Commit Graph

30 Commits

Author SHA1 Message Date
Clément Léger
3ac49712e3 lib: sbi: sse: Add support for SSTATUS.SDT
Similarly to what is done for SPELP, handle SSTATUS.SDT upon event
injection. In order to mimick an interrupt, set SDT to 1 for injection and
save its previous value in interrupted_flags[5:5]. Restore it upon
completion.

Signed-off-by: Clément Léger <cleger@rivosinc.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
2025-03-27 18:16:44 +05:30
Clément Léger
b4464b22e4 lib: sbi: sse: Add support for SSTATUS.SPELP
As raised during the ARC review, SPELP was not handled during the event
injection process. Save it as part of the interrupted flags, clear it
before injecting the event and restore it after completion.

Signed-off-by: Clément Léger <cleger@rivosinc.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
2025-03-27 18:16:28 +05:30
Clément Léger
53d322f8ae lib: sbi: sse: Remove superfluous parenthesis around MSTATUS_* values
For some reason, there was a pair of useless parenthesis around MSTATUS_*
value usage. Remove them.

Signed-off-by: Clément Léger <cleger@rivosinc.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
2025-03-27 18:16:19 +05:30
Clément Léger
41fb89cb29 lib: sbi: sse: Rename STATUS* interrupted flags to SSTATUS*
As raised by Andrew on the kvm-unit-test review, this flags are meant to
hold SSTATUS bits in the specification. Rename them to match that.

Signed-off-by: Clément Léger <cleger@rivosinc.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
2025-03-27 18:15:44 +05:30
Clément Léger
1e7258d6a8 lib: sbi: sse: Return SBI_EDENIED for read only parameters.
The SSE specification did specified that read only parameters should
return SBI_EBADRANGE but was modified recently to return SBI_EDENIED.

Signed-off-by: Clément Léger <cleger@rivosinc.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
2025-03-27 18:15:25 +05:30
Clément Léger
5dc7a6db6f lib: sbi: sse: Remove printf from sbi_sse_exit()
This printf is mainly useful for debugging, remove it.

Signed-off-by: Clément Léger <cleger@rivosinc.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
2025-03-27 18:15:10 +05:30
Clément Léger
601bea45c5 lib: sbi: sse: Update SSE event ids
The latest specification added new high priority RAS events and renamed
the PMU to PMU_OVERFLOW.

Signed-off-by: Clément Léger <cleger@rivosinc.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
2025-03-27 18:03:41 +05:30
Himanshu Chauhan
b2e8e6986d lib: sbi: Return SBI_EALREADY error code if SSE event is present
Return SBI_EALREADY error code instead of SBI_EINVAL, in case an
event is already added to the supported list.

Signed-off-by: Himanshu Chauhan <hchauhan@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2025-03-23 21:17:36 +05:30
Clément Léger
f354400ebf lib: sbi: sse: fix invalid errors returned for sse_hart_mask/unmask()
When called twice, sse_hart_mask()/sse_hart_unmask() should return
SBI_EALREADY_STOPPED/SBI_EALREADY_STARTED. This was currently inverted.

Fixes: b919daf495 ("lib: sbi: Add support to mask/unmask SSE events")
Reported-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Clément Léger <cleger@rivosinc.com>
Reviewed-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2025-02-19 17:18:13 +05:30
Clément Léger
ecab71e19a lib: sbi: sse: return SBI_ENOTSUPP for unsupported events
If a standard event was not found in the list of events that are handled
by harts but belongs to the standard event list defined by the
specification, return SBI_ENOTSUPP. Without that, we can not
distinguish a non implemented standard event from a non valid one.

Signed-off-by: Clément Léger <cleger@rivosinc.com>
Reviewed-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
2025-01-30 10:42:27 +05:30
Clément Léger
93f7d819fd lib: sbi: sse: allow adding new events
In order to allow events to be dynamically added, remove the existing
static array of events and use a simply linked list of supported events.
This allows us to move the cb_ops into this list and associated it with
an event_id. Drivers can now register cb_ops before bringing up the sse
core to handle additional events (platform ones for instance).

sbi_sse_init() now allocates as many events as present in the linked
list. Events can now be added with sbi_sse_add_event() which allows to
add new supported events with some callback operations if any. If an
event is not to be supported, then sbi_sse_add_event() should not be
called. This approach currently consider that local events are to be
supported on all harts (ie, they all support the same ISA or
dependencies). If per-hart event availability needs to be supported,
then, an is_supported() callback could be added later and called for
each hart.

Signed-off-by: Clément Léger <cleger@rivosinc.com>
Reviewed-by: Samuel Holland <samuel.holland@sifive.com>
2025-01-30 10:40:49 +05:30
Clément Léger
e05782b8ff lib: sbi: sse: return an error value from sse_event_get()
Since event support will be checked in the next commits, return a value
from sse_event_get() to allow propagating it. This will be used to
report SBI_ERR_NOT_SUPPORTED when an event isn't supported.

Signed-off-by: Clément Léger <cleger@rivosinc.com>
Reviewed-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
2025-01-30 10:34:14 +05:30
Clément Léger
b47fcd01b3 lib: sbi: sse: Fix a6 and a7 register content upon injection
The specification states that a6 contains the current hart id and
a7 contains the entry argument. This was inverted in the current
implementation.

Reported-by: Andrew Jones <andrew.jones@linux.dev>
Signed-off-by: Clément Léger <cleger@rivosinc.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2024-12-15 11:53:53 +05:30
Clément Léger
b0a7e4b853 lib: sbi: send a double trap SSE event to supervisor
In case the double trap handler is called and the double trap happened
in supervisor mode, send a double trap SSE event.

