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, 235 insertions, 0 deletions

diff --git a/Documentation/gpu/afbc.rst b/Documentation/gpu/afbc.rst
new file mode 100644
index 000000000..4d38dc49d
--- /dev/null
+++ b/Documentation/gpu/afbc.rst
@@ -0,0 +1,235 @@
+.. SPDX-License-Identifier: GPL-2.0+
+
+===================================
+ Arm Framebuffer Compression (AFBC)
+===================================
+
+AFBC is a proprietary lossless image compression protocol and format.
+It provides fine-grained random access and minimizes the amount of
+data transferred between IP blocks.
+
+AFBC can be enabled on drivers which support it via use of the AFBC
+format modifiers defined in drm_fourcc.h. See DRM_FORMAT_MOD_ARM_AFBC(*).
+
+All users of the AFBC modifiers must follow the usage guidelines laid
+out in this document, to ensure compatibility across different AFBC
+producers and consumers.
+
+Components and Ordering
+=======================
+
+AFBC streams can contain several components - where a component
+corresponds to a color channel (i.e. R, G, B, X, A, Y, Cb, Cr).
+The assignment of input/output color channels must be consistent
+between the encoder and the decoder for correct operation, otherwise
+the consumer will interpret the decoded data incorrectly.
+
+Furthermore, when the lossless colorspace transform is used
+(AFBC_FORMAT_MOD_YTR, which should be enabled for RGB buffers for
+maximum compression efficiency), the component order must be:
+
+ * Component 0: R
+ * Component 1: G
+ * Component 2: B
+
+The component ordering is communicated via the fourcc code in the
+fourcc:modifier pair. In general, component '0' is considered to
+reside in the least-significant bits of the corresponding linear
+format. For example, COMP(bits):
+
+ * DRM_FORMAT_ABGR8888
+
+   * Component 0: R(8)
+   * Component 1: G(8)
+   * Component 2: B(8)
+   * Component 3: A(8)
+
+ * DRM_FORMAT_BGR888
+
+   * Component 0: R(8)
+   * Component 1: G(8)
+   * Component 2: B(8)
+
+ * DRM_FORMAT_YUYV
+
+   * Component 0: Y(8)
+   * Component 1: Cb(8, 2x1 subsampled)
+   * Component 2: Cr(8, 2x1 subsampled)
+
+In AFBC, 'X' components are not treated any differently from any other
+component. Therefore, an AFBC buffer with fourcc DRM_FORMAT_XBGR8888
+encodes with 4 components, like so:
+
+ * DRM_FORMAT_XBGR8888
+
+   * Component 0: R(8)
+   * Component 1: G(8)
+   * Component 2: B(8)
+   * Component 3: X(8)
+
+Please note, however, that the inclusion of a "wasted" 'X' channel is
+bad for compression efficiency, and so it's recommended to avoid
+formats containing 'X' bits. If a fourth component is
+required/expected by the encoder/decoder, then it is recommended to
+instead use an equivalent format with alpha, setting all alpha bits to
+'1'. If there is no requirement for a fourth component, then a format
+which doesn't include alpha can be used, e.g. DRM_FORMAT_BGR888.
+
+Number of Planes
+================
+
+Formats which are typically multi-planar in linear layouts (e.g. YUV
+420), can be encoded into one, or multiple, AFBC planes. As with
+component order, the encoder and decoder must agree about the number
+of planes in order to correctly decode the buffer. The fourcc code is
+used to determine the number of encoded planes in an AFBC buffer,
+matching the number of planes for the linear (unmodified) format.
+Within each plane, the component ordering also follows the fourcc
+code:
+
+For example:
+
+ * DRM_FORMAT_YUYV: nplanes = 1
+
+   * Plane 0:
+
+     * Component 0: Y(8)
+     * Component 1: Cb(8, 2x1 subsampled)
+     * Component 2: Cr(8, 2x1 subsampled)
+
+ * DRM_FORMAT_NV12: nplanes = 2
+
+   * Plane 0:
+
+     * Component 0: Y(8)
+
+   * Plane 1:
+
+     * Component 0: Cb(8, 2x1 subsampled)
+     * Component 1: Cr(8, 2x1 subsampled)
+
+Cross-device interoperability
+=============================
+
+For maximum compatibility across devices, the table below defines
+canonical formats for use between AFBC-enabled devices. Formats which
+are listed here must be used exactly as specified when using the AFBC
+modifiers. Formats which are not listed should be avoided.
+
+.. flat-table:: AFBC formats
+
+   * - Fourcc code
+     - Description
+     - Planes/Components
+
+   * - DRM_FORMAT_ABGR2101010
+     - 10-bit per component RGB, with 2-bit alpha
+     - Plane 0: 4 components
+              * Component 0: R(10)
+              * Component 1: G(10)
+              * Component 2: B(10)
+              * Component 3: A(2)
+
+   * - DRM_FORMAT_ABGR8888
+     - 8-bit per component RGB, with 8-bit alpha
+     - Plane 0: 4 components
+              * Component 0: R(8)
+              * Component 1: G(8)
+              * Component 2: B(8)
+              * Component 3: A(8)
+
+   * - DRM_FORMAT_BGR888
+     - 8-bit per component RGB
+     - Plane 0: 3 components
+              * Component 0: R(8)
+              * Component 1: G(8)
+              * Component 2: B(8)
+
+   * - DRM_FORMAT_BGR565
+     - 5/6-bit per component RGB
+     - Plane 0: 3 components
+              * Component 0: R(5)
+              * Component 1: G(6)
+              * Component 2: B(5)
+
+   * - DRM_FORMAT_ABGR1555
+     - 5-bit per component RGB, with 1-bit alpha
+     - Plane 0: 4 components
+              * Component 0: R(5)
+              * Component 1: G(5)
+              * Component 2: B(5)
+              * Component 3: A(1)
+
+   * - DRM_FORMAT_VUY888
+     - 8-bit per component YCbCr 444, single plane
+     - Plane 0: 3 components
+              * Component 0: Y(8)
+              * Component 1: Cb(8)
+              * Component 2: Cr(8)
+
+   * - DRM_FORMAT_VUY101010
+     - 10-bit per component YCbCr 444, single plane
+     - Plane 0: 3 components
+              * Component 0: Y(10)
+              * Component 1: Cb(10)
+              * Component 2: Cr(10)
+
+   * - DRM_FORMAT_YUYV
+     - 8-bit per component YCbCr 422, single plane
+     - Plane 0: 3 components
+              * Component 0: Y(8)
+              * Component 1: Cb(8, 2x1 subsampled)
+              * Component 2: Cr(8, 2x1 subsampled)
+
+   * - DRM_FORMAT_NV16
+     - 8-bit per component YCbCr 422, two plane
+     - Plane 0: 1 component
+              * Component 0: Y(8)
+       Plane 1: 2 components
+              * Component 0: Cb(8, 2x1 subsampled)
+              * Component 1: Cr(8, 2x1 subsampled)
+
+   * - DRM_FORMAT_Y210
+     - 10-bit per component YCbCr 422, single plane
+     - Plane 0: 3 components
+              * Component 0: Y(10)
+              * Component 1: Cb(10, 2x1 subsampled)
+              * Component 2: Cr(10, 2x1 subsampled)
+
+   * - DRM_FORMAT_P210
+     - 10-bit per component YCbCr 422, two plane
+     - Plane 0: 1 component
+              * Component 0: Y(10)
+       Plane 1: 2 components
+              * Component 0: Cb(10, 2x1 subsampled)
+              * Component 1: Cr(10, 2x1 subsampled)
+
+   * - DRM_FORMAT_YUV420_8BIT
+     - 8-bit per component YCbCr 420, single plane
+     - Plane 0: 3 components
+              * Component 0: Y(8)
+              * Component 1: Cb(8, 2x2 subsampled)
+              * Component 2: Cr(8, 2x2 subsampled)
+
+   * - DRM_FORMAT_YUV420_10BIT
+     - 10-bit per component YCbCr 420, single plane
+     - Plane 0: 3 components
+              * Component 0: Y(10)
+              * Component 1: Cb(10, 2x2 subsampled)
+              * Component 2: Cr(10, 2x2 subsampled)
+
+   * - DRM_FORMAT_NV12
+     - 8-bit per component YCbCr 420, two plane
+     - Plane 0: 1 component
+              * Component 0: Y(8)
+       Plane 1: 2 components
+              * Component 0: Cb(8, 2x2 subsampled)
+              * Component 1: Cr(8, 2x2 subsampled)
+
+   * - DRM_FORMAT_P010
+     - 10-bit per component YCbCr 420, two plane
+     - Plane 0: 1 component
+              * Component 0: Y(10)
+       Plane 1: 2 components
+              * Component 0: Cb(10, 2x2 subsampled)
+              * Component 1: Cr(10, 2x2 subsampled)