[1/3] ACPI / blacklist: add acpi_match_oemlist() interface

[1/3] ACPI / blacklist: add acpi_match_oemlist() interface

[Borislav Petkov]

On Tue, Jul 18, 2017 at 06:49:51PM +0000, Kani, Toshimitsu wrote:
> ghes_edac uses this structure as a while-list, so the term backlist is
> misleading.

So this matching function gets both blacklists and whitelists. No wonder
it is confusing. Now I finally understand what you wanna do: you want to
call all those lists something agnostic as platform_list or so because
they contain exactly that: platforms - not OEMs.

And then you want to match *platforms*. *Not* OEMs.

*Now* I understand what you're trying to tell me.

[1/3] ACPI / blacklist: add acpi_match_oemlist() interface

[Toshi Kani]

On Tue, 2017-07-18 at 21:32 +0200, Borislav Petkov wrote:
> On Tue, Jul 18, 2017 at 06:49:51PM +0000, Kani, Toshimitsu wrote:
> > ghes_edac uses this structure as a while-list, so the term backlist
> > is misleading.
> 
> So this matching function gets both blacklists and whitelists. No
> wonder it is confusing. Now I finally understand what you wanna do:
> you want to call all those lists something agnostic as platform_list
> or so because they contain exactly that: platforms - not OEMs.

Right.

> And then you want to match *platforms*. *Not* OEMs.

True, there is some stretch to use OEMIDs for detecting platforms.  But
we do not have other standard interfaces better than this one.

> *Now* I understand what you're trying to tell me.

:-)

Thanks,
-Toshi

[1/3] ACPI / blacklist: add acpi_match_oemlist() interface

[Toshi Kani]

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b2wuDQoNClRoYW5rcywNCi1Ub3NoaQ0K
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[1/3] ACPI / blacklist: add acpi_match_oemlist() interface

[Borislav Petkov]

On Tue, Jul 18, 2017 at 05:24:50PM +0000, Kani, Toshimitsu wrote:
> Well, a list does not need to be a black-list.

But this one *is* a blacklist.

> So, I tried to avoid putting any usage to the structure name.

So OEM is a usage. The moment you need to use it for something else
besides an OEM, it is not an OEM list anymore - it is a generic
blacklist which blacklists OEMs too.

[1/3] ACPI / blacklist: add acpi_match_oemlist() interface

[Toshi Kani]

T24gVHVlLCAyMDE3LTA3LTE4IGF0IDE4OjQzICswMjAwLCBCb3Jpc2xhdiBQZXRrb3Ygd3JvdGU6
DQo+IE9uIFR1ZSwgSnVsIDE4LCAyMDE3IGF0IDAzOjQ4OjU0UE0gKzAwMDAsIEthbmksIFRvc2hp
bWl0c3Ugd3JvdGU6DQo+ID4gVGhpcyBwYXRjaCBkZWZpbmVzICdzdHJ1Y3QgYWNwaV9vZW1saXN0
JyBpbiAiaW5jbHVkZS9saW51eC9hY3BpLmgiDQo+ID4gYXMgYQ0KPiANCj4gSSBzZWUgdGhhdC4N
Cj4gDQo+ID4gY29tbW9uIHN0cnVjdHVyZSwgYW5kIHJlcGxhY2VzIHRoaXMgc3BlY2lmaWMgJ3N0
cnVjdA0KPiA+IGFjcGlfYmxhY2tsaXN0Jy4NCj4gDQo+IEFuZCB3aGF0IG1ha2VzIGFjcGlfb2Vt
bGlzdCAiY29tbW9uIiBhbmQgYWNwaV9ibGFja2xpc3QgInNwZWNpZmljIj8NCj4gDQo+IFNvIGxl
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IGFjcGlfb2VtbGlzdF9wcmVkIHByZWRpY2F0ZTsNCj4gDQo+IAllbnVtIGFjcGlfcHJlZGljYXRl
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Ci1Ub3NoaQ0K
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[1/3] ACPI / blacklist: add acpi_match_oemlist() interface

[Borislav Petkov]

On Tue, Jul 18, 2017 at 03:48:54PM +0000, Kani, Toshimitsu wrote:
> This patch defines 'struct acpi_oemlist' in "include/linux/acpi.h" as a

I see that.

