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authorLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
committerLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
commit5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 (patch)
treecc5c2d0a898769fd59549594fedb3ee6f84e59a0 /drivers/gpu/drm/display/drm_dsc_helper.c
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Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted
Pull networking updates from Jakub Kicinski: "Core: - Add dedicated kmem_cache for typical/small skb->head, avoid having to access struct page at kfree time, and improve memory use. - Introduce sysctl to set default RPS configuration for new netdevs. - Define Netlink protocol specification format which can be used to describe messages used by each family and auto-generate parsers. Add tools for generating kernel data structures and uAPI headers. - Expose all net/core sysctls inside netns. - Remove 4s sleep in netpoll if carrier is instantly detected on boot. - Add configurable limit of MDB entries per port, and port-vlan. - Continue populating drop reasons throughout the stack. - Retire a handful of legacy Qdiscs and classifiers. Protocols: - Support IPv4 big TCP (TSO frames larger than 64kB). - Add IP_LOCAL_PORT_RANGE socket option, to control local port range on socket by socket basis. - Track and report in procfs number of MPTCP sockets used. - Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path manager. - IPv6: don't check net.ipv6.route.max_size and rely on garbage collection to free memory (similarly to IPv4). - Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986). - ICMP: add per-rate limit counters. - Add support for user scanning requests in ieee802154. - Remove static WEP support. - Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate reporting. - WiFi 7 EHT channel puncturing support (client & AP). BPF: - Add a rbtree data structure following the "next-gen data structure" precedent set by recently added linked list, that is, by using kfunc + kptr instead of adding a new BPF map type. - Expose XDP hints via kfuncs with initial support for RX hash and timestamp metadata. - Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to better support decap on GRE tunnel devices not operating in collect metadata. - Improve x86 JIT's codegen for PROBE_MEM runtime error checks. - Remove the need for trace_printk_lock for bpf_trace_printk and bpf_trace_vprintk helpers. - Extend libbpf's bpf_tracing.h support for tracing arguments of kprobes/uprobes and syscall as a special case. - Significantly reduce the search time for module symbols by livepatch and BPF. - Enable cpumasks to be used as kptrs, which is useful for tracing programs tracking which tasks end up running on which CPUs in different time intervals. - Add support for BPF trampoline on s390x and riscv64. - Add capability to export the XDP features supported by the NIC. - Add __bpf_kfunc tag for marking kernel functions as kfuncs. - Add cgroup.memory=nobpf kernel parameter option to disable BPF memory accounting for container environments. Netfilter: - Remove the CLUSTERIP target. It has been marked as obsolete for years, and we still have WARN splats wrt races of the out-of-band /proc interface installed by this target. - Add 'destroy' commands to nf_tables. They are identical to the existing 'delete' commands, but do not return an error if the referenced object (set, chain, rule...) did not exist. Driver API: - Improve cpumask_local_spread() locality to help NICs set the right IRQ affinity on AMD platforms. - Separate C22 and C45 MDIO bus transactions more clearly. - Introduce new DCB table to control DSCP rewrite on egress. - Support configuration of Physical Layer Collision Avoidance (PLCA) Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of shared medium Ethernet. - Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing preemption of low priority frames by high priority frames. - Add support for controlling MACSec offload using netlink SET. - Rework devlink instance refcounts to allow registration and de-registration under the instance lock. Split the code into multiple files, drop some of the unnecessarily granular locks and factor out common parts of netlink operation handling. - Add TX frame aggregation parameters (for USB drivers). - Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning messages with notifications for debug. - Allow offloading of UDP NEW connections via act_ct. - Add support for per action HW stats in TC. - Support hardware miss to TC action (continue processing in SW from a specific point in the action chain). - Warn if old Wireless Extension user space interface is used with modern cfg80211/mac80211 drivers. Do not support Wireless Extensions for Wi-Fi 7 devices at all. Everyone should switch to using nl80211 interface instead. - Improve the CAN bit timing configuration. Use extack to