Re: [Qemu-devel] [RFC PATCH v2 05/23] spapr: Reorganize CPU dt generation code

[David Gibson <david@gibson.dropbear.id.au>]

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On Mon, Mar 23, 2015 at 07:05:46PM +0530, Bharata B Rao wrote:
> Reorganize CPU device tree generation code so that it be reused from
> hotplug path. CPU dt entries are now generated from spapr_finalize_fdt()
> instead of spapr_create_fdt_skel().
> 
> Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
> ---
>  hw/ppc/spapr.c | 288 ++++++++++++++++++++++++++++++---------------------------
>  1 file changed, 154 insertions(+), 134 deletions(-)
> 
> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> index 36ff754..1a25cc0 100644
> --- a/hw/ppc/spapr.c
> +++ b/hw/ppc/spapr.c
> @@ -206,24 +206,50 @@ static int spapr_fixup_cpu_smt_dt(void *fdt, int offset, PowerPCCPU *cpu,
>      return ret;
>  }
>  
> +static int spapr_fixup_cpu_numa_smt_dt(void *fdt, int offset, CPUState *cs,
> +                                        sPAPREnvironment *spapr)
> +{
> +    int ret;
> +    PowerPCCPU *cpu = POWERPC_CPU(cs);
> +    int index = ppc_get_vcpu_dt_id(cpu);
> +    uint32_t pft_size_prop[] = {0, cpu_to_be32(spapr->htab_shift)};
> +    uint32_t associativity[] = {cpu_to_be32(0x5),
> +                                cpu_to_be32(0x0),
> +                                cpu_to_be32(0x0),
> +                                cpu_to_be32(0x0),
> +                                cpu_to_be32(cs->numa_node),
> +                                cpu_to_be32(index)};
> +
> +    /* Advertise NUMA via ibm,associativity */
> +    if (nb_numa_nodes > 1) {
> +        ret = fdt_setprop(fdt, offset, "ibm,associativity", associativity,
> +                          sizeof(associativity));
> +        if (ret < 0) {
> +            return ret;
> +        }
> +    }
> +
> +    ret = fdt_setprop(fdt, offset, "ibm,pft-size",
> +                      pft_size_prop, sizeof(pft_size_prop));
> +    if (ret < 0) {
> +        return ret;
> +    }

The pft-size property isn't actually related to NUMA, so it doesn't
really belong in this function.

> +    return spapr_fixup_cpu_smt_dt(fdt, offset, cpu,
> +                                 ppc_get_compat_smt_threads(cpu));

Likewise calling the smt fixup function from the numa fixup function
just seems odd to me; just be explicit and call the two sequentially.

Overall this seems an odd way to split things.  Why not just make a
spapr_fixup_one_cpu_dt() function, or similar, which should do all the
necessary pieces.

