* [RFC PATCH 2/2] ACPI/IORT: Workaround for IORT ID count "minus one" issue
@ 2019-12-23 9:23 ` Hanjun Guo
0 siblings, 0 replies; 16+ messages in thread
From: Hanjun Guo @ 2019-12-23 9:23 UTC (permalink / raw)
To: Lorenzo Pieralisi, Sudeep Holla, Rafael J. Wysocki,
Pankaj Bansal, Erik Schmauss
Cc: linux-acpi, linuxarm, linux-arm-kernel, Hanjun Guo
The IORT spec [0] says Number of IDs = The number of IDs in the range minus
one, it is confusing but it was written down in the first version of the
IORT spec. But the IORT ID mapping function iort_id_map() did something
wrong from the start, which bails out if:
the request ID >= the input base + number of IDs
This is wrong because it ignored the "minus one", and breaks some valid
usecases such as ID mapping to contain single device mapping without
single mapping flag set.
Pankaj Bansal proposed a solution to fix the issue [1], which bails
out if:
the request ID > the input base + number of IDs
This works as the spec defined, unfortunately some firmware didn't
minus one for the number of IDs in the range, and the propoased
solution will break those systems in this way:
PCI hostbridge mapping entry 1:
Input base: 0x1000
ID Count: 0x100
Output base: 0x1000
Output reference: 0xC4 //ITS reference
PCI hostbridge mapping entry 2:
Input base: 0x1100
ID Count: 0x100
Output base: 0x2000
Output reference: 0xD4 //ITS reference
Two mapping entries which the second entry's Input base = the first
entry's Input base + ID count, so for requester ID 0x1100 will map
to ITS 0xC4 not 0xD4 if we update '>=' to '>'.
So introduce a workaround to match the IORT's OEM information for
the broken firmware, also update the logic of the ID mapping for
firmwares report the number of IDs as the IORT spec defined, to
make the code compatible for both kinds of system.
I checked the ACPI tables in the tianocore/edk2-platforms [2], only
HiSilicon HIP07/08 did wrong, so just add HIP07/08 to the workaround
info table, if we break other platforms, we can add that later.
[0]: http://infocenter.arm.com/help/topic/com.arm.doc.den0049d/DEN0049D_IO_Remapping_Table.pdf
[1]: https://patchwork.kernel.org/patch/11292823/
[2]: https://github.com/tianocore/edk2-platforms
Cc: Pankaj Bansal <pankaj.bansal@nxp.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Hanjun Guo <guohanjun@huawei.com>
---
drivers/acpi/arm64/iort.c | 54 ++++++++++++++++++++++++++++++++++++++++++++---
1 file changed, 51 insertions(+), 3 deletions(-)
diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
index 33f7198..112b1b0 100644
--- a/drivers/acpi/arm64/iort.c
+++ b/drivers/acpi/arm64/iort.c
@@ -298,6 +298,41 @@ static acpi_status iort_match_node_callback(struct acpi_iort_node *node,
return status;
}
+struct iort_workaround_oem_info {
+ char oem_id[ACPI_OEM_ID_SIZE + 1];
+ char oem_table_id[ACPI_OEM_TABLE_ID_SIZE + 1];
+ u32 oem_revision;
+};
+
+static bool apply_id_count_workaround;
+
+static struct iort_workaround_oem_info wa_info[] __initdata = {
+ {
+ .oem_id = "HISI ",
+ .oem_table_id = "HIP07 ",
+ .oem_revision = 0,
+ }, {
+ .oem_id = "HISI ",
+ .oem_table_id = "HIP08 ",
+ .oem_revision = 0,
+ }
+};
+
+static void __init
+iort_check_id_count_workaround(struct acpi_table_header *tbl)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(wa_info); i++) {
+ if (!memcmp(wa_info[i].oem_id, tbl->oem_id, ACPI_OEM_ID_SIZE) &&
+ !memcmp(wa_info[i].oem_table_id, tbl->oem_table_id, ACPI_OEM_TABLE_ID_SIZE) &&
+ wa_info[i].oem_revision == tbl->oem_revision) {
+ apply_id_count_workaround = true;
+ break;
+ }
+ }
+}
+
static int iort_id_map(struct acpi_iort_id_mapping *map, u8 type, u32 rid_in,
u32 *rid_out)
{
@@ -314,9 +349,21 @@ static int iort_id_map(struct acpi_iort_id_mapping *map, u8 type, u32 rid_in,
return -ENXIO;
}
- if (rid_in < map->input_base ||
- (rid_in >= map->input_base + map->id_count))
- return -ENXIO;
+ /*
+ * IORT spec says Number of IDs = The number of IDs in the range minus
+ * one, but the IORT code ingored the "minus one", and some firmware
+ * did that too, so apply a workaround here to keep compatible with
+ * both new and old versions of the firmware.
+ */
+ if (apply_id_count_workaround) {
+ if (rid_in < map->input_base ||
+ (rid_in >= map->input_base + map->id_count))
+ return -ENXIO;
+ } else {
+ if (rid_in < map->input_base ||
+ (rid_in > map->input_base + map->id_count))
+ return -ENXIO;
+ }
*rid_out = map->output_base + (rid_in - map->input_base);
return 0;
@@ -1631,5 +1678,6 @@ void __init acpi_iort_init(void)
return;
}
+ iort_check_id_count_workaround(iort_table);
iort_init_platform_devices();
}
--
1.7.12.4
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related [flat|nested] 16+ messages in thread* Re: [RFC PATCH 2/2] ACPI/IORT: Workaround for IORT ID count "minus one" issue
2019-12-23 9:23 ` Hanjun Guo
@ 2019-12-23 12:17 ` Pankaj Bansal
-1 siblings, 0 replies; 16+ messages in thread
From: Pankaj Bansal @ 2019-12-23 12:17 UTC (permalink / raw)
To: Hanjun Guo, Lorenzo Pieralisi, Sudeep Holla, Rafael J. Wysocki,
Erik Schmauss
Cc: linux-acpi, linux-arm-kernel, linuxarm
Can we put a warning of the sort to update the ACPI table with correct values?
eventually i would like that this workaround be removed from linux, when sufficient time has passed and all the platforms' ACPI tables have been updated.?
