| Message ID | 20231017025358.1773598-3-Jun.Ma2@amd.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Delegated to: | Johannes Berg |
| Headers | show |
| Series | Enable Wifi RFI interference mitigation feature support | expand |
On Tue, 17 Oct 2023, Ma Jun wrote: > Due to electrical and mechanical constraints in certain platform designs > there may be likely interference of relatively high-powered harmonics of > the (G-)DDR memory clocks with local radio module frequency bands used > by Wifi 6/6e/7. > > To mitigate this, AMD has introduced a mechanism that devices can use to > notify active use of particular frequencies so that other devices can make > relative internal adjustments as necessary to avoid this resonance. > > Co-Developed-by: Evan Quan <quanliangl@hotmail.com> > Signed-off-by: Evan Quan <quanliangl@hotmail.com> > Signed-off-by: Ma Jun <Jun.Ma2@amd.com> > > -- > v11: > - fix typo(Simon) > v12: > - Fix the code (Rafael) > - Move amd_wbrf.c to drivers/platform/x86/amd/wbrf.c > - Updated Evan's email because he's no longer at AMD.Thanks > for his work in earlier versions. > --- > drivers/platform/x86/amd/Kconfig | 15 ++ > drivers/platform/x86/amd/Makefile | 1 + > drivers/platform/x86/amd/wbrf.c | 402 ++++++++++++++++++++++++++++++ > include/linux/acpi_amd_wbrf.h | 101 ++++++++ > 4 files changed, 519 insertions(+) > create mode 100644 drivers/platform/x86/amd/wbrf.c > create mode 100644 include/linux/acpi_amd_wbrf.h > > diff --git a/drivers/platform/x86/amd/Kconfig b/drivers/platform/x86/amd/Kconfig > index d9685aef0887..fa5a978a2d22 100644 > --- a/drivers/platform/x86/amd/Kconfig > +++ b/drivers/platform/x86/amd/Kconfig > @@ -32,3 +32,18 @@ config AMD_HSMP > > If you choose to compile this driver as a module the module will be > called amd_hsmp. > + > +config AMD_WBRF > + bool "AMD Wifi RF Band mitigations (WBRF)" > + depends on ACPI > + default n > + help > + WBRF(Wifi Band RFI mitigation) mechanism allows Wifi drivers > + to notify the frequencies they are using so that other hardware > + can be reconfigured to avoid harmonic conflicts. > + > + AMD provides an ACPI based mechanism to support WBRF on platform with > + appropriate underlying support. > + > + This mechanism will only be activated on platforms that advertise a > + need for it. > diff --git a/drivers/platform/x86/amd/Makefile b/drivers/platform/x86/amd/Makefile > index 65732f0a3913..62b98b048b17 100644 > --- a/drivers/platform/x86/amd/Makefile > +++ b/drivers/platform/x86/amd/Makefile > @@ -9,3 +9,4 @@ obj-$(CONFIG_AMD_PMC) += amd-pmc.o > amd_hsmp-y := hsmp.o > obj-$(CONFIG_AMD_HSMP) += amd_hsmp.o > obj-$(CONFIG_AMD_PMF) += pmf/ > +obj-$(CONFIG_AMD_WBRF) += wbrf.o > diff --git a/drivers/platform/x86/amd/wbrf.c b/drivers/platform/x86/amd/wbrf.c > new file mode 100644 > index 000000000000..fb414564f576 > --- /dev/null > +++ b/drivers/platform/x86/amd/wbrf.c > @@ -0,0 +1,402 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Wifi Frequency Band Manage Interface > + * Copyright (C) 2023 Advanced Micro Devices > + */ > + > +#include <linux/acpi.h> > +#include <linux/acpi_amd_wbrf.h> > + > +#define ACPI_AMD_WBRF_METHOD "\\WBRF" > + > +/* > + * Functions bit vector for WBRF method > + * > + * Bit 0: WBRF supported. > + * Bit 1: Function 1 (Add / Remove frequency) is supported. > + * Bit 2: Function 2 (Get frequency list) is supported. > + */ > +#define WBRF_ENABLED 0x0 > +#define WBRF_RECORD 0x1 > +#define WBRF_RETRIEVE 0x2 > + > +#define WBRF_REVISION 0x1 > + > +/* > + * The data structure used for WBRF_RETRIEVE is not naturally aligned. > + * And unfortunately the design has been settled down. > + */ > +struct amd_wbrf_ranges_out { > + u32 num_of_ranges; > + struct freq_band_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); > + > +/* > + * Used to notify consumer (amdgpu driver currently) about > + * the wifi frequency is change. > + */ > +static BLOCKING_NOTIFIER_HEAD(wbrf_chain_head); > + > +static int wbrf_record(struct acpi_device *adev, uint8_t action, > + struct wbrf_ranges_in_out *in) > +{ > + union acpi_object argv4; > + union acpi_object *tmp; > + union acpi_object *obj; > + u32 num_of_ranges = 0; > + u32 num_of_elements; > + u32 arg_idx = 0; > + u32 loop_idx; > + int ret; > + > + if (!in) > + return -EINVAL; > + > + /* > + * The num_of_ranges value in the "in" object supplied by > + * the caller is required to be equal to the number of > + * entries in the band_list array in there. > + */ > + for (loop_idx = 0; loop_idx < ARRAY_SIZE(in->band_list); > + loop_idx++) This fits easily to one line. What extra information loop_idx provides over the usual i? I see zero extra value, only extra characters. > + if (in->band_list[loop_idx].start && > + in->band_list[loop_idx].end) One line. > + num_of_ranges++; > + > + if (num_of_ranges != in->num_of_ranges) > + return -EINVAL; Can't you just exit in the loop directly? Seriously, this v12 of your series and nobody has noticed any of these? > + > + /* > + * Every input frequency band comes with two end points(start/end) > + * and each 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 + 2; > + > + 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; > + > + /* save the number of ranges*/ > + tmp[0].integer.type = ACPI_TYPE_INTEGER; > + tmp[0].integer.value = num_of_ranges; > + > + /* save the action(WBRF_RECORD_ADD/REMOVE/RETRIEVE) */ > + tmp[1].integer.type = ACPI_TYPE_INTEGER; > + tmp[1].integer.value = action; > + > + arg_idx = 2; > + for (loop_idx = 0; loop_idx < ARRAY_SIZE(in->band_list); > + loop_idx++) { Ditto. > + 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; > + } > + > + obj = acpi_evaluate_dsm(adev->handle, &wifi_acpi_dsm_guid, > + WBRF_REVISION, WBRF_RECORD, &argv4); > + > + if (!obj) > + return -EINVAL; > + > + if (obj->type != ACPI_TYPE_INTEGER) { > + ret = -EINVAL; > + goto out; > + } > + > + ret = obj->integer.value; > + if (ret) > + ret = -EINVAL; > + > +out: > + ACPI_FREE(obj); > + > + kfree(tmp); Remove the newline between ACPI_FREE and kfree. > + > + return ret; > +} > + > +/** > + * acpi_amd_wbrf_add_remove - add or remove the frequency band the device is using > + * > + * @dev: device pointer > + * @action: remove or add the frequency band into bios > + * @in: input structure containing the frequency band the device is using > + * > + * Broadcast to other consumers the frequency band the device starts > + * to use. Underneath the surface the information is cached into an > + * internal buffer first. Then a notification is sent to all those > + * registered consumers. So then they can retrieve that buffer to > + * know the latest active frequency bands. Consumers that haven't > + * yet been registered can retrieve the information from the cache > + * when they register. > + * > + * Return: > + * 0 for success add/remove wifi frequency band. > + * Returns a negative error code for failure. > + */ > +int acpi_amd_wbrf_add_remove(struct device *dev, uint8_t action, > + struct wbrf_ranges_in_out *in) > +{ > + struct acpi_device *adev = ACPI_COMPANION(dev); > + int ret; > + > + if (!adev) > + return -ENODEV; To make this much easier to read, put the assignment right before it's error handling, like this (it's 1 line more but much easier to follow): adev = ACPI_COMPANION(dev); if (!adev) return -ENODEV; > + > + ret = wbrf_record(adev, action, in); > + if (ret) > + return ret; > + > + blocking_notifier_call_chain(&wbrf_chain_head, > + WBRF_CHANGED, > + NULL); > + > + return 0; > +} > +EXPORT_SYMBOL_GPL(acpi_amd_wbrf_add_remove); > + > +static bool acpi_amd_wbrf_supported_system(void) > +{ > + acpi_status status; > + acpi_handle handle; > + > + status = acpi_get_handle(NULL, ACPI_AMD_WBRF_METHOD, &handle); > + > + return ACPI_SUCCESS(status); > +} > + > +/** > + * acpi_amd_wbrf_supported_producer - determine if the WBRF can be enabled > + * for the device as a producer > + * > + * @dev: device pointer > + * > + * Check if the platform equipped with necessary implementations to > + * support WBRF for the device as a producer. > + * > + * Return: > + * true if WBRF is supported, otherwise returns false > + */ > +bool acpi_amd_wbrf_supported_producer(struct device *dev) > +{ > + struct acpi_device *adev = ACPI_COMPANION(dev); > + > + if (!adev) > + return false; Ditto. > + > + if (!acpi_amd_wbrf_supported_system()) > + return false; > + > + > + return acpi_check_dsm(adev->handle, &wifi_acpi_dsm_guid, > + WBRF_REVISION, > + BIT(WBRF_RECORD)); > +} > +EXPORT_SYMBOL_GPL(acpi_amd_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_FAILURE(ret)) > + return NULL; > + > + return buf.pointer; > +} > + > +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) > + return true; > + > + return false; You can directly return the condition's value, no need to wrap it into if. > +} > + > +/** > + * acpi_amd_wbrf_supported_consumer - determine if the WBRF can be enabled > + * for the device as a consumer > + * > + * @dev: device pointer > + * > + * Determine if the platform equipped with necessary implementations to > + * support WBRF for the device as a consumer. > + * > + * Return: > + * true if WBRF is supported, otherwise returns false. > + */ > +bool acpi_amd_wbrf_supported_consumer(struct device *dev) > +{ > + struct acpi_device *adev = ACPI_COMPANION(dev); > + > + if (!adev) > + return false; Group call + its error handling together. > + > + if (!acpi_amd_wbrf_supported_system()) > + return false; > + > + return check_acpi_wbrf(adev->handle, > + WBRF_REVISION, > + BIT(WBRF_RETRIEVE)); Fits one line. > +} > +EXPORT_SYMBOL_GPL(acpi_amd_wbrf_supported_consumer); > + > +/** > + * amd_wbrf_retrieve_freq_band - retrieve current active frequency > + * bands > + * > + * @dev: device pointer > + * @out: output structure containing all the active frequency bands > + * > + * Retrieve the current active frequency bands which were broadcasted > + * by other producers. The consumer who calls this API should take > + * proper actions if any of the frequency band may cause RFI with its > + * own frequency band used. > + * > + * Return: > + * 0 for getting wifi freq band successfully. > + * Returns a negative error code for failure. > + */ > +int amd_wbrf_retrieve_freq_band(struct device *dev, > + struct wbrf_ranges_in_out *out) > +{ > + struct acpi_device *adev = ACPI_COMPANION(dev); > + struct amd_wbrf_ranges_out acpi_out = {0}; > + union acpi_object *obj; > + int ret = 0; > + > + if (!adev) > + return -ENODEV; > + > + obj = acpi_evaluate_wbrf(adev->handle, > + WBRF_REVISION, > + WBRF_RETRIEVE); One line. I'm now very confused what those constants actually mean, since you seem to sometimes use them with BIT() and sometimes not. How can I know while reviewing each is done correctly? The only difference I can quickly pick up is "func" vs "funcs" in the argument name given to the function (which of course lacked documentation what it expects to be given to it)?!? > + 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) { One line. Use in_range(). > + dev_err(dev, "Wrong sized WBRT information"); > + ret = -EINVAL; > + goto out; > + } > + 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)); > + > +out: > + ACPI_FREE(obj); > + > + return ret; > +} > +EXPORT_SYMBOL_GPL(amd_wbrf_retrieve_freq_band); > + > +/** > + * amd_wbrf_register_notifier - register for notifications of frequency > + * band update > + * > + * @nb: driver notifier block > + * > + * The consumer should register itself via this API so that it can get > + * notified on the frequency band updates from other producers. > + * > + * Return: > + * 0 for registering a consumer driver successfully. > + * Returns a negative error code for failure. > + */ > +int