> +}
> +
>  static int spapr_fixup_cpu_dt(void *fdt, sPAPREnvironment *spapr)
>  {
>      int ret = 0, offset, cpus_offset;
>      CPUState *cs;
>      char cpu_model[32];
>      int smt = kvmppc_smt_threads();
> -    uint32_t pft_size_prop[] = {0, cpu_to_be32(spapr->htab_shift)};
>  
>      CPU_FOREACH(cs) {
>          PowerPCCPU *cpu = POWERPC_CPU(cs);
>          DeviceClass *dc = DEVICE_GET_CLASS(cs);
>          int index = ppc_get_vcpu_dt_id(cpu);
> -        uint32_t associativity[] = {cpu_to_be32(0x5),
> -                                    cpu_to_be32(0x0),
> -                                    cpu_to_be32(0x0),
> -                                    cpu_to_be32(0x0),
> -                                    cpu_to_be32(cs->numa_node),
> -                                    cpu_to_be32(index)};
>  
>          if ((index % smt) != 0) {
>              continue;
> @@ -247,22 +273,7 @@ static int spapr_fixup_cpu_dt(void *fdt, sPAPREnvironment *spapr)
>              }
>          }
>  
> -        if (nb_numa_nodes > 1) {
> -            ret = fdt_setprop(fdt, offset, "ibm,associativity", associativity,
> -                              sizeof(associativity));
> -            if (ret < 0) {
> -                return ret;
> -            }
> -        }
> -
> -        ret = fdt_setprop(fdt, offset, "ibm,pft-size",
> -                          pft_size_prop, sizeof(pft_size_prop));
> -        if (ret < 0) {
> -            return ret;
> -        }
> -
> -        ret = spapr_fixup_cpu_smt_dt(fdt, offset, cpu,
> -                                     ppc_get_compat_smt_threads(cpu));
> +        ret = spapr_fixup_cpu_numa_smt_dt(fdt, offset, cs, spapr);
>          if (ret < 0) {
>              return ret;
>          }
> @@ -341,18 +352,13 @@ static void *spapr_create_fdt_skel(hwaddr initrd_base,
>                                     uint32_t epow_irq)
>  {
>      void *fdt;
> -    CPUState *cs;
>      uint32_t start_prop = cpu_to_be32(initrd_base);
>      uint32_t end_prop = cpu_to_be32(initrd_base + initrd_size);
>      GString *hypertas = g_string_sized_new(256);
>      GString *qemu_hypertas = g_string_sized_new(256);
>      uint32_t refpoints[] = {cpu_to_be32(0x4), cpu_to_be32(0x4)};
>      uint32_t interrupt_server_ranges_prop[] = {0, cpu_to_be32(max_cpus)};
> -    int smt = kvmppc_smt_threads();
>      unsigned char vec5[] = {0x0, 0x0, 0x0, 0x0, 0x0, 0x80};
> -    QemuOpts *opts = qemu_opts_find(qemu_find_opts("smp-opts"), NULL);
> -    unsigned sockets = opts ? qemu_opt_get_number(opts, "sockets", 0) : 0;
> -    uint32_t cpus_per_socket = sockets ? (smp_cpus / sockets) : 1;
>      char *buf;
>  
>      add_str(hypertas, "hcall-pft");
> @@ -441,107 +447,6 @@ static void *spapr_create_fdt_skel(hwaddr initrd_base,
>  
>      _FDT((fdt_end_node(fdt)));
>  
> -    /* cpus */
> -    _FDT((fdt_begin_node(fdt, "cpus")));
> -
> -    _FDT((fdt_property_cell(fdt, "#address-cells", 0x1)));
> -    _FDT((fdt_property_cell(fdt, "#size-cells", 0x0)));
> -
> -    CPU_FOREACH(cs) {
> -        PowerPCCPU *cpu = POWERPC_CPU(cs);
> -        CPUPPCState *env = &cpu->env;
> -        DeviceClass *dc = DEVICE_GET_CLASS(cs);
> -        PowerPCCPUClass *pcc = POWERPC_CPU_GET_CLASS(cs);
> -        int index = ppc_get_vcpu_dt_id(cpu);
> -        char *nodename;
> -        uint32_t segs[] = {cpu_to_be32(28), cpu_to_be32(40),
> -                           0xffffffff, 0xffffffff};
> -        uint32_t tbfreq = kvm_enabled() ? kvmppc_get_tbfreq() : TIMEBASE_FREQ;
> -        uint32_t cpufreq = kvm_enabled() ? kvmppc_get_clockfreq() : 1000000000;
> -        uint32_t page_sizes_prop[64];
> -        size_t page_sizes_prop_size;
> -
> -        if ((index % smt) != 0) {
> -            continue;
> -        }
> -
> -        nodename = g_strdup_printf("%s@%x", dc->fw_name, index);
> -
> -        _FDT((fdt_begin_node(fdt, nodename)));
> -
> -        g_free(nodename);
> -
> -        _FDT((fdt_property_cell(fdt, "reg", index)));
> -        _FDT((fdt_property_string(fdt, "device_type", "cpu")));
> -
> -        _FDT((fdt_property_cell(fdt, "cpu-version", env->spr[SPR_PVR])));
> -        _FDT((fdt_property_cell(fdt, "d-cache-block-size",
> -                                env->dcache_line_size)));
> -        _FDT((fdt_property_cell(fdt, "d-cache-line-size",
> -                                env->dcache_line_size)));
> -        _FDT((fdt_property_cell(fdt, "i-cache-block-size",
> -                                env->icache_line_size)));
> -        _FDT((fdt_property_cell(fdt, "i-cache-line-size",
> -                                env->icache_line_size)));
> -
> -        if (pcc->l1_dcache_size) {
> -            _FDT((fdt_property_cell(fdt, "d-cache-size", pcc->l1_dcache_size)));
> -        } else {
> -            fprintf(stderr, "Warning: Unknown L1 dcache size for cpu\n");
> -        }
> -        if (pcc->l1_icache_size) {
> -            _FDT((fdt_property_cell(fdt, "i-cache-size", pcc->l1_icache_size)));
> -        } else {
> -            fprintf(stderr, "Warning: Unknown L1 icache size for cpu\n");
> -        }
> -
> -        _FDT((fdt_property_cell(fdt, "timebase-frequency", tbfreq)));
> -        _FDT((fdt_property_cell(fdt, "clock-frequency", cpufreq)));
> -        _FDT((fdt_property_cell(fdt, "ibm,slb-size", env->slb_nr)));
> -        _FDT((fdt_property_string(fdt, "status", "okay")));
> -        _FDT((fdt_property(fdt, "64-bit", NULL, 0)));
> -
> -        if (env->spr_cb[SPR_PURR].oea_read) {
> -            _FDT((fdt_property(fdt, "ibm,purr", NULL, 0)));
> -        }
> -
> -        if (env->mmu_model & POWERPC_MMU_1TSEG) {
