On Tue, Mar 15, 2022 at 7:43 AM Atish Patra <ati...@rivosinc.com> wrote: > > The Linux kernel parses the ISA extensions from "riscv,isa" DT > property. It used to parse only the single letter base extensions > until now. A generic ISA extension parsing framework was proposed[1] > recently that can parse multi-letter ISA extensions as well. > > Generate the extended ISA string by appending the available ISA extensions
nits: remove one space after "appending" > to the "riscv,isa" string if it is enabled so that kernel can process it. > > [1] https://lkml.org/lkml/2022/2/15/263 Could you please post a link to the "riscv,isa" DT bindings spec or discussion thread? It seems not mentioned in the above LKML thread. > > Reviewed-by: Anup Patel <a...@brainfault.org> > Reviewed-by: Alistair Francis <alistair.fran...@wdc.com> > Suggested-by: Heiko Stubner <he...@sntech.de> > Signed-off-by: Atish Patra <ati...@rivosinc.com> > --- > Changes from v4->v5: > 1. Fixed the order of Zxx extensions. > 2. Added a comment clearly describing the rules of extension order. > > Changes from v3->v4: > 1. Fixed the order of the extension names. > 2. Added all the available ISA extensions in Qemu. > > Changes from v2->v3: > 1. Used g_strconcat to replace snprintf & a max isa string length as > suggested by Anup. > 2. I have not included the Tested-by Tag from Heiko because the > implementation changed from v2 to v3. > > Changes from v1->v2: > 1. Improved the code redability by using arrays instead of individual check > --- > target/riscv/cpu.c | 61 ++++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 61 insertions(+) > > diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c > index ddda4906ffb7..097c42f5c50f 100644 > --- a/target/riscv/cpu.c > +++ b/target/riscv/cpu.c > @@ -34,6 +34,12 @@ > > /* RISC-V CPU definitions */ > > +/* This includes the null terminated character '\0' */ > +struct isa_ext_data { > + const char *name; > + bool enabled; > +}; > + > static const char riscv_exts[26] = "IEMAFDQCLBJTPVNSUHKORWXYZG"; > > const char * const riscv_int_regnames[] = { > @@ -898,6 +904,60 @@ 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} > + > +static void riscv_isa_string_ext(RISCVCPU *cpu, char **isa_str, int > max_str_len) > +{ > + char *old = *isa_str; > + char *new = *isa_str; > + int i; > + > + /** > + * Here are the ordering rules of extension naming defined by RISC-V > + * specification : > + * 1. All extensions should be separated from other multi-letter > extensions > + * from other multi-letter extensions by an underscore. redundant "from other multi-letter extensions" > + * 2. The first letter following the 'Z' conventionally indicates the > most Should this be lower case "z"? > + * closely related alphabetical extension category, IMAFDQLCBKJTPVH. > + * If multiple 'Z' extensions are named, they should be ordered first > + * by category, then alphabetically within a category. > + * 3. Standard supervisor-level extensions (starts with 'S') should be lower case "s"? > + * listed after standard unprivileged extensions. If multiple > + * supervisor-level extensions are listed, they should be ordered > + * alphabetically. > + * 4. Non-standard extensions (starts with 'X') must be listed after all > + * standard extensions. They must be separated from other multi-letter > + * extensions by an underscore. > + */ > + struct isa_ext_data isa_edata_arr[] = { > + ISA_EDATA_ENTRY(zfh, ext_zfhmin), This should be (zfh, ext_zfh) > + ISA_EDATA_ENTRY(zfhmin, ext_zfhmin), > + ISA_EDATA_ENTRY(zfinx, ext_zfinx), > + ISA_EDATA_ENTRY(zdinx, ext_zdinx), Should "zdinx" come before "zfinx" *alphabetically* ? > + ISA_EDATA_ENTRY(zba, ext_zba), > + ISA_EDATA_ENTRY(zbb, ext_zbb), > + ISA_EDATA_ENTRY(zbc, ext_zbc), > + ISA_EDATA_ENTRY(zbs, ext_zbs), I don't understand why "zb*" come after "zf*". Alphabetically they should come before. > + ISA_EDATA_ENTRY(zve32f, ext_zve32f), > + ISA_EDATA_ENTRY(zve64f, ext_zve64f), > + ISA_EDATA_ENTRY(zhinx, ext_zhinx), > + ISA_EDATA_ENTRY(zhinxmin, ext_zhinxmin), > + ISA_EDATA_ENTRY(svinval, ext_svinval), > + ISA_EDATA_ENTRY(svnapot, ext_svnapot), > + ISA_EDATA_ENTRY(svpbmt, ext_svpbmt), > + }; > + > + for (i = 0; i < ARRAY_SIZE(isa_edata_arr); i++) { > + if (isa_edata_arr[i].enabled) { > + new = g_strconcat(old, "_", isa_edata_arr[i].name, NULL); > + g_free(old); > + old = new; > + } > + } > + > + *isa_str = new; > +} > + > char *riscv_isa_string(RISCVCPU *cpu) > { > int i; > @@ -910,6 +970,7 @@ char *riscv_isa_string(RISCVCPU *cpu) > } > } > *p = '\0'; > + riscv_isa_string_ext(cpu, &isa_str, maxlen); > return isa_str; > } > Regards, Bin