From: Hanjun Guo <guohanjun@huawei.com>
Sent: Monday, December 23, 2019 2:53 PM
To: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>; Sudeep Holla <sudeep.holla@arm.com>; Rafael J. Wysocki <rafael@kernel.org>; Pankaj Bansal <pankaj.bansal@nxp.com>; Erik Schmauss <erik.schmauss@intel.com>
Cc: linux-acpi@vger.kernel.org <linux-acpi@vger.kernel.org>; linux-arm-kernel@lists.infradead.org <linux-arm-kernel@lists.infradead.org>; linuxarm@huawei.com <linuxarm@huawei.com>; Hanjun Guo <guohanjun@huawei.com>
Subject: [RFC PATCH 2/2] ACPI/IORT: Workaround for IORT ID count "minus one" issue
The IORT spec [0] says Number of IDs = The number of IDs in the range minus
one, it is confusing but it was written down in the first version of the
IORT spec. But the IORT ID mapping function iort_id_map() did something
wrong from the start, which bails out if:
the request ID >= the input base + number of IDs
This is wrong because it ignored the "minus one", and breaks some valid
usecases such as ID mapping to contain single device mapping without
single mapping flag set.
Pankaj Bansal proposed a solution to fix the issue [1], which bails
out if:
the request ID > the input base + number of IDs
This works as the spec defined, unfortunately some firmware didn't
minus one for the number of IDs in the range, and the propoased
solution will break those systems in this way:
PCI hostbridge mapping entry 1:
Input base: 0x1000
ID Count: 0x100
Output base: 0x1000
Output reference: 0xC4 //ITS reference
PCI hostbridge mapping entry 2:
Input base: 0x1100
ID Count: 0x100
Output base: 0x2000
Output reference: 0xD4 //ITS reference
Two mapping entries which the second entry's Input base = the first
entry's Input base + ID count, so for requester ID 0x1100 will map
to ITS 0xC4 not 0xD4 if we update '>=' to '>'.
So introduce a workaround to match the IORT's OEM information for
the broken firmware, also update the logic of the ID mapping for
firmwares report the number of IDs as the IORT spec defined, to
make the code compatible for both kinds of system.
I checked the ACPI tables in the tianocore/edk2-platforms [2], only
HiSilicon HIP07/08 did wrong, so just add HIP07/08 to the workaround
info table, if we break other platforms, we can add that later.
[0]:
https://eur01.safelinks.protection.outlook.com/?url=http%3A%2F%2Finfocenter.arm.com%2Fhelp%2Ftopic%2Fcom.arm.doc.den0049d%2FDEN0049D_IO_Remapping_Table.pdf&data=02%7C01%7Cpankaj.bansal%40nxp.com%7Cb4823c8648a74a3781c908d7878a80e7%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C1%7C637126901245015642&sdata=y2hx8g10J73ngUv5ZFIsfsXxfoOWGZN8%2B7PmIARKgJI%3D&reserved=0
[1]:
https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fpatchwork.kernel.org%2Fpatch%2F11292823%2F&data=02%7C01%7Cpankaj.bansal%40nxp.com%7Cb4823c8648a74a3781c908d7878a80e7%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C1%7C637126901245015642&sdata=XmpNP688fed2bbjm8Wu4L5ftxECRzmkr7vp1Y4QXziQ%3D&reserved=0
[2]:
https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com%2Ftianocore%2Fedk2-platforms&data=02%7C01%7Cpankaj.bansal%40nxp.com%7Cb4823c8648a74a3781c908d7878a80e7%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C1%7C637126901245015642&sdata=xlmD8Xu6Wc5adwhouzDKRGlwCAwRwsD0cEyW4ioa7Xg%3D&reserved=0
Cc: Pankaj Bansal <pankaj.bansal@nxp.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Hanjun Guo <guohanjun@huawei.com>
---
drivers/acpi/arm64/iort.c | 54 ++++++++++++++++++++++++++++++++++++++++++++---
1 file changed, 51 insertions(+), 3 deletions(-)
diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
index 33f7198..112b1b0 100644
--- a/drivers/acpi/arm64/iort.c
+++ b/drivers/acpi/arm64/iort.c
@@ -298,6 +298,41 @@ static acpi_status iort_match_node_callback(struct acpi_iort_node *node,
return status;
}
+struct iort_workaround_oem_info {
+ char oem_id[ACPI_OEM_ID_SIZE + 1];
+ char oem_table_id[ACPI_OEM_TABLE_ID_SIZE + 1];
+ u32 oem_revision;
+};
+
+static bool apply_id_count_workaround;
+
+static struct iort_workaround_oem_info wa_info[] __initdata = {
+ {
+ .oem_id = "HISI ",
+ .oem_table_id = "HIP07 ",
+ .oem_revision = 0,
+ }, {
+ .oem_id = "HISI ",
+ .oem_table_id = "HIP08 ",
+ .oem_revision = 0,
+ }
+};
+
+static void __init
+iort_check_id_count_workaround(struct acpi_table_header *tbl)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(wa_info); i++) {
+ if (!memcmp(wa_info[i].oem_id, tbl->oem_id, ACPI_OEM_ID_SIZE) &&
+ !memcmp(wa_info[i].oem_table_id, tbl->oem_table_id, ACPI_OEM_TABLE_ID_SIZE) &&
+ wa_info[i].oem_revision == tbl->oem_revision) {
+ apply_id_count_workaround = true;
+ break;
+ }
+ }
+}
+
static int iort_id_map(struct acpi_iort_id_mapping *map, u8 type, u32 rid_in,
u32 *rid_out)
{
@@ -314,9 +349,21 @@ static int iort_id_map(struct acpi_iort_id_mapping *map, u8 type, u32 rid_in,
return -ENXIO;
}
- if (rid_in < map->input_base ||
- (rid_in >= map->input_base + map->id_count))
- return -ENXIO;
+ /*
+ * IORT spec says Number of IDs = The number of IDs in the range minus
+ * one, but the IORT code ingored the "minus one", and some firmware
+ * did that too, so apply a workaround here to keep compatible with
+ * both new and old versions of the firmware.
