Re: [PATCH v9 6/7] ACPI: APEI: EINJ: Enable EINJv2 error injections

[Zaid Alali <zaidal@os.amperecomputing.com>]

On Fri, Jun 13, 2025 at 12:37:54PM -0500, Ira Weiny wrote:
> Zaid Alali wrote:
> > Enable injection using EINJv2 mode of operation.
> > 
> > [Tony: Mostly Zaid's original code. I just changed how the error ID
> > and syndrome bits are implemented. Also swapped out some camelcase
> > variable names]
> > 
> > Co-developed-by: Tony Luck <tony.luck@intel.com>
> > Signed-off-by: Tony Luck <tony.luck@intel.com>
> > Signed-off-by: Zaid Alali <zaidal@os.amperecomputing.com>
> > ---
> >  drivers/acpi/apei/einj-core.c | 56 ++++++++++++++++++++++++++++-------
> >  1 file changed, 45 insertions(+), 11 deletions(-)
> > 
> > diff --git a/drivers/acpi/apei/einj-core.c b/drivers/acpi/apei/einj-core.c
> > index 8d60e5f1785c..7741c2082f33 100644
> > --- a/drivers/acpi/apei/einj-core.c
> > +++ b/drivers/acpi/apei/einj-core.c
> > @@ -87,6 +87,7 @@ enum {
> >  	SETWA_FLAGS_APICID = 1,
> >  	SETWA_FLAGS_MEM = 2,
> >  	SETWA_FLAGS_PCIE_SBDF = 4,
> > +	SETWA_FLAGS_EINJV2 = 8,
> >  };
> >  
> >  /*
> > @@ -181,6 +182,7 @@ bool einj_initialized __ro_after_init;
> >  
> >  static void __iomem *einj_param;
> >  static u32 v5param_size;
> > +static bool is_v2;
> >  
> >  static void einj_exec_ctx_init(struct apei_exec_context *ctx)
> >  {
> > @@ -507,12 +509,20 @@ static int __einj_error_trigger(u64 trigger_paddr, u32 type,
> >  	return rc;
> >  }
> >  
> > +static bool is_end_of_list(u8 *val)
> > +{
> > +	for (int i = 0; i < COMPONENT_LEN; ++i) {
> 
> Back in patch 3/7 these are defined using a hard coded value.
> 
> I think it might be better to at least use COMPONENT_LEN for those
> definitions.

Thats a good idea! I will update this in the next revision.

> 
> I'm also wondering if it would be better to have some type safety here...
> but probably fine.
> 
> > +		if (val[i] != 0xFF)
> > +			return false;
> > +	}
> > +	return true;
> 
> I'm unclear of the way this list is terminated.  The cover letter does not
> mention it.  I read the documentation patch and it looks like you echo ''
> to the id to terminate.  How does that work here?
> 
> From the documentation patch.
> 
>   # echo '' > component_id2			# Mark id2 invalid to terminate list
> 
> 

As shown in ptach 7/7 "Writing just a newline to any of these files  sets
an invalid (all-ones) value."

