@@ -611,3 +611,10 @@ config X86_PM_TIMER
You should nearly always say Y here because many modern
systems require this timer.
+
+config ACPI_WBRF
+ bool "ACPI Wifi band RF mitigation mechanism"
+ help
+ Wifi band RF mitigation mechanism allows multiple drivers from
+ different domains to notify the frequencies in use so that hardware
+ can be reconfigured to avoid harmonic conflicts.
\ No newline at end of file
@@ -131,3 +131,5 @@ obj-y += dptf/
obj-$(CONFIG_ARM64) += arm64/
obj-$(CONFIG_ACPI_VIOT) += viot.o
+
+obj-$(CONFIG_ACPI_WBRF) += acpi_wbrf.o
\ No newline at end of file
new file mode 100644
@@ -0,0 +1,343 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * AMD Wifi Band Exclusion Interface
+ * Copyright (C) 2023 Advanced Micro Devices
+ *
+ */
+
+#include <linux/wbrf.h>
+
+/* functions */
+#define WBRF_RECORD 0x1
+#define WBRF_RETRIEVE 0x2
+
+/* record actions */
+#define WBRF_RECORD_ADD 0x0
+#define WBRF_RECORD_REMOVE 0x1
+
+#define WBRF_REVISION 0x1
+
+#define KHZ_TO_HZ(freq) ((freq) * 1000ULL)
+
+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:
+ if (!*out) {
+ rc = -EINVAL;
+ break;
+ }
+ *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;
+ uint32_t num_of_ranges = 0;
+ uint32_t arg_idx = 0;
+ uint32_t 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++;
+
+ argv4 = kzalloc(sizeof(*argv4) * (2 * num_of_ranges + 2 + 1), GFP_KERNEL);
+ if (!argv4)
+ return -ENOMEM;
+
+ argv4[arg_idx].package.type = ACPI_TYPE_PACKAGE;
+ argv4[arg_idx].package.count = 2 + 2 * num_of_ranges;
+ argv4[arg_idx++].package.elements = &argv4[1];
+ argv4[arg_idx].integer.type = ACPI_TYPE_INTEGER;
+ argv4[arg_idx++].integer.value = num_of_ranges;
+ argv4[arg_idx].integer.type = ACPI_TYPE_INTEGER;
+ argv4[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;
+
+ argv4[arg_idx].integer.type = ACPI_TYPE_INTEGER;
+ argv4[arg_idx++].integer.value = in->band_list[loop_idx].start;
+ argv4[arg_idx].integer.type = ACPI_TYPE_INTEGER;
+ argv4[arg_idx++].integer.value = in->band_list[loop_idx].end;
+ }
+
+ ret = wbrf_dsm(adev, WBRF_RECORD, argv4, NULL);
+
+ kfree(argv4);
+
+ return ret;
+}
+
+int wbrf_add_exclusion(struct acpi_device *adev,
+ struct wbrf_ranges_in *in)
+{
+ return wbrf_record(adev, WBRF_RECORD_ADD, in);
+}
+EXPORT_SYMBOL_GPL(wbrf_add_exclusion);
+
+int wbrf_remove_exclusion(struct acpi_device *adev,
+ struct wbrf_ranges_in *in)
+{
+ return wbrf_record(adev, WBRF_RECORD_REMOVE, in);
+}
+EXPORT_SYMBOL_GPL(wbrf_remove_exclusion);
+
+static int chan_width_to_mhz(enum nl80211_chan_width chan_width)
+{
+ int mhz;
+
+ switch (chan_width) {
+ case NL80211_CHAN_WIDTH_1:
+ mhz = 1;
+ break;
+ case NL80211_CHAN_WIDTH_2:
+ mhz = 2;
+ break;
+ case NL80211_CHAN_WIDTH_4:
+ mhz = 4;
+ break;
+ case NL80211_CHAN_WIDTH_8:
+ mhz = 8;
+ break;
+ case NL80211_CHAN_WIDTH_16:
+ mhz = 16;
+ break;
+ case NL80211_CHAN_WIDTH_5:
+ mhz = 5;
+ break;
