Re: [Qemu-devel] [PATCH] arm: virt-acpi: each MADT.GICC entry as enabled unconditionally

[Shannon Zhao <zhaoshenglong@huawei.com>]

On 2016/1/29 22:24, Igor Mammedov wrote:
> in current impl. condition
> 
> build_madt() {
>   ...
>   if (test_bit(i, cpuinfo->found_cpus))
> 
> is always true since loop handles only present CPUs
> in range [0..smp_cpus).
> But to fill usless cpuinfo->found_cpus we do unnecessary
> scan over QOM tree to find the same CPUs.
> So mark GICC as present always and drop not needed
> code that fills cpuinfo->found_cpus.
> 
> Signed-off-by: Igor Mammedov <imammedo@redhat.com>
> ---
> It's just simple cleanup but I'm trying to generalize
> a bit CPU related ACPI tables and as part of it get rid
> of found_cpus bitmap and if possible cpu_index usage
> in ACPI parts of code.
> ---
>  hw/arm/virt-acpi-build.c | 26 +++-----------------------
>  1 file changed, 3 insertions(+), 23 deletions(-)
> 
> diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c
> index 87fbe7c..3ed39fc 100644
> --- a/hw/arm/virt-acpi-build.c
> +++ b/hw/arm/virt-acpi-build.c
> @@ -46,20 +46,6 @@
>  #define ARM_SPI_BASE 32
>  #define ACPI_POWER_BUTTON_DEVICE "PWRB"
>  
> -typedef struct VirtAcpiCpuInfo {
> -    DECLARE_BITMAP(found_cpus, VIRT_ACPI_CPU_ID_LIMIT);
The definition of VIRT_ACPI_CPU_ID_LIMIT should be removed as well.

Otherwise:

Reviewed-by: Shannon Zhao <shannon.zhao@linaro.org>

> -} VirtAcpiCpuInfo;
> -
> -static void virt_acpi_get_cpu_info(VirtAcpiCpuInfo *cpuinfo)
> -{
> -    CPUState *cpu;
> -
> -    memset(cpuinfo->found_cpus, 0, sizeof cpuinfo->found_cpus);
> -    CPU_FOREACH(cpu) {
> -        set_bit(cpu->cpu_index, cpuinfo->found_cpus);
> -    }
> -}
> -
>  static void acpi_dsdt_add_cpus(Aml *scope, int smp_cpus)
>  {
>      uint16_t i;
> @@ -458,8 +444,7 @@ build_gtdt(GArray *table_data, GArray *linker)
>  
>  /* MADT */
>  static void
> -build_madt(GArray *table_data, GArray *linker, VirtGuestInfo *guest_info,
> -           VirtAcpiCpuInfo *cpuinfo)
> +build_madt(GArray *table_data, GArray *linker, VirtGuestInfo *guest_info)
>  {
>      int madt_start = table_data->len;
>      const MemMapEntry *memmap = guest_info->memmap;
> @@ -489,9 +474,7 @@ build_madt(GArray *table_data, GArray *linker, VirtGuestInfo *guest_info,
>          gicc->cpu_interface_number = i;
>          gicc->arm_mpidr = armcpu->mp_affinity;
>          gicc->uid = i;
> -        if (test_bit(i, cpuinfo->found_cpus)) {
> -            gicc->flags = cpu_to_le32(ACPI_GICC_ENABLED);
> -        }
> +        gicc->flags = cpu_to_le32(ACPI_GICC_ENABLED);
>      }
>  
>      if (guest_info->gic_version == 3) {
> @@ -599,11 +582,8 @@ void virt_acpi_build(VirtGuestInfo *guest_info, AcpiBuildTables *tables)
>  {
>      GArray *table_offsets;
>      unsigned dsdt, rsdt;
> -    VirtAcpiCpuInfo cpuinfo;
>      GArray *tables_blob = tables->table_data;
>  
> -    virt_acpi_get_cpu_info(&cpuinfo);
> -
>      table_offsets = g_array_new(false, true /* clear */,
>                                          sizeof(uint32_t));
>  
> @@ -630,7 +610,7 @@ void virt_acpi_build(VirtGuestInfo *guest_info, AcpiBuildTables *tables)
>      build_fadt(tables_blob, tables->linker, dsdt);
>  
>      acpi_add_table(table_offsets, tables_blob);
> -    build_madt(tables_blob, tables->linker, guest_info, &cpuinfo);
> +    build_madt(tables_blob, tables->linker, guest_info);
>  
>      acpi_add_table(table_offsets, tables_blob);
>      build_gtdt(tables_blob, tables->linker);

-- 
Shannon