This patch adds proper support for per-domain floating-point (FP) and
vector (V) contexts in the domain context switch logic. Each domain
now maintains its own FP and vector state, which is saved and restored
during domain switches.
Conditionalize FP and Vector save/restore based on extensions, unconditional
save and restore of floating-point (FP) and Vector registers fails on
generic platform firmware. This firmware must run on multiple platforms
that may lack these extensions.
Address this by conditionally executing FP save/restore only if the underlying
hart supports the F or D extensions. Similarly, perform Vector save/restore
only if the hart supports the Vector extension.
This improves support for multi-domain systems with FP and Vector
extensions, and prevents corruption of FP/Vector state during domain
switches.
Signed-off-by: Dave Patel <dave.patel@riscstar.com>
Signed-off-by: Anup Patel <anup.patel@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20260518083023.997323-4-anup.patel@oss.qualcomm.com
Signed-off-by: Anup Patel <anup@brainfault.org>
Add support for saving and restoring RISC-V floating-point (F/D) extension
state in OpenSBI. This introduces a floating-point context structure and
helper routines to perform full context save and restore.
The floating-point context includes storage for all 32 FPi registers (f0–f31)
along with the fcsr control and status register. The register state is saved
and restored using double-precision load/store instructions (fsd/fld), and
single-precision load/store instructions (fsw/flw) on an RV64 system with
F and D-extension support.
The implementation follows an eager context switching model where the entire
FP state is saved and restored on every context switch. This avoids the need
for trap-based lazy management and keeps the design simple and deterministic.
Signed-off-by: Dave Patel <dave.patel@riscstar.com>
Signed-off-by: Anup Patel <anup.patel@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20260518083023.997323-3-anup.patel@oss.qualcomm.com
Signed-off-by: Anup Patel <anup@brainfault.org>
Eager context switch: Add support for saving and restoring RISC-V vector
extension state in OpenSBI. This introduces a per-hart vector context
structure and helper routines to perform full context save and restore.
The vector context includes vcsr CSRs along with storage for all 32 vector
registers. The register state is saved and restored using byte-wise vector
load/store instructions (vs8r/vl8r).
The implementation follows an eager context switching model where the entire
vector state is saved and restored on every context switch. This provides a
simple and deterministic mechanism without requiring lazy trap-based
management.
Signed-off-by: Dave Patel <dave.patel@riscstar.com>
Signed-off-by: Anup Patel <anup.patel@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20260518083023.997323-2-anup.patel@oss.qualcomm.com
Signed-off-by: Anup Patel <anup@brainfault.org>
sbi_domain_check_addr_range() computes `max = addr + size` without
checking for integer overflow. When a caller passes a size large enough
to wrap around (e.g. addr=0x80000000, size=0xFFFFFFFF80000000), max
becomes less than addr, causing the while(addr < max) validation loop
to be skipped entirely. The function then returns true without
performing any permission checks.
This allows an S-mode caller to bypass domain memory protection and
access M-mode memory through SBI extensions that use address range
validation (e.g. DBCN console write/read).
Add an overflow check after computing max: if size is non-zero and
max wrapped to a value <= addr, reject the request.
Signed-off-by: Takumi Hara <takumihara1226@gmail.com>
Reviewed-by: Rahul Pathak <rahul@summations.net>
Link: https://lore.kernel.org/r/20260319132232.51572-1-takumihara1226@gmail.com
Signed-off-by: Anup Patel <anup@brainfault.org>
Add a simple SpacemiT I2C driver for basic byte transfers over the I2C
bus, prioritizing simplicity over performance. The driver operates in
PIO mode and does not use interrupts, FIFO, or DMA.
The controller is reset at the start of each transaction to ensure a
known initial state, regardless of prior configuration by the kernel.
This also avoids the need for additional error recovery code.
This will be used for communication with onboard PMIC to reset and
power-off the board.
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Tested-by: Anand Moon <linux.amoon@gmail.com>
Link: https://lore.kernel.org/r/20260419150857.2705843-2-aurelien@aurel32.net
Signed-off-by: Anup Patel <anup@brainfault.org>
The reg_stride field represents the address stride in bytes between
consecutive registers. The Linux kernel regmap framework validates
register accesses using IS_ALIGNED(reg, map->reg_stride) as an address
alignment check (drivers/base/regmap/regmap.c). The Linux kernel syscon
driver (drivers/mfd/syscon.c) sets reg_stride directly to reg_io_width:
syscon_config.reg_stride = reg_io_width;
The current OpenSBI code incorrectly multiplies reg_io_width by 8,
converting a byte value to bits. Fix this by using reg_io_width directly
as the stride value, consistent with the Linux kernel.