+ */
+ if (apply_id_count_workaround) {
+ if (rid_in < map->input_base ||
+ (rid_in >= map->input_base + map->id_count))
+ return -ENXIO;
+ } else {
+ if (rid_in < map->input_base ||
+ (rid_in > map->input_base + map->id_count))
+ return -ENXIO;
+ }
*rid_out = map->output_base + (rid_in - map->input_base);
return 0;
@@ -1631,5 +1678,6 @@ void __init acpi_iort_init(void)
return;
}
+ iort_check_id_count_workaround(iort_table);
iort_init_platform_devices();
}
--
1.7.12.4
^ permalink raw reply [flat|nested] 16+ messages in thread* Re: [RFC PATCH 2/2] ACPI/IORT: Workaround for IORT ID count "minus one" issue
@ 2019-12-23 12:17 ` Pankaj Bansal
0 siblings, 0 replies; 16+ messages in thread
From: Pankaj Bansal @ 2019-12-23 12:17 UTC (permalink / raw)
To: Hanjun Guo, Lorenzo Pieralisi, Sudeep Holla, Rafael J. Wysocki,
Erik Schmauss
Cc: linux-acpi, linuxarm, linux-arm-kernel
Can we put a warning of the sort to update the ACPI table with correct values?
eventually i would like that this workaround be removed from linux, when sufficient time has passed and all the platforms' ACPI tables have been updated.?
From: Hanjun Guo <guohanjun@huawei.com>
Sent: Monday, December 23, 2019 2:53 PM
To: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>; Sudeep Holla <sudeep.holla@arm.com>; Rafael J. Wysocki <rafael@kernel.org>; Pankaj Bansal <pankaj.bansal@nxp.com>; Erik Schmauss <erik.schmauss@intel.com>
Cc: linux-acpi@vger.kernel.org <linux-acpi@vger.kernel.org>; linux-arm-kernel@lists.infradead.org <linux-arm-kernel@lists.infradead.org>; linuxarm@huawei.com <linuxarm@huawei.com>; Hanjun Guo <guohanjun@huawei.com>
Subject: [RFC PATCH 2/2] ACPI/IORT: Workaround for IORT ID count "minus one" issue
The IORT spec [0] says Number of IDs = The number of IDs in the range minus
one, it is confusing but it was written down in the first version of the
IORT spec. But the IORT ID mapping function iort_id_map() did something
wrong from the start, which bails out if:
the request ID >= the input base + number of IDs
This is wrong because it ignored the "minus one", and breaks some valid
usecases such as ID mapping to contain single device mapping without
single mapping flag set.
Pankaj Bansal proposed a solution to fix the issue [1], which bails
out if:
the request ID > the input base + number of IDs
This works as the spec defined, unfortunately some firmware didn't
minus one for the number of IDs in the range, and the propoased
solution will break those systems in this way:
PCI hostbridge mapping entry 1:
Input base: 0x1000
ID Count: 0x100
Output base: 0x1000
Output reference: 0xC4 //ITS reference
PCI hostbridge mapping entry 2:
Input base: 0x1100
ID Count: 0x100
Output base: 0x2000
Output reference: 0xD4 //ITS reference
Two mapping entries which the second entry's Input base = the first
entry's Input base + ID count, so for requester ID 0x1100 will map
to ITS 0xC4 not 0xD4 if we update '>=' to '>'.
So introduce a workaround to match the IORT's OEM information for
the broken firmware, also update the logic of the ID mapping for
firmwares report the number of IDs as the IORT spec defined, to
make the code compatible for both kinds of system.
I checked the ACPI tables in the tianocore/edk2-platforms [2], only
HiSilicon HIP07/08 did wrong, so just add HIP07/08 to the workaround
info table, if we break other platforms, we can add that later.
[0]:
https://eur01.safelinks.protection.outlook.com/?url=http%3A%2F%2Finfocenter.arm.com%2Fhelp%2Ftopic%2Fcom.arm.doc.den0049d%2FDEN0049D_IO_Remapping_Table.pdf&data=02%7C01%7Cpankaj.bansal%40nxp.com%7Cb4823c8648a74a3781c908d7878a80e7%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C1%7C637126901245015642&sdata=y2hx8g10J73ngUv5ZFIsfsXxfoOWGZN8%2B7PmIARKgJI%3D&reserved=0
[1]:
https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fpatchwork.kernel.org%2Fpatch%2F11292823%2F&data=02%7C01%7Cpankaj.bansal%40nxp.com%7Cb4823c8648a74a3781c908d7878a80e7%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C1%7C637126901245015642&sdata=XmpNP688fed2bbjm8Wu4L5ftxECRzmkr7vp1Y4QXziQ%3D&reserved=0
[2]:
https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com%2Ftianocore%2Fedk2-platforms&data=02%7C01%7Cpankaj.bansal%40nxp.com%7Cb4823c8648a74a3781c908d7878a80e7%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C1%7C637126901245015642&sdata=xlmD8Xu6Wc5adwhouzDKRGlwCAwRwsD0cEyW4ioa7Xg%3D&reserved=0
Cc: Pankaj Bansal <pankaj.bansal@nxp.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Hanjun Guo <guohanjun@huawei.com>
---
drivers/acpi/arm64/iort.c | 54 ++++++++++++++++++++++++++++++++++++++++++++---
1 file changed, 51 insertions(+), 3 deletions(-)
diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
index 33f7198..112b1b0 100644
--- a/drivers/acpi/arm64/iort.c
+++ b/drivers/acpi/arm64/iort.c
@@ -298,6 +298,41 @@ static acpi_status iort_match_node_callback(struct acpi_iort_node *node,
return status;
}
+struct iort_workaround_oem_info {
+ char oem_id[ACPI_OEM_ID_SIZE + 1];
+ char oem_table_id[ACPI_OEM_TABLE_ID_SIZE + 1];
+ u32 oem_revision;
+};
+
+static bool apply_id_count_workaround;
+
+static struct iort_workaround_oem_info wa_info[] __initdata = {
+ {
+ .oem_id = "HISI ",
+ .oem_table_id = "HIP07 ",
+ .oem_revision = 0,
+ }, {
+ .oem_id = "HISI ",
+ .oem_table_id = "HIP08 ",
+ .oem_revision = 0,
+ }
+};
+
+static void __init
+iort_check_id_count_workaround(struct acpi_table_header *tbl)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(wa_info); i++) {
+ if (!memcmp(wa_info[i].oem_id, tbl->oem_id, ACPI_OEM_ID_SIZE) &&
+ !memcmp(wa_info[i].oem_table_id, tbl->oem_table_id, ACPI_OEM_TABLE_ID_SIZE) &&
+ wa_info[i].oem_revision == tbl->oem_revision) {
+ apply_id_count_workaround = true;
+ break;
+ }
+ }
+}
+
static int iort_id_map(struct acpi_iort_id_mapping *map, u8 type, u32 rid_in,
u32 *rid_out)
{
@@ -314,9 +349,21 @@ static int iort_id_map(struct acpi_iort_id_mapping *map, u8 type, u32 rid_in,
return -ENXIO;
}
- if (rid_in < map->input_base ||
- (rid_in >= map->input_base + map->id_count))
- return -ENXIO;
+ /*
+ * IORT spec says Number of IDs = The number of IDs in the range minus
+ * one, but the IORT code ingored the "minus one", and some firmware
+ * did that too, so apply a workaround here to keep compatible with
+ * both new and old versions of the firmware.
