From 6f51e39d78dfc6fdd1add732e282de119600447c Mon Sep 17 00:00:00 2001
From: Naushir Patuck <naush@raspberrypi.com>
Date: Mon, 16 Nov 2020 14:37:56 +0000
Subject: pipeline: raspberrypi: Use MappedFrameBuffer for embedded data
 buffers

Use a MappedFrameBuffer to mmap embedded data buffers for the pipeline
handler to use in the cases where the sensor does not fill it in. This
avoids the need to mmap and unmap on every frame.

Signed-off-by: Naushir Patuck <naush@raspberrypi.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
---
 src/libcamera/pipeline/raspberrypi/raspberrypi.cpp | 33 ++++++++++++++++------
 1 file changed, 25 insertions(+), 8 deletions(-)

diff --git a/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp b/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
index 7ad66f21..a80413f9 100644
--- a/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
+++ b/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
@@ -24,6 +24,7 @@
 #include <linux/videodev2.h>
 
 #include "libcamera/internal/bayer_format.h"
+#include "libcamera/internal/buffer.h"
 #include "libcamera/internal/camera_sensor.h"
 #include "libcamera/internal/device_enumerator.h"
 #include "libcamera/internal/ipa_manager.h"
@@ -165,6 +166,12 @@ public:
 	/* Stores the ids of the buffers mapped in the IPA. */
 	std::unordered_set<unsigned int> ipaBuffers_;
 
+	/*
+	 * Map of (internal) mmaped embedded data buffers, to avoid having to
+	 * map/unmap on every frame.
+	 */
+	std::map<unsigned int, MappedFrameBuffer> mappedEmbeddedBuffers_;
+
 	/* DMAHEAP allocation helper. */
 	RPi::DmaHeap dmaHeap_;
 	FileDescriptor lsTable_;
@@ -1061,6 +1068,13 @@ int PipelineHandlerRPi::prepareBuffers(Camera *camera)
 			return ret;
 	}
 
+	if (!data->sensorMetadata_) {
+		for (auto const &it : data->unicam_[Unicam::Embedded].getBuffers()) {
+			MappedFrameBuffer fb(it.second, PROT_READ | PROT_WRITE);
+			data->mappedEmbeddedBuffers_.emplace(it.first, std::move(fb));
+		}
+	}
+
 	/*
 	 * Pass the stats and embedded data buffers to the IPA. No other
 	 * buffers need to be passed.
@@ -1099,6 +1113,7 @@ void PipelineHandlerRPi::freeBuffers(Camera *camera)
 	std::vector<unsigned int> ipaBuffers(data->ipaBuffers_.begin(), data->ipaBuffers_.end());
 	data->ipa_->unmapBuffers(ipaBuffers);
 	data->ipaBuffers_.clear();
+	data->mappedEmbeddedBuffers_.clear();
 
 	for (auto const stream : data->streams_)
 		stream->releaseBuffers();
@@ -1349,14 +1364,16 @@ void RPiCameraData::unicamBufferDequeue(FrameBuffer *buffer)
 		 * metadata buffer.
 		 */
 		if (!sensorMetadata_) {
-			const FrameBuffer &fb = buffer->planes();
-			uint32_t *mem = static_cast<uint32_t *>(::mmap(nullptr, fb.planes()[0].length,
-								       PROT_READ | PROT_WRITE,
-								       MAP_SHARED,
-								       fb.planes()[0].fd.fd(), 0));
-			mem[0] = ctrl[V4L2_CID_EXPOSURE];
-			mem[1] = ctrl[V4L2_CID_ANALOGUE_GAIN];
-			munmap(mem, fb.planes()[0].length);
+			unsigned int bufferId = unicam_[Unicam::Embedded].getBufferId(buffer);
+			auto it = mappedEmbeddedBuffers_.find(bufferId);
+			if (it != mappedEmbeddedBuffers_.end()) {
+				uint32_t *mem = reinterpret_cast<uint32_t *>(it->second.maps()[0].data());
+				mem[0] = ctrl[V4L2_CID_EXPOSURE];
+				mem[1] = ctrl[V4L2_CID_ANALOGUE_GAIN];
+			} else {
+				LOG(RPI, Warning) << "Failed to find embedded buffer "
+						  << bufferId;
+			}
 		}
 	}
 
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