> common structure, and replaces this specific 'struct acpi_blacklist'.

And what makes acpi_oemlist "common" and acpi_blacklist "specific"?

So let me save you some time - "oemlist" is more specific than
"blacklist" and I can imagine a blacklist item not always being
oem-specific.

What I'm hinting at is, don't change that name. acpi_blacklist is just
fine.

> Agreed.  Will change to a shorter name like below. 
> 
> 	enum acpi_oemlist_pred predicate;

	enum acpi_predicate pred;

is even better.

[1/3] ACPI / blacklist: add acpi_match_oemlist() interface

[Toshi Kani]

On Tue, 2017-07-18 at 07:34 +0200, Borislav Petkov wrote:
> On Mon, Jul 17, 2017 at 03:59:10PM -0600, Toshi Kani wrote:
> > ACPI OEM ID / OEM Table ID / Revision can be used to identify
> > platform type based on ACPI firmware.  acpi_blacklisted(),
> > intel_pstate_platform_pwr_mgmt_exists() and some other funcs
> > have been using this type of check to detect a list of platforms
> > that require special handlings.
> > 
> > Move the platform type check in acpi_blacklisted() to a common
> > utility function, acpi_match_oemlist(), so that other drivers
> > do not have to implement their own.
> > 
> > There is no change in functionality.
 :
> >  /*
> >   * POLICY: If *anything* doesn't work, put it on the blacklist.
> >   *	   If they are critical errors, mark it critical, and
> > abort driver load.
> >   */
> > -static struct acpi_blacklist_item acpi_blacklist[] __initdata = {
> > +static struct acpi_oemlist acpi_blacklist[] __initdata = {
> 
> Why the arbitrary rename?

This patch defines 'struct acpi_oemlist' in "include/linux/acpi.h" as a
common structure, and replaces this specific 'struct acpi_blacklist'.

> If anything, you should shorten that
> 
> 	enum acpi_blacklist_predicates oem_revision_predicate;
> 
> unreadable insanity.

Agreed.  Will change to a shorter name like below. 

	enum acpi_oemlist_pred predicate;

+	i = acpi_match_oemlist(acpi_blacklist);
> > +	if (i >= 0) {
> > +		pr_err(PREFIX "Vendor \"%6.6s\" System \"%8.8s\" "
> > +		       "Revision 0x%x has a known ACPI BIOS
> > problem.\n",
> 
> Put that string on a single line for grepping. checkpatch catches
> that error, didn't you see it?

Will do.

Thanks!
-Toshi

[1/3] ACPI / blacklist: add acpi_match_oemlist() interface

[Borislav Petkov]

On Mon, Jul 17, 2017 at 03:59:10PM -0600, Toshi Kani wrote:
> ACPI OEM ID / OEM Table ID / Revision can be used to identify
> platform type based on ACPI firmware.  acpi_blacklisted(),
> intel_pstate_platform_pwr_mgmt_exists() and some other funcs
> have been using this type of check to detect a list of platforms
> that require special handlings.
> 
> Move the platform type check in acpi_blacklisted() to a common
> utility function, acpi_match_oemlist(), so that other drivers
> do not have to implement their own.
> 
> There is no change in functionality.
> 
> Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
> Cc: Borislav Petkov <bp@alien8.de>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> ---
>  drivers/acpi/blacklist.c |   84 ++++++++--------------------------------------
>  drivers/acpi/utils.c     |   40 ++++++++++++++++++++++
>  include/linux/acpi.h     |   19 ++++++++++
>  3 files changed, 74 insertions(+), 69 deletions(-)
> 
> diff --git a/drivers/acpi/blacklist.c b/drivers/acpi/blacklist.c
> index bb542ac..288fe4d 100644
> --- a/drivers/acpi/blacklist.c
> +++ b/drivers/acpi/blacklist.c
> @@ -30,30 +30,13 @@
>  
>  #include "internal.h"
>  
> -enum acpi_blacklist_predicates {
> -	all_versions,
> -	less_than_or_equal,
> -	equal,
> -	greater_than_or_equal,
> -};
> -
> -struct acpi_blacklist_item {
> -	char oem_id[7];
> -	char oem_table_id[9];
> -	u32 oem_revision;
> -	char *table;
> -	enum acpi_blacklist_predicates oem_revision_predicate;
> -	char *reason;
> -	u32 is_critical_error;
> -};
> -
>  static struct dmi_system_id acpi_rev_dmi_table[] __initdata;
>  
>  /*
>   * POLICY: If *anything* doesn't work, put it on the blacklist.
>   *	   If they are critical errors, mark it critical, and abort driver load.
>   */
> -static struct acpi_blacklist_item acpi_blacklist[] __initdata = {
> +static struct acpi_oemlist acpi_blacklist[] __initdata = {

Why the arbitrary rename?