+ */
+ if (apply_id_count_workaround) {
+ if (rid_in < map->input_base ||
+ (rid_in >= map->input_base + map->id_count))
+ return -ENXIO;
+ } else {
+ if (rid_in < map->input_base ||
+ (rid_in > map->input_base + map->id_count))
+ return -ENXIO;
+ }
*rid_out = map->output_base + (rid_in - map->input_base);
return 0;
@@ -1631,5 +1678,6 @@ void __init acpi_iort_init(void)
return;
}
+ iort_check_id_count_workaround(iort_table);
iort_init_platform_devices();
}
--
1.7.12.4
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 16+ messages in thread* Re: [RFC PATCH 2/2] ACPI/IORT: Workaround for IORT ID count "minus one" issue
2019-12-23 12:17 ` Pankaj Bansal
@ 2019-12-24 1:08 ` Hanjun Guo
-1 siblings, 0 replies; 16+ messages in thread
From: Hanjun Guo @ 2019-12-24 1:08 UTC (permalink / raw)
To: Pankaj Bansal, Lorenzo Pieralisi, Sudeep Holla,
Rafael J. Wysocki, Erik Schmauss
Cc: linux-acpi, linux-arm-kernel, linuxarm
On 2019/12/23 20:17, Pankaj Bansal wrote:
>
> Can we put a warning of the sort to update the> ACPI table with correct values?
Good point, I will add the firmware bug warning
in iort_check_id_count_workaround().
> eventually i would like that this workaround be removed from
> linux, when sufficient time has passed and all the
> platforms' ACPI tables have been updated.?
I agree with you but it will take much longer time than expected.
Thanks
Hanjun
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [RFC PATCH 2/2] ACPI/IORT: Workaround for IORT ID count "minus one" issue
@ 2019-12-24 1:08 ` Hanjun Guo
0 siblings, 0 replies; 16+ messages in thread
From: Hanjun Guo @ 2019-12-24 1:08 UTC (permalink / raw)
To: Pankaj Bansal, Lorenzo Pieralisi, Sudeep Holla,
Rafael J. Wysocki, Erik Schmauss
Cc: linux-acpi, linuxarm, linux-arm-kernel
On 2019/12/23 20:17, Pankaj Bansal wrote:
>
> Can we put a warning of the sort to update the> ACPI table with correct values?
Good point, I will add the firmware bug warning
in iort_check_id_count_workaround().
> eventually i would like that this workaround be removed from
> linux, when sufficient time has passed and all the
> platforms' ACPI tables have been updated.?
I agree with you but it will take much longer time than expected.
Thanks
Hanjun
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 16+ messages in thread
* RE: [RFC PATCH 2/2] ACPI/IORT: Workaround for IORT ID count "minus one" issue
2019-12-23 9:23 ` Hanjun Guo
@ 2020-01-02 10:20 ` Shameerali Kolothum Thodi
-1 siblings, 0 replies; 16+ messages in thread
From: Shameerali Kolothum Thodi @ 2020-01-02 10:20 UTC (permalink / raw)
To: Guohanjun (Hanjun Guo),
Lorenzo Pieralisi, Sudeep Holla, Rafael J. Wysocki,
Pankaj Bansal, Erik Schmauss
Cc: linux-acpi, Linuxarm, linux-arm-kernel
Hi Hanjun,
> -----Original Message-----
> From: Linuxarm [mailto:linuxarm-bounces@huawei.com] On Behalf Of Hanjun
> Guo
> Sent: 23 December 2019 09:23
> To: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>; Sudeep Holla
> <sudeep.holla@arm.com>; Rafael J. Wysocki <rafael@kernel.org>; Pankaj
> Bansal <pankaj.bansal@nxp.com>; Erik Schmauss <erik.schmauss@intel.com>
> Cc: linux-acpi@vger.kernel.org; Linuxarm <linuxarm@huawei.com>;
> linux-arm-kernel@lists.infradead.org
> Subject: [RFC PATCH 2/2] ACPI/IORT: Workaround for IORT ID count "minus
> one" issue
>
> The IORT spec [0] says Number of IDs = The number of IDs in the range minus
> one, it is confusing but it was written down in the first version of the
> IORT spec. But the IORT ID mapping function iort_id_map() did something
> wrong from the start, which bails out if:
>
> the request ID >= the input base + number of IDs
>
> This is wrong because it ignored the "minus one", and breaks some valid
> usecases such as ID mapping to contain single device mapping without
> single mapping flag set.
