staging: vc04_services: Add new vc-sm-cma driver

Add Broadcom VideoCore Shared Memory support.

This new driver allows contiguous memory blocks to be imported
into the VideoCore VPU memory map, and manages the lifetime of
those objects, only releasing the source dmabuf once the VPU has
confirmed it has finished with it.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>

drivers/staging/vc04_services/Kconfig

@@ -43,6 +43,8 @@ source "drivers/staging/vc04_services/bcm2835-audio/Kconfig"
 
 source "drivers/staging/vc04_services/bcm2835-camera/Kconfig"
 
+source "drivers/staging/vc04_services/vc-sm-cma/Kconfig"
+
 source "drivers/staging/vc04_services/vchiq-mmal/Kconfig"
 
 endif

drivers/staging/vc04_services/Makefile

@@ -14,6 +14,7 @@ endif
 obj-$(CONFIG_SND_BCM2835)		+= bcm2835-audio/
 obj-$(CONFIG_VIDEO_BCM2835)		+= bcm2835-camera/
 obj-$(CONFIG_BCM2835_VCHIQ_MMAL)	+= vchiq-mmal/
+obj-$(CONFIG_BCM_VC_SM_CMA)		+= vc-sm-cma/
 
 ccflags-y += -I $(srctree)/$(src)/include
 

drivers/staging/vc04_services/include/linux/broadcom/vc_sm_cma_ioctl.h

@@ -0,0 +1,114 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+/*
+ * Copyright 2019 Raspberry Pi (Trading) Ltd.  All rights reserved.
+ *
+ * Based on vmcs_sm_ioctl.h Copyright Broadcom Corporation.
+ */
+
+#ifndef __VC_SM_CMA_IOCTL_H
+#define __VC_SM_CMA_IOCTL_H
+
+/* ---- Include Files ---------------------------------------------------- */
+
+#if defined(__KERNEL__)
+#include <linux/types.h>	/* Needed for standard types */
+#else
+#include <stdint.h>
+#endif
+
+#include <linux/ioctl.h>
+
+/* ---- Constants and Types ---------------------------------------------- */
+
+#define VC_SM_CMA_RESOURCE_NAME               32
+#define VC_SM_CMA_RESOURCE_NAME_DEFAULT       "sm-host-resource"
+
+/* Type define used to create unique IOCTL number */
+#define VC_SM_CMA_MAGIC_TYPE                  'J'
+
+/* IOCTL commands on /dev/vc-sm-cma */
+enum vc_sm_cma_cmd_e {
+	VC_SM_CMA_CMD_ALLOC = 0x5A,	/* Start at 0x5A arbitrarily */
+
+	VC_SM_CMA_CMD_IMPORT_DMABUF,
+
+	VC_SM_CMA_CMD_CLEAN_INVALID2,
+
+	VC_SM_CMA_CMD_LAST	/* Do not delete */
+};
+
+/* Cache type supported, conveniently matches the user space definition in
+ * user-vcsm.h.
+ */
+enum vc_sm_cma_cache_e {
+	VC_SM_CMA_CACHE_NONE,
+	VC_SM_CMA_CACHE_HOST,
+	VC_SM_CMA_CACHE_VC,
+	VC_SM_CMA_CACHE_BOTH,
+};
+
+/* IOCTL Data structures */
+struct vc_sm_cma_ioctl_alloc {
+	/* user -> kernel */
+	__u32 size;
+	__u32 num;
+	__u32 cached;		/* enum vc_sm_cma_cache_e */
+	__u32 pad;
+	__u8 name[VC_SM_CMA_RESOURCE_NAME];
+
+	/* kernel -> user */
+	__s32 handle;
+	__u32 vc_handle;
+	__u64 dma_addr;
+};
+
+struct vc_sm_cma_ioctl_import_dmabuf {
+	/* user -> kernel */
+	__s32 dmabuf_fd;
+	__u32 cached;		/* enum vc_sm_cma_cache_e */
+	__u8 name[VC_SM_CMA_RESOURCE_NAME];
+
+	/* kernel -> user */
+	__s32 handle;
+	__u32 vc_handle;
+	__u32 size;
+	__u32 pad;
+	__u64 dma_addr;
+};
+
+/*
+ * Cache functions to be set to struct vc_sm_cma_ioctl_clean_invalid2
+ * invalidate_mode.
+ */
+#define VC_SM_CACHE_OP_NOP       0x00
+#define VC_SM_CACHE_OP_INV       0x01
+#define VC_SM_CACHE_OP_CLEAN     0x02
+#define VC_SM_CACHE_OP_FLUSH     0x03
+
+struct vc_sm_cma_ioctl_clean_invalid2 {
+	__u32 op_count;
+	__u32 pad;
+	struct vc_sm_cma_ioctl_clean_invalid_block {
+		__u32 invalidate_mode;
+		__u32 block_count;
+		void *  __user start_address;
+		__u32 block_size;
+		__u32 inter_block_stride;
+	} s[0];
+};
+
+/* IOCTL numbers */
+#define VC_SM_CMA_IOCTL_MEM_ALLOC\
+	_IOR(VC_SM_CMA_MAGIC_TYPE, VC_SM_CMA_CMD_ALLOC,\
+	 struct vc_sm_cma_ioctl_alloc)
+
+#define VC_SM_CMA_IOCTL_MEM_IMPORT_DMABUF\
+	_IOR(VC_SM_CMA_MAGIC_TYPE, VC_SM_CMA_CMD_IMPORT_DMABUF,\
+	 struct vc_sm_cma_ioctl_import_dmabuf)
+
+#define VC_SM_CMA_IOCTL_MEM_CLEAN_INVALID2\
+	_IOR(VC_SM_CMA_MAGIC_TYPE, VC_SM_CMA_CMD_CLEAN_INVALID2,\
+	 struct vc_sm_cma_ioctl_clean_invalid2)
+
+#endif /* __VC_SM_CMA_IOCTL_H */

drivers/staging/vc04_services/vc-sm-cma/Kconfig

@@ -0,0 +1,10 @@
+config BCM_VC_SM_CMA
+	tristate "VideoCore Shared Memory (CMA) driver"
+	select BCM2835_VCHIQ
+	select RBTREE
+	select DMA_SHARED_BUFFER
+	help
+	  Say Y here to enable the shared memory interface that
+	  supports sharing dmabufs with VideoCore.
+	  This operates over the VCHIQ interface to a service
+	  running on VideoCore.

drivers/staging/vc04_services/vc-sm-cma/Makefile

@@ -0,0 +1,12 @@
+ccflags-y += \
+	-I$(srctree)/$(src)/../ \
+	-I$(srctree)/$(src)/../interface/vchiq_arm\
+	-I$(srctree)/$(src)/../include
+
+ccflags-y += \
+	-D__VCCOREVER__=0
+
+vc-sm-cma-$(CONFIG_BCM_VC_SM_CMA) := \
+	vc_sm.o vc_sm_cma_vchi.o
+
+obj-$(CONFIG_BCM_VC_SM_CMA) += vc-sm-cma.o

drivers/staging/vc04_services/vc-sm-cma/TODO

@@ -0,0 +1 @@
+No currently outstanding tasks except some clean-up.