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Date: Mon, 22 Apr 2024 17:43:25 +0100
From: Jonathan Cameron <Jonathan.Cameron@Huawei.com>
To: Robert Richter <rrichter@amd.com>
CC: "Rafael J. Wysocki" <rafael@kernel.org>, Dave Hansen
	<dave.hansen@linux.intel.com>, Dan Williams <dan.j.williams@intel.com>,
	Alison Schofield <alison.schofield@intel.com>, <linux-acpi@vger.kernel.org>,
	<linux-kernel@vger.kernel.org>, <linux-cxl@vger.kernel.org>, Len Brown
	<lenb@kernel.org>
Subject: Re: [PATCH v3 2/5] ACPI/NUMA: Print CXL Early Discovery Table
 (CEDT)
Message-ID: <20240422174325.000058ba@Huawei.com>
In-Reply-To: <20240419140203.1996635-3-rrichter@amd.com>
References: <20240419140203.1996635-1-rrichter@amd.com>
	<20240419140203.1996635-3-rrichter@amd.com>
Organization: Huawei Technologies Research and Development (UK) Ltd.
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On Fri, 19 Apr 2024 16:02:00 +0200
Robert Richter <rrichter@amd.com> wrote:

> The CEDT contains similar entries as the SRAT. For diagnostic reasons
> print the CEDT same style as the SRAT.
> 
> Adding also a pr_info() when successfully adding a CFMWS memory range.
> 
> Suggested-by: Alison Schofield <alison.schofield@intel.com> # CEDT node info
> Signed-off-by: Robert Richter <rrichter@amd.com>
Hi Robert,

Comments inline,

Jonathan


> ---
>  drivers/acpi/numa/srat.c | 122 ++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 121 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/acpi/numa/srat.c b/drivers/acpi/numa/srat.c
> index e45e64993c50..43417b4920da 100644
> --- a/drivers/acpi/numa/srat.c
> +++ b/drivers/acpi/numa/srat.c
> @@ -300,6 +300,114 @@ acpi_numa_memory_affinity_init(struct acpi_srat_mem_affinity *ma)
>  	return -EINVAL;
>  }
>  
> +static int __init
> +__acpi_table_print_cedt_entry(union acpi_subtable_headers *__header,
> +			      void *arg, const unsigned long table_end)
> +{
> +	struct acpi_cedt_header *header = (struct acpi_cedt_header *)__header;

As below. There is very little shred by the different types in here, so
I'd break it up into separate functions and just call the relevant
one.

> +
> +	switch (header->type) {
> +	case ACPI_CEDT_TYPE_CHBS:
> +		{
> +			struct acpi_cedt_chbs *p =
> +				(struct acpi_cedt_chbs *)header;
> +
> +			if (header->length < sizeof(struct acpi_cedt_chbs)) {
sizeof(*p) perhaps?
> +				pr_warn("CEDT: unsupported CHBS entry: size %d\n",
> +					 header->length);
> +				break;
> +			}
> +
> +			pr_debug("CEDT: CHBS (0x%llx length 0x%llx uid %lu) %s (%d)\n",
> +				(unsigned long long)p->base,
> +				(unsigned long long)p->length,
> +				(unsigned long)p->uid,
> +				(p->cxl_version == ACPI_CEDT_CHBS_VERSION_CXL11) ?
> +				"cxl11" :
> +				(p->cxl_version == ACPI_CEDT_CHBS_VERSION_CXL20) ?
> +				"cxl20" :
> +				"unsupported version",
> +				p->cxl_version);
> +		}
> +		break;
> +	case ACPI_CEDT_TYPE_CFMWS:
> +		{
> +			struct acpi_cedt_cfmws *p =
> +				(struct acpi_cedt_cfmws *)header;
> +			int eiw_to_ways[] = {1, 2, 4, 8, 16, 3, 6, 12};
> +			int targets = -1;
> +
> +			if (header->length < sizeof(struct acpi_cedt_cfmws)) {

sizeof(*p) perhaps?

> +				pr_warn("CEDT: unsupported CFMWS entry: size %d\n",
> +					header->length);
> +				break;
> +			}
> +
> +			if (p->interleave_ways < ARRAY_SIZE(eiw_to_ways))
> +				targets = eiw_to_ways[p->interleave_ways];
> +			if (header->length < struct_size(
> +					p, interleave_targets, targets))
> +				targets = -1;

Not a warning?

> +
> +			pr_debug("CEDT: CFMWS (0x%llx length 0x%llx) with %d target%s",
> +				(unsigned long long)p->base_hpa,
> +				(unsigned long long)p->window_size,
> +				targets, targets > 1 ? "s" : "");
> +			for (int i = 0; i < targets; i++)
> +				pr_cont("%s%lu", i ? ", " : " (",
> +					(unsigned long)p->interleave_targets[i]);

This seems odd. I don't think there is a good way to do combined pr_debug() and pr_cont()
There was a discussion about this a few years ago...