>
> Pankaj Bansal proposed a solution to fix the issue [1], which bails
> out if:
>
> the request ID > the input base + number of IDs
>
> This works as the spec defined, unfortunately some firmware didn't
> minus one for the number of IDs in the range, and the propoased
> solution will break those systems in this way:
>
> PCI hostbridge mapping entry 1:
> Input base: 0x1000
> ID Count: 0x100
> Output base: 0x1000
> Output reference: 0xC4 //ITS reference
>
> PCI hostbridge mapping entry 2:
> Input base: 0x1100
> ID Count: 0x100
> Output base: 0x2000
> Output reference: 0xD4 //ITS reference
>
> Two mapping entries which the second entry's Input base = the first
> entry's Input base + ID count, so for requester ID 0x1100 will map
> to ITS 0xC4 not 0xD4 if we update '>=' to '>'.
>
> So introduce a workaround to match the IORT's OEM information for
> the broken firmware, also update the logic of the ID mapping for
> firmwares report the number of IDs as the IORT spec defined, to
> make the code compatible for both kinds of system.
>
> I checked the ACPI tables in the tianocore/edk2-platforms [2], only
> HiSilicon HIP07/08 did wrong, so just add HIP07/08 to the workaround
> info table, if we break other platforms, we can add that later.
>
> [0]:
> http://infocenter.arm.com/help/topic/com.arm.doc.den0049d/DEN0049D_IO_
> Remapping_Table.pdf
> [1]: https://patchwork.kernel.org/patch/11292823/
> [2]: https://github.com/tianocore/edk2-platforms
>
> Cc: Pankaj Bansal <pankaj.bansal@nxp.com>
> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
> Signed-off-by: Hanjun Guo <guohanjun@huawei.com>
> ---
> drivers/acpi/arm64/iort.c | 54
> ++++++++++++++++++++++++++++++++++++++++++++---
> 1 file changed, 51 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
> index 33f7198..112b1b0 100644
> --- a/drivers/acpi/arm64/iort.c
> +++ b/drivers/acpi/arm64/iort.c
> @@ -298,6 +298,41 @@ static acpi_status iort_match_node_callback(struct
> acpi_iort_node *node,
> return status;
> }
>
> +struct iort_workaround_oem_info {
> + char oem_id[ACPI_OEM_ID_SIZE + 1];
> + char oem_table_id[ACPI_OEM_TABLE_ID_SIZE + 1];
> + u32 oem_revision;
> +};
> +
> +static bool apply_id_count_workaround;
> +
> +static struct iort_workaround_oem_info wa_info[] __initdata = {
> + {
> + .oem_id = "HISI ",
> + .oem_table_id = "HIP07 ",
> + .oem_revision = 0,
> + }, {
> + .oem_id = "HISI ",
> + .oem_table_id = "HIP08 ",
> + .oem_revision = 0,
> + }
> +};
> +
> +static void __init
> +iort_check_id_count_workaround(struct acpi_table_header *tbl)
> +{
> + int i;
> +
> + for (i = 0; i < ARRAY_SIZE(wa_info); i++) {
> + if (!memcmp(wa_info[i].oem_id, tbl->oem_id, ACPI_OEM_ID_SIZE)
> &&
> + !memcmp(wa_info[i].oem_table_id, tbl->oem_table_id,
> ACPI_OEM_TABLE_ID_SIZE) &&
> + wa_info[i].oem_revision == tbl->oem_revision) {
> + apply_id_count_workaround = true;
> + break;
> + }
> + }
> +}
> +
Can we get rid of the above and instead use acpi_match_platform_list() ? Please
take a look at the pmcg_plat_info used for the HIP08 SMMUv3 PMCG erratum.
Thanks,
Shameer
> static int iort_id_map(struct acpi_iort_id_mapping *map, u8 type, u32 rid_in,
> u32 *rid_out)
> {
> @@ -314,9 +349,21 @@ static int iort_id_map(struct acpi_iort_id_mapping
> *map, u8 type, u32 rid_in,
> return -ENXIO;
> }
>
> - if (rid_in < map->input_base ||
> - (rid_in >= map->input_base + map->id_count))
> - return -ENXIO;
> + /*
> + * IORT spec says Number of IDs = The number of IDs in the range minus
> + * one, but the IORT code ingored the "minus one", and some firmware
> + * did that too, so apply a workaround here to keep compatible with
> + * both new and old versions of the firmware.
> + */
> + if (apply_id_count_workaround) {
> + if (rid_in < map->input_base ||
> + (rid_in >= map->input_base + map->id_count))
> + return -ENXIO;
> + } else {
> + if (rid_in < map->input_base ||
> + (rid_in > map->input_base + map->id_count))
> + return -ENXIO;
> + }
>
> *rid_out = map->output_base + (rid_in - map->input_base);
> return 0;
> @@ -1631,5 +1678,6 @@ void __init acpi_iort_init(void)
> return;
> }
>
> + iort_check_id_count_workaround(iort_table);
> iort_init_platform_devices();
> }
> --
> 1.7.12.4
>
> _______________________________________________
> Linuxarm mailing list
> Linuxarm@huawei.com
> http://hulk.huawei.com/mailman/listinfo/linuxarm
^ permalink raw reply [flat|nested] 16+ messages in thread* RE: [RFC PATCH 2/2] ACPI/IORT: Workaround for IORT ID count "minus one" issue
@ 2020-01-02 10:20 ` Shameerali Kolothum Thodi
0 siblings, 0 replies; 16+ messages in thread
From: Shameerali Kolothum Thodi @ 2020-01-02 10:20 UTC (permalink / raw)
To: Guohanjun (Hanjun Guo),
Lorenzo Pieralisi, Sudeep Holla, Rafael J. Wysocki,
Pankaj Bansal, Erik Schmauss
Cc: linux-acpi, Linuxarm, linux-arm-kernel
Hi Hanjun,
> -----Original Message-----
> From: Linuxarm [mailto:linuxarm-bounces@huawei.com] On Behalf Of Hanjun
> Guo
> Sent: 23 December 2019 09:23
> To: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>; Sudeep Holla
> <sudeep.holla@arm.com>; Rafael J. Wysocki <rafael@kernel.org>; Pankaj
> Bansal <pankaj.bansal@nxp.com>; Erik Schmauss <erik.schmauss@intel.com>
> Cc: linux-acpi@vger.kernel.org; Linuxarm <linuxarm@huawei.com>;
> linux-arm-kernel@lists.infradead.org
> Subject: [RFC PATCH 2/2] ACPI/IORT: Workaround for IORT ID count "minus
> one" issue
>
> The IORT spec [0] says Number of IDs = The number of IDs in the range minus
> one, it is confusing but it was written down in the first version of the
> IORT spec. But the IORT ID mapping function iort_id_map() did something
> wrong from the start, which bails out if:
>
> the request ID >= the input base + number of IDs
>
> This is wrong because it ignored the "minus one", and breaks some valid
> usecases such as ID mapping to contain single device mapping without
> single mapping flag set.