amd_wbrf_register_notifier(struct notifier_block *nb) > +{ > + return blocking_notifier_chain_register(&wbrf_chain_head, nb); > +} > +EXPORT_SYMBOL_GPL(amd_wbrf_register_notifier); > + > +/** > + * amd_wbrf_unregister_notifier - unregister for notifications of > + * frequency band update > + * > + * @nb: driver notifier block > + * > + * The consumer should call this API when it is longer interested with > + * the frequency band updates from other producers. Usually, this should > + * be performed during driver cleanup. > + * > + * Return: > + * 0 for unregistering a consumer driver. > + * Returns a negative error code for failure. > + */ > +int amd_wbrf_unregister_notifier(struct notifier_block *nb) > +{ > + return blocking_notifier_chain_unregister(&wbrf_chain_head, nb); > +} > +EXPORT_SYMBOL_GPL(amd_wbrf_unregister_notifier); > diff --git a/include/linux/acpi_amd_wbrf.h b/include/linux/acpi_amd_wbrf.h > new file mode 100644 > index 000000000000..298779807312 > --- /dev/null > +++ b/include/linux/acpi_amd_wbrf.h > @@ -0,0 +1,101 @@ > +/* 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/device.h> > +#include <linux/notifier.h> > + > +/* > + * The maximum number of frequency band ranges > + */ No need to use multi-line comment. > +#define MAX_NUM_OF_WBRF_RANGES 11 > + > +/* Record actions */ > +#define WBRF_RECORD_ADD 0x0 > +#define WBRF_RECORD_REMOVE 0x1 > + > +/* > + * A freq_band_range is defined as a wifi frequency band with start > + * and end frequency point specified(in Hz). And a valid range should Lacking space. > + * have its start and end frequency point filled with non-zero values. > + * Meanwhile, the maximum number of wbrf ranges is limited as > + * `MAX_NUM_OF_WBRF_RANGES`. Use kerneldoc compatible syntax %MAX_NUM_OF_WBRF_RANGES instead (no need to mark it). To me it seems with small effort, you could convert these into proper kerneldoc for both this and the next struct... > + */ > + > +struct freq_band_range { > + u64 start; > + u64 end; > +}; > + > +struct wbrf_ranges_in_out { > + u64 num_of_ranges; > + struct freq_band_range band_list[MAX_NUM_OF_WBRF_RANGES]; > +}; > + > +/* > + * The notification types for the consumers are defined as below. > + * The consumers may need to take different actions in response to > + * different notifications. > + * WBRF_CHANGED: there was some frequency band updates. The consumers > + * should retrieve the latest active frequency bands. Make formatting compatible with kerneldoc. > + */ > +enum wbrf_notifier_actions { > + WBRF_CHANGED, > +}; > + > +#if IS_ENABLED(CONFIG_AMD_WBRF) > +bool acpi_amd_wbrf_supported_producer(struct device *dev); > +int acpi_amd_wbrf_add_remove(struct device *dev, uint8_t action, > + struct wbrf_ranges_in_out *in); Fix alignment. > +bool acpi_amd_wbrf_supported_consumer(struct device *dev); > +int amd_wbrf_retrieve_freq_band(struct device *dev, > + struct wbrf_ranges_in_out *out); Fix alignment. Optionally, you could put these definitions on a single lines since they're <100 chars so that they'd have better greppablity. > +int amd_wbrf_register_notifier(struct notifier_block *nb); > +int amd_wbrf_unregister_notifier(struct notifier_block *nb); > +#else > +static inline > +bool acpi_amd_wbrf_supported_consumer(struct device *dev) > +{ > + return false; > +} > +static inline > +int acpi_amd_wbrf_remove_exclusion(struct device *dev, > + struct wbrf_ranges_in_out *in) > +{ > + return -ENODEV; > +} > +static inline > +int acpi_amd_wbrf_add_exclusion(struct device *dev, > + struct wbrf_ranges_in_out *in) > +{ > + return -ENODEV; > +} > +static inline > +bool acpi_amd_wbrf_supported_producer(struct device *dev) > +{ > + return false; > +} > +static inline > +int amd_wbrf_retrieve_freq_band(struct device *dev, > + struct wbrf_ranges_in_out *out) Another case of inconsistent alignment.