return error messages directly to user space, update the SJW handling, including the definition of a new default value that will benefit CAN-FD controllers, by increasing their oscillator tolerance. New hardware / drivers: - Ethernet: - nVidia BlueField-3 support (control traffic driver) - Ethernet support for imx93 SoCs - Motorcomm yt8531 gigabit Ethernet PHY - onsemi NCN26000 10BASE-T1S PHY (with support for PLCA) - Microchip LAN8841 PHY (incl. cable diagnostics and PTP) - Amlogic gxl MDIO mux - WiFi: - RealTek RTL8188EU (rtl8xxxu) - Qualcomm Wi-Fi 7 devices (ath12k) - CAN: - Renesas R-Car V4H Drivers: - Bluetooth: - Set Per Platform Antenna Gain (PPAG) for Intel controllers. - Ethernet NICs: - Intel (1G, igc): - support TSN / Qbv / packet scheduling features of i226 model - Intel (100G, ice): - use GNSS subsystem instead of TTY - multi-buffer XDP support - extend support for GPIO pins to E823 devices - nVidia/Mellanox: - update the shared buffer configuration on PFC commands - implement PTP adjphase function for HW offset control - TC support for Geneve and GRE with VF tunnel offload - more efficient crypto key management method - multi-port eswitch support - Netronome/Corigine: - add DCB IEEE support - support IPsec offloading for NFP3800 - Freescale/NXP (enetc): - support XDP_REDIRECT for XDP non-linear buffers - improve reconfig, avoid link flap and waiting for idle - support MAC Merge layer - Other NICs: - sfc/ef100: add basic devlink support for ef100 - ionic: rx_push mode operation (writing descriptors via MMIO) - bnxt: use the auxiliary bus abstraction for RDMA - r8169: disable ASPM and reset bus in case of tx timeout - cpsw: support QSGMII mode for J721e CPSW9G - cpts: support pulse-per-second output - ngbe: add an mdio bus driver - usbnet: optimize usbnet_bh() by avoiding unnecessary queuing - r8152: handle devices with FW with NCM support - amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation - virtio-net: support multi buffer XDP - virtio/vsock: replace virtio_vsock_pkt with sk_buff - tsnep: XDP support - Ethernet high-speed switches: - nVidia/Mellanox (mlxsw): - add support for latency TLV (in FW control messages) - Microchip (sparx5): - separate explicit and implicit traffic forwarding rules, make the implicit rules always active - add support for egress DSCP rewrite - IS0 VCAP support (Ingress Classification) - IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS etc.) - ES2 VCAP support (Egress Access Control) - support for Per-Stream Filtering and Policing (802.1Q, 8.6.5.1) - Ethernet embedded switches: - Marvell (mv88e6xxx): - add MAB (port auth) offload support - enable PTP receive for mv88e6390 - NXP (ocelot): - support MAC Merge layer - support for the the vsc7512 internal copper phys - Microchip: - lan9303: convert to PHYLINK - lan966x: support TC flower filter statistics - lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x - lan937x: support Credit Based Shaper configuration - ksz9477: support Energy Efficient Ethernet - other: - qca8k: convert to regmap read/write API, use bulk operations - rswitch: Improve TX timestamp accuracy - Intel WiFi (iwlwifi): - EHT (Wi-Fi 7) rate reporting - STEP equalizer support: transfer some STEP (connection to radio on platforms with integrated wifi) related parameters from the BIOS to the firmware. - Qualcomm 802.11ax WiFi (ath11k): - IPQ5018 support - Fine Timing Measurement (FTM) responder role support - channel 177 support - MediaTek WiFi (mt76): - per-PHY LED support - mt7996: EHT (Wi-Fi 7) support - Wireless Ethernet Dispatch (WED) reset support - switch to using page pool allocator - RealTek WiFi (rtw89): - support new version of Bluetooth co-existance - Mobile: - rmnet: support TX aggregation" * tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits) page_pool: add a comment explaining the fragment counter usage net: ethtool: fix __ethtool_dev_mm_supported() implementation ethtool: pse-pd: Fix double word in comments xsk: add linux/vmalloc.h to xsk.c sefltests: netdevsim: wait for devlink instance after netns removal selftest: fib_tests: Always cleanup before exit net/mlx5e: Align IPsec ASO result memory to be as required by hardware net/mlx5e: TC, Set CT miss to the specific ct action instance net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG net/mlx5: Refactor tc miss handling to a single function net/mlx5: Kconfig: Make tc offload depend on tc skb extension net/sched: flower: Support hardware miss to tc action net/sched: flower: Move filter handle initialization earlier net/sched: cls_api: Support hardware miss to tc action net/sched: Rename user cookie and act cookie sfc: fix builds without CONFIG_RTC_LIB sfc: clean up some inconsistent indentings net/mlx4_en: Introduce flexible array to silence overflow warning net: lan966x: Fix possible deadlock inside PTP net/ulp: Remove redundant ->clone() test in inet_clone_ulp(). ...
