@@ -131,3 +131,5 @@ obj-y += dptf/
obj-$(CONFIG_ARM64) += arm64/
obj-$(CONFIG_ACPI_VIOT) += viot.o
+
+obj-$(CONFIG_WBRF_AMD_ACPI) += amd_wbrf.o
new file mode 100644
@@ -0,0 +1,282 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Wifi Band Exclusion Interface (AMD ACPI Implementation)
+ * Copyright (C) 2023 Advanced Micro Devices
+ *
+ */
+
+#include <linux/acpi.h>
+#include <linux/acpi_amd_wbrf.h>
+
+/*
+ * 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_SUPPORT_OTHER_FUNCTION 0x0
+#define WBRF_RECORD 0x1
+#define WBRF_RETRIEVE 0x2
+
+/* record actions */
+#define WBRF_RECORD_ADD 0x0
+#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, &wifi_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)
+ return -ENOMEM;
+
+ argv4.package.type = ACPI_TYPE_PACKAGE;
+ argv4.package.count = num_of_elements;
+ argv4.package.elements = tmp;
+
+ tmp[arg_idx].integer.type = ACPI_TYPE_INTEGER;
+ tmp[arg_idx++].integer.value = num_of_ranges;
+ tmp[arg_idx].integer.type = ACPI_TYPE_INTEGER;
+ tmp[arg_idx++].integer.value = action;
+
+ 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)
+ continue;
+
+ tmp[arg_idx].integer.type = ACPI_TYPE_INTEGER;
+ tmp[arg_idx++].integer.value = in->band_list[loop_idx].start;
+ tmp[arg_idx].integer.type = ACPI_TYPE_INTEGER;
+ tmp[arg_idx++].integer.value = in->band_list[loop_idx].end;
+ }
+
+ ret = wbrf_dsm(adev, WBRF_RECORD, &argv4, NULL);
+
+ kfree(tmp);
+
+ return ret;
+}
+
+int acpi_amd_wbrf_add_exclusion(struct device *dev,
+ struct wbrf_ranges_in *in)
+{
+ struct acpi_device *adev = ACPI_COMPANION(dev);
+
+ if (!adev)
+ return -ENODEV;
+
+ return wbrf_record(adev, WBRF_RECORD_ADD, in);
+}
+
+int acpi_amd_wbrf_remove_exclusion(struct device *dev,
+ struct wbrf_ranges_in *in)
+{
+ struct acpi_device *adev = ACPI_COMPANION(dev);
+
+ if (!adev)
+ return -ENODEV;
+
+ return wbrf_record(adev, WBRF_RECORD_REMOVE, in);
+}
+
+bool acpi_amd_wbrf_supported_producer(struct device *dev)
+{
+ struct acpi_device *adev = ACPI_COMPANION(dev);
+
+ if (!adev)
+ return false;
+
+ return acpi_check_dsm(adev->handle, &wifi_acpi_dsm_guid,
+ WBRF_REVISION,
+ BIT(WBRF_RECORD));
+}
+
+static union acpi_object *
+acpi_evaluate_wbrf(acpi_handle handle, u64 rev, u64 func)
+{
+ acpi_status ret;
+ struct acpi_buffer buf = {ACPI_ALLOCATE_BUFFER, NULL};
+ union acpi_object params[4];
+ struct acpi_object_list input = {
+ .count = 4,
+ .pointer = params,
+ };
+
+ params[0].type = ACPI_TYPE_INTEGER;
+ params[0].integer.value = rev;
+ params[1].type = ACPI_TYPE_INTEGER;
+ params[1].integer.value = func;
+ params[2].type = ACPI_TYPE_PACKAGE;
+ params[2].package.count = 0;
+ params[2].package.elements = NULL;
+ params[3].type = ACPI_TYPE_STRING;
+ params[3].string.length = 0;
+ params[3].string.pointer = NULL;
+
+ ret = acpi_evaluate_object(handle, "WBRF", &input, &buf);
+ if (ACPI_SUCCESS(ret))
+ return (union acpi_object *)buf.pointer;
+
+ return NULL;
+}
+
+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_SUPPORT_OTHER_FUNCTION)) &&
+ (mask & funcs) == funcs)
+ return true;
+
+ return false;
+}
+
+bool acpi_amd_wbrf_supported_consumer(struct device *dev)
+{
+ struct acpi_device *adev = ACPI_COMPANION(dev);
+
+ if (!adev)
+ return false;
+
+ return check_acpi_wbrf(adev->handle,
+ WBRF_REVISION,
+ BIT(WBRF_RETRIEVE));
+}
+
+int acpi_amd_wbrf_retrieve_exclusions(struct device *dev,
+ struct wbrf_ranges_out *out)
+{
+ struct acpi_device *adev = ACPI_COMPANION(dev);
+ struct amd_wbrf_ranges_out acpi_out = {0};
+ union acpi_object *obj;
+
+ if (!adev)
+ return -ENODEV;
+
+ obj = acpi_evaluate_wbrf(adev->handle,
+ WBRF_REVISION,
+ WBRF_RETRIEVE);
+ if (!obj)
+ return -EINVAL;
+
+ /*
+ * The return buffer is with variable length and the format below:
+ * number_of_entries(1 DWORD): Number of entries
+ * start_freq of 1st entry(1 QWORD): Start frequency of the 1st entry
+ * end_freq of 1st entry(1 QWORD): End frequency of the 1st entry
+ * ...
