[PATCH v3 07/11] RISC-V: add single letter extensions to riscv_isa_ext

Conor Dooley
2023-07-03T10:29:42Z

So that riscv_fill_hwcap() can use riscv_isa_ext to probe for single
letter extensions, add them to it.
As a result, what gets spat out in /proc/cpuinfo will become borked, as
single letter extensions will be printed as part of the base extensions
and while printing from riscv_isa_arr. Take the opportunity to unify the
printing of the isa string, using the new member of riscv_isa_ext_data
in the process.

Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
---
Changes in v2:
- Drop the multi_letter member, in exchange for calling strnlen() in two
places.
---
arch/riscv/kernel/cpu.c | 37 ++++++++++------------------------
arch/riscv/kernel/cpufeature.c | 13 ++++++++++++
2 files changed, 24 insertions(+), 26 deletions(-)

diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c
index aa17eeb0ec9a..4f1f12f34b63 100644
--- a/arch/riscv/kernel/cpu.c
+++ b/arch/riscv/kernel/cpu.c
@@ -164,41 +164,26 @@ arch_initcall(riscv_cpuinfo_init);

#ifdef CONFIG_PROC_FS

-static void print_isa_ext(struct seq_file *f)
-{
- for (int i = 0; i < riscv_isa_ext_count; i++) {
- const struct riscv_isa_ext_data *edata = &riscv_isa_ext[i];
- if (!__riscv_isa_extension_available(NULL, edata->id))
- continue;
-
- seq_printf(f, "_%s", edata->name);
- }
-}
-
-/*
- * These are the only valid base (single letter) ISA extensions as per the spec.
- * It also specifies the canonical order in which it appears in the spec.
- * Some of the extension may just be a place holder for now (B, K, P, J).
- * This should be updated once corresponding extensions are ratified.
- */
-static const char base_riscv_exts[13] = "imafdqcbkjpvh";
-
static void print_isa(struct seq_file *f)
{
- int i;
-
seq_puts(f, "isa\t\t: ");
+
if (IS_ENABLED(CONFIG_32BIT))
seq_write(f, "rv32", 4);
else
seq_write(f, "rv64", 4);

- for (i = 0; i < sizeof(base_riscv_exts); i++) {
- if (__riscv_isa_extension_available(NULL, base_riscv_exts[i] - 'a'))
- /* Print only enabled the base ISA extensions */
- seq_write(f, &base_riscv_exts[i], 1);
+ for (int i = 0; i < riscv_isa_ext_count; i++) {
+ if (!__riscv_isa_extension_available(NULL, riscv_isa_ext[i].id))
+ continue;
+
+ /* Only multi-letter extensions are split by underscores */
+ if (strnlen(riscv_isa_ext[i].name, 2) != 1)
+ seq_puts(f, "_");
+
+ seq_printf(f, "%s", riscv_isa_ext[i].name);
}
- print_isa_ext(f);
+
seq_puts(f, "\n");
}

diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
index 6d8cd45af723..bf7e8e8852f0 100644
--- a/arch/riscv/kernel/cpufeature.c
+++ b/arch/riscv/kernel/cpufeature.c
@@ -144,6 +144,19 @@ static bool riscv_isa_extension_check(int id)
* New entries to this struct should follow the ordering rules described above.
*/
const struct riscv_isa_ext_data riscv_isa_ext[] = {
+ __RISCV_ISA_EXT_DATA(i, RISCV_ISA_EXT_i),
+ __RISCV_ISA_EXT_DATA(m, RISCV_ISA_EXT_m),
+ __RISCV_ISA_EXT_DATA(a, RISCV_ISA_EXT_a),
+ __RISCV_ISA_EXT_DATA(f, RISCV_ISA_EXT_f),
+ __RISCV_ISA_EXT_DATA(d, RISCV_ISA_EXT_d),
+ __RISCV_ISA_EXT_DATA(q, RISCV_ISA_EXT_q),
+ __RISCV_ISA_EXT_DATA(c, RISCV_ISA_EXT_c),
+ __RISCV_ISA_EXT_DATA(b, RISCV_ISA_EXT_b),
+ __RISCV_ISA_EXT_DATA(k, RISCV_ISA_EXT_k),
+ __RISCV_ISA_EXT_DATA(j, RISCV_ISA_EXT_j),
+ __RISCV_ISA_EXT_DATA(p, RISCV_ISA_EXT_p),
+ __RISCV_ISA_EXT_DATA(v, RISCV_ISA_EXT_v),
+ __RISCV_ISA_EXT_DATA(h, RISCV_ISA_EXT_h),
__RISCV_ISA_EXT_DATA(zicbom, RISCV_ISA_EXT_ZICBOM),
__RISCV_ISA_EXT_DATA(zicboz, RISCV_ISA_EXT_ZICBOZ),
__RISCV_ISA_EXT_DATA(zicntr, RISCV_ISA_EXT_ZICNTR),
--
2.40.1