> +			pr_cont("%s%s%s%s%s%s\n",
> +				targets > 0 ? ")" : "",
> +				(p->restrictions & ACPI_CEDT_CFMWS_RESTRICT_TYPE2) ?
> +				" type2" : "",
> +				(p->restrictions & ACPI_CEDT_CFMWS_RESTRICT_TYPE3) ?
> +				" type3" : "",
> +				(p->restrictions & ACPI_CEDT_CFMWS_RESTRICT_VOLATILE) ?
> +				" volatile" : "",
> +				(p->restrictions & ACPI_CEDT_CFMWS_RESTRICT_PMEM) ?
> +				" pmem" : "",
> +				(p->restrictions & ACPI_CEDT_CFMWS_RESTRICT_FIXED) ?
> +				" fixed" : "");
> +		}
> +		break;
> +	case ACPI_CEDT_TYPE_CXIMS:
> +		{
> +			struct acpi_cedt_cxims *p =
> +				(struct acpi_cedt_cxims *)header;
> +
> +			if (header->length < sizeof(struct acpi_cedt_cxims)) {

sizeof(*p) perhaps?

> +				pr_warn("CEDT: unsupported CXIMS entry: size %d\n",
> +					header->length);
> +				break;

I'd go with direct returns in these to make the code flow easier to read.

> +			}
> +
> +			pr_debug("CEDT: CXIMS (hbig %u nr_xormaps %u)\n",
> +				(unsigned int)p->hbig,
> +				(unsigned int)p->nr_xormaps);
> +		}
> +		break;
> +	default:
> +		pr_warn("CEDT: Found unsupported entry (type = 0x%x)\n",
> +			header->type);
> +		break;
> +	}
> +
> +	return 0;
> +}
> +
> +static void __init acpi_table_print_cedt_entry(enum acpi_cedt_type id)
> +{
> +	acpi_table_parse_cedt(id, __acpi_table_print_cedt_entry, NULL);
> +}
> +
> +static void __init acpi_table_print_cedt(void)
> +{
> +	/* Print only implemented CEDT types */
> +	acpi_table_print_cedt_entry(ACPI_CEDT_TYPE_CHBS);
> +	acpi_table_print_cedt_entry(ACPI_CEDT_TYPE_CFMWS);
> +	acpi_table_print_cedt_entry(ACPI_CEDT_TYPE_CXIMS);

Would this be cleaner just breaking these up?

	acpi_table_parse_cedt(ACPI_CEDT_TYPE_CHBS, print_chbs_entry, NULL);
	acpi_table_parse_cedt(ACPI_CEDT_TYPE_CFMWS, print_cfmws_entry, NULL);
	acpi_table_parse_cedt(ACPI_CEDT_TYPE_CXIMS, print_cxims_entry, NULL);


> +}
> +
>  static int __init acpi_parse_cfmws(union acpi_subtable_headers *header,
>  				   void *arg, const unsigned long table_end)
>  {
> @@ -318,8 +426,11 @@ static int __init acpi_parse_cfmws(union acpi_subtable_headers *header,
>  	 * found for any portion of the window to cover the entire
>  	 * window.
>  	 */
> -	if (!numa_fill_memblks(start, end))
> +	if (!numa_fill_memblks(start, end)) {
> +		pr_info("CEDT: memblk extended [mem %#010Lx-%#010Lx]\n",
> +			(unsigned long long) start, (unsigned long long) end - 1);
>  		return 0;
> +	}
>  
>  	/* No SRAT description. Create a new node. */
>  	node = acpi_map_pxm_to_node(*fake_pxm);
> @@ -334,13 +445,19 @@ static int __init acpi_parse_cfmws(union acpi_subtable_headers *header,
>  		pr_warn("ACPI NUMA: Failed to add memblk for CFMWS node %d [mem %#llx-%#llx]\n",
>  			node, start, end);
>  	}
> +

Unrelated changed.  Best to clean this out to avoid the (really minor) noise.

>  	node_set(node, numa_nodes_parsed);
>  
> +	pr_info("CEDT: Node %u PXM %u [mem %#010Lx-%#010Lx]\n",
> +		node, *fake_pxm,
> +		(unsigned long long) start, (unsigned long long) end - 1);
> +
>  	/* Set the next available fake_pxm value */
>  	(*fake_pxm)++;
>  	return 0;
>  }
>  #else
> +static inline void acpi_table_print_cedt(void) {}
>  static int __init acpi_parse_cfmws(union acpi_subtable_headers *header,
>  				   void *arg, const unsigned long table_end)
>  {
> @@ -526,6 +643,9 @@ int __init acpi_numa_init(void)
>  	/* SLIT: System Locality Information Table */
>  	acpi_table_parse(ACPI_SIG_SLIT, acpi_parse_slit);
>  
> +	/* CEDT: CXL Early Discovery Table */
> +	acpi_table_print_cedt();
> +
>  	/*
>  	 * CXL Fixed Memory Window Structures (CFMWS) must be parsed
>  	 * after the SRAT. Create NUMA Nodes for CXL memory ranges that