Hi, On 10/17/23 04:53, Ma Jun wrote: > Due to electrical and mechanical constraints in certain platform designs > there may be likely interference of relatively high-powered harmonics of > the (G-)DDR memory clocks with local radio module frequency bands used > by Wifi 6/6e/7. > > To mitigate this, AMD has introduced a mechanism that devices can use to > notify active use of particular frequencies so that other devices can make > relative internal adjustments as necessary to avoid this resonance. > > Co-Developed-by: Evan Quan <quanliangl@hotmail.com> > Signed-off-by: Evan Quan <quanliangl@hotmail.com> > Signed-off-by: Ma Jun <Jun.Ma2@amd.com> <snip> > +bool acpi_amd_wbrf_supported_producer(struct device *dev) > +{ > + struct acpi_device *adev = ACPI_COMPANION(dev); > + > + if (!adev) > + return false; > + > + if (!acpi_amd_wbrf_supported_system()) > + return false; > + > + > + return acpi_check_dsm(adev->handle, &wifi_acpi_dsm_guid, > + WBRF_REVISION, > + BIT(WBRF_RECORD)); > +} > +EXPORT_SYMBOL_GPL(acpi_amd_wbrf_supported_producer); So until here you use acpi_dsm methods (1), which matches with patch 1/9 which says that both producers and consumers use a _DSM for WBRF. 1) With the exception of the weird acpi_amd_wbrf_supported_system() helper. > +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_FAILURE(ret)) > + return NULL; > + > + return buf.pointer; > +} But now all of a sudden you start calling a WBRF method directly instead of calling a _DSM by GUID, which seems to be intended for consumers. This contradicts with the documentation which says that consumers also use the _DSM. And this looks a lot like acpi_evaluate_dsm and ... (continued below) > + > +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) > + return true; > + > + return false; > +} This looks exactly like acpi_check_dsm(). > + > +/** > + * acpi_amd_wbrf_supported_consumer - determine if the WBRF can be enabled > + * for the device as a consumer > + * > + * @dev: device pointer > + * > + * Determine if the platform equipped with necessary implementations to > + * support WBRF for the device as a consumer. > + * > + * Return: > + * true if WBRF is supported, otherwise returns false. > + */ > +bool acpi_amd_wbrf_supported_consumer(struct device *dev) > +{ > + struct acpi_device *adev = ACPI_COMPANION(dev); > + > + if (!adev) > + return false; > + > + if (!acpi_amd_wbrf_supported_system()) > + return false; > + > + return check_acpi_wbrf(adev->handle, > + WBRF_REVISION, > + BIT(WBRF_RETRIEVE)); > +} > +EXPORT_SYMBOL_GPL(acpi_amd_wbrf_supported_consumer); So I would expect this to just use acpi_check_dsm like is done for the producers. > + > +/** > + * amd_wbrf_retrieve_freq_band - retrieve current active frequency > + * bands > + * > + * @dev: device pointer > + * @out: output structure containing all the active frequency bands > + * > + * Retrieve the current active frequency bands which were broadcasted > + * by other producers. The consumer who calls this API should take > + * proper actions if any of the frequency band may cause RFI with its > + * own frequency band used. > + * > + * Return: > + * 0 for getting wifi freq band successfully. > + * Returns a negative error code for failure. > + */ > +int amd_wbrf_retrieve_freq_band(struct device *dev, > + struct wbrf_ranges_in_out *out) > +{ > + struct acpi_device *adev = ACPI_COMPANION(dev); > + struct amd_wbrf_ranges_out acpi_out = {0}; > + union acpi_object *obj; > + int ret = 0; > + > + if (!adev) > + return -ENODEV; > + > + obj = acpi_evaluate_wbrf(adev->handle, > + WBRF_REVISION, > + WBRF_RETRIEVE); > + if (!obj) > + return -EINVAL; And I would expect this to use acpi_evaluate_dsm(), or preferably if possible acpi_evaluate_dsm_typed(). Is there any reason why the code is directly calling a method called WBRF here instead of going through the _DSM method ? And if there is such a reason then please update the documentation to say so, instead of having the docs clam that consumers also use the _DSM method. Regards, Hans