>
> Pankaj Bansal proposed a solution to fix the issue [1], which bails
> out if:
>
> the request ID > the input base + number of IDs
>
> This works as the spec defined, unfortunately some firmware didn't
> minus one for the number of IDs in the range, and the propoased
> solution will break those systems in this way:
>
> PCI hostbridge mapping entry 1:
> Input base: 0x1000
> ID Count: 0x100
> Output base: 0x1000
> Output reference: 0xC4 //ITS reference
>
> PCI hostbridge mapping entry 2:
> Input base: 0x1100
> ID Count: 0x100
> Output base: 0x2000
> Output reference: 0xD4 //ITS reference
>
> Two mapping entries which the second entry's Input base = the first
> entry's Input base + ID count, so for requester ID 0x1100 will map
> to ITS 0xC4 not 0xD4 if we update '>=' to '>'.
>
> So introduce a workaround to match the IORT's OEM information for
> the broken firmware, also update the logic of the ID mapping for
> firmwares report the number of IDs as the IORT spec defined, to
> make the code compatible for both kinds of system.
>
> I checked the ACPI tables in the tianocore/edk2-platforms [2], only
> HiSilicon HIP07/08 did wrong, so just add HIP07/08 to the workaround
> info table, if we break other platforms, we can add that later.
>
> [0]:
> http://infocenter.arm.com/help/topic/com.arm.doc.den0049d/DEN0049D_IO_
> Remapping_Table.pdf
> [1]: https://patchwork.kernel.org/patch/11292823/
> [2]: https://github.com/tianocore/edk2-platforms
>
> Cc: Pankaj Bansal <pankaj.bansal@nxp.com>
> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
> Signed-off-by: Hanjun Guo <guohanjun@huawei.com>
> ---
> drivers/acpi/arm64/iort.c | 54
> ++++++++++++++++++++++++++++++++++++++++++++---
> 1 file changed, 51 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
> index 33f7198..112b1b0 100644
> --- a/drivers/acpi/arm64/iort.c
> +++ b/drivers/acpi/arm64/iort.c
> @@ -298,6 +298,41 @@ static acpi_status iort_match_node_callback(struct
> acpi_iort_node *node,
> return status;
> }
>
> +struct iort_workaround_oem_info {
> + char oem_id[ACPI_OEM_ID_SIZE + 1];
> + char oem_table_id[ACPI_OEM_TABLE_ID_SIZE + 1];
> + u32 oem_revision;
> +};
> +
> +static bool apply_id_count_workaround;
> +
> +static struct iort_workaround_oem_info wa_info[] __initdata = {
> + {
> + .oem_id = "HISI ",
> + .oem_table_id = "HIP07 ",
> + .oem_revision = 0,
> + }, {
> + .oem_id = "HISI ",
> + .oem_table_id = "HIP08 ",
> + .oem_revision = 0,
> + }
> +};
> +
> +static void __init
> +iort_check_id_count_workaround(struct acpi_table_header *tbl)
> +{
> + int i;
> +
> + for (i = 0; i < ARRAY_SIZE(wa_info); i++) {
> + if (!memcmp(wa_info[i].oem_id, tbl->oem_id, ACPI_OEM_ID_SIZE)
> &&
> + !memcmp(wa_info[i].oem_table_id, tbl->oem_table_id,
> ACPI_OEM_TABLE_ID_SIZE) &&
> + wa_info[i].oem_revision == tbl->oem_revision) {
> + apply_id_count_workaround = true;
> + break;
> + }
> + }
> +}
> +
Can we get rid of the above and instead use acpi_match_platform_list() ? Please
take a look at the pmcg_plat_info used for the HIP08 SMMUv3 PMCG erratum.
Thanks,
Shameer
> static int iort_id_map(struct acpi_iort_id_mapping *map, u8 type, u32 rid_in,
> u32 *rid_out)
> {
> @@ -314,9 +349,21 @@ static int iort_id_map(struct acpi_iort_id_mapping
> *map, u8 type, u32 rid_in,
> return -ENXIO;
> }
>
> - if (rid_in < map->input_base ||
> - (rid_in >= map->input_base + map->id_count))
> - return -ENXIO;
> + /*
> + * IORT spec says Number of IDs = The number of IDs in the range minus
> + * one, but the IORT code ingored the "minus one", and some firmware
> + * did that too, so apply a workaround here to keep compatible with
> + * both new and old versions of the firmware.
