RE: [PATCH V8 2/9] drivers core: add ACPI based WBRF mechanism introduced by AMD
[AMD Official Use Only - General]
> -Original Message-
> From: Simon Horman
> Sent: Friday, August 11, 2023 5:38 PM
> To: Quan, Evan
> Cc: raf...@kernel.org; l...@kernel.org; Deucher, Alexander
> ; Koenig, Christian
> ; Pan, Xinhui ;
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> da...@davemloft.net; eduma...@google.com; k...@kernel.org;
> pab...@redhat.com; Limonciello, Mario ;
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> Subject: Re: [PATCH V8 2/9] drivers core: add ACPI based WBRF mechanism
> introduced by AMD
>
> On Thu, Aug 10, 2023 at 03:37:56PM +0800, Evan Quan wrote:
> > AMD has introduced an ACPI based mechanism to support WBRF for some
> > platforms with AMD dGPU + WLAN. This needs support from BIOS equipped
> > with necessary AML implementations and dGPU firmwares.
> >
> > For those systems without the ACPI mechanism and developing solutions,
> > user can use/fall-back the generic WBRF solution for diagnosing potential
> > interference issues.
> >
> > And for the platform which does not equip with the necessary AMD ACPI
> > implementations but with CONFIG_WBRF_AMD_ACPI built as 'y', it will
> > fall back to generic WBRF solution if the `wbrf` is set as "on".
> >
> > Co-developed-by: Mario Limonciello
> > Signed-off-by: Mario Limonciello
> > Co-developed-by: Evan Quan
> > Signed-off-by: Evan Quan
>
> ...
>
> > diff --git a/drivers/acpi/amd_wbrf.c b/drivers/acpi/amd_wbrf.c
>
> ...
>
> > +static bool check_acpi_wbrf(acpi_handle handle, u64 rev, u64 funcs)
> > +{
> > + int i;
> > + u64 mask = 0;
> > + union acpi_object *obj;
> > +
> > + if (funcs == 0)
> > + return false;
> > +
> > + obj = acpi_evaluate_wbrf(handle, rev, 0);
> > + if (!obj)
> > + return false;
> > +
> > + if (obj->type != ACPI_TYPE_BUFFER)
> > + return false;
> > +
> > + /*
> > +* Bit vector providing supported functions information.
> > +* Each bit marks support for one specific function of the WBRF
> method.
> > +*/
> > + for (i = 0; i < obj->buffer.length && i < 8; i++)
> > + mask |= (((u64)obj->buffer.pointer[i]) << (i * 8));
> > +
> > + ACPI_FREE(obj);
> > +
> > + if ((mask & BIT(WBRF_ENABLED)) &&
> > +(mask & funcs) == funcs)
>
> Hi Evan,
>
> a minor nit from my side: the indentation of the line above seems odd.
Thanks. Will update this.
Evan
>
> if ((mask & BIT(WBRF_ENABLED)) &&
> (mask & funcs) == funcs)
>
> > + return true;
> > +
> > + return false;
> > +}
>
> ...
Re: [PATCH V8 2/9] drivers core: add ACPI based WBRF mechanism introduced by AMD
On Thu, Aug 10, 2023 at 03:37:56PM +0800, Evan Quan wrote:
> AMD has introduced an ACPI based mechanism to support WBRF for some
> platforms with AMD dGPU + WLAN. This needs support from BIOS equipped
> with necessary AML implementations and dGPU firmwares.
>
> For those systems without the ACPI mechanism and developing solutions,
> user can use/fall-back the generic WBRF solution for diagnosing potential
> interference issues.
>
> And for the platform which does not equip with the necessary AMD ACPI
> implementations but with CONFIG_WBRF_AMD_ACPI built as 'y', it will
> fall back to generic WBRF solution if the `wbrf` is set as "on".
>
> Co-developed-by: Mario Limonciello
> Signed-off-by: Mario Limonciello
> Co-developed-by: Evan Quan
> Signed-off-by: Evan Quan
...
> diff --git a/drivers/acpi/amd_wbrf.c b/drivers/acpi/amd_wbrf.c
...
> +static bool check_acpi_wbrf(acpi_handle handle, u64 rev, u64 funcs)
> +{
> + int i;
> + u64 mask = 0;
> + union acpi_object *obj;
> +
> + if (funcs == 0)
> + return false;
> +
> + obj = acpi_evaluate_wbrf(handle, rev, 0);
> + if (!obj)
> + return false;
> +
> + if (obj->type != ACPI_TYPE_BUFFER)
> + return false;
> +
> + /*
> + * Bit vector providing supported functions information.
> + * Each bit marks support for one specific function of the WBRF method.
> + */
> + for (i = 0; i < obj->buffer.length && i < 8; i++)
> + mask |= (((u64)obj->buffer.pointer[i]) << (i * 8));
> +
> + ACPI_FREE(obj);
> +
> + if ((mask & BIT(WBRF_ENABLED)) &&
> + (mask & funcs) == funcs)
Hi Evan,
a minor nit from my side: the indentation of the line above seems odd.
if ((mask & BIT(WBRF_ENABLED)) &&
(mask & funcs) == funcs)
> + return true;
> +
> + return false;
> +}
...
[PATCH V8 2/9] drivers core: add ACPI based WBRF mechanism introduced by AMD
AMD has introduced an ACPI based mechanism to support WBRF for some
platforms with AMD dGPU + WLAN. This needs support from BIOS equipped
with necessary AML implementations and dGPU firmwares.
