[v2,1/3] ACPI / adxl: Address translation interface using ACPI DSM

[v2,1/3] ACPI / adxl: Address translation interface using ACPI DSM

[Luck, Tony]

Some new servers provide an interface so that the OS can ask the
BIOS to translate a system physical address to a memory address
(socket, memory controller, channel, rank, dimm, etc.). This is
useful for EDAC drivers that want to take the address of an error
reported in a machine check bank and let the user know which
DIMM may need to be replaced.

Specification for this interface is available at:

    https://cdrdv2.intel.com/v1/dl/getContent/603354

[Based on earlier code by Qiuxu Zhuo <qiuxu.zhuo@intel.com>]

Tested-by: Qiuxu Zhuo <qiuxu.zhuo@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
---
 drivers/acpi/Kconfig     |   3 +
 drivers/acpi/Makefile    |   3 +
 drivers/acpi/acpi_adxl.c | 199 +++++++++++++++++++++++++++++++++++++++
 include/linux/adxl.h     |  25 +++++
 4 files changed, 230 insertions(+)
 create mode 100644 drivers/acpi/acpi_adxl.c
 create mode 100644 include/linux/adxl.h

diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
index dd1eea90f67f..09991cc91b89 100644
--- a/drivers/acpi/Kconfig
+++ b/drivers/acpi/Kconfig
@@ -498,6 +498,9 @@ config ACPI_EXTLOG
 	  driver adds support for that functionality with corresponding
 	  tracepoint which carries that information to userspace.
 
+config ACPI_ADXL
+	bool
+
 menuconfig PMIC_OPREGION
 	bool "PMIC (Power Management Integrated Circuit) operation region support"
 	help
diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
index 6d59aa109a91..edc039313cd6 100644
--- a/drivers/acpi/Makefile
+++ b/drivers/acpi/Makefile
@@ -61,6 +61,9 @@ acpi-$(CONFIG_ACPI_LPIT)	+= acpi_lpit.o
 acpi-$(CONFIG_ACPI_GENERIC_GSI) += irq.o
 acpi-$(CONFIG_ACPI_WATCHDOG)	+= acpi_watchdog.o
 
+# Address translation
+acpi-$(CONFIG_ACPI_ADXL)	+= acpi_adxl.o
+
 # These are (potentially) separate modules
 