Fixes: f21d8f7d59 ("lib: utils/regmap: Add simple FDT based syscon regmap driver")
Signed-off-by: David E. Garcia Porras <david.garcia@aheadcomputing.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/20260403202903.3407945-1-david.garcia@aheadcomputing.com
Signed-off-by: Anup Patel <anup@brainfault.org>
Currently when searching for a hardware counter for an event, if no
programmable counter is available, the code falls back to using a fixed
counter (mcycle/minstret) if one matches the event.
However the fallback is incorrect when sscofpmf is present but
smcntrpmf is not. That's because with sscofpmf, programmable counters
support mode filtering, but the fixed counters do not (without
smcntrpmf). Even if the caller didn't configure mode filtering, by
default programmable counters don't count M mode when sscofpmf is
present, whereas mcycle/minstret do.
Fix the logic to not fallback to a fixed counter if sscofpmf is present
but smcntrpmf is not.
Fixes: 0c304b6619 ("lib: sbi: Allow programmable counters to monitor cycle/instret events")
Signed-off-by: Michael Ellerman <mpe@kernel.org>
Reviewed-by: Anup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/20260324-mcycle-fix-v1-1-1444e9fe5c32@kernel.org
Signed-off-by: Anup Patel <anup@brainfault.org>
When using GDB for debugging, if FW_TEXT_START is not set to 0x80000000
during compilation, the following error occurs:
Reading symbols from build/platform/generic/firmware/fw_payload.elf...
Remote debugging using localhost:1234
mips_warm_boot ()
at /home/zrmin/opensbi/platform/generic/mips/mips_warm_boot.S:11
11 j _start_warm
(gdb) b _start
Breakpoint 1 at 0x0: file /home/zrmin/opensbi/firmware/fw_base.S, line 50.
(gdb) c
Continuing.
Remote connection closed
(gdb)
With FW_TEXT_START=0x80000000, debugging works correctly:
Reading symbols from build/platform/generic/firmware/fw_payload.elf...
Remote debugging using localhost:1234
0x0000000000001000 in ?? ()
(gdb) b _start
Breakpoint 1 at 0x80000000: file /home/zrmin/opensbi/firmware/fw_base.S, line 50.
(gdb) c
Continuing.
Breakpoint 1, _start () at /home/zrmin/opensbi/firmware/fw_base.S:50
50 MOV_3R s0, a0, s1, a1, s2, a2
(gdb)
This is because QEMU loads OpenSBI at address 0x80000000. When
FW_TEXT_START does not match this address, the debug symbols are
incorrectly offset, causing GDB to fail to set breakpoints properly.
Signed-off-by: Zhang RunMin <runmin.zhang@ingenic.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/20260319125641.480161-1-runmin.zhang@ingenic.com
Signed-off-by: Anup Patel <anup@brainfault.org>
The following compile error is seen with LLVM compiler:
CC platform/generic/lib/utils/mpxy/fdt_mpxy_rpmi_mm.o
lib/utils/mpxy/fdt_mpxy_rpmi_mm.c:17:6: error: use of GNU 'missing =' extension in
designator [-Werror,-Wgnu-designator]
17 | [0] {
| ^
| =
lib/utils/mpxy/fdt_mpxy_rpmi_mm.c:24:6: error: use of GNU 'missing =' extension in
designator [-Werror,-Wgnu-designator]
24 | [1] {
| ^
| =
2 errors generated.
Add missing "=" in mm_srvcdata[] array initialization to address
the above issue.
Fixes: 0b041e58c0 ("lib: utils: Add MPXY client driver for RPMI MM service group")
Signed-off-by: Anup Patel <anup.patel@oss.qualcomm.com>
Reviewed-by: Ranbir Singh <ranbir.singh@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20260509161849.2935816-1-anup.patel@oss.qualcomm.com
Signed-off-by: Anup Patel <anup@brainfault.org>
The location of the RNMI/E trap vectors in the Smrnmi extension is
implementation-defined, so platforms with vendor-specific NMI vector
mechanisms must install the firmware's NMI entry points themselves.
Add an smrnmi_handlers_init() callback to sbi_platform_operations that
receives the firmware entry points and lets platform code install them
at the hardware-specific vector locations. Two pointers are passed:
- _trap_rnmi_handler: the dedicated RNMI entry point that saves
context using the Smrnmi MN* CSRs and returns via mnret.
- _trap_handler: the regular M-mode trap entry since RNME is taken
as a regular M-mode trap with NMIE=0.
