hexagon: L2 cache handling rework (dirty bit tracking with lazy flushing) and more MUL_MAT updates (#25762)

* hex-mm: fix artificial limit in the solver that restricted number of act-prep threads

* hex-mm: fix warning

* hex-prof: do not apply --top to the timeline report

* hmx-mm: add suport for tiled act-processing to better distribute hvx work

* hex-l2: add tracing for l2flush events

* workqueue: redo the legacy workpool api to match hmx-queue and dma-queue

* hmx-mm: fix f32 activation buffer alignmnet for nhvx=5,6,7

* hex-work: minor cleanup for work-queue apis

* hex-work: further cleanup of the work-queue api

* hex-l2: optimize l2flushes at the opbatch level

* hex-work: remove unused mask

* hex-work: no need to drop hvx ctx in the work-queue

* hex-work: add explicit wakeup/suspend and make threads spin

* hex-bufs: mark any non-weight tensor as compute

* hex-dma: dma-queue support for alias queues and cached dma

* hex-l2: track tensor aliases and delay or skip flushes as much as possible

* hex-l2: simplify tensor alias handling

* hex-l2: handle overlapping views as a circular list of aliases

* hex-tens: add flags helper

* hex-l2: add helper for marking tensors clearn/dirty

* hex-l2: mark binary and rope outputs as l2-clean and keep the rest as is for now

* hex-l2: proper support for handling all tensor overlap scenarios

* hex-trace: instrument matmul init code and cleanup trace checks

* hex-thread: introduce dedicated main thread with explicit stack and priority

* hex-l2: track dirty state as bitmap and introduce threaded flush

* hex-trace: remove redundant checks for ctx != null

* hex-l2: allocate entire context as one buffer and l2fetch it after big flushes

* hex-l2: disable tensor clearing in binary and rope for now seems to cause issues with fusion

* hmx-mm: update act proc to use fastdivs and fix DMA overflow

* hmx-mm: make MUL_MAT_ID kernels robust to multi-chunk cases (start_row>0)

* hex-queue: remove obsolete queue interfaces and flush hmx-queue at the end of the op-batch

* hex-queue: dont use early wakeup for small op-batches

* hex-tensors: properly cap max_tensors in op-batches and dirty_map

* hex-l2: make sure threaded l2flush does proper rounding

* hex-l2: factor out htp_tensor_flush for reuse (if needed)

* hex-l2: optimize tensor flushes by coalescing flush-all

* hex-l2: optimize multi-threaded flush

* hex-drv: futureproof version checks

* hexagon: fix errors and warnings on windows

* hex-main: update main thread to only use dspqueue_read, dspqueue_peek is not available on some platforms

* hex-main: add fallback mode for dspqueue with callbacks

* hex-main: introduce fallback mode for using dspqueue callbacks for full op processing

* hex-main: remove early wakeup, not helping and seems to cause some errors with certain batch sizes

* hex-l2: make sure to use invalidate version of flushall

* hex-l2: dont try to trace early l2flush at the start of op-batch

* hex-main: remove offset_ctx that must be zero anyway

* hex-hmx: fix hmx_queue_depth to use idx_write - idx_read

* hex-hmx: use atomic_load for idx_read/write

* hex-main: add static assert to make sure n_threads are aligned

ggml/src/ggml-hexagon/htp/htp-ops.h

@@ -108,8 +108,7 @@ enum htp_op_code {
 #define HTP_OP_MAX_KERN_PARAMS 32
 
 #define HTP_OP_MAX_BUFS    16
-#define HTP_OP_MAX_REQS    256
-#define HTP_OP_MAX_TENSORS (HTP_OP_MAX_REQS * HTP_OP_MAX_INPUTS + HTP_OP_MAX_REQS)
+#define HTP_OP_MAX_TENSORS 8192 // must stay under 64K (uint16)
 
 #define HTP_OP_MAX_VMEM_DEFAULT (3355443200u)
 
@@ -117,16 +116,18 @@ enum htp_op_code {
 
 enum htp_tensor_flags {
     HTP_TENSOR_COMPUTE = (1U << 0), // Tensor buffer temporal compute data (not weights)
-    HTP_TENSOR_FLUSHED = (1U << 1)  // Tensor buffer has been flushed (set by the NPU)
+    HTP_TENSOR_DIRTY   = (1U << 1)  // Tensor buffer is dirty and needs to be flushed
 };
 
 // Tensor descriptor
 struct htp_tensor {
     uint32_t data;                 // Buffer offset in the messages, and data pointer on the NPU
+    uint32_t alias;                // Index of the canonical tensor for this memory buffer
     uint32_t size;                 // Data size in bytes
     uint32_t flags;                // Buffer / tensor flags
-    uint16_t type;                 // Data type
+    uint32_t type;                 // Data type
     uint16_t bi;                   // Buffer index
+    uint16_t ti;                   // Tensor index
     uint32_t ne[HTP_OP_MAX_DIMS];  // Number of elements
     uint32_t nb[HTP_OP_MAX_DIMS];  // Stride in bytes (see ggml.h ggml_tensor)
 };
@@ -169,6 +170,8 @@ enum htp_profiler_mode {
 
 enum htp_trace_event_id {
     HTP_TRACE_EVT_DMA                 = 0,
+    HTP_TRACE_EVT_L2FLUSH             = 1,
+    HTP_TRACE_EVT_INIT                = 2,
 
     HTP_TRACE_EVT_HVX_COMP            = 20,
     HTP_TRACE_EVT_HVX_A_QUANT         = 21,