
sites and provides a net reduction in code size.

Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2024-09-26 16:29:25 +05:30
Samuel Holland
7f5fa9f9a4 lib: utils/irqchip: Look up IMSIC data by hart index
This avoids needing to map a hartid to a hart index.

Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2024-09-25 18:06:59 +05:30
Zhang RunMin
ef4520b1c6 lib: Delete redundant ulong
In `csr_read_allowed` and `csr_write_allowed` macros, has already
converted second param to `ulong`. So delete redundant `ulong`
where uses csr_read/write_allowed macros.

Signed-off-by: Zhang RunMin <runmin.zhang@ingenic.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2024-08-24 14:42:14 +05:30
Gregor Haas
b0ad9e0bdd lib: utils: fdt_domain: Make opensbi-domain optional in CPU node
The domain_support.md documentation states that "the HART to domain instance
assignment can be parsed from the device tree using *optional* DT property
opensbi-domain in each CPU DT node". However, the current implementation does
not treat this parameter as optional when determining which HARTs to assign to
a freshly discovered domain from the device tree, causing an effect where every
HART in the system must be explicitly assigned to a domain only if a domain is
specified in the device tree. Instead, this patch simply ignores CPUs that do
not specify a domain, and does not attempt to assign them into the recently
discovered domain.

Signed-off-by: Gregor Haas <gregorhaas1997@gmail.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2024-08-24 14:08:00 +05:30
Yu Chien Peter Lin
a44df8024b util: atcsmu.c: modify sbi_printf() formatting
Beautify multi-line printing.

Signed-off-by: Leo Yu-Chi Liang <ycliang@andestech.com>
Reviewed-by: Yu Chien Peter Lin <peterlin@andestech.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2024-08-24 13:10:36 +05:30
Leo Yu-Chi Liang
f7a625884c util: atcsmu.c: fix typo "%s/hard/hart/"
%s/hard/hart

Signed-off-by: Leo Yu-Chi Liang <ycliang@andestech.com>
Reviewed-by: Yu Chien Peter Lin <peterlin@andestech.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2024-08-24 13:10:35 +05:30
Samuel Holland
c36801841e lib: utils/serial: Pass the FDT to fdt_serial_init()
Indicate that this function does not modify the FDT blob, and
deduplicate the call to fdt_get_address().

Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2024-08-24 13:03:01 +05:30
Samuel Holland
fa6dfce017 lib: utils/reset: Pass the FDT to fdt_reset_init()
Indicate that this function does not modify the FDT blob, and
deduplicate the call to fdt_get_address().

Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2024-08-24 13:02:58 +05:30
Samuel Holland
b15cc7715a lib: utils/timer: Constify FDT pointers in parsing functions
Indicate that none of these functions modify the devicetree by
constifying the parameter type.

Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2024-08-24 13:02:48 +05:30
Samuel Holland
bd76eb4950 lib: utils/serial: Constify FDT pointers in parsing functions
Indicate that none of these functions modify the devicetree by
constifying the parameter type.

Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2024-08-24 13:02:46 +05:30