Diffstat (limited to 'drivers/gpu/drm/display/drm_dsc_helper.c')
-rw-r--r--drivers/gpu/drm/display/drm_dsc_helper.c409
1 files changed, 409 insertions, 0 deletions
diff --git a/drivers/gpu/drm/display/drm_dsc_helper.c b/drivers/gpu/drm/display/drm_dsc_helper.c
new file mode 100644
index 000000000..c869c6e51
--- /dev/null
+++ b/drivers/gpu/drm/display/drm_dsc_helper.c
@@ -0,0 +1,409 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2018 Intel Corp
+ *
+ * Author:
+ * Manasi Navare <manasi.d.navare@intel.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/errno.h>
+#include <linux/byteorder/generic.h>
+
+#include <drm/display/drm_dp_helper.h>
+#include <drm/display/drm_dsc_helper.h>
+#include <drm/drm_print.h>
+
+/**
+ * DOC: dsc helpers
+ *
+ * VESA specification for DP 1.4 adds a new feature called Display Stream
+ * Compression (DSC) used to compress the pixel bits before sending it on
+ * DP/eDP/MIPI DSI interface. DSC is required to be enabled so that the existing
+ * display interfaces can support high resolutions at higher frames rates uisng
+ * the maximum available link capacity of these interfaces.
+ *
+ * These functions contain some common logic and helpers to deal with VESA
+ * Display Stream Compression standard required for DSC on Display Port/eDP or
+ * MIPI display interfaces.
+ */
+
+/**
+ * drm_dsc_dp_pps_header_init() - Initializes the PPS Header
+ * for DisplayPort as per the DP 1.4 spec.
+ * @pps_header: Secondary data packet header for DSC Picture
+ * Parameter Set as defined in &struct dp_sdp_header
+ *
+ * DP 1.4 spec defines the secondary data packet for sending the
+ * picture parameter infoframes from the source to the sink.
+ * This function populates the SDP header defined in
+ * &struct dp_sdp_header.
+ */
+void drm_dsc_dp_pps_header_init(struct dp_sdp_header *pps_header)
+{
+ memset(pps_header, 0, sizeof(*pps_header));
+
+ pps_header->HB1 = DP_SDP_PPS;
+ pps_header->HB2 = DP_SDP_PPS_HEADER_PAYLOAD_BYTES_MINUS_1;
+}
+EXPORT_SYMBOL(drm_dsc_dp_pps_header_init);
+
+/**
+ * drm_dsc_dp_rc_buffer_size - get rc buffer size in bytes
+ * @rc_buffer_block_size: block size code, according to DPCD offset 62h
+ * @rc_buffer_size: number of blocks - 1, according to DPCD offset 63h
+ *
+ * return:
+ * buffer size in bytes, or 0 on invalid input
+ */
+int drm_dsc_dp_rc_buffer_size(u8 rc_buffer_block_size, u8 rc_buffer_size)
+{
+ int size = 1024 * (rc_buffer_size + 1);
+
+ switch (rc_buffer_block_size) {
+ case DP_DSC_RC_BUF_BLK_SIZE_1:
+ return 1 * size;
+ case DP_DSC_RC_BUF_BLK_SIZE_4:
+ return 4 * size;
+ case DP_DSC_RC_BUF_BLK_SIZE_16:
+ return 16 * size;
+ case DP_DSC_RC_BUF_BLK_SIZE_64:
+ return 64 * size;
+ default:
+ return 0;
+ }
+}
+EXPORT_SYMBOL(drm_dsc_dp_rc_buffer_size);
+
+/**
+ * drm_dsc_pps_payload_pack() - Populates the DSC PPS
+ *
+ * @pps_payload:
+ * Bitwise struct for DSC Picture Parameter Set. This is defined
+ * by &struct drm_dsc_picture_parameter_set
+ * @dsc_cfg:
+ * DSC Configuration data filled by driver as defined by
+ * &struct drm_dsc_config
+ *
+ * DSC source device sends a picture parameter set (PPS) containing the
+ * information required by the sink to decode the compressed frame. Driver
+ * populates the DSC PPS struct using the DSC configuration parameters in
+ * the order expected by the DSC Display Sink device. For the DSC, the sink
+ * device expects the PPS payload in big endian format for fields
+ * that span more than 1 byte.