+ * ...
+ * start_freq of the last entry(1 QWORD)
+ * end_freq of the last entry(1 QWORD)
+ *
+ * Thus the buffer length is determined by the number of entries.
+ * - For zero entry scenario, the buffer length will be 4 bytes.
+ * - For one entry scenario, the buffer length will be 20 bytes.
+ */
+ if (obj->buffer.length > sizeof(acpi_out) ||
+ obj->buffer.length < 4) {
+ dev_err(dev, "BIOS FUBAR, ignoring wrong sized WBRT information");
+ ACPI_FREE(obj);
+ return -EINVAL;
+ }
+ memcpy(&acpi_out, obj->buffer.pointer, obj->buffer.length);
+
+ out->num_of_ranges = acpi_out.num_of_ranges;
+ memcpy(out->band_list, acpi_out.band_list, sizeof(acpi_out.band_list));
+
+ ACPI_FREE(obj);
+
+ return 0;
+}
@@ -250,4 +250,33 @@ config WBRF
different domains to notify the frequencies in use so that hardware
can be reconfigured to avoid harmonic conflicts.
+config WBRF_AMD_ACPI
+ bool "Use the ACPI mechanism introduced by AMD to support WBRF"
+ default n
+ depends on ACPI
+ select WBRF
+ help
+ AMD has introduced an ACPI based mechanism to support WBRF for some
+ platforms with AMD dGPU and WLAN. This needs support from BIOS equipped
+ with necessary AML implementations and dGPU firmwares.
+
+ Say Y to enable this ACPI based mechanism. It is suggested to confirm
+ with the hardware designer/provider first whether your platform
+ equipped with necessary BIOS and firmwares.
+
+config WBRF_GENERIC
+ bool "Use the generic WBRF solution"
+ default n
+ depends on !WBRF_AMD_ACPI
+ select WBRF
+ help
+ Ideally it is the hardware designer/provider who should provide a
+ solution for the possible RF interference issue. Since they know
+ well whether there could be RF interference issue with their
+ platforms.
+
+ Say Y to enable this generic WBRF solution for diagnosing potential
+ interference issues on systems without the ACPI mechanism and
+ developing solutions.
+
endmenu
@@ -6,9 +6,12 @@
*/
#include <linux/wbrf.h>
+#include <linux/acpi_amd_wbrf.h>
static BLOCKING_NOTIFIER_HEAD(wbrf_chain_head);
static DEFINE_MUTEX(wbrf_mutex);
+
+#if IS_ENABLED(CONFIG_WBRF_GENERIC)
static struct exclusion_range_pool wbrf_pool;
static int _wbrf_add_exclusion_ranges(struct wbrf_ranges_in *in)
@@ -91,6 +94,7 @@ static int _wbrf_retrieve_exclusion_ranges(struct wbrf_ranges_out *out)
return 0;
}
+#endif
/**
* wbrf_supported_producer - Determine if the device should report frequencies
@@ -99,10 +103,17 @@ static int _wbrf_retrieve_exclusion_ranges(struct wbrf_ranges_out *out)
*
* WBRF is used to mitigate devices that cause harmonic interference.
* This function will determine if this device should report such frequencies.
+ * For example, for AMD ACPI implementation it should say true only when the
+ * necessary AML code/logic supporting wbrf feature available for this device.