If anything, you should shorten that

	enum acpi_blacklist_predicates oem_revision_predicate;

unreadable insanity.

>  	/* Compaq Presario 1700 */
>  	{"PTLTD ", "  DSDT  ", 0x06040000, ACPI_SIG_DSDT, less_than_or_equal,
>  	 "Multiple problems", 1},
> @@ -67,65 +50,28 @@ static struct acpi_blacklist_item acpi_blacklist[] __initdata = {
>  	{"IBM   ", "TP600E  ", 0x00000105, ACPI_SIG_DSDT, less_than_or_equal,
>  	 "Incorrect _ADR", 1},
>  
> -	{""}
> +	{ }
>  };
>  
>  int __init acpi_blacklisted(void)
>  {
> -	int i = 0;
> +	int i;
>  	int blacklisted = 0;
> -	struct acpi_table_header table_header;
> -
> -	while (acpi_blacklist[i].oem_id[0] != '\0') {
> -		if (acpi_get_table_header(acpi_blacklist[i].table, 0, &table_header)) {
> -			i++;
> -			continue;
> -		}
> -
> -		if (strncmp(acpi_blacklist[i].oem_id, table_header.oem_id, 6)) {
> -			i++;
> -			continue;
> -		}
> -
> -		if (strncmp
> -		    (acpi_blacklist[i].oem_table_id, table_header.oem_table_id,
> -		     8)) {
> -			i++;
> -			continue;
> -		}
> -
> -		if ((acpi_blacklist[i].oem_revision_predicate == all_versions)
> -		    || (acpi_blacklist[i].oem_revision_predicate ==
> -			less_than_or_equal
> -			&& table_header.oem_revision <=
> -			acpi_blacklist[i].oem_revision)
> -		    || (acpi_blacklist[i].oem_revision_predicate ==
> -			greater_than_or_equal
> -			&& table_header.oem_revision >=
> -			acpi_blacklist[i].oem_revision)
> -		    || (acpi_blacklist[i].oem_revision_predicate == equal
> -			&& table_header.oem_revision ==
> -			acpi_blacklist[i].oem_revision)) {
>  
> -			printk(KERN_ERR PREFIX
> -			       "Vendor \"%6.6s\" System \"%8.8s\" "
> -			       "Revision 0x%x has a known ACPI BIOS problem.\n",
> -			       acpi_blacklist[i].oem_id,
> -			       acpi_blacklist[i].oem_table_id,
> -			       acpi_blacklist[i].oem_revision);
> +	i = acpi_match_oemlist(acpi_blacklist);
> +	if (i >= 0) {
> +		pr_err(PREFIX "Vendor \"%6.6s\" System \"%8.8s\" "
> +		       "Revision 0x%x has a known ACPI BIOS problem.\n",

Put that string on a single line for grepping. checkpatch catches that
error, didn't you see it?

> +		       acpi_blacklist[i].oem_id,
> +		       acpi_blacklist[i].oem_table_id,
> +		       acpi_blacklist[i].oem_revision);
>  
> -			printk(KERN_ERR PREFIX
> -			       "Reason: %s. This is a %s error\n",
> -			       acpi_blacklist[i].reason,
> -			       (acpi_blacklist[i].
> -				is_critical_error ? "non-recoverable" :
> -				"recoverable"));
> +		pr_err(PREFIX "Reason: %s. This is a %s error\n",
> +		       acpi_blacklist[i].reason,
> +		       (acpi_blacklist[i].data ?
> +			"non-recoverable" : "recoverable"));
>  
> -			blacklisted = acpi_blacklist[i].is_critical_error;
> -			break;
> -		} else {
> -			i++;
> -		}
> +		blacklisted = acpi_blacklist[i].data;
>  	}
>  
>  	(void)early_acpi_osi_init();

[1/3] ACPI / blacklist: add acpi_match_oemlist() interface

[Toshi Kani]

ACPI OEM ID / OEM Table ID / Revision can be used to identify
platform type based on ACPI firmware.  acpi_blacklisted(),
intel_pstate_platform_pwr_mgmt_exists() and some other funcs
have been using this type of check to detect a list of platforms
that require special handlings.

