qemu-devel
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Qemu-devel] [PATCH v3 1/8] ppc/xics: introduce an 'icp' backlink un


From: Cédric Le Goater
Subject: Re: [Qemu-devel] [PATCH v3 1/8] ppc/xics: introduce an 'icp' backlink under PowerPCCPU
Date: Wed, 29 Mar 2017 09:14:01 +0200
User-agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.8.0

On 03/29/2017 06:11 AM, David Gibson wrote:
> On Tue, Mar 28, 2017 at 09:32:25AM +0200, Cédric Le Goater wrote:
>> Today, the ICPState array of the sPAPR machine is indexed with
>> 'cpu_index' of the CPUState. This numbering of CPUs is internal to
>> QEMU and the guest only knows about what is exposed in the device
>> tree, that is the 'cpu_dt_id'. This is why sPAPR uses the helper
>> xics_get_cpu_index_by_dt_id() to do the mapping in a couple of places.
>>
>> To provide a more generic XICS layer, we need to abstract the IRQ
>> 'server' number and remove any assumption made on its nature. It
>> should not be used as a 'cpu_index' for lookups like xics_cpu_setup()
>> and xics_cpu_destroy() do.
>>
>> To reach that goal, we choose to introduce an 'icp' backlink under
>> PowerPCCPU, and let the machine core init routine do the ICPState
>> lookup. The resulting object is stored under PowerPCCPU which is
>> passed on to xics_cpu_setup(). The IRQ 'server' number in XICS is now
>> generic. sPAPR uses 'cpu_dt_id' and PowerNV will use 'PIR' number.
>>
>> This also has the benefit of simplifying the sPAPR hcall routines
>> which do not need to do any ICPState lookups anymore.
> 
> Since you've changed the type to a generic Object *, the name needs to
> be changed to something generic as well.  Maybe 'intc' or
> 'irq_private'.

yes. I think 'intc' is a good choice, unless we make the type 
'void *' and in that case 'irq_private' would be better.

I took a quick look at the other machines under ppc. It is not 
obvious how we could use that 'intc' pointer. May be for the 
objects TYPE_OPENPIC and heathrow_pic.

The ppc405 machines could use it to store 'qemu_irq *pic' but 
I am not sure there is much benefit doing that. To be studied.

Anyhow I will change the name.

Thanks,

C. 

