Introduce Protection Domain Restart (PDR) Helpers

Qualcomm SoCs (starting with MSM8998) allow for multiple protection domains (PDs) to run on the same Q6 sub-system. This allows for services like AVS AUDIO to have their own separate address space and crash/recover without disrupting the other PDs running on the same Q6 ADSP. This patch series introduces pdr helper library and adds PD tracking functionality for "avs/audio" allowing apr services to register themselves asynchronously once the dependent PDs are up.

Userspace Links:
pd-mapper: https://github.com/andersson/pd-mapper/tree/json
diag-router: https://github.com/andersson/diag

Testing PDR with APR on SDM845 SoCs:
pd-mapper adspua.jsn &
diag-router &
send_data 75 37 03 144 00

V7:
* Address Bjorn's comments on exiting early in pdr_locator_work
* SERVREG_LOCATOR_UNKNOWN_SERVICE is no longer propagated to clients allowing for lookups to recover on restarting pd-mapper with the proper database.
* Non-recoverable SERVREG_LOCATOR_ERR errors are still communicated to the clients.

V6:
* Fix minor compilation error introduced in V5
* Pick up Rob's R-b

V5:
* Pick up Bjorn's R-b
* Service all pending lookup, notifier_register and notifier_remove requests.
* Propagate error from pdr_register_listener
* Remove notifier_init_complete flag workaround with the introduction of in-kernel ns.
* Remove depends-on in Kconfig and add module license.

V4:
* Drop handling db_rev_count error handling since it remains unused in upstream/downstream pd-mapper
* Fixup dt bindings and examples. [Rob]
* Dropping r-b from Bjorn/Srini for the dt bindings.
* Privatize pdr_service/pdr_handle. [Srini/Bjorn]
* Introduce notifier_init_complete to deal with cases where qmi_handle_net_reset is not enough to reset the port. This is to deal with cases where qrtr-ns starts after the adsp.
* Introduce per addr per pds to deal with multiple service_paths per pdr_handle.
* Uniformly rename servreg -> notifier, servloc -> locator. [Narendra]
* Drop pdr_servreg_link_create tracking the service_path tracks all pds associated with it. [Bjorn]
* Remove safe traversal for all cases where list is left unmodified. [Bjorn]
* Address review comments in the apr driver and add comments. [Bjorn]
* Other misc fixes. [Narendra/Bjorn]

V3:
* patches 2 and 3 remain unchanged.
* reset servloc_addr/servreg_addr.
* fixup the helpers to handle servloc_work/servreg_work asynchronously.
* fixup useage of list_lock across traversals, insertions and deletions.
* fixup the helpers to use a single lookup list.
* skip waiting for response on ind_ack send.
* introduce pdr_servreg_link_create to re-use existing qmi connection to servreg instances. This helps tracking PDs running on the same remote processor.
* have a per node curr_state in pdr_list_node to preserve all state updates during indack_cb.
* introduce additional servreg_service_state values to help the client distinguish between a fatal and non-fatal pdr_lookup errors.
* re-order pdr_handle_release sequence.
* fixup "!ind_msg->service_path returns true always" warning.
* fixup comments.

V2:
* fixup pd_status callback to return void.
* return 0 from pdr_get_domain_list on success.
* introduce status_lock to linearize the pd_status reported back to the clients.
* use the correct service name length across various string operations performed.
* service locator will now schedule the pending lookups registered when it comes up.
* other minor cleanups that Bjorn suggested.
* use pr_warn to indicate that the wait for service locator timed out.
* add Bjorn/Srini's "Reviewed-by" for the dt-bindings.

Sibi Sankar (3):
soc: qcom: Introduce Protection Domain Restart helpers
dt-bindings: soc: qcom: apr: Add protection domain bindings
soc: qcom: apr: Add avs/audio tracking functionality

 .../devicetree/bindings/soc/qcom/qcom,apr.txt |  50 ++
 drivers/soc/qcom/Kconfig                      |   5 +
 drivers/soc/qcom/Makefile                     |   1 +
 drivers/soc/qcom/apr.c                        | 123 ++-
 drivers/soc/qcom/pdr_interface.c              | 757 ++++++++++++++++++
 drivers/soc/qcom/pdr_internal.h               | 379 +++++++++
 include/linux/soc/qcom/apr.h                  |   1 +
 include/linux/soc/qcom/pdr.h                  |  29 +
 include/linux/soc/qcom/qmi.h                  |   1 +
 9 files changed, 1337 insertions(+), 9 deletions(-)
 create mode 100644 drivers/soc/qcom/pdr_interface.c
 create mode 100644 drivers/soc/qcom/pdr_internal.h
 create mode 100644 include/linux/soc/qcom/pdr.h

The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

Qualcomm SoCs (starting with MSM8998) allow for multiple protection domains to run on the same Q6 sub-system. This allows for services like ATH10K WLAN FW to have their own separate address space and crash/recover without disrupting the modem and other PDs running on the same sub-system. The PDR helpers introduces an abstraction that allows for tracking/controlling the life cycle of protection domains running on various Q6 sub-systems.