+ */
+void drm_dsc_pps_payload_pack(struct drm_dsc_picture_parameter_set *pps_payload,
+ const struct drm_dsc_config *dsc_cfg)
+{
+ int i;
+
+ /* Protect against someone accidentally changing struct size */
+ BUILD_BUG_ON(sizeof(*pps_payload) !=
+ DP_SDP_PPS_HEADER_PAYLOAD_BYTES_MINUS_1 + 1);
+
+ memset(pps_payload, 0, sizeof(*pps_payload));
+
+ /* PPS 0 */
+ pps_payload->dsc_version =
+ dsc_cfg->dsc_version_minor |
+ dsc_cfg->dsc_version_major << DSC_PPS_VERSION_MAJOR_SHIFT;
+
+ /* PPS 1, 2 is 0 */
+
+ /* PPS 3 */
+ pps_payload->pps_3 =
+ dsc_cfg->line_buf_depth |
+ dsc_cfg->bits_per_component << DSC_PPS_BPC_SHIFT;
+
+ /* PPS 4 */
+ pps_payload->pps_4 =
+ ((dsc_cfg->bits_per_pixel & DSC_PPS_BPP_HIGH_MASK) >>
+ DSC_PPS_MSB_SHIFT) |
+ dsc_cfg->vbr_enable << DSC_PPS_VBR_EN_SHIFT |
+ dsc_cfg->simple_422 << DSC_PPS_SIMPLE422_SHIFT |
+ dsc_cfg->convert_rgb << DSC_PPS_CONVERT_RGB_SHIFT |
+ dsc_cfg->block_pred_enable << DSC_PPS_BLOCK_PRED_EN_SHIFT;
+
+ /* PPS 5 */
+ pps_payload->bits_per_pixel_low =
+ (dsc_cfg->bits_per_pixel & DSC_PPS_LSB_MASK);
+
+ /*
+ * The DSC panel expects the PPS packet to have big endian format
+ * for data spanning 2 bytes. Use a macro cpu_to_be16() to convert
+ * to big endian format. If format is little endian, it will swap
+ * bytes to convert to Big endian else keep it unchanged.
