On Sat, Apr 30, 2022 at 8:39 AM Frank Chang <frank.ch...@sifive.com> wrote:
>
> Hi Anup,
>
> If we want to limit the generated ISA string to/after a specific privilege
> spec version.
> Shouldn't we also check the privilege spec version when these extensions are
> enabled?
> Otherwise, it's possible that one extension is enabled,
> but the privilege spec version is smaller than the one in which the extension
> is supported.
> (This is possible if user specifies the privileged spec version through the
> command line.)
> The ISA string therefore won't include the enabled extension.
This patch is only a temporary fix for the sifive_u machine where I am
seeing some
of these new extensions available in ISA string.
We need a separate series to have the priv spec version influence
individual extension
enabling/disabling.
Regards,
Anup
>
> Regards,
> Frank Chang
>
>
> On Fri, Apr 29, 2022 at 11:49 PM Anup Patel <apa...@ventanamicro.com> wrote:
>>
>> Most of the multi-letter extensions (such as Svpbmt, Svnapot, Svinval,
>> etc) are only available after Priv spec v1.12 so ISA string generation
>> should check the minimum required priv spec version for all extensions.
>>
>> Fixes: a775398be2e ("target/riscv: Add isa extenstion strings to the
>> device tree")
>> Signed-off-by: Anup Patel <apa...@ventanamicro.com>
>> ---
>> target/riscv/cpu.c | 36 +++++++++++++++++++-----------------
>> 1 file changed, 19 insertions(+), 17 deletions(-)
>>
>> diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
>> index 02ee7d45d8..d8c88b96bc 100644
>> --- a/target/riscv/cpu.c
>> +++ b/target/riscv/cpu.c
>> @@ -44,6 +44,7 @@ static const char riscv_single_letter_exts[] =
>> "IEMAFDQCPVH";
>> struct isa_ext_data {
>> const char *name;
>> bool enabled;
>> + uint32_t min_priv_ver;
>> };
>>
>> const char * const riscv_int_regnames[] = {
>> @@ -974,7 +975,7 @@ static void riscv_cpu_class_init(ObjectClass *c, void
>> *data)
>> device_class_set_props(dc, riscv_cpu_properties);
>> }
>>
>> -#define ISA_EDATA_ENTRY(name, prop) {#name, cpu->cfg.prop}
>> +#define ISA_EDATA_ENTRY(name, prop, priv) {#name, cpu->cfg.prop, priv}
>>
>> static void riscv_isa_string_ext(RISCVCPU *cpu, char **isa_str, int
>> max_str_len)
>> {
>> @@ -1000,25 +1001,26 @@ static void riscv_isa_string_ext(RISCVCPU *cpu, char
>> **isa_str, int max_str_len)
>> * extensions by an underscore.
>> */
>> struct isa_ext_data isa_edata_arr[] = {
>> - ISA_EDATA_ENTRY(zfh, ext_zfh),
>> - ISA_EDATA_ENTRY(zfhmin, ext_zfhmin),
>> - ISA_EDATA_ENTRY(zfinx, ext_zfinx),
>> - ISA_EDATA_ENTRY(zhinx, ext_zhinx),
>> - ISA_EDATA_ENTRY(zhinxmin, ext_zhinxmin),
>> - ISA_EDATA_ENTRY(zdinx, ext_zdinx),
>> - ISA_EDATA_ENTRY(zba, ext_zba),
>> - ISA_EDATA_ENTRY(zbb, ext_zbb),
>> - ISA_EDATA_ENTRY(zbc, ext_zbc),
>> - ISA_EDATA_ENTRY(zbs, ext_zbs),
>> - ISA_EDATA_ENTRY(zve32f, ext_zve32f),
>> - ISA_EDATA_ENTRY(zve64f, ext_zve64f),
>> - ISA_EDATA_ENTRY(svinval, ext_svinval),
>> - ISA_EDATA_ENTRY(svnapot, ext_svnapot),
>> - ISA_EDATA_ENTRY(svpbmt, ext_svpbmt),
>> + ISA_EDATA_ENTRY(zfh, ext_zfh, PRIV_VERSION_1_12_0),
>> + ISA_EDATA_ENTRY(zfhmin, ext_zfhmin, PRIV_VERSION_1_12_0),
>> + ISA_EDATA_ENTRY(zfinx, ext_zfinx, PRIV_VERSION_1_12_0),
>> + ISA_EDATA_ENTRY(zhinx, ext_zhinx, PRIV_VERSION_1_12_0),
>> + ISA_EDATA_ENTRY(zhinxmin, ext_zhinxmin, PRIV_VERSION_1_12_0),
>> + ISA_EDATA_ENTRY(zdinx, ext_zdinx, PRIV_VERSION_1_12_0),
>> + ISA_EDATA_ENTRY(zba, ext_zba, PRIV_VERSION_1_12_0),
>> + ISA_EDATA_ENTRY(zbb, ext_zbb, PRIV_VERSION_1_12_0),
>> + ISA_EDATA_ENTRY(zbc, ext_zbc, PRIV_VERSION_1_12_0),
>> + ISA_EDATA_ENTRY(zbs, ext_zbs, PRIV_VERSION_1_12_0),
>> + ISA_EDATA_ENTRY(zve32f, ext_zve32f, PRIV_VERSION_1_12_0),
>> + ISA_EDATA_ENTRY(zve64f, ext_zve64f, PRIV_VERSION_1_12_0),
>> + ISA_EDATA_ENTRY(svinval, ext_svinval, PRIV_VERSION_1_12_0),
>> + ISA_EDATA_ENTRY(svnapot, ext_svnapot, PRIV_VERSION_1_12_0),
>> + ISA_EDATA_ENTRY(svpbmt, ext_svpbmt, PRIV_VERSION_1_12_0),
>> };
>>
>> for (i = 0; i < ARRAY_SIZE(isa_edata_arr); i++) {
>> - if (isa_edata_arr[i].enabled) {
>> + if (isa_edata_arr[i].enabled &&
>> + cpu->env.priv_ver >= isa_edata_arr[i].min_priv_ver) {
>> new = g_strconcat(old, "_", isa_edata_arr[i].name, NULL);
>> g_free(old);
>> old = new;
>> --
>> 2.34.1
>>
>>