> -            _FDT((fdt_property(fdt, "ibm,processor-segment-sizes",
> -                               segs, sizeof(segs))));
> -        }
> -
> -        /* Advertise VMX/VSX (vector extensions) if available
> -         *   0 / no property == no vector extensions
> -         *   1               == VMX / Altivec available
> -         *   2               == VSX available */
> -        if (env->insns_flags & PPC_ALTIVEC) {
> -            uint32_t vmx = (env->insns_flags2 & PPC2_VSX) ? 2 : 1;
> -
> -            _FDT((fdt_property_cell(fdt, "ibm,vmx", vmx)));
> -        }
> -
> -        /* Advertise DFP (Decimal Floating Point) if available
> -         *   0 / no property == no DFP
> -         *   1               == DFP available */
> -        if (env->insns_flags2 & PPC2_DFP) {
> -            _FDT((fdt_property_cell(fdt, "ibm,dfp", 1)));
> -        }
> -
> -        page_sizes_prop_size = create_page_sizes_prop(env, page_sizes_prop,
> -                                                      sizeof(page_sizes_prop));
> -        if (page_sizes_prop_size) {
> -            _FDT((fdt_property(fdt, "ibm,segment-page-sizes",
> -                               page_sizes_prop, page_sizes_prop_size)));
> -        }
> -
> -        _FDT((fdt_property_cell(fdt, "ibm,chip-id",
> -                                cs->cpu_index / cpus_per_socket)));
> -
> -        _FDT((fdt_end_node(fdt)));
> -    }
> -
> -    _FDT((fdt_end_node(fdt)));
> -
>      /* RTAS */
>      _FDT((fdt_begin_node(fdt, "rtas")));
>  
> @@ -739,6 +644,124 @@ static int spapr_populate_memory(sPAPREnvironment *spapr, void *fdt)
>      return 0;
>  }
>  
> +static void spapr_populate_cpu_dt(CPUState *cs, void *fdt, int offset)
> +{
> +    PowerPCCPU *cpu = POWERPC_CPU(cs);
> +    CPUPPCState *env = &cpu->env;
> +    PowerPCCPUClass *pcc = POWERPC_CPU_GET_CLASS(cs);
> +    int index = ppc_get_vcpu_dt_id(cpu);
> +    uint32_t segs[] = {cpu_to_be32(28), cpu_to_be32(40),
> +                       0xffffffff, 0xffffffff};
> +    uint32_t tbfreq = kvm_enabled() ? kvmppc_get_tbfreq() : TIMEBASE_FREQ;
> +    uint32_t cpufreq = kvm_enabled() ? kvmppc_get_clockfreq() : 1000000000;
> +    uint32_t page_sizes_prop[64];
> +    size_t page_sizes_prop_size;
> +    QemuOpts *opts = qemu_opts_find(qemu_find_opts("smp-opts"), NULL);
> +    unsigned sockets = opts ? qemu_opt_get_number(opts, "sockets", 0) : 0;
> +    uint32_t cpus_per_socket = sockets ? (smp_cpus / sockets) : 1;
> +
> +    _FDT((fdt_setprop_cell(fdt, offset, "reg", index)));
> +    _FDT((fdt_setprop_string(fdt, offset, "device_type", "cpu")));
> +
> +    _FDT((fdt_setprop_cell(fdt, offset, "cpu-version", env->spr[SPR_PVR])));
> +    _FDT((fdt_setprop_cell(fdt, offset, "d-cache-block-size",
> +                            env->dcache_line_size)));
> +    _FDT((fdt_setprop_cell(fdt, offset, "d-cache-line-size",
> +                            env->dcache_line_size)));
> +    _FDT((fdt_setprop_cell(fdt, offset, "i-cache-block-size",
> +                            env->icache_line_size)));
> +    _FDT((fdt_setprop_cell(fdt, offset, "i-cache-line-size",
> +                            env->icache_line_size)));
> +
> +    if (pcc->l1_dcache_size) {
> +        _FDT((fdt_setprop_cell(fdt, offset, "d-cache-size",
> +                             pcc->l1_dcache_size)));
> +    } else {
> +        fprintf(stderr, "Warning: Unknown L1 dcache size for cpu\n");
> +    }
> +    if (pcc->l1_icache_size) {
> +        _FDT((fdt_setprop_cell(fdt, offset, "i-cache-size",
> +                             pcc->l1_icache_size)));
> +    } else {
> +        fprintf(stderr, "Warning: Unknown L1 icache size for cpu\n");
> +    }
> +
> +    _FDT((fdt_setprop_cell(fdt, offset, "timebase-frequency", tbfreq)));
> +    _FDT((fdt_setprop_cell(fdt, offset, "clock-frequency", cpufreq)));
> +    _FDT((fdt_setprop_cell(fdt, offset, "ibm,slb-size", env->slb_nr)));
> +    _FDT((fdt_setprop_string(fdt, offset, "status", "okay")));
> +    _FDT((fdt_setprop(fdt, offset, "64-bit", NULL, 0)));
> +
> +    if (env->spr_cb[SPR_PURR].oea_read) {
> +        _FDT((fdt_setprop(fdt, offset, "ibm,purr", NULL, 0)));
> +    }
> +
> +    if (env->mmu_model & POWERPC_MMU_1TSEG) {
> +        _FDT((fdt_setprop(fdt, offset, "ibm,processor-segment-sizes",
> +                           segs, sizeof(segs))));
> +    }
> +
> +    /* Advertise VMX/VSX (vector extensions) if available
> +     *   0 / no property == no vector extensions
> +     *   1               == VMX / Altivec available
> +     *   2               == VSX available */
> +    if (env->insns_flags & PPC_ALTIVEC) {
> +        uint32_t vmx = (env->insns_flags2 & PPC2_VSX) ? 2 : 1;
> +
> +        _FDT((fdt_setprop_cell(fdt, offset, "ibm,vmx", vmx)));
> +    }
> +
> +    /* Advertise DFP (Decimal Floating Point) if available
> +     *   0 / no property == no DFP
> +     *   1               == DFP available */
> +    if (env->insns_flags2 & PPC2_DFP) {
> +        _FDT((fdt_setprop_cell(fdt, offset, "ibm,dfp", 1)));
> +    }
> +
> +    page_sizes_prop_size = create_page_sizes_prop(env, page_sizes_prop,
> +                                                  sizeof(page_sizes_prop));
> +    if (page_sizes_prop_size) {
> +        _FDT((fdt_setprop(fdt, offset, "ibm,segment-page-sizes",
> +                           page_sizes_prop, page_sizes_prop_size)));
> +    }
> +
> +    _FDT((fdt_setprop_cell(fdt, offset, "ibm,chip-id",
> +                            cs->cpu_index / cpus_per_socket)));
> +
> +    _FDT(spapr_fixup_cpu_numa_smt_dt(fdt, offset, cs, spapr));
> +}
> +
> +static void spapr_populate_cpu_dt_node(void *fdt, sPAPREnvironment *spapr)