+ case NL80211_CHAN_WIDTH_10:
+ mhz = 10;
+ break;
+ case NL80211_CHAN_WIDTH_20:
+ case NL80211_CHAN_WIDTH_20_NOHT:
+ mhz = 20;
+ break;
+ case NL80211_CHAN_WIDTH_40:
+ mhz = 40;
+ break;
+ case NL80211_CHAN_WIDTH_80P80:
+ case NL80211_CHAN_WIDTH_80:
+ mhz = 80;
+ break;
+ case NL80211_CHAN_WIDTH_160:
+ mhz = 160;
+ break;
+ case NL80211_CHAN_WIDTH_320:
+ mhz = 320;
+ break;
+ default:
+ WARN_ON_ONCE(1);
+ return -1;
+ }
+ return mhz;
+}
+
+static void get_chan_freq_boundary(u32 center_freq,
+ u32 bandwidth,
+ u64 *start,
+ u64 *end)
+{
+ bandwidth = MHZ_TO_KHZ(bandwidth);
+ center_freq = MHZ_TO_KHZ(center_freq);
+
+ *start = center_freq - bandwidth / 2;
+ *end = center_freq + bandwidth / 2;
+
+ /* Frequency in HZ is expected in BIOS */
+ *start = KHZ_TO_HZ(*start);
+ *end = KHZ_TO_HZ(*end);
+}
+
+static int wbrf_get_ranges_from_chandef(struct cfg80211_chan_def *chandef,
+ struct wbrf_ranges_in *ranges_in)
+{
+ u64 start_freq1, end_freq1;
+ u64 start_freq2, end_freq2;
+ int bandwidth;
+
+ bandwidth = chan_width_to_mhz(chandef->width);
+ if (bandwidth < 0)
+ return -EINVAL;
+
+ get_chan_freq_boundary(chandef->center_freq1,
+ bandwidth,
+ &start_freq1,
+ &end_freq1);
+
+ ranges_in->band_list[0].start = start_freq1;
+ ranges_in->band_list[0].end = end_freq1;
+
+ if (chandef->width == NL80211_CHAN_WIDTH_80P80) {
+ get_chan_freq_boundary(chandef->center_freq2,
+ bandwidth,
+ &start_freq2,
+ &end_freq2);
+
+ ranges_in->band_list[1].start = start_freq2;
+ ranges_in->band_list[1].end = end_freq2;
+ }
+
+ return 0;
+}
+
+int wbrf_add_exclusion_wlan(struct acpi_device *adev,
+ struct cfg80211_chan_def *chandef)
+{
+ struct wbrf_ranges_in ranges_in = {0};
+ int ret;
+
+ ret = wbrf_get_ranges_from_chandef(chandef, &ranges_in);
+ if (ret)
+ return ret;
+
+ return wbrf_add_exclusion(adev, &ranges_in);
+}
+EXPORT_SYMBOL_GPL(wbrf_add_exclusion_wlan);
+
+int wbrf_remove_exclusion_wlan(struct acpi_device *adev,
+ struct cfg80211_chan_def *chandef)
+{
+ struct wbrf_ranges_in ranges_in = {0};
+ int ret;
+
+ ret = wbrf_get_ranges_from_chandef(chandef, &ranges_in);
+ if (ret)
+ return ret;
+
+ return wbrf_remove_exclusion(adev, &ranges_in);
+}
+EXPORT_SYMBOL_GPL(wbrf_remove_exclusion_wlan);
+
+bool wbrf_supported_producer(struct acpi_device *adev)
+{
+ return acpi_check_dsm(adev->handle, &wifi_acpi_dsm_guid,
+ WBRF_REVISION,
+ (1ULL << WBRF_RECORD) | (1ULL << WBRF_RETRIEVE));
+}
+EXPORT_SYMBOL_GPL(wbrf_supported_producer);
+
+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;
+
+ if (ret != AE_NOT_FOUND)
+ acpi_handle_warn(handle,
+ "failed to evaluate WBRF(0x%x)\n", ret);
+
+ 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;
+
+ for (i = 0; i < obj->buffer.length && i < 8; i++)
+ mask |= (((u64)obj->buffer.pointer[i]) << (i * 8));
+ ACPI_FREE(obj);
+
+ /*
+ * Bit 0 indicates whether there's support for any functions other than
+ * function 0.