+ */
+
+ /* PPS 6, 7 */
+ pps_payload->pic_height = cpu_to_be16(dsc_cfg->pic_height);
+
+ /* PPS 8, 9 */
+ pps_payload->pic_width = cpu_to_be16(dsc_cfg->pic_width);
+
+ /* PPS 10, 11 */
+ pps_payload->slice_height = cpu_to_be16(dsc_cfg->slice_height);
+
+ /* PPS 12, 13 */
+ pps_payload->slice_width = cpu_to_be16(dsc_cfg->slice_width);
+
+ /* PPS 14, 15 */
+ pps_payload->chunk_size = cpu_to_be16(dsc_cfg->slice_chunk_size);
+
+ /* PPS 16 */
+ pps_payload->initial_xmit_delay_high =
+ ((dsc_cfg->initial_xmit_delay &
+ DSC_PPS_INIT_XMIT_DELAY_HIGH_MASK) >>
+ DSC_PPS_MSB_SHIFT);
+
+ /* PPS 17 */
+ pps_payload->initial_xmit_delay_low =
+ (dsc_cfg->initial_xmit_delay & DSC_PPS_LSB_MASK);
+
+ /* PPS 18, 19 */
+ pps_payload->initial_dec_delay =
+ cpu_to_be16(dsc_cfg->initial_dec_delay);
+
+ /* PPS 20 is 0 */
+
+ /* PPS 21 */
+ pps_payload->initial_scale_value =
+ dsc_cfg->initial_scale_value;
+
+ /* PPS 22, 23 */
+ pps_payload->scale_increment_interval =
+ cpu_to_be16(dsc_cfg->scale_increment_interval);
+
+ /* PPS 24 */
+ pps_payload->scale_decrement_interval_high =
+ ((dsc_cfg->scale_decrement_interval &
+ DSC_PPS_SCALE_DEC_INT_HIGH_MASK) >>
+ DSC_PPS_MSB_SHIFT);
+
+ /* PPS 25 */
+ pps_payload->scale_decrement_interval_low =
+ (dsc_cfg->scale_decrement_interval & DSC_PPS_LSB_MASK);
+
+ /* PPS 26[7:0], PPS 27[7:5] RESERVED */
+
+ /* PPS 27 */
+ pps_payload->first_line_bpg_offset =
+ dsc_cfg->first_line_bpg_offset;
+
+ /* PPS 28, 29 */
+ pps_payload->nfl_bpg_offset =
+ cpu_to_be16(dsc_cfg->nfl_bpg_offset);
+
+ /* PPS 30, 31 */
+ pps_payload->slice_bpg_offset =
+ cpu_to_be16(dsc_cfg->slice_bpg_offset);
+
+ /* PPS 32, 33 */
+ pps_payload->initial_offset =
+ cpu_to_be16(dsc_cfg->initial_offset);
+
+ /* PPS 34, 35 */
+ pps_payload->final_offset = cpu_to_be16(dsc_cfg->final_offset);
+
+ /* PPS 36 */
+ pps_payload->flatness_min_qp = dsc_cfg->flatness_min_qp;
+
+ /* PPS 37 */
+ pps_payload->flatness_max_qp = dsc_cfg->flatness_max_qp;
+
+ /* PPS 38, 39 */
+ pps_payload->rc_model_size = cpu_to_be16(dsc_cfg->rc_model_size);
+
+ /* PPS 40 */
+ pps_payload->rc_edge_factor = DSC_RC_EDGE_FACTOR_CONST;
+
+ /* PPS 41 */
+ pps_payload->rc_quant_incr_limit0 =
+ dsc_cfg->rc_quant_incr_limit0;
+
+ /* PPS 42 */
+ pps_payload->rc_quant_incr_limit1 =
+ dsc_cfg->rc_quant_incr_limit1;
+
+ /* PPS 43 */
+ pps_payload->rc_tgt_offset = DSC_RC_TGT_OFFSET_LO_CONST |
+ DSC_RC_TGT_OFFSET_HI_CONST << DSC_PPS_RC_TGT_OFFSET_HI_SHIFT;
+
+ /* PPS 44 - 57 */
+ for (i = 0; i < DSC_NUM_BUF_RANGES - 1; i++)
+ pps_payload->rc_buf_thresh[i] =
+ dsc_cfg->rc_buf_thresh[i];
+
+ /* PPS 58 - 87 */
+ /*
+ * For DSC sink programming the RC Range parameter fields
+ * are as follows: Min_qp[15:11], max_qp[10:6], offset[5:0]
+ */
+ for (i = 0; i < DSC_NUM_BUF_RANGES; i++) {
+ pps_payload->rc_range_parameters[i] =
+ cpu_to_be16((dsc_cfg->rc_range_params[i].range_min_qp <<
+ DSC_PPS_RC_RANGE_MINQP_SHIFT) |
+ (dsc_cfg->rc_range_params[i].range_max_qp <<
+ DSC_PPS_RC_RANGE_MAXQP_SHIFT) |
+ (dsc_cfg->rc_range_params[i].range_bpg_offset));
+ }
+
+ /* PPS 88 */
+ pps_payload->native_422_420 = dsc_cfg->native_422 |
+ dsc_cfg->native_420 << DSC_PPS_NATIVE_420_SHIFT;
+
+ /* PPS 89 */
+ pps_payload->second_line_bpg_offset =
+ dsc_cfg->second_line_bpg_offset;
+
+ /* PPS 90, 91 */
+ pps_payload->nsl_bpg_offset =
+ cpu_to_be16(dsc_cfg->nsl_bpg_offset);
+
+ /* PPS 92, 93 */
+ pps_payload->second_line_offset_adj =
+ cpu_to_be16(dsc_cfg->second_line_offset_adj);
+
+ /* PPS 94 - 127 are O */
+}
+EXPORT_SYMBOL(drm_dsc_pps_payload_pack);
+
+/**
+ * drm_dsc_compute_rc_parameters() - Write rate control
+ * parameters to the dsc configuration defined in
+ * &struct drm_dsc_config in accordance with the DSC 1.2
+ * specification. Some configuration fields must be present
+ * beforehand.
+ *
+ * @vdsc_cfg:
+ * DSC Configuration data partially filled by driver
+ */
+int drm_dsc_compute_rc_parameters(struct drm_dsc_config *vdsc_cfg)
+{
+ unsigned long groups_per_line = 0;
+ unsigned long groups_total = 0;
+ unsigned long num_extra_mux_bits = 0;
+ unsigned long slice_bits = 0;
+ unsigned long hrd_delay = 0;
+ unsigned long final_scale = 0;
+ unsigned long rbs_min = 0;
+
+ if (vdsc_cfg->native_420 || vdsc_cfg->native_422) {
+ /* Number of groups used to code each line of a slice */
+ groups_per_line = DIV_ROUND_UP(vdsc_cfg->slice_width / 2,
+ DSC_RC_PIXELS_PER_GROUP);
+
+ /* chunksize in Bytes */
+ vdsc_cfg->slice_chunk_size = DIV_ROUND_UP(vdsc_cfg->slice_width / 2 *
+ vdsc_cfg->bits_per_pixel,
+ (8 * 16));
+ } else {
+ /* Number of groups used to code each line of a slice */
+ groups_per_line = DIV_ROUND_UP(vdsc_cfg->slice_width,
+ DSC_RC_PIXELS_PER_GROUP);
+
+ /* chunksize in Bytes */
+ vdsc_cfg->slice_chunk_size = DIV_ROUND_UP(vdsc_cfg->slice_width *
+ vdsc_cfg->bits_per_pixel,
+ (8 * 16));
+ }
+
+ if (vdsc_cfg->convert_rgb)
+ num_extra_mux_bits = 3 * (vdsc_cfg->mux_word_size +
+ (4 * vdsc_cfg->bits_per_component + 4)
+ - 2);
+ else if (vdsc_cfg->native_422)
+ num_extra_mux_bits = 4 * vdsc_cfg->mux_word_size +
+ (4 * vdsc_cfg->bits_per_component + 4) +
+ 3 * (4 * vdsc_cfg->bits_per_component) - 2;
+ else
+ num_extra_mux_bits = 3 * vdsc_cfg->mux_word_size +
+ (4 * vdsc_cfg->bits_per_component + 4) +
+ 2 * (4 * vdsc_cfg->bits_per_component) - 2;
+ /* Number of bits in one Slice */
+ slice_bits = 8 * vdsc_cfg->slice_chunk_size * vdsc_cfg->slice_height;
+
+ while ((num_extra_mux_bits > 0) &&
+ ((slice_bits - num_extra_mux_bits) % vdsc_cfg->mux_word_size))
+ num_extra_mux_bits--;
+
+ if (groups_per_line < vdsc_cfg->initial_scale_value - 8)
+ vdsc_cfg->initial_scale_value = groups_per_line + 8;
+
+ /* scale_decrement_interval calculation according to DSC spec 1.11 */
+ if (vdsc_cfg->initial_scale_value > 8)
+ vdsc_cfg->scale_decrement_interval = groups_per_line /
+ (vdsc_cfg->initial_scale_value - 8);
+ else
+ vdsc_cfg->scale_decrement_interval = DSC_SCALE_DECREMENT_INTERVAL_MAX;
+
+ vdsc_cfg->final_offset = vdsc_cfg->rc_model_size -
+ (vdsc_cfg->initial_xmit_delay *
+ vdsc_cfg->bits_per_pixel + 8) / 16 + num_extra_mux_bits;
+
+ if (vdsc_cfg->final_offset >= vdsc_cfg->rc_model_size) {
+ DRM_DEBUG_KMS("FinalOfs < RcModelSze for this InitialXmitDelay\n");
+ return -ERANGE;
+ }
+
+ final_scale = (vdsc_cfg->rc_model_size * 8) /
+ (vdsc_cfg->rc_model_size - vdsc_cfg->final_offset);
+ if (vdsc_cfg->slice_height > 1)
+ /*
+ * NflBpgOffset is 16 bit value with 11 fractional bits
+ * hence we multiply by 2^11 for preserving the
+ * fractional part
+ */
+ vdsc_cfg->nfl_bpg_offset = DIV_ROUND_UP((vdsc_cfg->first_line_bpg_offset << 11),
+ (vdsc_cfg->slice_height - 1));
+ else
+ vdsc_cfg->nfl_bpg_offset = 0;
+
+ /* Number of groups used to code the entire slice */
+ groups_total = groups_per_line * vdsc_cfg->slice_height;
+
+ /* slice_bpg_offset is 16 bit value with 11 fractional bits */
+ vdsc_cfg->slice_bpg_offset = DIV_ROUND_UP(((vdsc_cfg->rc_model_size -
+ vdsc_cfg->initial_offset +
+ num_extra_mux_bits) << 11),
+ groups_total);
+
+ if (final_scale > 9) {
+ /*
+ * ScaleIncrementInterval =
+ * finaloffset/((NflBpgOffset + SliceBpgOffset)*8(finalscale - 1.125))
+ * as (NflBpgOffset + SliceBpgOffset) has 11 bit fractional value,
+ * we need divide by 2^11 from pstDscCfg values
+ */
+ vdsc_cfg->scale_increment_interval =
+ (vdsc_cfg->final_offset * (1 << 11)) /
+ ((vdsc_cfg->nfl_bpg_offset +
+ vdsc_cfg->slice_bpg_offset) *
+ (final_scale - 9));
+ } else {
+ /*
+ * If finalScaleValue is less than or equal to 9, a value of 0 should
+ * be used to disable the scale increment at the end of the slice
+ */
+ vdsc_cfg->scale_increment_interval = 0;
+ }
+
+ /*
+ * DSC spec mentions that bits_per_pixel specifies the target
+ * bits/pixel (bpp) rate that is used by the encoder,
+ * in steps of 1/16 of a bit per pixel
+ */
+ rbs_min = vdsc_cfg->rc_model_size - vdsc_cfg->initial_offset +
+ DIV_ROUND_UP(vdsc_cfg->initial_xmit_delay *
+ vdsc_cfg->bits_per_pixel, 16) +
+ groups_per_line * vdsc_cfg->first_line_bpg_offset;
+
+ hrd_delay = DIV_ROUND_UP((rbs_min * 16), vdsc_cfg->bits_per_pixel);
+ vdsc_cfg->rc_bits = (hrd_delay * vdsc_cfg->bits_per_pixel) / 16;
+ vdsc_cfg->initial_dec_delay = hrd_delay - vdsc_cfg->initial_xmit_delay;
+
+ return 0;
+}
+EXPORT_SYMBOL(drm_dsc_compute_rc_parameters);