*/
bool wbrf_supported_producer(struct device *dev)
{
+#if IS_ENABLED(CONFIG_WBRF_AMD_ACPI)
+ return acpi_amd_wbrf_supported_producer(dev);
+#elif IS_ENABLED(CONFIG_WBRF_GENERIC)
return true;
+#endif
+ return false;
}
EXPORT_SYMBOL_GPL(wbrf_supported_producer);
@@ -118,12 +129,15 @@ EXPORT_SYMBOL_GPL(wbrf_supported_producer);
int wbrf_add_exclusion(struct device *dev,
struct wbrf_ranges_in *in)
{
- int r;
+ int r = -ENODEV;
mutex_lock(&wbrf_mutex);
+#if IS_ENABLED(CONFIG_WBRF_AMD_ACPI)
+ r = acpi_amd_wbrf_add_exclusion(dev, in);
+#elif IS_ENABLED(CONFIG_WBRF_GENERIC)
r = _wbrf_add_exclusion_ranges(in);
-
+#endif
mutex_unlock(&wbrf_mutex);
if (r)
return r;
@@ -146,12 +160,15 @@ EXPORT_SYMBOL_GPL(wbrf_add_exclusion);
int wbrf_remove_exclusion(struct device *dev,
struct wbrf_ranges_in *in)
{
- int r;
+ int r = -ENODEV;
mutex_lock(&wbrf_mutex);
+#if IS_ENABLED(CONFIG_WBRF_AMD_ACPI)
+ r = acpi_amd_wbrf_remove_exclusion(dev, in);
+#elif IS_ENABLED(CONFIG_WBRF_GENERIC)
r = _wbrf_remove_exclusion_ranges(in);
-
+#endif
mutex_unlock(&wbrf_mutex);
if (r)
return r;
@@ -169,11 +186,18 @@ EXPORT_SYMBOL_GPL(wbrf_remove_exclusion);
*
* WBRF is used to mitigate devices that cause harmonic interference.
* This function will determine if this device should react to reports from
- * other devices for such frequencies.
+ * other devices for such frequencies. For example, for AMD ACPI implementation
+ * it should say true only when the necessary AML code/logic supporting wbrf
+ * feature available for this device.
*/
bool wbrf_supported_consumer(struct device *dev)
{
+#if IS_ENABLED(CONFIG_WBRF_AMD_ACPI)
+ return acpi_amd_wbrf_supported_consumer(dev);
+#elif IS_ENABLED(CONFIG_WBRF_GENERIC)
return true;
+#endif
+ return false;
}
EXPORT_SYMBOL_GPL(wbrf_supported_consumer);
@@ -216,12 +240,15 @@ EXPORT_SYMBOL_GPL(wbrf_unregister_notifier);
int wbrf_retrieve_exclusions(struct device *dev,
struct wbrf_ranges_out *out)
{
- int r;
+ int r = -ENODEV;
mutex_lock(&wbrf_mutex);
+#if IS_ENABLED(CONFIG_WBRF_AMD_ACPI)
+ r = acpi_amd_wbrf_retrieve_exclusions(dev, out);
+#elif IS_ENABLED(CONFIG_WBRF_GENERIC)
r = _wbrf_retrieve_exclusion_ranges(out);
-
+#endif
mutex_unlock(&wbrf_mutex);
return r;
new file mode 100644
@@ -0,0 +1,24 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Wifi Band Exclusion Interface (AMD ACPI Implementation)
+ * Copyright (C) 2023 Advanced Micro Devices
+ *
+ */
+
+#ifndef _ACPI_AMD_WBRF_H
+#define _ACPI_AMD_WBRF_H
+
+#include <linux/wbrf.h>
+
+#if IS_ENABLED(CONFIG_WBRF_AMD_ACPI)
+bool acpi_amd_wbrf_supported_consumer(struct device *dev);
+bool acpi_amd_wbrf_supported_producer(struct device *dev);
+int acpi_amd_wbrf_remove_exclusion(struct device *dev,
+ struct wbrf_ranges_in *in);
+int acpi_amd_wbrf_add_exclusion(struct device *dev,
+ struct wbrf_ranges_in *in);
+int acpi_amd_wbrf_retrieve_exclusions(struct device *dev,
+ struct wbrf_ranges_out *out);
+#endif
+
+#endif /* _ACPI_AMD_WBRF_H */
@@ -18,10 +18,12 @@ struct exclusion_range {
u64 end;
};
+#if IS_ENABLED(CONFIG_WBRF_GENERIC)
struct exclusion_range_pool {
struct exclusion_range band_list[MAX_NUM_OF_WBRF_RANGES];
u64 ref_counter[MAX_NUM_OF_WBRF_RANGES];
};
+#endif
struct wbrf_ranges_in {
/* valid entry: `start` and `end` filled with non-zero values */