Re: [Qemu-devel] [PATCH v4 07/20] ppc/pnv: add XSCOM handlers to PnvCore

["Cédric Le Goater" <clg@kaod.org>]

On 10/13/2016 02:51 AM, David Gibson wrote:
> On Mon, Oct 03, 2016 at 09:24:43AM +0200, Cédric Le Goater wrote:
>> Now that we are using real HW ids for the cores in PowerNV chips, we
>> can route the XSCOM accesses to them. We just need to attach a
>> specific XSCOM memory region to each core in the appropriate window
>> for the core number.
>>
>> To start with, let's install the DTS (Digital Thermal Sensor) handlers
>> which should return 38°C for each core.
>>
>> Signed-off-by: Cédric Le Goater <clg@kaod.org>
>> ---
>>
>>  Changes since v3:
>>
>>  - moved to new XSCOM model
>>  - kept the write op on the XSCOM memory region for later use
>>
>>  Changes since v2:
>>
>>  - added a XSCOM memory region to handle access to the EX core
>>    registers   
>>  - extended the PnvCore object with a XSCOM_INTERFACE so that we can
>>    use pnv_xscom_pcba() and pnv_xscom_addr() to handle XSCOM address
>>    translation.
>>
>>  hw/ppc/pnv.c               |  4 ++++
>>  hw/ppc/pnv_core.c          | 50 ++++++++++++++++++++++++++++++++++++++++++++++
>>  include/hw/ppc/pnv_core.h  |  2 ++
>>  include/hw/ppc/pnv_xscom.h | 19 ++++++++++++++++++
>>  4 files changed, 75 insertions(+)
>>
>> diff --git a/hw/ppc/pnv.c b/hw/ppc/pnv.c
>> index 5e19b6880387..ffe245fe59d2 100644
>> --- a/hw/ppc/pnv.c
>> +++ b/hw/ppc/pnv.c
>> @@ -620,6 +620,10 @@ static void pnv_chip_realize(DeviceState *dev, Error **errp)
>>                                   &error_fatal);
>>          object_unref(OBJECT(pnv_core));
>>          i++;
>> +
>> +        memory_region_add_subregion(&chip->xscom,
>> +                         PNV_XSCOM_EX_CORE_BASE(core_hwid) << 3,
>> +                         &PNV_CORE(pnv_core)->xscom_regs);
> 
> Might be worth adding some convenience functions for doing the various
> bits of xscom MR juggling, otherwise this looks fine.

To do the 8 byte shifting ? or something like this :
 
	void pnv_xscom_add_subregion(PnvChip *chip, uint32_t pcba,
			     	     MemoryRegion *subregion);

or even :

	void pnv_xscom_add_subregion(PnvChip *chip, PnvXScomInterface *obj)

but that would require some more handlers under  PnvXScomInterface.

Thanks,

C.


