On Fri, Dec 08, 2023 at 12:07:22PM +0000, Conor Dooley wrote: > From: Conor Dooley <conor.doo...@microchip.com> > > A few months ago I submitted a patch to various lists, deprecating > "riscv,isa" with a lengthy commit message [0] that is now commit > aeb71e42caae ("dt-bindings: riscv: deprecate riscv,isa") in the Linux > kernel tree. Primarily, the goal was to replace "riscv,isa" with a new > set of properties that allowed for strictly defining the meaning of > various extensions, where "riscv,isa" was tied to whatever definitions > inflicted upon us by the ISA manual, which have seen some variance over > time. > > Two new properties were introduced: "riscv,isa-base" and > "riscv,isa-extensions". The former is a simple string to communicate the > base ISA implemented by a hart and the latter an array of strings used > to communicate the set of ISA extensions supported, per the definitions > of each substring in extensions.yaml [1]. A beneficial side effect was > also the ability to define vendor extensions in a more "official" way, > as the ISA manual and other RVI specifications only covered the format > for vendor extensions in the ISA string, but not the meaning of vendor > extensions, for obvious reasons. > > Add support for setting these two new properties in the devicetrees for > the various devicetree platforms supported by QEMU for RISC-V. The Linux > kernel already supports parsing ISA extensions from these new > properties, and documenting them in the dt-binding is a requirement for > new extension detection being added to the kernel. > > A side effect of the implementation is that the meaning for elements in > "riscv,isa" and in "riscv,isa-extensions" are now tied together as they > are constructed from the same source. The same applies to the ISA string > provided in ACPI tables, but there does not appear to be any strict > definitions of meanings in ACPI land either. > > Link: > https://lore.kernel.org/qemu-riscv/20230702-eats-scorebook-c951f170d29f@spud/ > [0] > Link: > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/devicetree/bindings/riscv/extensions.yaml > [1] > Signed-off-by: Conor Dooley <conor.doo...@microchip.com> > --- > Changes in v2: > - use g_strdup() for multiletter extension string copying > - wrap stuff in #ifndef to prevent breaking the user mode build > - rename riscv_isa_set_props() -> riscv_isa_write_fdt() > > CC: Alistair Francis <alistair.fran...@wdc.com> > CC: Bin Meng <bin.m...@windriver.com> > CC: Palmer Dabbelt <pal...@dabbelt.com> > CC: Weiwei Li <liwei1...@gmail.com> > CC: Daniel Henrique Barboza <dbarb...@ventanamicro.com> > CC: Liu Zhiwei <zhiwei_...@linux.alibaba.com> > CC: qemu-ri...