NOTE: this commit depends on the ratification of the new SSE event
id for double trap [1].

Link: https://lists.riscv.org/g/tech-prs/message/985 [1]
Signed-off-by: Clément Léger <cleger@rivosinc.com>
Reviewed-by: Samuel Holland <samuel.holland@sifive.com>
2024-10-25 23:58:39 +05:30
Himanshu Chauhan
b919daf495 lib: sbi: Add support to mask/unmask SSE events
Add functions to globally mask/unmask supervisor software events
on the calling hart.

Signed-off-by: Himanshu Chauhan <hchauhan@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2024-10-25 23:04:43 +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
d73a4c741c lib: sbi_sse: Cache the event's target hart index
This avoids needing to map the target hartid to a hart index when
enabling or disabling an event, and provides a net code size reduction.

Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2024-09-25 18:04:25 +05:30
Clément Léger
70f3441452 lib: sse: remove unused sse_inject_out() parameter
This parameters was a remnant of a previous version, remove it now that
it is unused.

Signed-off-by: Clément Léger <cleger@rivosinc.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2024-08-24 13:15:58 +05:30
Anup Patel
94c3c53a56 lib: sbi: Allow forceful queueing of data in sbi_fifo_enqueue()
Extend sbi_fifo_enqueue() to allow forceful queueing by droping
data from the tail.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-By: Himanshu Chauhan <hchauhan@ventanamicro.com>
2024-07-24 12:18:36 +05:30
Clément Léger
ae5ef1848d lib: sbi: sse: handle missing writable attributes
The spec states that a6, a7, flags and sepc are writable but the
implementation was not allowing that. Add support for these 4 writable
attributes.

Signed-off-by: Clément Léger <cleger@rivosinc.com>
Reviewed-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2024-05-23 10:53:02 +05:30
Anup Patel
533067d182 lib: sbi: Put event after use in sbi_sse_exit() loop
Currently, the sbi_sse_exit() gets event in a loop but does not put
it back after use. This results in global events remaining locked
causing hangs on sub-sequent calls to sse_event_get() for global
events.

Fixes: c8cdf01d8f ("lib: sbi: Add support for Supervisor Software Events extension")
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Himanshu Chauhan <hchauhan@ventanamicro.com>
2024-05-15 11:54:43 +05:30
Clément Léger
033104da08 lib: sbi: sse: check handler entry to belong to supervisor mode
When registering an SSE event, check for the handler_entry_pc to belong
to supervisor mode domain using sbi_domain_check_addr_range().

Signed-off-by: Clément Léger <cleger@rivosinc.com>
Reported-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2024-05-07 17:31:08 +05:30
Clément Léger
bd007658f8 lib: sbi: sse: use PRV_S instead of hardcoded value for mode
Rather then passing 1 to sbi_domain_check_addr_range() for supervisor
mode, use PRV_S.

Signed-off-by: Clément Léger <cleger@rivosinc.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2024-05-07 17:29:36 +05:30
Clément Léger
ce3c82cb2e lib: sbi: sse: call enable callback before sending IPI
Move the enable callback call before sending the IPI. Even though the
event is locked and no race condition can happen, this is more logical.

Signed-off-by: Clément Léger <cleger@rivosinc.com>
Reported-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2024-05-07 17:28:44 +05:30
Clément Léger
d528dbfd4b lib: sbi: sse: remove superfluous sbi_list_empty() check
The list loop below that check is actually not looping if the list is
empty so there was no need for this check.

Signed-off-by: Clément Léger <cleger@rivosinc.com>
Reported-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2024-05-07 17:27:31 +05:30
Clément Léger
22ff75099c lib: sbi: sse: simplify 32bits overflow check
Rather than checking 32bits overflow with some absolute value, check the
value to be different from the cast itself.

Signed-off-by: Clément Léger <cleger@rivosinc.com>
Reported-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2024-05-07 17:26:14 +05:30
Clément Léger
7aa80ea495 lib: sbi: sse: rename sse_hart_unlock() to sse_enabled_event_unlock()
There was a naming incoherency between enabled events list lock/unlock.
Rename sse_hart_unlock() to sse_enabled_event_unlock() to be coherent
and reword comments above lock()/unlock() functions.

Signed-off-by: Clément Léger <cleger@rivosinc.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2024-05-07 17:25:28 +05:30
Clément Léger
c21c99db6a lib: sbi: sse: fix typos, comments and spacing errors
Fix some errors spotted by Samuel while reviewing the SSE implementation.

Signed-off-by: Clément Léger <cleger@rivosinc.com>
Reported-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2024-05-07 17:24:11 +05:30
Heinrich Schuchardt
37e1544a86 lib: sbi: sse_event_get() may return NULL
sse_event_get() may return NULL. We should not dereference the return value
in sbi_sse_exit() without checking.

Fixes: c8cdf01d8f ("lib: sbi: Add support for Supervisor Software Events extension")
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2024-04-10 09:38:24 +05:30
Clément Léger
c8cdf01d8f lib: sbi: Add support for Supervisor Software Events extension
This extension [1] allows to deliver events from SBI to supervisor via
a software mechanism. This extension defines events (either local or
global) which are signaled by the SBI on specific signal sources (IRQ,
exceptions, etc) and are injected to be executed in supervisor mode.

[1] https://lists.riscv.org/g/tech-prs/message/798

Signed-off-by: Clément Léger <cleger@rivosinc.com>
Reviewed-by: Himanshu Chauhan <hchauhan@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2024-04-05 15:47:30 +05:30