 # IPMI may be used by other drivers, so it has to initialise before them
diff --git a/drivers/acpi/acpi_adxl.c b/drivers/acpi/acpi_adxl.c
new file mode 100644
index 000000000000..22b12822f25d
--- /dev/null
+++ b/drivers/acpi/acpi_adxl.c
@@ -0,0 +1,199 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Address translation interface via ACPI DSM.
+ * Copyright (C) 2018 Intel Corporation
+ *
+ * Specification for this interface is available at:
+ *
+ *	https://cdrdv2.intel.com/v1/dl/getContent/603354
+ */
+
+#ifdef CONFIG_ACPI_ADXL
+#include <linux/acpi.h>
+#include <linux/adxl.h>
+
+#define ADXL_REVISION			0x1
+#define ADXL_IDX_GET_ADDR_PARAMS	0x1
+#define ADXL_IDX_FORWARD_TRANSLATE	0x2
+#define ACPI_ADXL_PATH			"\\_SB.ADXL"
+
+/*
+ * The specification doesn't provide a limit on how many
+ * components are in a memory address. But since we allocate
+ * memory based on the number the BIOS tells us, we should
+ * defend against insane values.
+ */
+#define ADXL_MAX_COMPONENTS		500
+
+#undef pr_fmt
+#define pr_fmt(fmt) "ADXL: " fmt
+
+static acpi_handle handle;
+static union acpi_object *params;
+static const guid_t adxl_guid =
+	GUID_INIT(0xAA3C050A, 0x7EA4, 0x4C1F,
+		  0xAF, 0xDA, 0x12, 0x67, 0xDF, 0xD3, 0xD4, 0x8D);
+
+static int adxl_count;
+static char **adxl_component_names;
+
+static union acpi_object *adxl_dsm(int cmd, union acpi_object argv[])
+{
+	union acpi_object *obj, *o;
+
+	obj = acpi_evaluate_dsm_typed(handle, &adxl_guid, ADXL_REVISION,
+				      cmd, argv, ACPI_TYPE_PACKAGE);
+	if (!obj) {
+		pr_info("DSM call failed for cmd=%d\n", cmd);
+		return NULL;
+	}
+
+	if (obj->package.count != 2) {
+		pr_info("Bad pkg count %d\n", obj->package.count);
+		goto err;
+	}
+
+	o = obj->package.elements;
+	if (o->type != ACPI_TYPE_INTEGER) {
+		pr_info("Bad 1st element type %d\n", o->type);
+		goto err;
+	}
+	if (o->integer.value) {
+		pr_info("Bad ret val %llu\n", o->integer.value);
+		goto err;
+	}
+
+	o = obj->package.elements + 1;
+	if (o->type != ACPI_TYPE_PACKAGE) {
+		pr_info("Bad 2nd element type %d\n", o->type);
+		goto err;
+	}
+	return obj;
+
+err:
+	ACPI_FREE(obj);
+	return NULL;
+}
+
+/**
+ * adxl_get_component_names - get list of memory component names
+ * Returns NULL terminated list of string names
+ *
+ * Give the caller a pointer to the list of memory component names
+ * e.g. { "SystemAddress", "ProcessorSocketId", "ChannelId", ... NULL }
+ * Caller should count how many strings in order to allocate a buffer
+ * for the return from adxl_decode().
+ */
+const char * const *adxl_get_component_names(void)
+{
+	return (const char * const *)adxl_component_names;
+}
+EXPORT_SYMBOL_GPL(adxl_get_component_names);
+
+/**
+ * adxl_decode - ask BIOS to decode a system address to memory address
+ * @addr: the address to decode
+ * @component_values: pointer to array of values for each component
+ * Returns 0 on success, negative error code otherwise
+ *
+ * The index of each value returned in the array matches the index of
+ * each component name returned by adxl_get_component_names().
+ * Components that are not defined for this address translation (e.g.
+ * mirror channel number for a non-mirrored address) are set to ~0ull.
+ */
+int adxl_decode(u64 addr, u64 component_values[])
+{
+	union acpi_object argv4[2], *results, *r;
+	int i, cnt;
+
+	if (!adxl_component_names)
+		return -EOPNOTSUPP;
+
+	argv4[0].type = ACPI_TYPE_PACKAGE;
+	argv4[0].package.count = 1;
+	argv4[0].package.elements = &argv4[1];
+	argv4[1].integer.type = ACPI_TYPE_INTEGER;
+	argv4[1].integer.value = addr;
+
+	results = adxl_dsm(ADXL_IDX_FORWARD_TRANSLATE, argv4);
+	if (!results)
+		return -EINVAL;
+
+	r = results->package.elements + 1;
+	cnt = r->package.count;
+	if (cnt != adxl_count) {
+		ACPI_FREE(results);
+		return -EINVAL;
+	}
+	r = r->package.elements;
+
+	for (i = 0; i < cnt; i++)
+		component_values[i] = r[i].integer.value;
+
+	ACPI_FREE(results);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(adxl_decode);
+
+static bool adxl_detect(void)
+{
+	char *path = ACPI_ADXL_PATH;
+	union acpi_object *p;
+	acpi_status status;
+	int i;
+
+	status = acpi_get_handle(NULL, path, &handle);
+	if (ACPI_FAILURE(status)) {
+		pr_info("No ACPI handle for path %s\n", path);
+		return false;
+	}
+
+	if (!acpi_has_method(handle, "_DSM")) {
+		pr_info("No DSM method\n");
+		return false;
+	}
+
+	if (!acpi_check_dsm(handle, &adxl_guid, ADXL_REVISION,
+			    ADXL_IDX_GET_ADDR_PARAMS |
+			    ADXL_IDX_FORWARD_TRANSLATE)) {
+		pr_info("No ADXL DSM methods\n");
+		return false;
+	}
+
+	params = adxl_dsm(ADXL_IDX_GET_ADDR_PARAMS, NULL);
+	if (!params) {
+		pr_info("Failed to get params\n");
+		return false;
+	}
+
+	p = params->package.elements + 1;
+	adxl_count = p->package.count;
+	if (adxl_count > ADXL_MAX_COMPONENTS) {
+		pr_info("Insane number of address component names %d\n", adxl_count);
+		ACPI_FREE(params);
+		return false;
+	}
+	p = p->package.elements;
+
+	adxl_component_names = kcalloc(adxl_count + 1, sizeof(char *), GFP_KERNEL);
+	if (!adxl_component_names) {
+		ACPI_FREE(params);
+		return false;
+	}
+
+	for (i = 0; i < adxl_count; i++)
+		adxl_component_names[i] = p[i].string.pointer;
+
+	return true;
+}
+
+static int __init adxl_init(void)
+{
+	if (!adxl_detect())
+		return -ENODEV;
+	return 0;
+}
+subsys_initcall(adxl_init);
+
+#endif /* CONFIG_ACPI_ADXL */
diff --git a/include/linux/adxl.h b/include/linux/adxl.h
new file mode 100644
index 000000000000..6023704e5d0b
--- /dev/null
+++ b/include/linux/adxl.h
@@ -0,0 +1,25 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Address translation interface via ACPI DSM.
+ * Copyright (C) 2018 Intel Corporation
+ */
+
+#ifndef _LINUX_ADXL_H
+#define _LINUX_ADXL_H
+
+#ifdef CONFIG_ACPI_ADXL
+const char * const *adxl_get_component_names(void);
+int adxl_decode(u64 addr, u64 component_values[]);
+#else
+static inline const char * const *adxl_get_component_names(void)
+{
+	return NULL;
+}
+
+static inline int adxl_decode(u64 addr, u64 component_values[])
+{
+	return -EOPNOTSUPP;
+}
+#endif
+
+#endif /* _LINUX_ADXL_H */

[v2,1/3] ACPI / adxl: Address translation interface using ACPI DSM

[Borislav Petkov]

> Subject: Re: [PATCH v2 1/3] ACPI / adxl: Address translation interface using ...

