[PATCH 1/2] ACPI/AEST: Initial AEST driver

[Tyler Baicar]

Hi Shuuichirou,

Thank you for your feedback!

On 12/9/2021 3:10 AM, ishii.shuuichir at fujitsu.com wrote:
> Hi, Tyler.
>
> We would like to make a few comments.
>
>> -----Original Message-----
>> From: Tyler Baicar <baicar at os.amperecomputing.com>
>> Sent: Thursday, November 25, 2021 2:07 AM
>> To: patches at amperecomputing.com; abdulhamid at os.amperecomputing.com;
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>> linux-arm-kernel at lists.infradead.org; kvmarm at lists.cs.columbia.edu;
>> linux-acpi at vger.kernel.org; linux-edac at vger.kernel.org; Ishii, Shuuichirou/石井
>> 周一郎 <ishii.shuuichir at fujitsu.com>; Vineeth.Pillai at microsoft.com
>> Cc: Tyler Baicar <baicar at os.amperecomputing.com>
>> Subject: [PATCH 1/2] ACPI/AEST: Initial AEST driver
>>
>> Add support for parsing the ARM Error Source Table and basic handling of
>> errors reported through both memory mapped and system register interfaces.
>>
>> Assume system register interfaces are only registered with private
>> peripheral interrupts (PPIs); otherwise there is no guarantee the
>> core handling the error is the core which took the error and has the
>> syndrome info in its system registers.
>>
>> Add logging for all detected errors and trigger a kernel panic if there is
>> any uncorrected error present.
>>
>> Signed-off-by: Tyler Baicar <baicar at os.amperecomputing.com>
>> ---
> [...]
>
>> +static int __init aest_init_node(struct acpi_aest_hdr *node)
>> +{
>> +	union acpi_aest_processor_data *proc_data;
>> +	union aest_node_spec *node_spec;
>> +	struct aest_node_data *data;
>> +	int ret;
>> +
>> +	data = kzalloc(sizeof(struct aest_node_data), GFP_KERNEL);
>> +	if (!data)
>> +		return -ENOMEM;
>> +
>> +	data->node_type = node->type;
>> +
>> +	node_spec = ACPI_ADD_PTR(union aest_node_spec, node,
>> node->node_specific_offset);
>> +
>> +	switch (node->type) {
>> +	case ACPI_AEST_PROCESSOR_ERROR_NODE:
>> +		memcpy(&data->data, node_spec, sizeof(struct
>> acpi_aest_processor));
>> +		break;
>> +	case ACPI_AEST_MEMORY_ERROR_NODE:
>> +		memcpy(&data->data, node_spec, sizeof(struct
>> acpi_aest_memory));
>> +		break;
>> +	case ACPI_AEST_SMMU_ERROR_NODE:
>> +		memcpy(&data->data, node_spec, sizeof(struct
>> acpi_aest_smmu));
>> +		break;
>> +	case ACPI_AEST_VENDOR_ERROR_NODE:
>> +		memcpy(&data->data, node_spec, sizeof(struct
>> acpi_aest_vendor));
>> +		break;
>> +	case ACPI_AEST_GIC_ERROR_NODE:
>> +		memcpy(&data->data, node_spec, sizeof(struct
>> acpi_aest_gic));
>> +		break;
>> +	default:
>> +		kfree(data);
>> +		return -EINVAL;
>> +	}
>> +
>> +	if (node->type == ACPI_AEST_PROCESSOR_ERROR_NODE) {
>> +		proc_data = ACPI_ADD_PTR(union acpi_aest_processor_data,
>> node_spec,
>> +					 sizeof(acpi_aest_processor));
>> +
>> +		switch (data->data.processor.resource_type) {
>> +		case ACPI_AEST_CACHE_RESOURCE:
>> +			memcpy(&data->proc_data, proc_data,
>> +			       sizeof(struct acpi_aest_processor_cache));
>> +			break;
>> +		case ACPI_AEST_TLB_RESOURCE:
>> +			memcpy(&data->proc_data, proc_data,
>> +			       sizeof(struct acpi_aest_processor_tlb));
>> +			break;
>> +		case ACPI_AEST_GENERIC_RESOURCE:
>> +			memcpy(&data->proc_data, proc_data,
>> +			       sizeof(struct acpi_aest_processor_generic));
>> +			break;
>> +		}
>> +	}
>> +
>> +	ret = aest_init_interface(node, data);
>> +	if (ret) {
>> +		kfree(data);
>> +		return ret;
>> +	}
>> +
>> +	return aest_init_interrupts(node, data);
> If aest_init_interrupts() failed, is it necessary to release
> the data pointer acquired by kzalloc?
aest_init_interrupts() returns an error if any of the interrupts in the 
interrupt list fails, but it's possible that some interrupts in the list 
registered successfully. So we attempt to keep chugging along in that 
scenario because some interrupts may be enabled and registered with the 
interface successfully. If any interrupt registration fails, there will 
be a print notifying that there was a failure when initializing that node.
>> +}
>> +
>> +static void aest_count_ppi(struct acpi_aest_hdr *node)
>> +{
>> +	struct acpi_aest_node_interrupt *interrupt;
>> +	int i;
>> +
>> +	interrupt = ACPI_ADD_PTR(struct acpi_aest_node_interrupt, node,
>> +				 node->node_interrupt_offset);
>> +
>> +	for (i = 0; i < node->node_interrupt_count; i++, interrupt++) {
>> +		if (interrupt->gsiv >= 16 && interrupt->gsiv < 32)
>> +			num_ppi++;
>> +	}
>> +}
>> +
>> +static int aest_starting_cpu(unsigned int cpu)
>> +{
>> +	int i;
>> +
>> +	for (i = 0; i < num_ppi; i++)
>> +		enable_percpu_irq(ppi_irqs[i], IRQ_TYPE_NONE);
>> +
>> +	return 0;
>> +}
>> +
>> +static int aest_dying_cpu(unsigned int cpu)
>> +{
> Wouldn't it be better to execute disable_percpu_irq(), which is paired
> with enable_percpu_irq(), in aest_dying_cpu()?

Good point. I will add that in the next version.

Thanks,

Tyler