When Smrnmi is present, install the platform's NMI vectors via the new
callback, initialize MNSCRATCH with the per-hart scratch pointer, and
set MNSTATUS.NMIE.
Smrnmi-enabled platforms must register smrnmi_handlers_init; if the
extension is detected but no callback is registered, sbi_panic() is
called since enabling NMIs without handlers in place would route
subsequent traps into nowhere.
Signed-off-by: Evgeny Voevodin <evvoevod@tenstorrent.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/88b1470e1e3348d454b4b995a11a85c01914f7af.1778176768.git.evvoevod@tenstorrent.com
Signed-off-by: Anup Patel <anup@brainfault.org>
Current placement of entropy initialization via Zkr extension requires a
trap-based mechanism to handle absent Zkr extension case. In presence of
Smrnmi extension no trap-based mechanisms should be used before Smrnmi is
detected and enabled otherwise trap will jump to undefined location.
Move stack guard initialization into init_coldboot function body after
device tree has been parsed so we know if Zkr extension is implemented by
the platform which helps to avoid trap-based discovery.
init_coldboot() is a safe place to initialize entropy because it doesn't
return so no check of __stack_chk_guard against value on entry
will be done.
Signed-off-by: Evgeny Voevodin <evvoevod@tenstorrent.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/acd52b0f3468758bc5f09e6a45662341b31d4d87.1778176768.git.evvoevod@tenstorrent.com
Signed-off-by: Anup Patel <anup@brainfault.org>
Implement basic Resumable NMI (RNMI) handler support for the RISC-V
Smrnmi extension.
The new _trap_rnmi_handler assembly entry point saves context using the
Smrnmi MN* CSRs (MNSCRATCH, MNEPC, MNSTATUS, MNCAUSE) and returns via
mnret. It dispatches to sbi_trap_rnmi_handler(), which optionally calls
a platform-specific ops->rnmi_handler callback for actual NMI
processing. If no platform handler is registered or it fails, the
event is reported as an unhandled NMI.
The RNMI handler reuses the generic trap context structure but stores MN*
CSR values (MNEPC, MNSTATUS, MNCAUSE) into the corresponding generic
fields (mepc, mstatus, cause) for compatibility with existing trap
infrastructure.
Signed-off-by: Evgeny Voevodin <evvoevod@tenstorrent.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/050ae6d2762ba8d5b9dfb3cc1960a23aa3d6c549.1778176768.git.evvoevod@tenstorrent.com
Signed-off-by: Anup Patel <anup@brainfault.org>
The original sbi_strchr implementation did not conform to the C standard
behavior. According to the C standard and POSIX specification, strchr(s, 0)
should return a pointer to the null terminator at the end of string s.
The previous implementation used a while loop that would terminate when
either reaching the end of string or finding the character, but it would
return NULL when searching for the null terminator instead of returning
a pointer to the null terminator itself.
The fixed implementation uses a do-while loop that ensures even when
searching for the null terminator, the function correctly returns a
pointer to the null terminator position rather than NULL.
This fix ensures sbi_strchr behavior aligns with standard library
function semantics, making it more predictable and safe for users
expecting standard C library behavior.
Signed-off-by: Chen Pei <cp0613@linux.alibaba.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/20260306094425.1918-3-cp0613@linux.alibaba.com
Signed-off-by: Anup Patel <anup@brainfault.org>
Set a default MMIO region with a single SmePMP entry, which allows us
to save entries for M-mode only devices. The default entry has M-/S-mode
shared permission, so system-level resource protection, such as RISC-V
World extension and WorldGuard checker, will be introduced to protect
M-mode only region access from lower privilege modes.
Reviewed-by: Greentime Hu <greentime.hu@sifive.com>
Reviewed-by: Zong Li <zong.li@sifive.com>
Signed-off-by: Yu-Chien Peter Lin <peter.lin@sifive.com>
Link: https://lore.kernel.org/r/20260224031733.3817148-3-peter.lin@sifive.com
Signed-off-by: Anup Patel <anup@brainfault.org>
It is possible to have platform where an irqchip device targets
a subset of harts and there are multiple irqchip devices to cover
all harts.
To support this scenario:
1) Add target_harts hartmask to struct sbi_irqchip_device which
represents the set of harts targetted by the irqchip device
2) Call warm_init() and process_hwirqs() callbacks of an irqchip
device on a hart only if irqchip device targets that particular
hart
Signed-off-by: Anup Patel <anup.patel@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20260213055342.3124872-6-anup.patel@oss.qualcomm.com
Signed-off-by: Anup Patel <anup@brainfault.org>
Samuel Holland