> > +}
> >  static int __einj_error_inject(u32 type, u32 flags, u64 param1, u64 param2,
> >  			       u64 param3, u64 param4)
> >  {
> >  	struct apei_exec_context ctx;
> >  	u64 val, trigger_paddr, timeout = FIRMWARE_TIMEOUT;
> > -	int rc;
> > +	int i, rc;
> >  
> >  	einj_exec_ctx_init(&ctx);
> >  
> > @@ -521,10 +531,10 @@ static int __einj_error_inject(u32 type, u32 flags, u64 param1, u64 param2,
> >  		return rc;
> >  	apei_exec_ctx_set_input(&ctx, type);
> >  	if (acpi5) {
> > -		struct set_error_type_with_address *v5param, v5_struct;
> > +		struct set_error_type_with_address *v5param;
> >  
> > -		v5param = &v5_struct;
> > -		memcpy_fromio(v5param, einj_param, sizeof(*v5param));
> > +		v5param = kmalloc(v5param_size, GFP_KERNEL);
> > +		memcpy_fromio(v5param, einj_param, v5param_size);
> >  		v5param->type = type;
> >  		if (type & ACPI5_VENDOR_BIT) {
> >  			switch (vendor_flags) {
> > @@ -544,8 +554,21 @@ static int __einj_error_inject(u32 type, u32 flags, u64 param1, u64 param2,
> >  			v5param->flags = flags;
> >  			v5param->memory_address = param1;
> >  			v5param->memory_address_range = param2;
> > -			v5param->apicid = param3;
> > -			v5param->pcie_sbdf = param4;
> > +
> > +			if (is_v2) {
> > +				for (i = 0; i < max_nr_components; i++) {
> > +					if (is_end_of_list(syndrome_data[i].comp_id.acpi_id))
> > +						break;
> > +					v5param->einjv2_struct.component_arr[i].comp_id =
> > +						syndrome_data[i].comp_id;
> > +					v5param->einjv2_struct.component_arr[i].comp_synd =
> > +						syndrome_data[i].comp_synd;
> > +				}
> > +				v5param->einjv2_struct.component_arr_count = i;
> > +			} else {
> > +				v5param->apicid = param3;
> > +				v5param->pcie_sbdf = param4;
> > +			}
> >  		} else {
> >  			switch (type) {
> >  			case ACPI_EINJ_PROCESSOR_CORRECTABLE:
> > @@ -569,7 +592,8 @@ static int __einj_error_inject(u32 type, u32 flags, u64 param1, u64 param2,
> >  				break;
> >  			}
> >  		}
> > -		memcpy_toio(einj_param, v5param, sizeof(*v5param));
> > +		memcpy_toio(einj_param, v5param, v5param_size);
> > +		kfree(v5param);
> >  	} else {
> >  		rc = apei_exec_run(&ctx, ACPI_EINJ_SET_ERROR_TYPE);
> >  		if (rc)
> > @@ -631,10 +655,15 @@ int einj_error_inject(u32 type, u32 flags, u64 param1, u64 param2, u64 param3,
> >  	u64 base_addr, size;
> >  
> >  	/* If user manually set "flags", make sure it is legal */
> > -	if (flags && (flags &
> > -		~(SETWA_FLAGS_APICID|SETWA_FLAGS_MEM|SETWA_FLAGS_PCIE_SBDF)))
> > +	if (flags && (flags & ~(SETWA_FLAGS_APICID | SETWA_FLAGS_MEM |
> > +		      SETWA_FLAGS_PCIE_SBDF | SETWA_FLAGS_EINJV2)))
> >  		return -EINVAL;
> >  
> > +	/* check if type is a valid EINJv2 error type */
> > +	if (is_v2) {
> > +		if (!(type & available_error_type_v2))
> > +			return -EINVAL;
> > +	}
> >  	/*
> >  	 * We need extra sanity checks for memory errors.
> >  	 * Other types leap directly to injection.
> > @@ -743,7 +772,7 @@ static int available_error_type_show(struct seq_file *m, void *v)
> >  		if (available_error_type & einj_error_type_string[pos].mask)
> >  			seq_printf(m, "0x%08x\t%s\n", einj_error_type_string[pos].mask,
> >  				   einj_error_type_string[pos].str);
> > -	if (available_error_type & ACPI65_EINJV2_SUPP) {
> > +	if ((available_error_type & ACPI65_EINJV2_SUPP) && einj_v2_enabled) {
> >  		for (int pos = 0; pos < ARRAY_SIZE(einjv2_error_type_string); pos++) {
> >  			if (available_error_type_v2 & einjv2_error_type_string[pos].mask)
> >  				seq_printf(m, "V2_0x%08x\t%s\n", einjv2_error_type_string[pos].mask,
> > @@ -785,7 +814,7 @@ int einj_validate_error_type(u64 type)
> >  	if (tval & (tval - 1))
> >  		return -EINVAL;
> >  	if (!vendor)
> > -		if (!(type & available_error_type))
> > +		if (!(type & (available_error_type | available_error_type_v2)))
> >  			return -EINVAL;
> >  
> >  	return 0;
> > @@ -804,9 +833,11 @@ static ssize_t error_type_set(struct file *file, const char __user *buf,
> >  	if (strncmp(einj_buf, "V2_", 3) == 0) {
> >  		if (!sscanf(einj_buf, "V2_%llx", &val))
> >  			return -EINVAL;
> > +		is_v2 = true;
> >  	} else {
> >  		if (!sscanf(einj_buf, "%llx", &val))
> >  			return -EINVAL;
> > +		is_v2 = false;
> >  	}
> >  
> >  	rc = einj_validate_error_type(val);
> > @@ -828,6 +859,9 @@ static int error_inject_set(void *data, u64 val)
> >  	if (!error_type)
> >  		return -EINVAL;
> >  
> > +	if (is_v2)
> > +		error_flags |= SETWA_FLAGS_EINJV2;
> > +
> > +
> 
> Does this flag need to be cleared if a v1 error is being used?
> 
> Ira

The driver depends on "is_v2" to determine if the injection is v1 or v2, and the user 
is supposed to set the flags for v1 and v2, but I think clearing the flag here is a good idea so
the user does not have to worry about that. I can see why someone would assume not needing
to set the flags when they see "V2_" prefix for v2 error types.
I'll also update this.

Zaid

> 
> >  	return einj_error_inject(error_type, error_flags, error_param1, error_param2,
> >  		error_param3, error_param4);
> >  }
> > -- 
> > 2.43.0
> >