Re: [PATCH] Changes to the ACPI/APEI/EINJ debugfs interface

[Naveen N. Rao]

On 2013/11/05 10:59AM, Tony Luck wrote:
> When I added support for ACPI5 I made the assumption that
> injected processor errors would just need to know the APICID,
> memory errors just the address and mask, and PCIe errors just the
> segment/bus/device/function. So I had the code check the type of injection
> and multiplex the "param1" value appropriately.
> 
> This was not a good assumption :-(
> 
> There are injection scenarios where we need to specify more than one of
> these items. E.g. injecting a cache error we need to specify an APICID
> of the cpu that owns the cache, and also an address (so that we can trip
> the error by accessing the address).
> 
> Add a "flags" file to give the user direct access to specify which items
> are valid in the ACPI SET_ERROR_TYPE_WITH_ADDRESS structure. Also add
> new files param3 and param4 to hold all these values.
> 
> For backwards compatability with old injection scripts we maintain the
> old behaviour if flags remains set at zero (or is reset to 0).
> 
> Signed-off-by: Tony Luck <tony.luck@xxxxxxxxx>

Patch
Acked-by: Naveen N. Rao <naveen.n.rao@xxxxxxxxxxxxxxxxxx>
with a small change below.

> 
> ---
> 
> diff --git a/Documentation/acpi/apei/einj.txt b/Documentation/acpi/apei/einj.txt
> index a58b63da1a36..f51861bcb07b 100644
> --- a/Documentation/acpi/apei/einj.txt
> +++ b/Documentation/acpi/apei/einj.txt
> @@ -45,11 +45,22 @@ directory apei/einj. The following files are provided.
>    injection. Before this, please specify all necessary error
>    parameters.
>  
> +- flags
> +  Present for kernel version 3.13 and above. Used to specify which
> +  of param{1..4} are valid and should be used by BIOS during injection.
> +  Value is a bitmask as specified in ACPI5.0 spec for the
> +  SET_ERROR_TYPE_WITH_ADDRESS data structure:
> +	Bit 0 - Processor APIC field valid (see param3 below)
> +	Bit 1 - Memory address and mask valid (param1 and param2)
> +	Bit 2 - PCIe (seg,bus,dev,fn) valid (param4 below)
> +  If set to zero, legacy behaviour is used where the type of injection
> +  specifies just one bit set, and param1 is multiplexed.
> +
>  - param1
>    This file is used to set the first error parameter value. Effect of
>    parameter depends on error_type specified. For example, if error
>    type is memory related type, the param1 should be a valid physical
> -  memory address.
> +  memory address. [Unless "flag" is set - see above]
>  
>  - param2
>    This file is used to set the second error parameter value. Effect of
> @@ -58,6 +69,12 @@ directory apei/einj. The following files are provided.
>    address mask. Linux requires page or narrower granularity, say,
>    0xfffffffffffff000.
>  
> +- param3
> +  Used when the 0x1 bit is set in "flag" to specify the APIC id
> +
> +- param4
> +  Used when the 0x4 bit is set in "flag" to specify target PCIe device
> +
>  - notrigger
>    The EINJ mechanism is a two step process. First inject the error, then
>    perform some actions to trigger it. Setting "notrigger" to 1 skips the
> diff --git a/drivers/acpi/apei/einj.c b/drivers/acpi/apei/einj.c
> index fb57d03e698b..23deab26ef86 100644
> --- a/drivers/acpi/apei/einj.c
> +++ b/drivers/acpi/apei/einj.c
> @@ -416,7 +416,8 @@ out:
>  	return rc;
>  }
>  
> -static int __einj_error_inject(u32 type, u64 param1, u64 param2)
> +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;
> @@ -446,6 +447,12 @@ static int __einj_error_inject(u32 type, u64 param1, u64 param2)
>  				break;
>  			}
>  			v5param->flags = vendor_flags;
> +		} else if (flags) {
> +				v5param->flags = flags;
> +				v5param->memory_address = param1;
> +				v5param->memory_address_range = param2;
> +				v5param->apicid = param3;
> +				v5param->pcie_sbdf = param4;
>  		} else {
>  			switch (type) {
>  			case ACPI_EINJ_PROCESSOR_CORRECTABLE:
> @@ -514,11 +521,17 @@ static int __einj_error_inject(u32 type, u64 param1, u64 param2)
>  }
>  
>  /* Inject the specified hardware error */
> -static int einj_error_inject(u32 type, u64 param1, u64 param2)
> +static int einj_error_inject(u32 type, u32 flags, u64 param1, u64 param2,
> +			     u64 param3, u64 param4)
>  {
>  	int rc;
>  	unsigned long pfn;
>  
> +	/* If user manually set "flags", make sure it is legal */
> +	if (flags && (flags &
> +		~(SETWA_FLAGS_APICID|SETWA_FLAGS_MEM|SETWA_FLAGS_PCIE_SBDF)))
> +		return -EINVAL;
> +
>  	/*
>  	 * We need extra sanity checks for memory errors.
>  	 * Other types leap directly to injection.
> @@ -532,6 +545,8 @@ static int einj_error_inject(u32 type, u64 param1, u64 param2)
>  	if (type & ACPI5_VENDOR_BIT) {
>  		if (vendor_flags != SETWA_FLAGS_MEM)
>  			goto inject;
> +	} else if (flags && (flags & SETWA_FLAGS_MEM)) {
> +		goto addrcheck;
>  	} else if (!(type & MEM_ERROR_MASK))
>  		goto inject;
>  
> @@ -540,21 +555,25 @@ static int einj_error_inject(u32 type, u64 param1, u64 param2)
>  	 * injection address almost anywhere. Insist on page or
>  	 * better granularity and that target address is normal RAM.
>  	 */
> +addrcheck:
>  	pfn = PFN_DOWN(param1 & param2);
>  	if (!page_is_ram(pfn) || ((param2 & PAGE_MASK) != PAGE_MASK))
>  		return -EINVAL;