---

V7:
* Address Bjorn's comments on exiting early in pdr_locator_work
* SERVREG_LOCATOR_UNKNOWN_SERVICE is no longer propagated to clients allowing for lookups to recover on restarting pd-mapper with the proper database.
* Non-recoverable SERVREG_LOCATOR_ERR errors are still communicated to the clients.

V6:
* Fix minor compilation error introduceed in v5 while propagating error from pdr_register_listener

 drivers/soc/qcom/Kconfig         |   4 +
 drivers/soc/qcom/Makefile        |   1 +
 drivers/soc/qcom/pdr_interface.c | 757 +++++++++++++++++++++++++++++++
 drivers/soc/qcom/pdr_internal.h  | 379 ++++++++++++++++
 include/linux/soc/qcom/pdr.h     |  29 ++
 include/linux/soc/qcom/qmi.h     |   1 +
 6 files changed, 1171 insertions(+)
 create mode 100644 drivers/soc/qcom/pdr_interface.c
 create mode 100644 drivers/soc/qcom/pdr_internal.h
 create mode 100644 include/linux/soc/qcom/pdr.h

index 80aa8b6c56e0d..48501f0245b0a 100644
@@ -76,6 +76,10 @@ config QCOM_OCMEM
 	  requirements. This is typically used by the GPU, camera/video, and
 	  audio components on some Snapdragon SoCs.
 
+config QCOM_PDR_HELPERS
+	tristate
+	select QCOM_QMI_HELPERS
+
 config QCOM_PM
 	bool "Qualcomm Power Management"
 	depends on ARCH_QCOM && !ARM64

index 9fb35c8a495e1..5d6b83dc58e82 100644
@@ -7,6 +7,7 @@ obj-$(CONFIG_QCOM_GLINK_SSR) +=	glink_ssr.o
 obj-$(CONFIG_QCOM_GSBI)	+=	qcom_gsbi.o
 obj-$(CONFIG_QCOM_MDT_LOADER)	+= mdt_loader.o
 obj-$(CONFIG_QCOM_OCMEM)	+= ocmem.o
+obj-$(CONFIG_QCOM_PDR_HELPERS)	+= pdr_interface.o
 obj-$(CONFIG_QCOM_PM)	+=	spm.o
 obj-$(CONFIG_QCOM_QMI_HELPERS)	+= qmi_helpers.o
 qmi_helpers-y	+= qmi_encdec.o qmi_interface.o

new file mode 100644
index 0000000000000..83a8ea612e69a
@@ -0,0 +1,29 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __QCOM_PDR_HELPER__
+#define __QCOM_PDR_HELPER__
+
+#include <linux/soc/qcom/qmi.h>
+
+#define SERVREG_NAME_LENGTH	64
+
+struct pdr_service;
+struct pdr_handle;
+
+enum servreg_service_state {
+	SERVREG_LOCATOR_ERR = 0x1,
+	SERVREG_SERVICE_STATE_DOWN = 0x0FFFFFFF,
+	SERVREG_SERVICE_STATE_UP = 0x1FFFFFFF,
+	SERVREG_SERVICE_STATE_EARLY_DOWN = 0x2FFFFFFF,
+	SERVREG_SERVICE_STATE_UNINIT = 0x7FFFFFFF,
+};
+
+struct pdr_handle *pdr_handle_alloc(void (*status)(int state,
+						   char *service_path,
+						   void *priv), void *priv);
+struct pdr_service *pdr_add_lookup(struct pdr_handle *pdr,
+				   const char *service_name,
+				   const char *service_path);
+int pdr_restart_pd(struct pdr_handle *pdr, struct pdr_service *pds);
+void pdr_handle_release(struct pdr_handle *pdr);
+
+#endif

index 5efa2b67fa557..e712f94b89fcc 100644
@@ -88,6 +88,7 @@ struct qmi_elem_info {
 #define QMI_ERR_CLIENT_IDS_EXHAUSTED_V01	5
 #define QMI_ERR_INVALID_ID_V01			41
 #define QMI_ERR_ENCODING_V01			58
+#define QMI_ERR_DISABLED_V01                    69
 #define QMI_ERR_INCOMPATIBLE_STATE_V01		90
 #define QMI_ERR_NOT_SUPPORTED_V01		94
 