diff --git a/drivers/platform/x86/amd/Kconfig b/drivers/platform/x86/amd/Kconfig index d9685aef0887..fa5a978a2d22 100644 --- a/drivers/platform/x86/amd/Kconfig +++ b/drivers/platform/x86/amd/Kconfig @@ -32,3 +32,18 @@ config AMD_HSMP If you choose to compile this driver as a module the module will be called amd_hsmp. + +config AMD_WBRF + bool "AMD Wifi RF Band mitigations (WBRF)" + depends on ACPI + default n + help + WBRF(Wifi Band RFI mitigation) mechanism allows Wifi drivers + to notify the frequencies they are using so that other hardware + can be reconfigured to avoid harmonic conflicts. + + AMD provides an ACPI based mechanism to support WBRF on platform with + appropriate underlying support. + + This mechanism will only be activated on platforms that advertise a + need for it. diff --git a/drivers/platform/x86/amd/Makefile b/drivers/platform/x86/amd/Makefile index 65732f0a3913..62b98b048b17 100644 --- a/drivers/platform/x86/amd/Makefile +++ b/drivers/platform/x86/amd/Makefile @@ -9,3 +9,4 @@ obj-$(CONFIG_AMD_PMC) += amd-pmc.o amd_hsmp-y := hsmp.o obj-$(CONFIG_AMD_HSMP) += amd_hsmp.o obj-$(CONFIG_AMD_PMF) += pmf/ +obj-$(CONFIG_AMD_WBRF) += wbrf.o diff --git a/drivers/platform/x86/amd/wbrf.c b/drivers/platform/x86/amd/wbrf.c new file mode 100644 index 000000000000..fb414564f576 --- /dev/null +++ b/drivers/platform/x86/amd/wbrf.c @@ -0,0 +1,402 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Wifi Frequency Band Manage Interface + * Copyright (C) 2023 Advanced Micro Devices + */ + +#include <linux/acpi.h> +#include <linux/acpi_amd_wbrf.h> + +#define ACPI_AMD_WBRF_METHOD "\\WBRF" + +/* + * Functions bit vector for WBRF method + * + * Bit 0: WBRF supported. + * Bit 1: Function 1 (Add / Remove frequency) is supported. + * Bit 2: Function 2 (Get frequency list) is supported. + */ +#define WBRF_ENABLED 0x0 +#define WBRF_RECORD 0x1 +#define WBRF_RETRIEVE 0x2 + +#define WBRF_REVISION 0x1 + +/* + * The data structure used for WBRF_RETRIEVE is not naturally aligned. + * And unfortunately the design has been settled down. + */ +struct amd_wbrf_ranges_out { + u32 num_of_ranges; + struct freq_band_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); + +/* + * Used to notify consumer (amdgpu driver currently) about + * the wifi frequency is change. + */ +static BLOCKING_NOTIFIER_HEAD(wbrf_chain_head); + +static int wbrf_record(struct acpi_device *adev, uint8_t action, + struct wbrf_ranges_in_out *in) +{ + union acpi_object argv4; + union acpi_object *tmp; + union acpi_object *obj; + u32 num_of_ranges = 0; + u32 num_of_elements; + u32 arg_idx = 0; + u32 loop_idx; + int ret; + + if (!in) + return -EINVAL; + + /* + * The num_of_ranges value in the "in" object supplied by + * the caller is required to be equal to the number of + * entries in the band_list array in there. + */ + 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++; + + if (num_of_ranges != in->num_of_ranges) + return -EINVAL; + + /* + * Every input frequency band comes with two end points(start/end) + * and each 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 + 2; + + 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; + + /* save the number of ranges*/ + tmp[0].integer.type = ACPI_TYPE_INTEGER; + tmp[0].integer.value = num_of_ranges; + + /* save the action(WBRF_RECORD_ADD/REMOVE/RETRIEVE) */ + tmp[1].integer.type = ACPI_TYPE_INTEGER; + tmp[1].integer.value = action; + + arg_idx = 2; + 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; + } + + obj = acpi_evaluate_dsm(adev->handle, &wifi_acpi_dsm_guid, + WBRF_REVISION, WBRF_RECORD, &argv4); + + if (!obj) + return -EINVAL; + + if (obj->type != ACPI_TYPE_INTEGER) { + ret = -EINVAL; + goto out; + } + + ret = obj->integer.value; + if (ret) + ret = -EINVAL; + +out: + ACPI_FREE(obj); + + kfree(tmp); + + return ret; +} + +/** + * acpi_amd_wbrf_add_remove - add or remove the frequency band the device is using + * + * @dev: device pointer + * @action: remove or add the frequency band into bios + * @in: input structure containing the frequency band the device is using + * + * Broadcast to other consumers the frequency band the device starts + * to use. Underneath the surface the information is cached into an + * internal buffer first. Then a notification is sent to all those + * registered consumers. So then they can retrieve that buffer to + * know the latest active frequency bands. Consumers that haven't + * yet been registered can retrieve the information from the cache + * when they register. + * + * Return: + * 0 for success add/remove wifi frequency band. + * Returns a negative error code for failure. + */ +int acpi_amd_wbrf_add_remove(struct device *dev, uint8_t action, + struct wbrf_ranges_in_out *in) +{ + struct acpi_device *adev = ACPI_COMPANION(dev); + int ret; + + if (!adev) + return -ENODEV; + + ret = wbrf_record(adev, action, in); + if (ret) + return ret; + + blocking_notifier_call_chain(&wbrf_chain_head, + WBRF_CHANGED, + NULL); + + return 0; +} +EXPORT_SYMBOL_GPL(acpi_amd_wbrf_add_remove); + +static bool acpi_amd_wbrf_supported_system(void) +{ + acpi_status status; + acpi_handle handle; + + status = acpi_get_handle(NULL, ACPI_AMD_WBRF_METHOD, &handle); + + return ACPI_SUCCESS(status); +} + +/** + * acpi_amd_wbrf_supported_producer - determine if the WBRF can be enabled + * for the device as a producer + * + * @dev: device pointer + * + * Check if the platform equipped with necessary implementations to + * support WBRF for the device as a producer. + * + * Return: + * true if WBRF is supported, otherwise returns false + */ +bool acpi_amd_wbrf_supported_producer(struct device *dev) +{ + struct acpi_device *adev = ACPI_COMPANION(dev); + + if (!adev) + return false; + + if (!acpi_amd_wbrf_supported_system()) + return false; + + + return acpi_check_dsm(adev->handle, &wifi_acpi_dsm_guid, + WBRF_REVISION, + BIT(WBRF_RECORD)); +} +EXPORT_SYMBOL_GPL(acpi_amd_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_FAILURE(ret)) + return NULL; + + return buf.pointer; +} + +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) + return true; + + return false; +} + +/** + * acpi_amd_wbrf_supported_consumer - determine if the WBRF can be enabled + * for the device as a consumer + * + * @dev: device pointer + * + * Determine if the platform equipped with necessary implementations to + * support WBRF for the device as a consumer. + * + * Return: + * true if WBRF is supported, otherwise returns false. + */ +bool acpi_amd_wbrf_supported_consumer(struct device *dev) +{ + struct acpi_device *adev = ACPI_COMPANION(dev); + + if (!adev) + return false; + + if (!acpi_amd_wbrf_supported_system()) + return false; + + return check_acpi_wbrf(adev->handle, + WBRF_REVISION, + BIT(WBRF_RETRIEVE)); +} +EXPORT_SYMBOL_GPL(acpi_amd_wbrf_supported_consumer); + +/** + * amd_wbrf_retrieve_freq_band - retrieve current active frequency + * bands + * + * @dev: device pointer + * @out: output structure containing all the active frequency bands + * + * Retrieve the current active frequency bands which were broadcasted + * by other producers. The consumer who calls this API should take + * proper actions if any of the frequency band may cause RFI with its + * own frequency band used. + * + * Return: + * 0 for getting wifi freq band successfully. + * Returns a negative error code for failure. + */ +int amd_wbrf_retrieve_freq_band(struct device *dev, + struct wbrf_ranges_in_out *out) +{ + struct acpi_device *adev = ACPI_COMPANION(dev); + struct amd_wbrf_ranges_out acpi_out = {0}; + union acpi_object *obj; + int ret = 0; + + 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, "Wrong sized WBRT information"); + ret = -EINVAL; + goto out; + } + 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)); + +out: + ACPI_FREE(obj); + + return ret; +} +EXPORT_SYMBOL_GPL(amd_wbrf_retrieve_freq_band); + +/** + * amd_wbrf_register_notifier - register for notifications of frequency + * band update + * + * @nb: driver notifier block + * + * The consumer should register itself via this API so that it can get + * notified on the frequency band updates from other producers. + * + * Return: + * 0 for registering a consumer driver successfully. + * Returns a negative error code for failure. + */ +int amd_wbrf_register_notifier(struct notifier_block *nb) +{ + return blocking_notifier_chain_register(&wbrf_chain_head, nb); +} +EXPORT_SYMBOL_GPL(amd_wbrf_register_notifier); + +/** + * amd_wbrf_unregister_notifier - unregister for notifications of + * frequency band update + * + * @nb: driver notifier block + * + * The consumer should call this API when it is longer interested with + * the frequency band updates from other producers. Usually, this should + * be performed during driver cleanup. + * + * Return: + * 0 for unregistering a consumer driver. + * Returns a negative error code for failure. + */ +int amd_wbrf_unregister_notifier(struct notifier_block *nb) +{ + return blocking_notifier_chain_unregister(&wbrf_chain_head, nb); +} +EXPORT_SYMBOL_GPL(amd_wbrf_unregister_notifier); diff --git a/include/linux/acpi_amd_wbrf.h b/include/linux/acpi_amd_wbrf.h new file mode 100644 index 000000000000..298779807312 --- /dev/null +++ b/include/linux/acpi_amd_wbrf.h @@ -0,0 +1,101 @@ +/* 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/device.h> +#include <linux/notifier.h> + +/* + * The maximum number of frequency band ranges + */ +#define MAX_NUM_OF_WBRF_RANGES 11 + +/* Record actions */ +#define WBRF_RECORD_ADD 0x0 +#define WBRF_RECORD_REMOVE 0x1 + +/* + * A freq_band_range is defined as a wifi frequency band with start + * and end frequency point specified(in Hz). And a valid range should + * have its start and end frequency point filled with non-zero values. + * Meanwhile, the maximum number of wbrf ranges is limited as + * `MAX_NUM_OF_WBRF_RANGES`. + */ + +struct freq_band_range { + u64 start; + u64 end; +}; + +struct wbrf_ranges_in_out { + u64 num_of_ranges; + struct freq_band_range band_list[MAX_NUM_OF_WBRF_RANGES]; +}; + +/* + * The notification types for the consumers are defined as below. + * The consumers may need to take different actions in response to + * different notifications. + * WBRF_CHANGED: there was some frequency band updates. The consumers + * should retrieve the latest active frequency bands. + */ +enum wbrf_notifier_actions { + WBRF_CHANGED, +}; + +#if IS_ENABLED(CONFIG_AMD_WBRF) +bool acpi_amd_wbrf_supported_producer(struct device *dev); +int acpi_amd_wbrf_add_remove(struct device *dev, uint8_t action, + struct wbrf_ranges_in_out *in); +bool acpi_amd_wbrf_supported_consumer(struct device *dev); +int amd_wbrf_retrieve_freq_band(struct device *dev, + struct wbrf_ranges_in_out *out); +int amd_wbrf_register_notifier(struct notifier_block *nb); +int amd_wbrf_unregister_notifier(struct notifier_block *nb); +#else +static inline +bool acpi_amd_wbrf_supported_consumer(struct device *dev) +{ + return false; +} +static inline +int acpi_amd_wbrf_remove_exclusion(struct device *dev, + struct wbrf_ranges_in_out *in) +{ + return -ENODEV; +} +static inline +int acpi_amd_wbrf_add_exclusion(struct device *dev, + struct wbrf_ranges_in_out *in) +{ + return -ENODEV; +} +static inline +bool acpi_amd_wbrf_supported_producer(struct device *dev) +{ + return false; +} +static inline +int amd_wbrf_retrieve_freq_band(struct device *dev, + struct wbrf_ranges_in_out *out) +{ + return -ENODEV; +} +static inline +int amd_wbrf_register_notifier(struct notifier_block *nb) +{ + return -ENODEV; +} +static inline +int amd_wbrf_unregister_notifier(struct notifier_block *nb) +{ + return -ENODEV; +} +#endif /* CONFIG_AMD_WBRF */ + +#endif /* _ACPI_AMD_WBRF_H */