Commit name needs a verb: "Add address translation..."

On Thu, Oct 11, 2018 at 02:12:34PM -0700, Tony Luck wrote:
> Some new servers provide an interface so that the OS can ask the
> BIOS to translate a system physical address to a memory address
> (socket, memory controller, channel, rank, dimm, etc.). This is
> useful for EDAC drivers that want to take the address of an error
> reported in a machine check bank and let the user know which
> DIMM may need to be replaced.
> 
> Specification for this interface is available at:
> 
>     https://cdrdv2.intel.com/v1/dl/getContent/603354

What do we do when that link dies?

 (And I've seen them die).

Normally we upload those docs in bugzilla.kernel.org but that link wants
me to "Accept".

> [Based on earlier code by Qiuxu Zhuo <qiuxu.zhuo@intel.com>]
> 
> Tested-by: Qiuxu Zhuo <qiuxu.zhuo@intel.com>
> Signed-off-by: Tony Luck <tony.luck@intel.com>
> ---
>  drivers/acpi/Kconfig     |   3 +
>  drivers/acpi/Makefile    |   3 +
>  drivers/acpi/acpi_adxl.c | 199 +++++++++++++++++++++++++++++++++++++++
>  include/linux/adxl.h     |  25 +++++
>  4 files changed, 230 insertions(+)
>  create mode 100644 drivers/acpi/acpi_adxl.c
>  create mode 100644 include/linux/adxl.h
> 
> diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
> index dd1eea90f67f..09991cc91b89 100644
> --- a/drivers/acpi/Kconfig
> +++ b/drivers/acpi/Kconfig
> @@ -498,6 +498,9 @@ config ACPI_EXTLOG
>  	  driver adds support for that functionality with corresponding
>  	  tracepoint which carries that information to userspace.
>  
> +config ACPI_ADXL
> +	bool
> +
>  menuconfig PMIC_OPREGION
>  	bool "PMIC (Power Management Integrated Circuit) operation region support"
>  	help
> diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
> index 6d59aa109a91..edc039313cd6 100644
> --- a/drivers/acpi/Makefile
> +++ b/drivers/acpi/Makefile
> @@ -61,6 +61,9 @@ acpi-$(CONFIG_ACPI_LPIT)	+= acpi_lpit.o
>  acpi-$(CONFIG_ACPI_GENERIC_GSI) += irq.o
>  acpi-$(CONFIG_ACPI_WATCHDOG)	+= acpi_watchdog.o
>  
> +# Address translation
> +acpi-$(CONFIG_ACPI_ADXL)	+= acpi_adxl.o
> +
>  # These are (potentially) separate modules
>  
>  # IPMI may be used by other drivers, so it has to initialise before them
> diff --git a/drivers/acpi/acpi_adxl.c b/drivers/acpi/acpi_adxl.c
> new file mode 100644
> index 000000000000..22b12822f25d
> --- /dev/null
> +++ b/drivers/acpi/acpi_adxl.c
> @@ -0,0 +1,199 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Address translation interface via ACPI DSM.
> + * Copyright (C) 2018 Intel Corporation
> + *
> + * Specification for this interface is available at:
> + *
> + *	https://cdrdv2.intel.com/v1/dl/getContent/603354
> + */
> +
> +#ifdef CONFIG_ACPI_ADXL

This can go now.

> +#include <linux/acpi.h>
> +#include <linux/adxl.h>
> +
> +#define ADXL_REVISION			0x1
> +#define ADXL_IDX_GET_ADDR_PARAMS	0x1
> +#define ADXL_IDX_FORWARD_TRANSLATE	0x2
> +#define ACPI_ADXL_PATH			"\\_SB.ADXL"
> +
> +/*
> + * The specification doesn't provide a limit on how many
> + * components are in a memory address. But since we allocate
> + * memory based on the number the BIOS tells us, we should
> + * defend against insane values.
> + */
> +#define ADXL_MAX_COMPONENTS		500
> +
> +#undef pr_fmt
> +#define pr_fmt(fmt) "ADXL: " fmt
> +
> +static acpi_handle handle;
> +static union acpi_object *params;
> +static const guid_t adxl_guid =
> +	GUID_INIT(0xAA3C050A, 0x7EA4, 0x4C1F,
> +		  0xAF, 0xDA, 0x12, 0x67, 0xDF, 0xD3, 0xD4, 0x8D);
> +
> +static int adxl_count;
> +static char **adxl_component_names;

...

