Re: [PATCH v5 3/4] hw/ssi/pnv_spi: Make bus names distinct for each controllers of a socket

[Chalapathi V <chalapathi.v@linux.ibm.com>]

On 28-02-2025 13:15, Cédric Le Goater wrote:
> On 2/28/25 04:03, Chalapathi V wrote:
>>
>> On 27-02-2025 07:24, Nicholas Piggin wrote:
>>> On Sat Jan 4, 2025 at 2:18 AM AEST, Chalapathi V wrote:
>>>> Create a spi buses with distict names on each socket so that 
>>>> responders
>>>> are attached to correct SPI controllers.
>>>>
>>>> QOM tree on a 2 socket machine:
>>>> (qemu) info qom-tree
>>>> /machine (powernv10-machine)
>>>>    /chip[0] (power10_v2.0-pnv-chip)
>>>>      /pib_spic[0] (pnv-spi)
>>>>        /chip0.pnv.spi.bus.0 (SSI)
>>>>        /xscom-spi[0] (memory-region)
>>>>    /chip[1] (power10_v2.0-pnv-chip)
>>>>      /pib_spic[0] (pnv-spi)
>>>>        /chip1.pnv.spi.bus.0 (SSI)
>>>>        /xscom-spi[0] (memory-region)
>>> Mechanics of the patch looks fine. I don't know about the name
>>> though.
>>>
>>> I think "pnv-spi-bus" is the right name for the bus. Using dots as
>>> with chip0. makes it seem like each element is part of a topology.
>>>
>>> Would chip0.pnv-spi-bus be better?
>> Will rename the bus name to chip0.pnv-spi-bus . Thank You
>
> Yep. I don't think the bus suffix is useful (minor).
>
> Will you be attaching flash devices from the command line ? Can you 
> provide
> an example if so ?
>
> Thanks,
>
> C.
>
Yes, I am attaching seeprom and TPM device from command line.
"-blockdev node-name=pib_spic2,driver=file,filename=%s -device 
25csm04,bus=chip0.pnv-spi-bus.2,cs=0,drive=pib_spic2"

"-chardev 
socket,id=chrtpm,path=/tmp/swtpm.chalap1.250227212039.rOWBH/swtpm-sock 
-tpmdev emulator,id=tpm0,chardev=chrtpm -device 
tpm-tis-spi,tpmdev=tpm0,bus=chip0.pnv-spi-bus.4"