The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

Qualcomm SoCs (starting with MSM8998) allow for multiple protection domains (PDs) to run on the same Q6 sub-system. This allows for services like AVS AUDIO to have their own separate address space and crash/recover without disrupting the other PDs running on the same Q6 ADSP. Add "qcom,protection-domain" bindings to capture the dependencies between the APR service and the PD on which the apr service runs.

---

V7:
* No change

V6:
* Picked up Rob's R-b

 .../devicetree/bindings/soc/qcom/qcom,apr.txt | 50 +++++++++++++++++++
 1 file changed, 50 insertions(+)

index db501269f47b8..f8fa71f5d84ba 100644
@@ -45,6 +45,18 @@ by the individual bindings for the specific service
 			12 - Ultrasound stream manager.
 			13 - Listen stream manager.
 
+- qcom,protection-domain
+	Usage: optional
+	Value type: <stringlist>
+	Definition: Must list the protection domain service name and path
+		    that the particular apr service has a dependency on.
+	Possible values are :
+			"avs/audio", "msm/adsp/audio_pd".
+			"kernel/elf_loader", "msm/modem/wlan_pd".
+			"tms/servreg", "msm/adsp/audio_pd".
+			"tms/servreg", "msm/modem/wlan_pd".
+			"tms/servreg", "msm/slpi/sensor_pd".
+
 = EXAMPLE
 The following example represents a QDSP based sound card on a MSM8996 device
 which uses apr as communication between Apps and QDSP.

@@ -82,3 +94,41 @@ which uses apr as communication between Apps and QDSP.
 			...
 		};
 	};
+
+= EXAMPLE 2
+The following example represents a QDSP based sound card with protection domain
+dependencies specified. Here some of the apr services are dependent on services
+running on protection domain hosted on ADSP/SLPI remote processors while others
+have no such dependency.
+
+	apr {
+		compatible = "qcom,apr-v2";
+		qcom,glink-channels = "apr_audio_svc";
+		qcom,apr-domain = <APR_DOMAIN_ADSP>;
+
+		q6core {
+			compatible = "qcom,q6core";
+			reg = <APR_SVC_ADSP_CORE>;
+		};
+
+		q6afe: q6afe {
+			compatible = "qcom,q6afe";
+			reg = <APR_SVC_AFE>;
+			qcom,protection-domain = "avs/audio", "msm/adsp/audio_pd";
+			...
+		};
+
+		q6asm: q6asm {
+			compatible = "qcom,q6asm";
+			reg = <APR_SVC_ASM>;
+			qcom,protection-domain = "tms/servreg", "msm/slpi/sensor_pd";
+			...
+		};
+
+		q6adm: q6adm {
+			compatible = "qcom,q6adm";
+			reg = <APR_SVC_ADM>;
+			qcom,protection-domain = "avs/audio", "msm/adsp/audio_pd";
+			...
+		};
+	};

The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

Use PDR helper functions to track the protection domains that the apr services are dependent upon on SDM845 SoC, specifically the "avs/audio" service running on ADSP Q6.

---

V7:
* No change

 drivers/soc/qcom/Kconfig     |   1 +
 drivers/soc/qcom/apr.c       | 123 ++++++++++++++++++++++++++++++++---
 include/linux/soc/qcom/apr.h |   1 +
 3 files changed, 116 insertions(+), 9 deletions(-)

index 48501f0245b0a..9ac6b0072e8ce 100644
@@ -200,6 +200,7 @@ config QCOM_APR
 	tristate "Qualcomm APR Bus (Asynchronous Packet Router)"
 	depends on ARCH_QCOM || COMPILE_TEST
 	depends on RPMSG
+	select QCOM_PDR_HELPERS
 	help
 	  Enable APR IPC protocol support between
 	  application processor and QDSP6. APR is

index c5d52e2cb275f..7f0bc3cf4d610 100644
@@ -85,6 +85,7 @@ struct apr_device {
 	uint16_t	domain_id;
 	uint32_t	version;
 	char name[APR_NAME_SIZE];
+	const char *service_path;
 	spinlock_t	lock;
 	struct list_head node;
 };

The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project