Re: [PATCH v4 4/7] platform/x86/amd/hsmp: Source metric-table size from firmware

["M K, Muralidhara" <muralimk@amd.com>]

On 6/10/2026 4:35 PM, Ilpo Järvinen wrote:
> Caution: This message originated from an External Source. Use proper caution when opening attachments, clicking links, or responding.
> 
> 
> On Thu, 28 May 2026, Muralidhara M K wrote:
> 
>> The driver hard-codes the metric-table region size to
>> sizeof(struct hsmp_metric_table). That is correct for HSMP protocol
>> version 6 but mis-sizes the ioremap of the SMU DRAM region on newer
>> platforms: Family 1Ah Model 50h-5Fh exposes a ~13 KB
>> hsmp_metric_table_zen6, and the table is expected to keep growing
>> on future firmware. The same hard-coded value also forces
>> hsmp_metric_tbl_read() to reject any read that follows the actual
>> firmware layout.
>>
>> Pick up the table size from firmware instead. SMU on Family 1Ah
>> Model 50h and later populates HSMP_GET_METRIC_TABLE_DRAM_ADDR's
>> args[2] with the DRAM region size in bytes; older firmware leaves
>> it 0. Bump the descriptor's response_sz to 3 so the field is read,
>> store the value in hsmp_pdev.hsmp_table_size at probe time, and
>> fall back to sizeof(struct hsmp_metric_table) when firmware reports
>> 0. Use hsmp_table_size both for the devm_ioremap() of the region
>> and as the upper bound for hsmp_metric_tbl_read().
>>
>> Behaviour on existing protocol-version-6 hardware is unchanged:
>> firmware returns 0, the fallback yields the same value as the
>> previous hard-coded one, and both the ioremap and the size check
>> produce the same result as before.
>>
>> The ioctl interface added later in this series uses the same
>> hsmp_table_size to validate the userspace request and to copy out
>> the full firmware-reported region.
>>
>> Co-developed-by: Muthusamy Ramalingam <muthusamy.ramalingam@amd.com>
>> Signed-off-by: Muthusamy Ramalingam <muthusamy.ramalingam@amd.com>
>> Signed-off-by: Muralidhara M K <muralidhara.mk@amd.com>
>> ---
>>   arch/x86/include/uapi/asm/amd_hsmp.h |  5 +++--
>>   drivers/platform/x86/amd/hsmp/hsmp.c | 11 ++++++++---
>>   drivers/platform/x86/amd/hsmp/hsmp.h |  1 +
>>   3 files changed, 12 insertions(+), 5 deletions(-)
>>
>> diff --git a/arch/x86/include/uapi/asm/amd_hsmp.h b/arch/x86/include/uapi/asm/amd_hsmp.h
>> index fce271282348..438ac38d0dc8 100644
>> --- a/arch/x86/include/uapi/asm/amd_hsmp.h
>> +++ b/arch/x86/include/uapi/asm/amd_hsmp.h
>> @@ -365,11 +365,12 @@ static const struct hsmp_msg_desc hsmp_msg_desc_table[]
>>        {0, 0, HSMP_GET},
>>
>>        /*
>> -      * HSMP_GET_METRIC_TABLE_DRAM_ADDR, num_args = 0, response_sz = 2
>> +      * HSMP_GET_METRIC_TABLE_DRAM_ADDR, num_args = 0, response_sz = 3
>>         * output: args[0] = lower 32 bits of the address
>>         * output: args[1] = upper 32 bits of the address
>> +      * output: args[2] = DRAM region size in bytes
>>         */
>> -     {0, 2, HSMP_GET},
>> +     {0, 3, HSMP_GET},
>>
>>        /*
>>         * HSMP_SET_XGMI_PSTATE_RANGE, num_args = 1, response_sz = 0
>> diff --git a/drivers/platform/x86/amd/hsmp/hsmp.c b/drivers/platform/x86/amd/hsmp/hsmp.c
>> index 9bad58fef304..cf9392f99298 100644
>> --- a/drivers/platform/x86/amd/hsmp/hsmp.c
>> +++ b/drivers/platform/x86/amd/hsmp/hsmp.c
>> @@ -356,8 +356,7 @@ ssize_t hsmp_metric_tbl_read(struct hsmp_socket *sock, char *buf, size_t size)
>>                return -ENOMEM;
>>        }
>>
>> -     /* Do not support lseek(), also don't allow more than the size of metric table */
>> -     if (size != sizeof(struct hsmp_metric_table)) {
>> +     if (size != hsmp_pdev.hsmp_table_size) {
>>                dev_err(sock->dev, "Wrong buffer size\n");
>>                return -EINVAL;
>>        }
>> @@ -398,8 +397,14 @@ int hsmp_get_tbl_dram_base(u16 sock_ind)
>>                dev_err(sock->dev, "Invalid DRAM address for metric table\n");
>>                return -ENOMEM;
>>        }
>> +     /* SMU returns table size from Family 1Ah Model 50h and forward */
>> +     if (msg.args[2])
>> +             hsmp_pdev.hsmp_table_size = msg.args[2];
>> +     else
>> +             hsmp_pdev.hsmp_table_size = sizeof(struct hsmp_metric_table);
>> +
>>        sock->metric_tbl_addr = devm_ioremap(sock->dev, dram_addr,
>> -                                          sizeof(struct hsmp_metric_table));
>> +                                          hsmp_pdev.hsmp_table_size);
>>        if (!sock->metric_tbl_addr) {
>>                dev_err(sock->dev, "Failed to ioremap metric table addr\n");
>>                return -ENOMEM;
>> diff --git a/drivers/platform/x86/amd/hsmp/hsmp.h b/drivers/platform/x86/amd/hsmp/hsmp.h
>> index b153527e0a0d..e7f051475728 100644
>> --- a/drivers/platform/x86/amd/hsmp/hsmp.h
>> +++ b/drivers/platform/x86/amd/hsmp/hsmp.h
>> @@ -55,6 +55,7 @@ struct hsmp_plat_device {
>>        u32 proto_ver;
>>        u16 num_sockets;
>>        bool is_probed;
>> +     size_t hsmp_table_size;
> 
> Please add types.h include.
>
In hsmp.h, size_t becomes visible without adding anything new, because 
the file already includes linux/device.h, and that pulls in linux/types.h

>>   };
>>
>>   int hsmp_cache_proto_ver(u16 sock_ind);
>>
> 
> --
>   i.
>