> + */
> + if (apply_id_count_workaround) {
> + if (rid_in < map->input_base ||
> + (rid_in >= map->input_base + map->id_count))
> + return -ENXIO;
> + } else {
> + if (rid_in < map->input_base ||
> + (rid_in > map->input_base + map->id_count))
> + return -ENXIO;
> + }
>
> *rid_out = map->output_base + (rid_in - map->input_base);
> return 0;
> @@ -1631,5 +1678,6 @@ void __init acpi_iort_init(void)
> return;
> }
>
> + iort_check_id_count_workaround(iort_table);
> iort_init_platform_devices();
> }
> --
> 1.7.12.4
>
> _______________________________________________
> Linuxarm mailing list
> Linuxarm@huawei.com
> http://hulk.huawei.com/mailman/listinfo/linuxarm
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 16+ messages in thread* Re: [RFC PATCH 2/2] ACPI/IORT: Workaround for IORT ID count "minus one" issue
2020-01-02 10:20 ` Shameerali Kolothum Thodi
@ 2020-01-03 10:14 ` Hanjun Guo
-1 siblings, 0 replies; 16+ messages in thread
From: Hanjun Guo @ 2020-01-03 10:14 UTC (permalink / raw)
To: Shameerali Kolothum Thodi, Lorenzo Pieralisi, Sudeep Holla,
Rafael J. Wysocki, Pankaj Bansal, Erik Schmauss
Cc: linux-acpi, Linuxarm, linux-arm-kernel
On 2020/1/2 18:20, Shameerali Kolothum Thodi wrote:
> Hi Hanjun,
>
>> -----Original Message-----
>> From: Linuxarm [mailto:linuxarm-bounces@huawei.com] On Behalf Of Hanjun
>> Guo
>> Sent: 23 December 2019 09:23
>> To: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>; Sudeep Holla
>> <sudeep.holla@arm.com>; Rafael J. Wysocki <rafael@kernel.org>; Pankaj
>> Bansal <pankaj.bansal@nxp.com>; Erik Schmauss <erik.schmauss@intel.com>
>> Cc: linux-acpi@vger.kernel.org; Linuxarm <linuxarm@huawei.com>;
>> linux-arm-kernel@lists.infradead.org
>> Subject: [RFC PATCH 2/2] ACPI/IORT: Workaround for IORT ID count "minus
>> one" issue
>>
>> The IORT spec [0] says Number of IDs = The number of IDs in the range minus
>> one, it is confusing but it was written down in the first version of the
>> IORT spec. But the IORT ID mapping function iort_id_map() did something
>> wrong from the start, which bails out if:
>>
>> the request ID >= the input base + number of IDs
>>
>> This is wrong because it ignored the "minus one", and breaks some valid
>> usecases such as ID mapping to contain single device mapping without
>> single mapping flag set.
>>
>> Pankaj Bansal proposed a solution to fix the issue [1], which bails
>> out if:
>>
>> the request ID > the input base + number of IDs
>>
>> This works as the spec defined, unfortunately some firmware didn't
>> minus one for the number of IDs in the range, and the propoased
>> solution will break those systems in this way:
>>
>> PCI hostbridge mapping entry 1:
>> Input base: 0x1000
>> ID Count: 0x100
>> Output base: 0x1000
>> Output reference: 0xC4 //ITS reference
>>
>> PCI hostbridge mapping entry 2:
>> Input base: 0x1100
>> ID Count: 0x100
>> Output base: 0x2000
>> Output reference: 0xD4 //ITS reference
>>
>> Two mapping entries which the second entry's Input base = the first
>> entry's Input base + ID count, so for requester ID 0x1100 will map
>> to ITS 0xC4 not 0xD4 if we update '>=' to '>'.
>>
>> So introduce a workaround to match the IORT's OEM information for
>> the broken firmware, also update the logic of the ID mapping for
>> firmwares report the number of IDs as the IORT spec defined, to
>> make the code compatible for both kinds of system.
>>
>> I checked the ACPI tables in the tianocore/edk2-platforms [2], only
>> HiSilicon HIP07/08 did wrong, so just add HIP07/08 to the workaround
>> info table, if we break other platforms, we can add that later.
>>
>> [0]:
>> http://infocenter.arm.com/help/topic/com.arm.doc.den0049d/DEN0049D_IO_
>> Remapping_Table.pdf
>> [1]: https://patchwork.kernel.org/patch/11292823/
>> [2]: https://github.com/tianocore/edk2-platforms
>>
>> Cc: Pankaj Bansal <pankaj.bansal@nxp.com>
>> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
>> Signed-off-by: Hanjun Guo <guohanjun@huawei.com>
>> ---
>> drivers/acpi/arm64/iort.c | 54
>> ++++++++++++++++++++++++++++++++++++++++++++---
>> 1 file changed, 51 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
>> index 33f7198..112b1b0 100644
>> --- a/drivers/acpi/arm64/iort.c
>> +++ b/drivers/acpi/arm64/iort.c
>> @@ -298,6 +298,41 @@ static acpi_status iort_match_node_callback(struct
>> acpi_iort_node *node,
>> return status;
>> }
>>
>> +struct iort_workaround_oem_info {
>> + char oem_id[ACPI_OEM_ID_SIZE + 1];
>> + char oem_table_id[ACPI_OEM_TABLE_ID_SIZE + 1];
>> + u32 oem_revision;
>> +};
>> +
>> +static bool apply_id_count_workaround;
>> +
>> +static struct iort_workaround_oem_info wa_info[] __initdata = {
>> + {
>> + .oem_id = "HISI ",
>> + .oem_table_id = "HIP07 ",
>> + .oem_revision = 0,
>> + }, {
>> + .oem_id = "HISI ",
>> + .oem_table_id = "HIP08 ",
>> + .oem_revision = 0,
>> + }
>> +};
>> +
>> +static void __init
>> +iort_check_id_count_workaround(struct acpi_table_header *tbl)
>> +{
>> + int i;
>> +
>> + for (i = 0; i < ARRAY_SIZE(wa_info); i++) {
>> + if (!memcmp(wa_info[i].oem_id, tbl->oem_id, ACPI_OEM_ID_SIZE)
>> &&
>> + !memcmp(wa_info[i].oem_table_id, tbl->oem_table_id,
>> ACPI_OEM_TABLE_ID_SIZE) &&
>> + wa_info[i].oem_revision == tbl->oem_revision) {
>> + apply_id_count_workaround = true;
>> + break;
>> + }
>> + }
>> +}
>> +
>
> Can we get rid of the above and instead use acpi_match_platform_list() ? Please
> take a look at the pmcg_plat_info used for the HIP08 SMMUv3 PMCG erratum.
Thanks for the reminding, I noticed acpi_match_platform_list() before but I
thought it was a little overkill (get the table header for each OEM info),
I will take a look further to see if I can consolidate the OEM information retrieve.
