12 Commits

Author SHA1 Message Date
Samuel Holland
62ff262227
riscv: Use the same CPU operations for all CPUs
RISC-V provides no binding (ACPI or DT) to describe per-cpu start/stop
operations, so cpu_set_ops() will always detect the same operations for
every CPU. Replace the cpu_ops array with a single pointer to save space
and reduce boot time.

Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20231121234736.3489608-4-samuel.holland@sifive.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-01-04 15:03:07 -08:00
Samuel Holland
79093f3ec3
riscv: Remove unused members from struct cpu_operations
name is not used anywhere at all. cpu_prepare and cpu_disable do nothing
and always return 0 if implemented.

Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20231121234736.3489608-3-samuel.holland@sifive.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-01-04 15:03:06 -08:00
Andrew Jones
41cad8284d
RISC-V: Align SBI probe implementation with spec
sbi_probe_extension() is specified with "Returns 0 if the given SBI
extension ID (EID) is not available, or 1 if it is available unless
defined as any other non-zero value by the implementation."
Additionally, sbiret.value is a long. Fix the implementation to
ensure any nonzero long value is considered a success, rather
than only positive int values.

Fixes: b9dcd9e41587 ("RISC-V: Add basic support for SBI v0.2")
Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230427163626.101042-1-ajones@ventanamicro.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-04-29 13:04:50 -07:00
Conor Dooley
87df2b5cbc
riscv: ensure cpu_ops_sbi is declared
Sparse complains that cpu_ops_sbi is used undeclared:
arch/riscv/kernel/cpu_ops_sbi.c:17:29: warning: symbol 'cpu_ops_sbi' was not declared. Should it be static?

Fix the warning by adding cpu_ops_sbi to cpu_ops_sbi.h & including that
where used.

Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20220714080235.3853374-1-conor.dooley@microchip.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-08-11 13:46:51 -07:00
Ben Dooks
da6d2128e5
RISC-V: Declare cpu_ops_spinwait in <asm/cpu_ops.h>
The cpu_ops_spinwait is used in a couple of places in arch/riscv
and is causing a sparse warning due to no declaration. Add this
to <asm/cpu_ops.h> with the others to fix the following:

arch/riscv/kernel/cpu_ops_spinwait.c:16:29: warning: symbol 'cpu_ops_spinwait' was not declared. Should it be static?

Signed-off-by: Ben Dooks <ben.dooks@sifive.com>
Link: https://lore.kernel.org/r/20220714071811.187491-1-ben.dooks@sifive.com
[Palmer: Drop the extern from cpu_ops.c]
Fixes: 2ffc48fc7071 ("RISC-V: Move spinwait booting method to its own config")
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-08-11 13:06:47 -07:00
Atish Patra
2ffc48fc70
RISC-V: Move spinwait booting method to its own config
The spinwait booting method should only be used for platforms with older
firmware without SBI HSM extension or M-mode firmware because spinwait
method can't support cpu hotplug, kexec or sparse hartid. It is better
to move the entire spinwait implementation to its own config which can
be disabled if required. It is enabled by default to maintain backward
compatibility and M-mode Linux.

Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-01-20 09:27:16 -08:00
Atish Patra
c78f94f35c
RISC-V: Use __cpu_up_stack/task_pointer only for spinwait method
The __cpu_up_stack/task_pointer array is only used for spinwait method
now. The per cpu array based lookup is also fragile for platforms with
discontiguous/sparse hartids. The spinwait method is only used for
M-mode Linux or older firmwares without SBI HSM extension. For general
Linux systems, ordered booting method is preferred anyways to support
cpu hotplug and kexec.

Make sure that __cpu_up_stack/task_pointer is only used for spinwait
method. Take this opportunity to rename it to
__cpu_spinwait_stack/task_pointer to emphasize the purpose as well.

Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-01-20 09:27:08 -08:00
Atish Patra
410bb20a69
RISC-V: Do not print the SBI version during HSM extension boot print
The HSM extension information log also prints the SBI version v0.2. This
is misleading as the underlying firmware SBI version may be different
from v0.2.

Remove the unncessary printing of SBI version.

Signed-off-by: Atish Patra <atishp@rivosinc.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-01-20 09:27:03 -08:00
Joe Perches
33def8498f treewide: Convert macro and uses of __section(foo) to __section("foo")
Use a more generic form for __section that requires quotes to avoid
complications with clang and gcc differences.

Remove the quote operator # from compiler_attributes.h __section macro.

Convert all unquoted __section(foo) uses to quoted __section("foo").
Also convert __attribute__((section("foo"))) uses to __section("foo")
even if the __attribute__ has multiple list entry forms.

Conversion done using the script at:

    https://lore.kernel.org/lkml/75393e5ddc272dc7403de74d645e6c6e0f4e70eb.camel@perches.com/2-convert_section.pl

Signed-off-by: Joe Perches <joe@perches.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@gooogle.com>
Reviewed-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-25 14:51:49 -07:00
Zong Li
d6d5161280
riscv: force __cpu_up_ variables to put in data section
Put __cpu_up_stack_pointer and __cpu_up_task_pointer in data section.
Currently, these two variables are put in bss section, there is a
potential risk that secondary harts get the uninitialized value before
main hart finishing the bss clearing. In this case, all secondary
harts would pass the waiting loop and enable the MMU before main hart
set up the page table.

This issue happens on random booting of multiple harts, which means
it will manifest for BBL and OpenSBI v0.6 (or older version). In OpenSBI
v0.7 (or higher version), we have HSM extension so all the secondary harts
are brought-up by Linux kernel in an orderly fashion. This means we don't
need this change for OpenSBI v0.7 (or higher version).

Signed-off-by: Zong Li <zong.li@sifive.com>
Reviewed-by: Greentime Hu <greentime.hu@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-05-04 15:03:25 -07:00
Atish Patra
cfafe26013
RISC-V: Add supported for ordered booting method using HSM
Currently, all harts have to jump Linux in RISC-V. This complicates the
multi-stage boot process as every transient stage also has to ensure all
harts enter to that stage and jump to Linux afterwards. It also obstructs
a clean Kexec implementation.

SBI HSM extension provides alternate solutions where only a single hart
need to boot and enter Linux. The booting hart can bring up secondary
harts one by one afterwards.

Add SBI HSM based cpu_ops that implements an ordered booting method in
RISC-V. This change is also backward compatible with older firmware not
implementing HSM extension. If a latest kernel is used with older
firmware, it will continue to use the default spinning booting method.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-03-31 11:27:50 -07:00
Atish Patra
2875fe0561
RISC-V: Add cpu_ops and modify default booting method
Currently, all non-booting harts start booting after the booting hart
updates the per-hart stack pointer. This is done in a way that, it's
difficult to implement any other booting method without breaking the
backward compatibility.

Define a cpu_ops method that allows to introduce other booting methods
in future. Modify the current booting method to be compatible with
cpu_ops.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-03-31 11:25:56 -07:00