For those systems without the ACPI mechanism and developing solutions,
user can use/fall-back the generic WBRF solution for diagnosing potential
interference issues.
And for the platform which does not equip with the necessary AMD ACPI
implementations but with CONFIG_WBRF_AMD_ACPI built as 'y', it will
fall back to generic WBRF solution if the `wbrf` is set as "on".
Co-developed-by: Mario Limonciello
Signed-off-by: Mario Limonciello
Co-developed-by: Evan Quan
Signed-off-by: Evan Quan
--
v4->v5:
- promote this to be a more generic solution with input argument taking
`struct device` and provide better scalability to support non-ACPI
scenarios(Andrew)
- update the APIs naming and some other minor fixes(Rafael)
v5->v6:
- make the code more readable and some other fixes(Andrew)
v6->v8:
- drop CONFIG_WBRF_GENERIC(Mario)
- add `wbrf` kernel parameter for policy control(Mario)
---
drivers/acpi/Makefile | 2 +
drivers/acpi/amd_wbrf.c | 294 ++
drivers/base/Kconfig | 20 +++
drivers/base/wbrf.c | 135 +---
include/linux/acpi_amd_wbrf.h | 25 +++
5 files changed, 452 insertions(+), 24 deletions(-)
create mode 100644 drivers/acpi/amd_wbrf.c
create mode 100644 include/linux/acpi_amd_wbrf.h
diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
index 3fc5a0d54f6e..9185d16e4495 100644
--- a/drivers/acpi/Makefile
+++ b/drivers/acpi/Makefile
@@ -133,3 +133,5 @@ obj-$(CONFIG_ARM64) += arm64/
obj-$(CONFIG_ACPI_VIOT)+= viot.o
obj-$(CONFIG_RISCV)+= riscv/
+
+obj-$(CONFIG_WBRF_AMD_ACPI)+= amd_wbrf.o
diff --git a/drivers/acpi/amd_wbrf.c b/drivers/acpi/amd_wbrf.c
new file mode 100644
index ..a3390d91cbea
--- /dev/null
+++ b/drivers/acpi/amd_wbrf.c
@@ -0,0 +1,294 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Wifi Band Exclusion Interface (AMD ACPI Implementation)
+ * Copyright (C) 2023 Advanced Micro Devices
+ *
+ */
+
+#include
+#include
+
+#define ACPI_AMD_WBRF_METHOD "\\WBRF"
+
+/*
+ * Functions bit vector for WBRF method
+ *
+ * Bit 0: Supported for any functions other than function 0.
+ * Bit 1: Function 1 (Add / Remove frequency) is supported.
+ * Bit 2: Function 2 (Get frequency list) is supported.
+ */
+#define WBRF_ENABLED 0x0
+#define WBRF_RECORD0x1
+#define WBRF_RETRIEVE 0x2
+
+/* record actions */
+#define WBRF_RECORD_ADD0x0
+#define WBRF_RECORD_REMOVE 0x1
+
+#define WBRF_REVISION 0x1
+
+/*
+ * The data structure used for WBRF_RETRIEVE is not natually aligned.
+ * And unfortunately the design has been settled down.
+ */
+struct amd_wbrf_ranges_out {
+ u32 num_of_ranges;
+ struct exclusion_range band_list[MAX_NUM_OF_WBRF_RANGES];
+} __packed;
+
+static const guid_t wifi_acpi_dsm_guid =
+ GUID_INIT(0x7b7656cf, 0xdc3d, 0x4c1c,
+ 0x83, 0xe9, 0x66, 0xe7, 0x21, 0xde, 0x30, 0x70);
+
+static int wbrf_dsm(struct acpi_device *adev, u8 fn,
+ union acpi_object *argv4,
+ union acpi_object **out)
+{
+ union acpi_object *obj;
+ int rc;
+
+ obj = acpi_evaluate_dsm(adev->handle, _acpi_dsm_guid,
+ WBRF_REVISION, fn, argv4);
+ if (!obj)
+ return -ENXIO;
+
+ switch (obj->type) {
+ case ACPI_TYPE_BUFFER:
+ *out = obj;
+ return 0;
+
+ case ACPI_TYPE_INTEGER:
+ rc = obj->integer.value ? -EINVAL : 0;
+ break;
+
+ default:
+ rc = -EOPNOTSUPP;
+ }
+
+ ACPI_FREE(obj);
+
+ return rc;
+}
+
+static int wbrf_record(struct acpi_device *adev, uint8_t action,
+ struct wbrf_ranges_in *in)
+{
+ union acpi_object argv4;
+ union acpi_object *tmp;
+ u32 num_of_ranges = 0;
+ u32 num_of_elements;
+ u32 arg_idx = 0;
+ u32 loop_idx;
+ int ret;
+
+ if (!in)
+ return -EINVAL;
+
+ for (loop_idx = 0; loop_idx < ARRAY_SIZE(in->band_list);
+loop_idx++)
+ if (in->band_list[loop_idx].start &&
+ in->band_list[loop_idx].end)
+ num_of_ranges++;
+
+ /*
+* Every range comes with two end points(start and end) and
+* each of them is accounted as an element. Meanwhile the range
+* count and action type are accounted as an element each.
+* So, the total element count = 2 * num_of_ranges + 1 + 1.
+*/
+ num_of_elements = 2 * num_of_ranges + 1 + 1;
+
+ tmp = kcalloc(num_of_elements, sizeof(*tmp), GFP_KERNEL);
+ if (!tmp)
+