> +static bool adxl_detect(void)
> +{
> +	char *path = ACPI_ADXL_PATH;
> +	union acpi_object *p;
> +	acpi_status status;
> +	int i;
> +
> +	status = acpi_get_handle(NULL, path, &handle);
> +	if (ACPI_FAILURE(status)) {
> +		pr_info("No ACPI handle for path %s\n", path);
> +		return false;
> +	}
> +
> +	if (!acpi_has_method(handle, "_DSM")) {
> +		pr_info("No DSM method\n");
> +		return false;
> +	}
> +
> +	if (!acpi_check_dsm(handle, &adxl_guid, ADXL_REVISION,
> +			    ADXL_IDX_GET_ADDR_PARAMS |
> +			    ADXL_IDX_FORWARD_TRANSLATE)) {
> +		pr_info("No ADXL DSM methods\n");
> +		return false;
> +	}
> +
> +	params = adxl_dsm(ADXL_IDX_GET_ADDR_PARAMS, NULL);
> +	if (!params) {
> +		pr_info("Failed to get params\n");
> +		return false;
> +	}
> +
> +	p = params->package.elements + 1;
> +	adxl_count = p->package.count;
> +	if (adxl_count > ADXL_MAX_COMPONENTS) {
> +		pr_info("Insane number of address component names %d\n", adxl_count);
> +		ACPI_FREE(params);
> +		return false;
> +	}
> +	p = p->package.elements;
> +
	/*
	 * Allocate one more for NULL termination.
	 */
> +	adxl_component_names = kcalloc(adxl_count + 1, sizeof(char *), GFP_KERNEL);
> +	if (!adxl_component_names) {

		pr_err("Error allocating... "

> +		ACPI_FREE(params);
> +		return false;
> +	}
> +
> +	for (i = 0; i < adxl_count; i++)
> +		adxl_component_names[i] = p[i].string.pointer;
> +
> +	return true;
> +}
> +
> +static int __init adxl_init(void)
> +{
> +	if (!adxl_detect())

I guess you don't need that adxl_detect() function and can move its body
in here.

> +		return -ENODEV;
> +	return 0;
> +}
> +subsys_initcall(adxl_init);
> +
> +#endif /* CONFIG_ACPI_ADXL */
> diff --git a/include/linux/adxl.h b/include/linux/adxl.h
> new file mode 100644
> index 000000000000..6023704e5d0b
> --- /dev/null
> +++ b/include/linux/adxl.h
> @@ -0,0 +1,25 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Address translation interface via ACPI DSM.
> + * Copyright (C) 2018 Intel Corporation
> + */
> +
> +#ifndef _LINUX_ADXL_H
> +#define _LINUX_ADXL_H
> +
> +#ifdef CONFIG_ACPI_ADXL
> +const char * const *adxl_get_component_names(void);
> +int adxl_decode(u64 addr, u64 component_values[]);
> +#else
> +static inline const char * const *adxl_get_component_names(void)
> +{
> +	return NULL;
> +}
> +
> +static inline int adxl_decode(u64 addr, u64 component_values[])
> +{
> +	return -EOPNOTSUPP;
> +}
> +#endif
> +
> +#endif /* _LINUX_ADXL_H */
> -- 
> 2.17.1
>

[v2,1/3] ACPI / adxl: Address translation interface using ACPI DSM

[Luck, Tony]

On Fri, Oct 12, 2018 at 10:01:11AM +0200, Borislav Petkov wrote:
> 
> > Subject: Re: [PATCH v2 1/3] ACPI / adxl: Address translation interface using ...
> 
> Commit name needs a verb: "Add address translation..."
> 
> On Thu, Oct 11, 2018 at 02:12:34PM -0700, Tony Luck wrote:
> > Some new servers provide an interface so that the OS can ask the
> > BIOS to translate a system physical address to a memory address
> > (socket, memory controller, channel, rank, dimm, etc.). This is
> > useful for EDAC drivers that want to take the address of an error
> > reported in a machine check bank and let the user know which
> > DIMM may need to be replaced.
> > 
> > Specification for this interface is available at:
> > 
> >     https://cdrdv2.intel.com/v1/dl/getContent/603354
> 
> What do we do when that link dies?
> 
>  (And I've seen them die).
> 
> Normally we upload those docs in bugzilla.kernel.org but that link wants
> me to "Accept".

I'm still working to get the page out from behind a click
to accept.  The interface is pretty simple though. I think
it is now pretty easy to reverse engineer from the code. So
if the link does go away it won't be a disaster.

-Tony