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Re: [Qemu-riscv] [Qemu-devel] [PATCH] riscv: virt: Add cpu-topology DT n
From: |
Alistair Francis |
Subject: |
Re: [Qemu-riscv] [Qemu-devel] [PATCH] riscv: virt: Add cpu-topology DT node. |
Date: |
Mon, 24 Jun 2019 16:24:00 -0700 |
On Mon, Jun 24, 2019 at 3:57 PM Atish Patra <address@hidden> wrote:
>
> Currently, there is no cpu topology defined in RISC-V.
> Define a device tree node that clearly describes the
> entire topology. This saves the trouble of scanning individual
> cache to figure out the topology.
>
> Here is the linux kernel patch series that enables topology
> for RISC-V.
>
> http://lists.infradead.org/pipermail/linux-riscv/2019-June/005072.html
>
> CPU topology after applying this patch in QEMU & above series in kernel
>
> / # cat /sys/devices/system/cpu/cpu2/topology/thread_siblings_list
> 2
> / # cat /sys/devices/system/cpu/cpu2/topology/physical_package_id
> 0
> / # cat /sys/devices/system/cpu/cpu2/topology/core_siblings_list
> 0-7
>
> Signed-off-by: Atish Patra <address@hidden>
> ---
> hw/riscv/virt.c | 21 +++++++++++++++++++--
> 1 file changed, 19 insertions(+), 2 deletions(-)
>
> diff --git a/hw/riscv/virt.c b/hw/riscv/virt.c
> index 84d94d0c42d8..da0b8aa18747 100644
> --- a/hw/riscv/virt.c
> +++ b/hw/riscv/virt.c
> @@ -203,9 +203,12 @@ static void *create_fdt(RISCVVirtState *s, const struct
> MemmapEntry *memmap,
> qemu_fdt_setprop_string(fdt, nodename, "status", "okay");
> qemu_fdt_setprop_cell(fdt, nodename, "reg", cpu);
> qemu_fdt_setprop_string(fdt, nodename, "device_type", "cpu");
> + qemu_fdt_setprop_cell(fdt, nodename, "phandle", cpu_phandle);
> + qemu_fdt_setprop_cell(fdt, nodename, "linux,phandle", cpu_phandle);
> + int intc_phandle = phandle++;
Don't declare variables in the middle of code. The variable must be
declared at the start of a block.
With that fixed:
Reviewed-by: Alistair Francis <address@hidden>
Alistair
> qemu_fdt_add_subnode(fdt, intc);
> - qemu_fdt_setprop_cell(fdt, intc, "phandle", cpu_phandle);
> - qemu_fdt_setprop_cell(fdt, intc, "linux,phandle", cpu_phandle);
> + qemu_fdt_setprop_cell(fdt, intc, "phandle", intc_phandle);
> + qemu_fdt_setprop_cell(fdt, intc, "linux,phandle", intc_phandle);
> 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);
> @@ -214,6 +217,20 @@ static void *create_fdt(RISCVVirtState *s, const struct
> MemmapEntry *memmap,
> g_free(nodename);
> }
>
> + /* Add cpu-topology node */
> + qemu_fdt_add_subnode(fdt, "/cpus/cpu-map");
> + qemu_fdt_add_subnode(fdt, "/cpus/cpu-map/cluster0");
> + for (cpu = s->soc.num_harts - 1; cpu >= 0; cpu--) {
> + char *core_nodename =
> g_strdup_printf("/cpus/cpu-map/cluster0/core%d",
> + cpu);
> + char *cpu_nodename = g_strdup_printf("/cpus/cpu@%d", cpu);
> + uint32_t intc_phandle = qemu_fdt_get_phandle(fdt, cpu_nodename);
> + qemu_fdt_add_subnode(fdt, core_nodename);
> + qemu_fdt_setprop_cell(fdt, core_nodename, "cpu", intc_phandle);
> + g_free(core_nodename);
> + g_free(cpu_nodename);
> + }
> +
> cells = g_new0(uint32_t, s->soc.num_harts * 4);
> for (cpu = 0; cpu < s->soc.num_harts; cpu++) {
> nodename =
> --
> 2.21.0
>
>