+ */
+ if ((mask & 0x1) && (mask & funcs) == funcs)
+ return true;
+
+ return false;
+}
+
+bool wbrf_supported_consumer(struct acpi_device *adev)
+{
+ return check_acpi_wbrf(adev->handle,
+ WBRF_REVISION,
+ 1ULL << WBRF_RETRIEVE);
+}
+EXPORT_SYMBOL_GPL(wbrf_supported_consumer);
+
+int wbrf_retrieve_exclusions(struct acpi_device *adev,
+ struct wbrf_ranges_out *exclusions_out)
+{
+ union acpi_object *obj;
+
+ obj = acpi_evaluate_wbrf(adev->handle,
+ WBRF_REVISION,
+ WBRF_RETRIEVE);
+ if (!obj)
+ return -EINVAL;
+
+ memcpy(exclusions_out, obj->buffer.pointer, obj->buffer.length);
+
+ ACPI_FREE(obj);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(wbrf_retrieve_exclusions);
new file mode 100644
@@ -0,0 +1,70 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * AMD Wifi Band Exclusion Interface
+ * Copyright (C) 2023 Advanced Micro Devices
+ */
+
+#ifndef _LINUX_WBRF_H
+#define _LINUX_WBRF_H
+
+#include <linux/acpi.h>
+#include <net/cfg80211.h>
+
+/* Maximum number of wbrf ranges */
+#define MAX_NUM_OF_WBRF_RANGES 11
+
+struct exclusion_range {
+ uint64_t start;
+ uint64_t end;
+};
+
+struct wbrf_ranges_in {
+ /* valid entry: `start` and `end` filled with non-zero values */
+ struct exclusion_range band_list[MAX_NUM_OF_WBRF_RANGES];
+};
+
+struct wbrf_ranges_out {
+ uint32_t num_of_ranges;
+ struct exclusion_range band_list[MAX_NUM_OF_WBRF_RANGES];
+} __attribute__((packed));
+
+/**
+ * APIs needed by drivers/subsystems for contributing frequencies:
+ * During probe, check `wbrf_supported_producer` to see if WBRF is supported.
+ * If adding frequencies, then call `wbrf_add_exclusion` with the
+ * start and end points specified for the frequency ranges added.
+ * If removing frequencies, then call `wbrf_remove_exclusion` with
+ * start and end points specified for the frequency ranges added.
+ */
+bool wbrf_supported_producer(struct acpi_device *adev);
+int wbrf_add_exclusion(struct acpi_device *adev,
+ struct wbrf_ranges_in *in);
+int wbrf_remove_exclusion(struct acpi_device *adev,
+ struct wbrf_ranges_in *in);
+/**
+ * The following two APIs are created specially for net/wireless subsystem(
+ * a main player for contributing frequencies) for adding and removing
+ * frequencies:
+ * If adding frequencies, then call `wbrf_add_exclusion_wlan` with
+ * `struct cfg80211_chan_def` which defines the center frequency points
+ * and bandwidth.
+ * If removing frequencies, then call `wbrf_remove_exclusion_wlan` with
+ * `struct cfg80211_chan_def` which defines the center frequency points
+ * and bandwidth.
+ */
+int wbrf_add_exclusion_wlan(struct acpi_device *adev,
+ struct cfg80211_chan_def *chandef);
+int wbrf_remove_exclusion_wlan(struct acpi_device *adev,
+ struct cfg80211_chan_def *chandef);
+
+/**
+ * APIs needed by drivers/subsystems responding to frequencies:
+ * During probe, check `wbrf_supported_consumer` to see if WBRF is supported.
+ * When receiving an ACPI notification for some frequencies change, run
+ * `wbrf_retrieve_exclusions` to retrieve the latest frequencies ranges.
+ */
+int wbrf_retrieve_exclusions(struct acpi_device *adev,
+ struct wbrf_ranges_out *out);
+bool wbrf_supported_consumer(struct acpi_device *adev);
+
+#endif /* _LINUX_WBRF_H */