Thank You,

Chalapathi

>
>>> I don't suppose there is a good way to create an alias so existing
>>> cmdline works and refers to the bus on chip0? Maybe the chip0 bus
>>> could just not have the chip0. prefix?
>>>
>>> Thanks,
>>> Nick
>> Would it be best to keep the chip0 prefix to have uniformity?
>>>> Signed-off-by: Chalapathi V<chalapathi.v@linux.ibm.com>
>>>> ---
>>>>   include/hw/ssi/pnv_spi.h           | 3 ++-
>>>>   hw/ppc/pnv.c                       | 2 ++
>>>>   hw/ssi/pnv_spi.c                   | 5 +++--
>>>>   tests/qtest/pnv-spi-seeprom-test.c | 2 +-
>>>>   4 files changed, 8 insertions(+), 4 deletions(-)
>>>>
>>>> diff --git a/include/hw/ssi/pnv_spi.h b/include/hw/ssi/pnv_spi.h
>>>> index 9878d9a25f..7fc5da1f84 100644
>>>> --- a/include/hw/ssi/pnv_spi.h
>>>> +++ b/include/hw/ssi/pnv_spi.h
>>>> @@ -31,7 +31,7 @@ OBJECT_DECLARE_SIMPLE_TYPE(PnvSpi, PNV_SPI)
>>>>   #define PNV_SPI_REG_SIZE 8
>>>>   #define PNV_SPI_REGS 7
>>>>   -#define TYPE_PNV_SPI_BUS "pnv-spi-bus"
>>>> +#define TYPE_PNV_SPI_BUS "pnv.spi.bus"
>>>>   typedef struct PnvSpi {
>>>>       SysBusDevice parent_obj;
>>>>   @@ -42,6 +42,7 @@ typedef struct PnvSpi {
>>>>       Fifo8 rx_fifo;
>>>>       /* SPI object number */
>>>>       uint32_t        spic_num;
>>>> +    uint32_t        chip_id;
>>>>       uint8_t         transfer_len;
>>>>       uint8_t         responder_select;
>>>>       /* To verify if shift_n1 happens prior to shift_n2 */
>>>> diff --git a/hw/ppc/pnv.c b/hw/ppc/pnv.c
>>>> index 11fd477b71..ce23892fdf 100644
>>>> --- a/hw/ppc/pnv.c
>>>> +++ b/hw/ppc/pnv.c
>>>> @@ -2226,6 +2226,8 @@ static void 
>>>> pnv_chip_power10_realize(DeviceState *dev, Error **errp)
>>>>           /* pib_spic[2] connected to 25csm04 which implements 1 
>>>> byte transfer */
>>>> object_property_set_int(OBJECT(&chip10->pib_spic[i]), "transfer_len",
>>>>                                   (i == 2) ? 1 : 4, &error_fatal);
>>>> + object_property_set_int(OBJECT(&chip10->pib_spic[i]), "chip-id",
>>>> +                                chip->chip_id, &error_fatal);
>>>>           if (!sysbus_realize(SYS_BUS_DEVICE(OBJECT
>>>> (&chip10->pib_spic[i])), errp)) {
>>>>               return;
>>>> diff --git a/hw/ssi/pnv_spi.c b/hw/ssi/pnv_spi.c
>>>> index 87eac666bb..41beb559c6 100644
>>>> --- a/hw/ssi/pnv_spi.c
>>>> +++ b/hw/ssi/pnv_spi.c
>>>> @@ -1116,14 +1116,15 @@ static const MemoryRegionOps 
>>>> pnv_spi_xscom_ops = {
>>>>     static const Property pnv_spi_properties[] = {
>>>>       DEFINE_PROP_UINT32("spic_num", PnvSpi, spic_num, 0),
>>>> +    DEFINE_PROP_UINT32("chip-id", PnvSpi, chip_id, 0),
>>>>       DEFINE_PROP_UINT8("transfer_len", PnvSpi, transfer_len, 4),
>>>>   };
>>>>     static void pnv_spi_realize(DeviceState *dev, Error **errp)
>>>>   {
>>>>       PnvSpi *s = PNV_SPI(dev);
>>>> -    g_autofree char *name = g_strdup_printf(TYPE_PNV_SPI_BUS ".%d",
>>>> -                    s->spic_num);
>>>> +    g_autofree char *name = g_strdup_printf("chip%d." 
>>>> TYPE_PNV_SPI_BUS ".%d",
>>>> +                    s->chip_id, s->spic_num);
>>>>       s->ssi_bus = ssi_create_bus(dev, name);
>>>>       s->cs_line = g_new0(qemu_irq, 1);
>>>>       qdev_init_gpio_out_named(DEVICE(s), s->cs_line, "cs", 1);
>>>> diff --git a/tests/qtest/pnv-spi-seeprom-test.c 
>>>> b/tests/qtest/pnv-spi-seeprom-test.c
>>>> index 57f20af76e..ef1005a926 100644
>>>> --- a/tests/qtest/pnv-spi-seeprom-test.c
>>>> +++ b/tests/qtest/pnv-spi-seeprom-test.c
>>>> @@ -92,7 +92,7 @@ static void test_spi_seeprom(const void *data)
>>>>       qts = qtest_initf("-machine powernv10 -smp 2,cores=2,"
>>>>                         "threads=1 -accel tcg,thread=single 
>>>> -nographic "
>>>>                         "-blockdev node-name=pib_spic2,driver=file,"
>>>> -                      "filename=%s -device 
>>>> 25csm04,bus=pnv-spi-bus.2,cs=0,"
>>>> +                      "filename=%s -device 
>>>> 25csm04,bus=chip0.pnv.spi.bus.2,cs=0,"
>>>>                         "drive=pib_spic2", tmp_path);
>>>>       spi_seeprom_transaction(qts, chip);
>>>>       qtest_quit(qts);
>