@nongnu.org > CC: qemu-devel@nongnu.org > --- > hw/riscv/sifive_u.c | 7 ++----- > hw/riscv/spike.c | 6 ++---- > hw/riscv/virt.c | 6 ++---- > target/riscv/cpu.c | 50 +++++++++++++++++++++++++++++++++++++++++++++ > target/riscv/cpu.h | 1 + > 5 files changed, 57 insertions(+), 13 deletions(-) > > diff --git a/hw/riscv/sifive_u.c b/hw/riscv/sifive_u.c > index ec76dce6c9..2f227f15bc 100644 > --- a/hw/riscv/sifive_u.c > +++ b/hw/riscv/sifive_u.c > @@ -171,7 +171,6 @@ static void create_fdt(SiFiveUState *s, const MemMapEntry > *memmap, > int cpu_phandle = phandle++; > nodename = g_strdup_printf("/cpus/cpu@%d", cpu); > char *intc = g_strdup_printf("/cpus/cpu@%d/interrupt-controller", > cpu); > - char *isa; > qemu_fdt_add_subnode(fdt, nodename); > /* cpu 0 is the management hart that does not have mmu */ > if (cpu != 0) { > @@ -180,11 +179,10 @@ static void create_fdt(SiFiveUState *s, const > MemMapEntry *memmap, > } else { > qemu_fdt_setprop_string(fdt, nodename, "mmu-type", > "riscv,sv48"); > } > - isa = riscv_isa_string(&s->soc.u_cpus.harts[cpu - 1]); > + riscv_isa_write_fdt(&s->soc.u_cpus.harts[cpu - 1], fdt, > nodename); > } else { > - isa = riscv_isa_string(&s->soc.e_cpus.harts[0]); > + riscv_isa_write_fdt(&s->soc.e_cpus.harts[0], fdt, nodename); > } > - qemu_fdt_setprop_string(fdt, nodename, "riscv,isa", isa); > qemu_fdt_setprop_string(fdt, nodename, "compatible", "riscv"); > qemu_fdt_setprop_string(fdt, nodename, "status", "okay"); > qemu_fdt_setprop_cell(fdt, nodename, "reg", cpu); > @@ -194,7 +192,6 @@ static void create_fdt(SiFiveUState *s, const MemMapEntry > *memmap, > qemu_fdt_setprop_string(fdt, intc, "compatible", "riscv,cpu-intc"); > qemu_fdt_setprop(fdt, intc, "interrupt-controller", NULL, 0); > qemu_fdt_setprop_cell(fdt, intc, "#interrupt-cells", 1); > - g_free(isa); > g_free(intc); > g_free(nodename); > } > diff --git a/hw/riscv/spike.c b/hw/riscv/spike.c > index 81f7e53aed..64074395bc 100644 > --- a/hw/riscv/spike.c > +++ b/hw/riscv/spike.c > @@ -59,7 +59,7 @@ static void create_fdt(SpikeState *s, const MemMapEntry > *memmap, > MachineState *ms = MACHINE(s); > uint32_t *clint_cells; > uint32_t cpu_phandle, intc_phandle, phandle = 1; > - char *name, *mem_name, *clint_name, *clust_name; > + char *mem_name, *clint_name, *clust_name; > char *core_name, *cpu_name, *intc_name; > static const char * const clint_compat[2] = { > "sifive,clint0", "riscv,clint0" > @@ -113,9 +113,7 @@ static void create_fdt(SpikeState *s, const MemMapEntry > *memmap, > } else { > qemu_fdt_setprop_string(fdt, cpu_name, "mmu-type", > "riscv,sv48"); > } > - name = riscv_isa_string(&s->soc[socket].harts[cpu]); > - qemu_fdt_setprop_string(fdt, cpu_name, "riscv,isa", name); > - g_free(name); > + riscv_isa_write_fdt(&s->soc[socket].harts[cpu], fdt, cpu_name); > qemu_fdt_setprop_string(fdt, cpu_name, "compatible", "riscv"); > qemu_fdt_setprop_string(fdt, cpu_name, "status", "okay"); > qemu_fdt_setprop_cell(fdt, cpu_name, "reg", > diff --git a/hw/riscv/virt.c b/hw/riscv/virt.c > index c7fc97e273..05beb0a297 100644 > --- a/hw/riscv/virt.c > +++ b/hw/riscv/virt.c > @@ -238,7 +238,7 @@ static void create_fdt_socket_cpus(RISCVVirtState *s, int > socket, > int cpu; > uint32_t cpu_phandle; > MachineState *ms = MACHINE(s); > - char *name, *cpu_name, *core_name, *intc_name, *sv_name; > + char *cpu_name, *core_name, *intc_name, *sv_name; > bool is_32_bit = riscv_is_32bit(&s->soc[0]); > uint8_t satp_mode_max; > > @@ -259,9 +259,7 @@ static void create_fdt_socket_cpus(RISCVVirtState *s, int > socket, > g_free(sv_name); > } > > - name = riscv_isa_string(cpu_ptr); > - qemu_fdt_setprop_string(ms->fdt, cpu_name, "riscv,isa", name); > - g_free(name); > + riscv_isa_write_fdt(cpu_ptr, ms->fdt, cpu_name); > > if (cpu_ptr->cfg.ext_zicbom) { > qemu_fdt_setprop_cell(ms->fdt, cpu_name, "riscv,cbom-block-size", > diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c > index 83c7c0cf07..ce413b9f00 100644 > --- a/target/riscv/cpu.c > +++ b/target/riscv/cpu.c > @@ -31,6 +31,7 @@ > #include "hw/qdev-properties.h" > #include "migration/vmstate.h" > #include "fpu/softfloat-helpers.h" > +#include "sysemu/device_tree.h" > #include "sysemu/kvm.h" > #include "sysemu/tcg.h" > #include "kvm/kvm_riscv.h" > @@ -1735,6 +1736,55 @@ char *riscv_isa_string(RISCVCPU *cpu) > return isa_str; > } > > +#ifndef CONFIG_USER_ONLY > +static char **riscv_isa_extensions_list(RISCVCPU *cpu, int *count) > +{ > + int maxlen = ARRAY_SIZE(riscv_single_letter_exts) + > ARRAY_SIZE(isa_edata_arr); > + char **extensions = g_new(char *, maxlen); > + > + for (int i = 0; i < sizeof(riscv_single_letter_exts) - 1; i++) { > + if (cpu->env.misa_ext & RV(riscv_single_letter_exts[i])) { > + extensions[*count] = g_new(char, 2); > + snprintf(extensions[*count], 2, "%c", > + qemu_tolower(riscv_single_letter_exts[i])); > + (*count)++; > + } > + } > + > + for (const RISCVIsaExtData *edata = isa_edata_arr; edata && edata->name; > edata++) { ^ edata can never be NULL (I know riscv_isa_string_ext() also has that check though...)
> + if (isa_ext_is_enabled(cpu, edata->ext_enable_offset)) { > + extensions[*count] = g_strdup(edata->name); > + (*count)++; > + } > + } > + > + return extensions; > +} > + > +void riscv_isa_write_fdt(RISCVCPU *cpu, void *fdt, char *nodename) > +{ > + const size_t maxlen = sizeof("rv128i"); > + g_autofree char *isa_base = g_new(char, maxlen); > + g_autofree char *riscv_isa; > + char **isa_extensions; > + int count = 0; > + > + riscv_isa = riscv_isa_string(cpu); > + qemu_fdt_setprop_string(fdt, nodename, "riscv,isa", riscv_isa); > + > + snprintf(isa_base, maxlen, "rv%di", TARGET_LONG_BITS); > + qemu_fdt_setprop_string(fdt, nodename, "riscv,isa-base", isa_base); > + > + isa_extensions = riscv_isa_extensions_list(cpu, &count); > + qemu_fdt_setprop_string_array(fdt, nodename, "riscv,isa-extensions", > + isa_extensions, count); > + > + for (int i = 0; i < count; i++) { > + g_free(isa_extensions[i]); > + } Need g_free(isa_extensions) here. > +} > +#endif > + > static gint riscv_cpu_list_compare(gconstpointer a, gconstpointer b) > { > ObjectClass *class_a = (ObjectClass *)a; > diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h > index bf58b0f0b5..5bbce607c4 100644 > --- a/target/riscv/cpu.h > +++ b/target/riscv/cpu.h > @@ -496,6 +496,7 @@ void riscv_cpu_list(void); > #define cpu_mmu_index riscv_cpu_mmu_index > > #ifndef CONFIG_USER_ONLY > +void riscv_isa_write_fdt(RISCVCPU *cpu, void *fdt, char *nodename); > void riscv_cpu_do_transaction_failed(CPUState *cs, hwaddr physaddr, > vaddr addr, unsigned size, > MMUAccessType access_type, > -- > 2.39.2 > > Otherwise, Reviewed-by: Andrew Jones <ajo...@ventanamicro.com> Thanks, drew