[PATCH v1 6/9] RISC-V: add single letter extensions to riscv_isa_ext

Conor Dooley
2023-06-26T11:21:12Z

So that riscv_fill_hwcap() can use riscv_isa_ext to probe for single
letter extensions, add them to it. riscv_isa_ext_data grows a new
member, signifying whether an extension is multi-letter & thus requiring
special handling.
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.

Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
---
arch/riscv/include/asm/hwcap.h | 1 +
arch/riscv/kernel/cpu.c | 36 ++++++----------------
arch/riscv/kernel/cpufeature.c | 56 +++++++++++++++++++++-------------
3 files changed, 46 insertions(+), 47 deletions(-)

diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hwcap.h
index a35bee219dd7..6ad896dc4342 100644
--- a/arch/riscv/include/asm/hwcap.h
+++ b/arch/riscv/include/asm/hwcap.h
@@ -77,6 +77,7 @@ unsigned long riscv_get_elf_hwcap(void);
struct riscv_isa_ext_data {
const unsigned int id;
const char *name;
+ const bool multi_letter;
};

extern const struct riscv_isa_ext_data riscv_isa_ext[];
diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c
index beb8b16bbf87..046d9d3dac16 100644
--- a/arch/riscv/kernel/cpu.c
+++ b/arch/riscv/kernel/cpu.c
@@ -160,41 +160,25 @@ 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;
+
+ if (riscv_isa_ext[i].multi_letter)
+ 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 b5e23506c4f0..5405d8a58537 100644
--- a/arch/riscv/kernel/cpufeature.c
+++ b/arch/riscv/kernel/cpufeature.c
@@ -99,9 +99,10 @@ static bool riscv_isa_extension_check(int id)
return true;
}

-#define __RISCV_ISA_EXT_DATA(_name, _id) { \
- .name = #_name, \
- .id = _id, \
+#define __RISCV_ISA_EXT_DATA(_name, _id, _multi) { \
+ .name = #_name, \
+ .id = _id, \
+ .multi_letter = _multi, \
}

/*
@@ -144,24 +145,37 @@ 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(zicbom, RISCV_ISA_EXT_ZICBOM),
- __RISCV_ISA_EXT_DATA(zicboz, RISCV_ISA_EXT_ZICBOZ),
- __RISCV_ISA_EXT_DATA(zicntr, RISCV_ISA_EXT_ZICNTR),
- __RISCV_ISA_EXT_DATA(zicsr, RISCV_ISA_EXT_ZICSR),
- __RISCV_ISA_EXT_DATA(zifencei, RISCV_ISA_EXT_ZIFENCEI),
- __RISCV_ISA_EXT_DATA(zihintpause, RISCV_ISA_EXT_ZIHINTPAUSE),
- __RISCV_ISA_EXT_DATA(zihpm, RISCV_ISA_EXT_ZIHPM),
- __RISCV_ISA_EXT_DATA(zba, RISCV_ISA_EXT_ZBA),
- __RISCV_ISA_EXT_DATA(zbb, RISCV_ISA_EXT_ZBB),
- __RISCV_ISA_EXT_DATA(zbs, RISCV_ISA_EXT_ZBS),
- __RISCV_ISA_EXT_DATA(smaia, RISCV_ISA_EXT_SMAIA),
- __RISCV_ISA_EXT_DATA(ssaia, RISCV_ISA_EXT_SSAIA),
- __RISCV_ISA_EXT_DATA(sscofpmf, RISCV_ISA_EXT_SSCOFPMF),
- __RISCV_ISA_EXT_DATA(sstc, RISCV_ISA_EXT_SSTC),
- __RISCV_ISA_EXT_DATA(svinval, RISCV_ISA_EXT_SVINVAL),
- __RISCV_ISA_EXT_DATA(svnapot, RISCV_ISA_EXT_SVNAPOT),
- __RISCV_ISA_EXT_DATA(svpbmt, RISCV_ISA_EXT_SVPBMT),
- __RISCV_ISA_EXT_DATA("", RISCV_ISA_EXT_MAX),
+ __RISCV_ISA_EXT_DATA(i, RISCV_ISA_EXT_i, false),
+ __RISCV_ISA_EXT_DATA(m, RISCV_ISA_EXT_m, false),
+ __RISCV_ISA_EXT_DATA(a, RISCV_ISA_EXT_a, false),
+ __RISCV_ISA_EXT_DATA(f, RISCV_ISA_EXT_f, false),
+ __RISCV_ISA_EXT_DATA(d, RISCV_ISA_EXT_d, false),
+ __RISCV_ISA_EXT_DATA(q, RISCV_ISA_EXT_q, false),
+ __RISCV_ISA_EXT_DATA(c, RISCV_ISA_EXT_c, false),
+ __RISCV_ISA_EXT_DATA(b, RISCV_ISA_EXT_b, false),
+ __RISCV_ISA_EXT_DATA(k, RISCV_ISA_EXT_k, false),
+ __RISCV_ISA_EXT_DATA(j, RISCV_ISA_EXT_j, false),
+ __RISCV_ISA_EXT_DATA(p, RISCV_ISA_EXT_p, false),
+ __RISCV_ISA_EXT_DATA(v, RISCV_ISA_EXT_v, false),
+ __RISCV_ISA_EXT_DATA(h, RISCV_ISA_EXT_h, false),
+ __RISCV_ISA_EXT_DATA(zicbom, RISCV_ISA_EXT_ZICBOM, true),
+ __RISCV_ISA_EXT_DATA(zicboz, RISCV_ISA_EXT_ZICBOZ, true),
+ __RISCV_ISA_EXT_DATA(zicntr, RISCV_ISA_EXT_ZICNTR, true),
+ __RISCV_ISA_EXT_DATA(zicsr, RISCV_ISA_EXT_ZICSR, true),
+ __RISCV_ISA_EXT_DATA(zifencei, RISCV_ISA_EXT_ZIFENCEI, true),
+ __RISCV_ISA_EXT_DATA(zihintpause, RISCV_ISA_EXT_ZIHINTPAUSE, true),
+ __RISCV_ISA_EXT_DATA(zihpm, RISCV_ISA_EXT_ZIHPM, true),
+ __RISCV_ISA_EXT_DATA(zba, RISCV_ISA_EXT_ZBA, true),
+ __RISCV_ISA_EXT_DATA(zbb, RISCV_ISA_EXT_ZBB, true),
+ __RISCV_ISA_EXT_DATA(zbs, RISCV_ISA_EXT_ZBS, true),
+ __RISCV_ISA_EXT_DATA(smaia, RISCV_ISA_EXT_SMAIA, true),
+ __RISCV_ISA_EXT_DATA(ssaia, RISCV_ISA_EXT_SSAIA, true),
+ __RISCV_ISA_EXT_DATA(sscofpmf, RISCV_ISA_EXT_SSCOFPMF, true),
+ __RISCV_ISA_EXT_DATA(sstc, RISCV_ISA_EXT_SSTC, true),
+ __RISCV_ISA_EXT_DATA(svinval, RISCV_ISA_EXT_SVINVAL, true),
+ __RISCV_ISA_EXT_DATA(svnapot, RISCV_ISA_EXT_SVNAPOT, true),
+ __RISCV_ISA_EXT_DATA(svpbmt, RISCV_ISA_EXT_SVPBMT, true),
+ __RISCV_ISA_EXT_DATA("", RISCV_ISA_EXT_MAX, true),
};

const size_t riscv_isa_ext_count = ARRAY_SIZE(riscv_isa_ext);
--
2.40.1