>>      }
>>      g_free(typename);
>>  }
>> diff --git a/hw/ppc/pnv_core.c b/hw/ppc/pnv_core.c
>> index d37788f142f4..a1c8a14f06b6 100644
>> --- a/hw/ppc/pnv_core.c
>> +++ b/hw/ppc/pnv_core.c
>> @@ -19,6 +19,7 @@
>>  #include "qemu/osdep.h"
>>  #include "sysemu/sysemu.h"
>>  #include "qapi/error.h"
>> +#include "qemu/log.h"
>>  #include "target-ppc/cpu.h"
>>  #include "hw/ppc/ppc.h"
>>  #include "hw/ppc/pnv.h"
>> @@ -64,6 +65,51 @@ static void powernv_cpu_init(PowerPCCPU *cpu, Error **errp)
>>      powernv_cpu_reset(cpu);
>>  }
>>  
>> +/*
>> + * These values are read by the PowerNV HW monitors under Linux
>> + */
>> +#define PNV_XSCOM_EX_DTS_RESULT0     0x50000
>> +#define PNV_XSCOM_EX_DTS_RESULT1     0x50001
>> +
>> +static uint64_t pnv_core_xscom_read(void *opaque, hwaddr addr,
>> +                                    unsigned int width)
>> +{
>> +    uint32_t offset = addr >> 3;
>> +    uint64_t val = 0;
>> +
>> +    /* The result should be 38 C */
>> +    switch (offset) {
>> +    case PNV_XSCOM_EX_DTS_RESULT0:
>> +        val = 0x26f024f023f0000ull;
>> +        break;
>> +    case PNV_XSCOM_EX_DTS_RESULT1:
>> +        val = 0x24f000000000000ull;
>> +        break;
>> +    default:
>> +        qemu_log_mask(LOG_UNIMP, "Warning: reading reg=0x%" HWADDR_PRIx,
>> +                  addr);
>> +    }
>> +
>> +    return val;
>> +}
>> +
>> +static void pnv_core_xscom_write(void *opaque, hwaddr addr, uint64_t val,
>> +                                 unsigned int width)
>> +{
>> +    qemu_log_mask(LOG_UNIMP, "Warning: writing to reg=0x%" HWADDR_PRIx,
>> +                  addr);
>> +}
>> +
>> +static const MemoryRegionOps pnv_core_xscom_ops = {
>> +    .read = pnv_core_xscom_read,
>> +    .write = pnv_core_xscom_write,
>> +    .valid.min_access_size = 8,
>> +    .valid.max_access_size = 8,
>> +    .impl.min_access_size = 8,
>> +    .impl.max_access_size = 8,
>> +    .endianness = DEVICE_BIG_ENDIAN,
>> +};
>> +
>>  static void pnv_core_realize_child(Object *child, Error **errp)
>>  {
>>      Error *local_err = NULL;
>> @@ -119,6 +165,10 @@ static void pnv_core_realize(DeviceState *dev, Error **errp)
>>              goto err;
>>          }
>>      }
>> +
>> +    snprintf(name, sizeof(name), "xscom-core.%d", cc->core_id);
>> +    memory_region_init_io(&pc->xscom_regs, OBJECT(dev), &pnv_core_xscom_ops,
>> +                          pc, name,  PNV_XSCOM_EX_CORE_SIZE << 3);
>>      return;
>>  
>>  err:
>> diff --git a/include/hw/ppc/pnv_core.h b/include/hw/ppc/pnv_core.h
>> index a151e281c017..2955a41c901f 100644
>> --- a/include/hw/ppc/pnv_core.h
>> +++ b/include/hw/ppc/pnv_core.h
>> @@ -36,6 +36,8 @@ typedef struct PnvCore {
>>      /*< public >*/
>>      void *threads;
>>      uint32_t pir;
>> +
>> +    MemoryRegion xscom_regs;
>>  } PnvCore;
>>  
>>  typedef struct PnvCoreClass {
>> diff --git a/include/hw/ppc/pnv_xscom.h b/include/hw/ppc/pnv_xscom.h
>> index f50eb0bc4099..79975a6cbe46 100644
>> --- a/include/hw/ppc/pnv_xscom.h
>> +++ b/include/hw/ppc/pnv_xscom.h
>> @@ -41,6 +41,25 @@ typedef struct PnvXScomInterfaceClass {
>>      int (*populate)(PnvXScomInterface *dev, void *fdt, int offset);
>>  } PnvXScomInterfaceClass;
>>  
>> +/*
>> + * Layout of the XSCOM PCB addresses of EX core 1
>> + *
>> + *   GPIO        0x1100xxxx
>> + *   SCOM        0x1101xxxx
>> + *   OHA         0x1102xxxx
>> + *   CLOCK CTL   0x1103xxxx
>> + *   FIR         0x1104xxxx
>> + *   THERM       0x1105xxxx
>> + *   <reserved>  0x1106xxxx
>> + *               ..
>> + *               0x110Exxxx
>> + *   PCB SLAVE   0x110Fxxxx
>> + */
>> +
>> +#define PNV_XSCOM_EX_BASE         0x10000000
>> +#define PNV_XSCOM_EX_CORE_BASE(i) (PNV_XSCOM_EX_BASE | (((uint64_t)i) << 24))
>> +#define PNV_XSCOM_EX_CORE_SIZE    0x100000
>> +
>>  extern void pnv_xscom_realize(PnvChip *chip, Error **errp);
>>  extern int pnv_xscom_populate(PnvChip *chip, void *fdt, int offset);
>>  
>