I'd suggest s/cpu/cpus/.  If anything "populate_cpu_dt_node" sounds
more like it covers a single cpu than "populate_cpu_dt".

> +{
> +    CPUState *cs;
> +    int cpus_offset;
> +    char *nodename;
> +    int smt = kvmppc_smt_threads();
> +
> +    cpus_offset = fdt_add_subnode(fdt, 0, "cpus");
> +    _FDT(cpus_offset);
> +    _FDT((fdt_setprop_cell(fdt, cpus_offset, "#address-cells", 0x1)));
> +    _FDT((fdt_setprop_cell(fdt, cpus_offset, "#size-cells", 0x0)));
> +
> +    CPU_FOREACH(cs) {
> +        PowerPCCPU *cpu = POWERPC_CPU(cs);
> +        int index = ppc_get_vcpu_dt_id(cpu);
> +        DeviceClass *dc = DEVICE_GET_CLASS(cs);
> +        int offset;
> +
> +        if ((index % smt) != 0) {
> +            continue;
> +        }
> +
> +        nodename = g_strdup_printf("%s@%x", dc->fw_name, index);
> +        offset = fdt_add_subnode(fdt, cpus_offset, nodename);
> +        g_free(nodename);
> +        _FDT(offset);
> +        spapr_populate_cpu_dt(cs, fdt, offset);
> +    }
> +
> +}
> +
>  static void spapr_finalize_fdt(sPAPREnvironment *spapr,
>                                 hwaddr fdt_addr,
>                                 hwaddr rtas_addr,
> @@ -782,11 +805,8 @@ static void spapr_finalize_fdt(sPAPREnvironment *spapr,
>          fprintf(stderr, "Couldn't set up RTAS device tree properties\n");
>      }
>  
> -    /* Advertise NUMA via ibm,associativity */
> -    ret = spapr_fixup_cpu_dt(fdt, spapr);
> -    if (ret < 0) {
> -        fprintf(stderr, "Couldn't finalize CPU device tree properties\n");
> -    }
> +    /* cpus */
> +    spapr_populate_cpu_dt_node(fdt, spapr);
>  
>      bootlist = get_boot_devices_list(&cb, true);
>      if (cb && bootlist) {

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

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