virtualization/linux-yocto: Backport virtio SCMI driver.

This patch series is a "RFC v2" implementation of a driver for
virtio SCMI device [1].

[1]: https://github.com/oasis-tcs/virtio-spec/blob/master/virtio-scmi.tex

Bug-AGL: SPEC-3865
Upstream-Status: Submitted [https://lore.kernel.org/linux-arm-kernel/20201105212116.411422-1-peter.hilber@opensynergy.com/]
Signed-off-by: Andriy Tryshnivskyy <andriy.tryshnivskyy@opensynergy.com>
Change-Id: I653cb44769232ae5434bd54169910fd0518f1db8

1 files changed, 119 insertions, 0 deletions

diff --git a/meta-egvirt/recipes-kernel/linux/linux-yocto/virtio-scmi/0001-firmware-arm_scmi-smccc-mailbox-Make-shmem-based-tra.patch b/meta-egvirt/recipes-kernel/linux/linux-yocto/virtio-scmi/0001-firmware-arm_scmi-smccc-mailbox-Make-shmem-based-tra.patch
new file mode 100644
index 00000000..3d9d0fdb
--- /dev/null
+++ b/meta-egvirt/recipes-kernel/linux/linux-yocto/virtio-scmi/0001-firmware-arm_scmi-smccc-mailbox-Make-shmem-based-tra.patch
@@ -0,0 +1,119 @@
+From 36269e8f5fa1f33a793c472935affe3039c052bd Mon Sep 17 00:00:00 2001
+From: Igor Skalkin <igor.skalkin@opensynergy.com>
+Date: Thu, 5 Nov 2020 22:21:07 +0100
+Subject: [PATCH] firmware: arm_scmi, smccc, mailbox: Make shmem based
+ transports optional
+
+Upon adding the virtio transport in this patch series, SCMI will also
+work without shared memory based transports. Also, the mailbox transport
+may not be needed if the smc transport is used.
+
+- Compile shmem.c only if a shmem based transport is available.
+
+- Remove hard dependency of SCMI on mailbox.
+
+Co-developed-by: Peter Hilber <peter.hilber@opensynergy.com>
+Signed-off-by: Peter Hilber <peter.hilber@opensynergy.com>
+Signed-off-by: Igor Skalkin <igor.skalkin@opensynergy.com>
+Signed-off-by: Vasyl Vavrychuk <vasyl.vavrychuk@opensynergy.com>
+---
+ drivers/firmware/Kconfig           | 9 ++++++++-
+ drivers/firmware/arm_scmi/Makefile | 2 +-
+ drivers/firmware/arm_scmi/common.h | 2 ++
+ drivers/firmware/arm_scmi/driver.c | 2 ++
+ drivers/firmware/smccc/Kconfig     | 1 +
+ drivers/mailbox/Kconfig            | 1 +
+ 6 files changed, 15 insertions(+), 2 deletions(-)
+
+diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig
+index 3315e3c21586..30a85d38d0c0 100644
+--- a/drivers/firmware/Kconfig
++++ b/drivers/firmware/Kconfig
+@@ -9,7 +9,7 @@ menu "Firmware Drivers"
+ config ARM_SCMI_PROTOCOL
+ 	tristate "ARM System Control and Management Interface (SCMI) Message Protocol"
+ 	depends on ARM || ARM64 || COMPILE_TEST
+-	depends on MAILBOX
++	depends on ARM_SCMI_HAVE_SHMEM
+ 	help
+ 	  ARM System Control and Management Interface (SCMI) protocol is a
+ 	  set of operating system-independent software interfaces that are
+@@ -27,6 +27,13 @@ config ARM_SCMI_PROTOCOL
+ 	  This protocol library provides interface for all the client drivers
+ 	  making use of the features offered by the SCMI.
+ 
++config ARM_SCMI_HAVE_SHMEM
++	bool
++	default n
++	help
++	  This declares whether a shared memory based transport for SCMI is
++	  available.
++
+ config ARM_SCMI_POWER_DOMAIN
+ 	tristate "SCMI power domain driver"
+ 	depends on ARM_SCMI_PROTOCOL || (COMPILE_TEST && OF)
+diff --git a/drivers/firmware/arm_scmi/Makefile b/drivers/firmware/arm_scmi/Makefile
+index bc0d54f8e861..3cc7fa40a464 100644
+--- a/drivers/firmware/arm_scmi/Makefile
++++ b/drivers/firmware/arm_scmi/Makefile
+@@ -1,7 +1,7 @@
+ # SPDX-License-Identifier: GPL-2.0-only
+ scmi-bus-y = bus.o
+ scmi-driver-y = driver.o notify.o
+-scmi-transport-y = shmem.o
++scmi-transport-$(CONFIG_ARM_SCMI_HAVE_SHMEM) = shmem.o
+ scmi-transport-$(CONFIG_MAILBOX) += mailbox.o
+ scmi-transport-$(CONFIG_HAVE_ARM_SMCCC_DISCOVERY) += smc.o
+ scmi-protocols-y = base.o clock.o perf.o power.o reset.o sensors.o system.o
+diff --git a/drivers/firmware/arm_scmi/common.h b/drivers/firmware/arm_scmi/common.h
+index 65063fa948d4..aed192238177 100644
+--- a/drivers/firmware/arm_scmi/common.h
++++ b/drivers/firmware/arm_scmi/common.h
+@@ -242,7 +242,9 @@ struct scmi_desc {
+ 	int max_msg_size;
+ };
+ 
++#ifdef CONFIG_MAILBOX
+ extern const struct scmi_desc scmi_mailbox_desc;
++#endif
+ #ifdef CONFIG_HAVE_ARM_SMCCC
+ extern const struct scmi_desc scmi_smc_desc;
+ #endif
+diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
+index 6b2ce3f28f7b..7efbf66f117b 100644
+--- a/drivers/firmware/arm_scmi/driver.c
++++ b/drivers/firmware/arm_scmi/driver.c
+@@ -918,7 +918,9 @@ ATTRIBUTE_GROUPS(versions);
+ 
+ /* Each compatible listed below must have descriptor associated with it */
+ static const struct of_device_id scmi_of_match[] = {
++#ifdef CONFIG_MAILBOX
+ 	{ .compatible = "arm,scmi", .data = &scmi_mailbox_desc },
++#endif
+ #ifdef CONFIG_HAVE_ARM_SMCCC_DISCOVERY
+ 	{ .compatible = "arm,scmi-smc", .data = &scmi_smc_desc},
+ #endif
+diff --git a/drivers/firmware/smccc/Kconfig b/drivers/firmware/smccc/Kconfig
+index 15e7466179a6..69c4d6cabf62 100644
+--- a/drivers/firmware/smccc/Kconfig
++++ b/drivers/firmware/smccc/Kconfig
+@@ -9,6 +9,7 @@ config HAVE_ARM_SMCCC_DISCOVERY
+ 	bool
+ 	depends on ARM_PSCI_FW
+ 	default y
++	select ARM_SCMI_HAVE_SHMEM
+ 	help
+ 	 SMCCC v1.0 lacked discoverability and hence PSCI v1.0 was updated
+ 	 to add SMCCC discovery mechanism though the PSCI firmware
+diff --git a/drivers/mailbox/Kconfig b/drivers/mailbox/Kconfig
+index 05b1009e2820..5ffe1ab0c869 100644
+--- a/drivers/mailbox/Kconfig
++++ b/drivers/mailbox/Kconfig
+@@ -1,6 +1,7 @@
+ # SPDX-License-Identifier: GPL-2.0-only
+ menuconfig MAILBOX
+ 	bool "Mailbox Hardware Support"
++	select ARM_SCMI_HAVE_SHMEM
+ 	help
+ 	  Mailbox is a framework to control hardware communication between
+ 	  on-chip processors through queued messages and interrupt driven