Move the platform type check in acpi_blacklisted() to a common
utility function, acpi_match_oemlist(), so that other drivers
do not have to implement their own.

There is no change in functionality.

Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
---
 drivers/acpi/blacklist.c |   84 ++++++++--------------------------------------
 drivers/acpi/utils.c     |   40 ++++++++++++++++++++++
 include/linux/acpi.h     |   19 ++++++++++
 3 files changed, 74 insertions(+), 69 deletions(-)

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diff --git a/drivers/acpi/blacklist.c b/drivers/acpi/blacklist.c
index bb542ac..288fe4d 100644
--- a/drivers/acpi/blacklist.c
+++ b/drivers/acpi/blacklist.c
@@ -30,30 +30,13 @@
 
 #include "internal.h"
 
-enum acpi_blacklist_predicates {
-	all_versions,
-	less_than_or_equal,
-	equal,
-	greater_than_or_equal,
-};
-
-struct acpi_blacklist_item {
-	char oem_id[7];
-	char oem_table_id[9];
-	u32 oem_revision;
-	char *table;
-	enum acpi_blacklist_predicates oem_revision_predicate;
-	char *reason;
-	u32 is_critical_error;
-};
-
 static struct dmi_system_id acpi_rev_dmi_table[] __initdata;
 
 /*
  * POLICY: If *anything* doesn't work, put it on the blacklist.
  *	   If they are critical errors, mark it critical, and abort driver load.
  */
-static struct acpi_blacklist_item acpi_blacklist[] __initdata = {
+static struct acpi_oemlist acpi_blacklist[] __initdata = {
 	/* Compaq Presario 1700 */
 	{"PTLTD ", "  DSDT  ", 0x06040000, ACPI_SIG_DSDT, less_than_or_equal,
 	 "Multiple problems", 1},
@@ -67,65 +50,28 @@ static struct acpi_blacklist_item acpi_blacklist[] __initdata = {
 	{"IBM   ", "TP600E  ", 0x00000105, ACPI_SIG_DSDT, less_than_or_equal,
 	 "Incorrect _ADR", 1},
 
-	{""}
+	{ }
 };
 
 int __init acpi_blacklisted(void)
 {
-	int i = 0;
+	int i;
 	int blacklisted = 0;
-	struct acpi_table_header table_header;
-
-	while (acpi_blacklist[i].oem_id[0] != '\0') {
-		if (acpi_get_table_header(acpi_blacklist[i].table, 0, &table_header)) {
-			i++;
-			continue;
-		}
-
-		if (strncmp(acpi_blacklist[i].oem_id, table_header.oem_id, 6)) {
-			i++;
-			continue;
-		}
-
-		if (strncmp
-		    (acpi_blacklist[i].oem_table_id, table_header.oem_table_id,
-		     8)) {
-			i++;
-			continue;
-		}
-
-		if ((acpi_blacklist[i].oem_revision_predicate == all_versions)
-		    || (acpi_blacklist[i].oem_revision_predicate ==
-			less_than_or_equal
-			&& table_header.oem_revision <=
-			acpi_blacklist[i].oem_revision)
-		    || (acpi_blacklist[i].oem_revision_predicate ==
-			greater_than_or_equal
-			&& table_header.oem_revision >=
-			acpi_blacklist[i].oem_revision)
-		    || (acpi_blacklist[i].oem_revision_predicate == equal
-			&& table_header.oem_revision ==
-			acpi_blacklist[i].oem_revision)) {
 