Thanks
Hanjun
^ permalink raw reply [flat|nested] 16+ messages in thread* Re: [RFC PATCH 2/2] ACPI/IORT: Workaround for IORT ID count "minus one" issue
@ 2020-01-03 10:14 ` Hanjun Guo
0 siblings, 0 replies; 16+ messages in thread
From: Hanjun Guo @ 2020-01-03 10:14 UTC (permalink / raw)
To: Shameerali Kolothum Thodi, Lorenzo Pieralisi, Sudeep Holla,
Rafael J. Wysocki, Pankaj Bansal, Erik Schmauss
Cc: linux-acpi, Linuxarm, linux-arm-kernel
On 2020/1/2 18:20, Shameerali Kolothum Thodi wrote:
> Hi Hanjun,
>
>> -----Original Message-----
>> From: Linuxarm [mailto:linuxarm-bounces@huawei.com] On Behalf Of Hanjun
>> Guo
>> Sent: 23 December 2019 09:23
>> To: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>; Sudeep Holla
>> <sudeep.holla@arm.com>; Rafael J. Wysocki <rafael@kernel.org>; Pankaj
>> Bansal <pankaj.bansal@nxp.com>; Erik Schmauss <erik.schmauss@intel.com>
>> Cc: linux-acpi@vger.kernel.org; Linuxarm <linuxarm@huawei.com>;
>> linux-arm-kernel@lists.infradead.org
>> Subject: [RFC PATCH 2/2] ACPI/IORT: Workaround for IORT ID count "minus
>> one" issue
>>
>> The IORT spec [0] says Number of IDs = The number of IDs in the range minus
>> one, it is confusing but it was written down in the first version of the
>> IORT spec. But the IORT ID mapping function iort_id_map() did something
>> wrong from the start, which bails out if:
>>
>> the request ID >= the input base + number of IDs
>>
>> This is wrong because it ignored the "minus one", and breaks some valid
>> usecases such as ID mapping to contain single device mapping without
>> single mapping flag set.
>>
>> Pankaj Bansal proposed a solution to fix the issue [1], which bails
>> out if:
>>
>> the request ID > the input base + number of IDs
>>
>> This works as the spec defined, unfortunately some firmware didn't
>> minus one for the number of IDs in the range, and the propoased
>> solution will break those systems in this way:
>>
>> PCI hostbridge mapping entry 1:
>> Input base: 0x1000
>> ID Count: 0x100
>> Output base: 0x1000
>> Output reference: 0xC4 //ITS reference
>>
>> PCI hostbridge mapping entry 2:
>> Input base: 0x1100
>> ID Count: 0x100
>> Output base: 0x2000
>> Output reference: 0xD4 //ITS reference
>>
>> Two mapping entries which the second entry's Input base = the first
>> entry's Input base + ID count, so for requester ID 0x1100 will map
>> to ITS 0xC4 not 0xD4 if we update '>=' to '>'.
>>
>> So introduce a workaround to match the IORT's OEM information for
>> the broken firmware, also update the logic of the ID mapping for
>> firmwares report the number of IDs as the IORT spec defined, to
>> make the code compatible for both kinds of system.
>>
>> I checked the ACPI tables in the tianocore/edk2-platforms [2], only
>> HiSilicon HIP07/08 did wrong, so just add HIP07/08 to the workaround
>> info table, if we break other platforms, we can add that later.
>>
>> [0]:
>> http://infocenter.arm.com/help/topic/com.arm.doc.den0049d/DEN0049D_IO_
>> Remapping_Table.pdf
>> [1]: https://patchwork.kernel.org/patch/11292823/
>> [2]: https://github.com/tianocore/edk2-platforms
>>
>> Cc: Pankaj Bansal <pankaj.bansal@nxp.com>
>> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
>> Signed-off-by: Hanjun Guo <guohanjun@huawei.com>
>> ---
>> drivers/acpi/arm64/iort.c | 54
>> ++++++++++++++++++++++++++++++++++++++++++++---
>> 1 file changed, 51 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
>> index 33f7198..112b1b0 100644
>> --- a/drivers/acpi/arm64/iort.c
>> +++ b/drivers/acpi/arm64/iort.c
>> @@ -298,6 +298,41 @@ static acpi_status iort_match_node_callback(struct
>> acpi_iort_node *node,
>> return status;
>> }
>>
>> +struct iort_workaround_oem_info {
>> + char oem_id[ACPI_OEM_ID_SIZE + 1];
>> + char oem_table_id[ACPI_OEM_TABLE_ID_SIZE + 1];
>> + u32 oem_revision;
>> +};
>> +
>> +static bool apply_id_count_workaround;
>> +
>> +static struct iort_workaround_oem_info wa_info[] __initdata = {
>> + {
>> + .oem_id = "HISI ",
>> + .oem_table_id = "HIP07 ",
>> + .oem_revision = 0,
>> + }, {
>> + .oem_id = "HISI ",
>> + .oem_table_id = "HIP08 ",
>> + .oem_revision = 0,
>> + }
>> +};
>> +
>> +static void __init
>> +iort_check_id_count_workaround(struct acpi_table_header *tbl)
>> +{
>> + int i;
>> +
>> + for (i = 0; i < ARRAY_SIZE(wa_info); i++) {
>> + if (!memcmp(wa_info[i].oem_id, tbl->oem_id, ACPI_OEM_ID_SIZE)
>> &&
>> + !memcmp(wa_info[i].oem_table_id, tbl->oem_table_id,
>> ACPI_OEM_TABLE_ID_SIZE) &&
>> + wa_info[i].oem_revision == tbl->oem_revision) {
>> + apply_id_count_workaround = true;
>> + break;
>> + }
>> + }
>> +}
>> +
>
> Can we get rid of the above and instead use acpi_match_platform_list() ? Please
> take a look at the pmcg_plat_info used for the HIP08 SMMUv3 PMCG erratum.
Thanks for the reminding, I noticed acpi_match_platform_list() before but I
thought it was a little overkill (get the table header for each OEM info),
I will take a look further to see if I can consolidate the OEM information retrieve.
Thanks
Hanjun
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