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RISC-V: hwprobe: Expose Zba, Zbb, and Zbs

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Add two new bits to the IMA_EXT_0 key for ZBA, ZBB, and ZBS extensions.
These are accurately reported per CPU.

Signed-off-by: Evan Green <evan@rivosinc.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Heiko Stuebner <heiko.stuebner@vrull.eu>
Link: https://lore.kernel.org/r/20230509182504.2997252-4-evan@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
This commit is contained in:
Evan Green 2023-05-09 11:25:03 -07:00 committed by Palmer Dabbelt
parent 82e9c66e81
commit c0baf32103
No known key found for this signature in database
GPG key ID: 2E1319F35FBB1889
3 changed files with 54 additions and 7 deletions
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10
Documentation/riscv/hwprobe.rst
View file

@ -64,6 +64,16 @@ The following keys are defined:
* :c:macro:`RISCV_HWPROBE_IMA_C`: The C extension is supported, as defined
by version 2.2 of the RISC-V ISA manual.
* :c:macro:`RISCV_HWPROBE_EXT_ZBA`: The Zba address generation extension is
supported, as defined in version 1.0 of the Bit-Manipulation ISA
extensions.
* :c:macro:`RISCV_HWPROBE_EXT_ZBB`: The Zbb extension is supported, as defined
in version 1.0 of the Bit-Manipulation ISA extensions.
* :c:macro:`RISCV_HWPROBE_EXT_ZBS`: The Zbs extension is supported, as defined
in version 1.0 of the Bit-Manipulation ISA extensions.
* :c:macro:`RISCV_HWPROBE_KEY_CPUPERF_0`: A bitmask that contains performance
information about the selected set of processors.

3
arch/riscv/include/uapi/asm/hwprobe.h
View file

@ -25,6 +25,9 @@ struct riscv_hwprobe {
#define RISCV_HWPROBE_KEY_IMA_EXT_0 4
#define RISCV_HWPROBE_IMA_FD (1 << 0)
#define RISCV_HWPROBE_IMA_C (1 << 1)
#define RISCV_HWPROBE_EXT_ZBA (1 << 2)
#define RISCV_HWPROBE_EXT_ZBB (1 << 3)
#define RISCV_HWPROBE_EXT_ZBS (1 << 4)
#define RISCV_HWPROBE_KEY_CPUPERF_0 5
#define RISCV_HWPROBE_MISALIGNED_UNKNOWN (0 << 0)
#define RISCV_HWPROBE_MISALIGNED_EMULATED (1 << 0)

48
arch/riscv/kernel/sys_riscv.c
View file

@ -121,6 +121,46 @@ static void hwprobe_arch_id(struct riscv_hwprobe *pair,
pair->value = id;
}
static void hwprobe_isa_ext0(struct riscv_hwprobe *pair,
const struct cpumask *cpus)
{
int cpu;
u64 missing = 0;
pair->value = 0;
if (has_fpu())
pair->value |= RISCV_HWPROBE_IMA_FD;
if (riscv_isa_extension_available(NULL, c))
pair->value |= RISCV_HWPROBE_IMA_C;
/*
* Loop through and record extensions that 1) anyone has, and 2) anyone
* doesn't have.
*/
for_each_cpu(cpu, cpus) {
struct riscv_isainfo *isainfo = &hart_isa[cpu];
if (riscv_isa_extension_available(isainfo->isa, ZBA))
pair->value |= RISCV_HWPROBE_EXT_ZBA;
else
missing |= RISCV_HWPROBE_EXT_ZBA;
if (riscv_isa_extension_available(isainfo->isa, ZBB))
pair->value |= RISCV_HWPROBE_EXT_ZBB;
else
missing |= RISCV_HWPROBE_EXT_ZBB;
if (riscv_isa_extension_available(isainfo->isa, ZBS))
pair->value |= RISCV_HWPROBE_EXT_ZBS;
else
missing |= RISCV_HWPROBE_EXT_ZBS;
}
/* Now turn off reporting features if any CPU is missing it. */
pair->value &= ~missing;
}
static u64 hwprobe_misaligned(const struct cpumask *cpus)
{
int cpu;
@ -164,13 +204,7 @@ static void hwprobe_one_pair(struct riscv_hwprobe *pair,
break;
case RISCV_HWPROBE_KEY_IMA_EXT_0:
pair->value = 0;
if (has_fpu())
pair->value |= RISCV_HWPROBE_IMA_FD;
if (riscv_isa_extension_available(NULL, c))
pair->value |= RISCV_HWPROBE_IMA_C;
hwprobe_isa_ext0(pair, cpus);
break;
case RISCV_HWPROBE_KEY_CPUPERF_0: