arm64/boot: Disable trapping of PMZR_EL0 writes to EL2grafted

__init_el2_fgt2() writes one mask to both HDFGRTR2_EL2 and HDFGWTR2_EL2.
PMZR_EL0 is write-only, so its trap bit, nPMZR_EL0, exists only in
HDFGWTR2_EL2 and is therefore never set: a PMZR_EL0 write from the host
traps to EL2, where the nVHE hypervisor has no handler and BUG()s. The
kernel never writes PMZR_EL0, but kernel.perf_user_access=1 has the PMU
driver set PMUSERENR_EL0.UEN for a task with a user-read event, so a
write from EL0 reaches the trap and takes the host down without a panic
message.

Accumulate the HDFGWTR2_EL2 bits separately, as __init_el2_fgt() already
does for HDFGWTR_EL2, and set nPMZR_EL0 with the other FEAT_PMUv3p9
bits.

Fixes: 858c7bfcb35e1 ("arm64/boot: Enable EL2 requirements for FEAT_PMUv3p9")
Cc: stable@vger.kernel.org
Signed-off-by: Fuad Tabba <fuad.tabba@linux.dev>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Oliver Upton <oupton@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>

1 files changed, 63 insertions, 0 deletions

diff --git a/include/media/media-dev-allocator.h b/include/media/media-dev-allocator.h
new file mode 100644
index 000000000..2ab54d426
--- /dev/null
+++ b/include/media/media-dev-allocator.h
@@ -0,0 +1,63 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * media-dev-allocator.h - Media Controller Device Allocator API
+ *
+ * Copyright (c) 2019 Shuah Khan <shuah@kernel.org>
+ *
+ * Credits: Suggested by Laurent Pinchart <laurent.pinchart@ideasonboard.com>
+ */
+
+/*
+ * This file adds a global ref-counted Media Controller Device Instance API.
+ * A system wide global media device list is managed and each media device
+ * includes a kref count. The last put on the media device releases the media
+ * device instance.
+ */
+
+#ifndef _MEDIA_DEV_ALLOCATOR_H
+#define _MEDIA_DEV_ALLOCATOR_H
+
+struct usb_device;
+
+#if defined(CONFIG_MEDIA_CONTROLLER) && IS_ENABLED(CONFIG_USB)
+/**
+ * media_device_usb_allocate() - Allocate and return struct &media device
+ *
+ * @udev:		struct &usb_device pointer
+ * @module_name:	should be filled with %KBUILD_MODNAME
+ * @owner:		struct module pointer %THIS_MODULE for the driver.
+ *			%THIS_MODULE is null for a built-in driver.
+ *			It is safe even when %THIS_MODULE is null.
+ *
+ * This interface should be called to allocate a Media Device when multiple
+ * drivers share usb_device and the media device. This interface allocates
+ * &media_device structure and calls media_device_usb_init() to initialize
+ * it.
+ *
+ */
+struct media_device *media_device_usb_allocate(struct usb_device *udev,
+					       const char *module_name,
+					       struct module *owner);
+/**
+ * media_device_delete() - Release media device. Calls kref_put().
+ *
+ * @mdev:		struct &media_device pointer
+ * @module_name:	should be filled with %KBUILD_MODNAME
+ * @owner:		struct module pointer %THIS_MODULE for the driver.
+ *			%THIS_MODULE is null for a built-in driver.
+ *			It is safe even when %THIS_MODULE is null.
+ *
+ * This interface should be called to put Media Device Instance kref.
+ */
+void media_device_delete(struct media_device *mdev, const char *module_name,
+			 struct module *owner);
+#else
+static inline struct media_device *media_device_usb_allocate(
+			struct usb_device *udev, const char *module_name,
+			struct module *owner)
+			{ return NULL; }
+static inline void media_device_delete(
+			struct media_device *mdev, const char *module_name,
+			struct module *owner) { }
+#endif /* CONFIG_MEDIA_CONTROLLER && CONFIG_USB */
+#endif /* _MEDIA_DEV_ALLOCATOR_H */