>>
>> Signed-off-by: Cédric Le Goater <address@hidden>
>> ---
>>
>> Changes since v2:
>>
>>  - changed the 'icp' backlink type to be an 'Object'
>>
>>  hw/intc/xics.c          |  4 ++--
>>  hw/intc/xics_spapr.c    | 20 +++++---------------
>>  hw/ppc/spapr_cpu_core.c |  5 ++++-
>>  target/ppc/cpu.h        |  1 +
>>  4 files changed, 12 insertions(+), 18 deletions(-)
>>
>> diff --git a/hw/intc/xics.c b/hw/intc/xics.c
>> index e740989a1162..bb485cc5b078 100644
>> --- a/hw/intc/xics.c
>> +++ b/hw/intc/xics.c
>> @@ -52,7 +52,7 @@ int xics_get_cpu_index_by_dt_id(int cpu_dt_id)
>>  void xics_cpu_destroy(XICSFabric *xi, PowerPCCPU *cpu)
>>  {
>>      CPUState *cs = CPU(cpu);
>> -    ICPState *icp = xics_icp_get(xi, cs->cpu_index);
>> +    ICPState *icp = ICP(cpu->icp);
>>  
>>      assert(icp);
>>      assert(cs == icp->cs);
>> @@ -65,7 +65,7 @@ void xics_cpu_setup(XICSFabric *xi, PowerPCCPU *cpu)
>>  {
>>      CPUState *cs = CPU(cpu);
>>      CPUPPCState *env = &cpu->env;
>> -    ICPState *icp = xics_icp_get(xi, cs->cpu_index);
>> +    ICPState *icp = ICP(cpu->icp);
>>      ICPStateClass *icpc;
>>  
>>      assert(icp);
>> diff --git a/hw/intc/xics_spapr.c b/hw/intc/xics_spapr.c
>> index 84d24b2837a7..6144f9876ae3 100644
>> --- a/hw/intc/xics_spapr.c
>> +++ b/hw/intc/xics_spapr.c
>> @@ -43,11 +43,9 @@
>>  static target_ulong h_cppr(PowerPCCPU *cpu, sPAPRMachineState *spapr,
>>                             target_ulong opcode, target_ulong *args)
>>  {
>> -    CPUState *cs = CPU(cpu);
>> -    ICPState *icp = xics_icp_get(XICS_FABRIC(spapr), cs->cpu_index);
>>      target_ulong cppr = args[0];
>>  
>> -    icp_set_cppr(icp, cppr);
>> +    icp_set_cppr(ICP(cpu->icp), cppr);
>>      return H_SUCCESS;
>>  }
>>  
>> @@ -69,9 +67,7 @@ static target_ulong h_ipi(PowerPCCPU *cpu, 
>> sPAPRMachineState *spapr,
>>  static target_ulong h_xirr(PowerPCCPU *cpu, sPAPRMachineState *spapr,
>>                             target_ulong opcode, target_ulong *args)
>>  {
>> -    CPUState *cs = CPU(cpu);
>> -    ICPState *icp = xics_icp_get(XICS_FABRIC(spapr), cs->cpu_index);
>> -    uint32_t xirr = icp_accept(icp);
>> +    uint32_t xirr = icp_accept(ICP(cpu->icp));
>>  
>>      args[0] = xirr;
>>      return H_SUCCESS;
>> @@ -80,9 +76,7 @@ static target_ulong h_xirr(PowerPCCPU *cpu, 
>> sPAPRMachineState *spapr,
>>  static target_ulong h_xirr_x(PowerPCCPU *cpu, sPAPRMachineState *spapr,
>>                               target_ulong opcode, target_ulong *args)
>>  {
>> -    CPUState *cs = CPU(cpu);
>> -    ICPState *icp = xics_icp_get(XICS_FABRIC(spapr), cs->cpu_index);
>> -    uint32_t xirr = icp_accept(icp);
>> +    uint32_t xirr = icp_accept(ICP(cpu->icp));
>>  
>>      args[0] = xirr;
>>      args[1] = cpu_get_host_ticks();
>> @@ -92,21 +86,17 @@ static target_ulong h_xirr_x(PowerPCCPU *cpu, 
>> sPAPRMachineState *spapr,
>>  static target_ulong h_eoi(PowerPCCPU *cpu, sPAPRMachineState *spapr,
>>                            target_ulong opcode, target_ulong *args)
>>  {
>> -    CPUState *cs = CPU(cpu);
>> -    ICPState *icp = xics_icp_get(XICS_FABRIC(spapr), cs->cpu_index);
>>      target_ulong xirr = args[0];
>>  
>> -    icp_eoi(icp, xirr);
>> +    icp_eoi(ICP(cpu->icp), xirr);
>>      return H_SUCCESS;
>>  }
>>  
>>  static target_ulong h_ipoll(PowerPCCPU *cpu, sPAPRMachineState *spapr,
>>                              target_ulong opcode, target_ulong *args)
>>  {
>> -    CPUState *cs = CPU(cpu);
>> -    ICPState *icp = xics_icp_get(XICS_FABRIC(spapr), cs->cpu_index);
>>      uint32_t mfrr;
>> -    uint32_t xirr = icp_ipoll(icp, &mfrr);
>> +    uint32_t xirr = icp_ipoll(ICP(cpu->icp), &mfrr);
>>  
>>      args[0] = xirr;
>>      args[1] = mfrr;
>> diff --git a/hw/ppc/spapr_cpu_core.c b/hw/ppc/spapr_cpu_core.c
>> index 6883f0991ae9..f9ca3f09a0f8 100644
>> --- a/hw/ppc/spapr_cpu_core.c
>> +++ b/hw/ppc/spapr_cpu_core.c
>> @@ -63,6 +63,8 @@ static void spapr_cpu_init(sPAPRMachineState *spapr, 
>> PowerPCCPU *cpu,
>>                             Error **errp)
>>  {
>>      CPUPPCState *env = &cpu->env;
>> +    XICSFabric *xi = XICS_FABRIC(spapr);
>> +    ICPState *icp = xics_icp_get(xi, CPU(cpu)->cpu_index);
>>  
>>      /* Set time-base frequency to 512 MHz */
>>      cpu_ppc_tb_init(env, SPAPR_TIMEBASE_FREQ);
>> @@ -80,7 +82,8 @@ static void spapr_cpu_init(sPAPRMachineState *spapr, 
>> PowerPCCPU *cpu,
>>          }
>>      }
>>  
>> -    xics_cpu_setup(XICS_FABRIC(spapr), cpu);
>> +    cpu->icp = OBJECT(icp);
>> +    xics_cpu_setup(xi, cpu);
>>  
>>      qemu_register_reset(spapr_cpu_reset, cpu);
>>      spapr_cpu_reset(cpu);
>> diff --git a/target/ppc/cpu.h b/target/ppc/cpu.h
>> index 5ee33b3fd315..774f2d717831 100644
>> --- a/target/ppc/cpu.h
>> +++ b/target/ppc/cpu.h
>> @@ -1196,6 +1196,7 @@ struct PowerPCCPU {
>>      uint32_t max_compat;
>>      uint32_t compat_pvr;
>>      PPCVirtualHypervisor *vhyp;
>> +    Object *icp;
>>  
>>      /* Fields related to migration compatibility hacks */
>>      bool pre_2_8_migration;
> 




reply via email to

[Prev in Thread] Current Thread [Next in Thread]