-			printk(KERN_ERR PREFIX
-			       "Vendor \"%6.6s\" System \"%8.8s\" "
-			       "Revision 0x%x has a known ACPI BIOS problem.\n",
-			       acpi_blacklist[i].oem_id,
-			       acpi_blacklist[i].oem_table_id,
-			       acpi_blacklist[i].oem_revision);
+	i = acpi_match_oemlist(acpi_blacklist);
+	if (i >= 0) {
+		pr_err(PREFIX "Vendor \"%6.6s\" System \"%8.8s\" "
+		       "Revision 0x%x has a known ACPI BIOS problem.\n",
+		       acpi_blacklist[i].oem_id,
+		       acpi_blacklist[i].oem_table_id,
+		       acpi_blacklist[i].oem_revision);
 
-			printk(KERN_ERR PREFIX
-			       "Reason: %s. This is a %s error\n",
-			       acpi_blacklist[i].reason,
-			       (acpi_blacklist[i].
-				is_critical_error ? "non-recoverable" :
-				"recoverable"));
+		pr_err(PREFIX "Reason: %s. This is a %s error\n",
+		       acpi_blacklist[i].reason,
+		       (acpi_blacklist[i].data ?
+			"non-recoverable" : "recoverable"));
 
-			blacklisted = acpi_blacklist[i].is_critical_error;
-			break;
-		} else {
-			i++;
-		}
+		blacklisted = acpi_blacklist[i].data;
 	}
 
 	(void)early_acpi_osi_init();
diff --git a/drivers/acpi/utils.c b/drivers/acpi/utils.c
index b9d956c..e5909d5 100644
--- a/drivers/acpi/utils.c
+++ b/drivers/acpi/utils.c
@@ -816,3 +816,43 @@ static int __init acpi_backlight(char *str)
 	return 1;
 }
 __setup("acpi_backlight=", acpi_backlight);
+
+/**
+ * acpi_match_oemlist - Check if the system matches with an oem list
+ * @oem: pointer to acpi_oemlist table terminated by a NULL entry
+ *
+ * Return the matched index if the system is found in the oem list.
+ * Otherwise, return a negative error code.
+ */
+int acpi_match_oemlist(const struct acpi_oemlist *oem)
+{
+	struct acpi_table_header hdr;
+	int idx = 0;
+
+	if (acpi_disabled)
+		return -ENODEV;
+
+	for (; oem->oem_id[0]; oem++, idx++) {
+		if (ACPI_FAILURE(acpi_get_table_header(oem->table, 0, &hdr)))
+			continue;
+
+		if (strncmp(oem->oem_id, hdr.oem_id, ACPI_OEM_ID_SIZE))
+			continue;
+
+		if (strncmp(oem->oem_table_id, hdr.oem_table_id,
+			    ACPI_OEM_TABLE_ID_SIZE))
+			continue;
+
+		if ((oem->oem_revision_predicate == all_versions) ||
+		    (oem->oem_revision_predicate == less_than_or_equal
+			&& hdr.oem_revision <= oem->oem_revision) ||
+		    (oem->oem_revision_predicate == greater_than_or_equal
+			&& hdr.oem_revision >= oem->oem_revision) ||
+		    (oem->oem_revision_predicate == equal
+			&& hdr.oem_revision == oem->oem_revision))
+			return idx;
+	}
+
+	return -ENODEV;
+}
+EXPORT_SYMBOL(acpi_match_oemlist);
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index c749eef..86479b5 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -556,6 +556,25 @@ extern acpi_status acpi_pci_osc_control_set(acpi_handle handle,
 #define ACPI_OST_SC_DRIVER_LOAD_FAILURE		0x81
 #define ACPI_OST_SC_INSERT_NOT_SUPPORTED	0x82
 
+enum acpi_oemlist_predicates {
+	all_versions,
+	less_than_or_equal,
+	equal,
+	greater_than_or_equal,
+};
+
+/* Table must be terminted by a NULL entry */
+struct acpi_oemlist {
+	char	oem_id[ACPI_OEM_ID_SIZE];
+	char	oem_table_id[ACPI_OEM_TABLE_ID_SIZE];
+	u32	oem_revision;
+	char	*table;
+	enum	acpi_oemlist_predicates oem_revision_predicate;
+	char	*reason;
+	u32	data;
+};
+int acpi_match_oemlist(const struct acpi_oemlist *oem);
+
 extern void acpi_early_init(void);
 extern void acpi_subsystem_init(void);