This can be simplified:
	if (type & ACPI5_VENDOR_BIT) {
		if (vendor_flags != SETWA_FLAGS_MEM)
			goto inject;
	} else if (!(type & MEM_ERROR_MASK) &&
                   !(flags & SETWA_FLAGS_MEM)))
		goto inject;


Regards,
Naveen

>  
>  inject:
>  	mutex_lock(&einj_mutex);
> -	rc = __einj_error_inject(type, param1, param2);
> +	rc = __einj_error_inject(type, flags, param1, param2, param3, param4);
>  	mutex_unlock(&einj_mutex);
>  
>  	return rc;
>  }
>  
>  static u32 error_type;
> +static u32 error_flags;
>  static u64 error_param1;
>  static u64 error_param2;
> +static u64 error_param3;
> +static u64 error_param4;
>  static struct dentry *einj_debug_dir;
>  
>  static int available_error_type_show(struct seq_file *m, void *v)
> @@ -648,7 +667,8 @@ static int error_inject_set(void *data, u64 val)
>  	if (!error_type)
>  		return -EINVAL;
>  
> -	return einj_error_inject(error_type, error_param1, error_param2);
> +	return einj_error_inject(error_type, error_flags, error_param1, error_param2,
> +		error_param3, error_param4);
>  }
>  
>  DEFINE_SIMPLE_ATTRIBUTE(error_inject_fops, NULL,
> @@ -729,6 +749,10 @@ static int __init einj_init(void)
>  	rc = -ENOMEM;
>  	einj_param = einj_get_parameter_address();
>  	if ((param_extension || acpi5) && einj_param) {
> +		fentry = debugfs_create_x32("flags", S_IRUSR | S_IWUSR,
> +					    einj_debug_dir, &error_flags);
> +		if (!fentry)
> +			goto err_unmap;
>  		fentry = debugfs_create_x64("param1", S_IRUSR | S_IWUSR,
>  					    einj_debug_dir, &error_param1);
>  		if (!fentry)
> @@ -737,6 +761,14 @@ static int __init einj_init(void)
>  					    einj_debug_dir, &error_param2);
>  		if (!fentry)
>  			goto err_unmap;
> +		fentry = debugfs_create_x64("param3", S_IRUSR | S_IWUSR,
> +					    einj_debug_dir, &error_param3);
> +		if (!fentry)
> +			goto err_unmap;
> +		fentry = debugfs_create_x64("param4", S_IRUSR | S_IWUSR,
> +					    einj_debug_dir, &error_param4);
> +		if (!fentry)
> +			goto err_unmap;
>  
>  		fentry = debugfs_create_x32("notrigger", S_IRUSR | S_IWUSR,
>  					    einj_debug_dir, &notrigger);

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