| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-Id: <20260105-b4-vc-sm-cma-v2-4-4daea749ced9@ideasonboard.com>
Date: Mon, 05 Jan 2026 14:26:50 +0530
From: Jai Luthra <jai.luthra@...asonboard.com>
To: Florian Fainelli <florian.fainelli@...adcom.com>,
Raspberry Pi Kernel Maintenance <kernel-list@...pberrypi.com>,
bcm-kernel-feedback-list@...adcom.com,
Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
Dave Stevenson <dave.stevenson@...pberrypi.com>
Cc: Phil Elwell <phil@...pberrypi.com>, Stefan Wahren <wahrenst@....net>,
Laurent Pinchart <laurent.pinchart@...asonboard.com>,
Kieran Bingham <kieran.bingham@...asonboard.com>,
Sumit Semwal <sumit.semwal@...aro.org>,
Christian König <christian.koenig@....com>,
linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
linux-rpi-kernel@...ts.infradead.org,
Jai Luthra <jai.luthra@...asonboard.com>
Subject: [PATCH v2 4/6] platform/raspberrypi: vchiq-mmal: Use vc-sm-cma to
support zero copy
From: Dave Stevenson <dave.stevenson@...pberrypi.com>
With the vc-sm-cma driver we can support zero copy of buffers between
the kernel and VPU. Add this support to mmal-vchiq.
Signed-off-by: Dave Stevenson <dave.stevenson@...pberrypi.com>
Signed-off-by: Jai Luthra <jai.luthra@...asonboard.com>
---
drivers/platform/raspberrypi/vchiq-mmal/Kconfig | 3 +-
.../platform/raspberrypi/vchiq-mmal/mmal-common.h | 4 ++
.../platform/raspberrypi/vchiq-mmal/mmal-vchiq.c | 65 ++++++++++++++++++++--
.../platform/raspberrypi/vchiq-mmal/mmal-vchiq.h | 1 +
4 files changed, 68 insertions(+), 5 deletions(-)
diff --git a/drivers/platform/raspberrypi/vchiq-mmal/Kconfig b/drivers/platform/raspberrypi/vchiq-mmal/Kconfig
index c99525a0bb4525d497c74984b8b44a9079279b6f..5df9198cdab1786353aeab287f83ea7f0630b317 100644
--- a/drivers/platform/raspberrypi/vchiq-mmal/Kconfig
+++ b/drivers/platform/raspberrypi/vchiq-mmal/Kconfig
@@ -1,6 +1,7 @@
config BCM2835_VCHIQ_MMAL
tristate "BCM2835 MMAL VCHIQ service"
- depends on BCM2835_VCHIQ
+ select BCM2835_VCHIQ
+ select BCM_VC_SM_CMA
help
Enables the MMAL API over VCHIQ interface as used for the
majority of the multimedia services on VideoCore.
diff --git a/drivers/platform/raspberrypi/vchiq-mmal/mmal-common.h b/drivers/platform/raspberrypi/vchiq-mmal/mmal-common.h
index b33129403a30347fe762d0377cacbda77434c211..6c5092a68b99594a0234f56b48b785fbc611bf5a 100644
--- a/drivers/platform/raspberrypi/vchiq-mmal/mmal-common.h
+++ b/drivers/platform/raspberrypi/vchiq-mmal/mmal-common.h
@@ -50,6 +50,10 @@ struct mmal_buffer {
struct mmal_msg_context *msg_context;
+ struct dma_buf *dma_buf;/* Exported dmabuf fd from videobuf2 */
+ void *vcsm_handle; /* VCSM handle having imported the dmabuf */
+ u32 vc_handle; /* VC handle to that dmabuf */
+
unsigned long length;
u32 mmal_flags;
s64 dts;
diff --git a/drivers/platform/raspberrypi/vchiq-mmal/mmal-vchiq.c b/drivers/platform/raspberrypi/vchiq-mmal/mmal-vchiq.c
index e76551948bd9c4f60bef1138280fe8dd9d32477b..fe6fb571b745e04545d2d7fe7f37a486792d398f 100644
--- a/drivers/platform/raspberrypi/vchiq-mmal/mmal-vchiq.c
+++ b/drivers/platform/raspberrypi/vchiq-mmal/mmal-vchiq.c
@@ -23,12 +23,13 @@
#include <linux/slab.h>
#include <linux/completion.h>
#include <linux/raspberrypi/vchiq.h>
+#include <linux/raspberrypi/vchiq_arm.h>
+#include <linux/raspberrypi/vc_sm_knl.h>
#include <linux/vmalloc.h>
#include <media/videobuf2-vmalloc.h>
-#include <linux/raspberrypi/vchiq_arm.h>
-
#include "mmal-common.h"
+#include "mmal-parameters.h"
#include "mmal-vchiq.h"
#include "mmal-msg.h"
@@ -422,8 +423,12 @@ buffer_from_host(struct vchiq_mmal_instance *instance,
/* buffer header */
m.u.buffer_from_host.buffer_header.cmd = 0;
- m.u.buffer_from_host.buffer_header.data =
- (u32)(unsigned long)buf->buffer;
+ if (port->zero_copy)
+ m.u.buffer_from_host.buffer_header.data = buf->vc_handle;
+ else
+ m.u.buffer_from_host.buffer_header.data =
+ (u32)(unsigned long)buf->buffer;
+
m.u.buffer_from_host.buffer_header.alloc_size = buf->buffer_size;
m.u.buffer_from_host.buffer_header.length = 0; /* nothing used yet */
m.u.buffer_from_host.buffer_header.offset = 0; /* no offset */
@@ -484,6 +489,20 @@ static void buffer_to_host_cb(struct vchiq_mmal_instance *instance,
msg_context->u.bulk.status = msg->h.status;
+ } else if (msg->u.buffer_from_host.is_zero_copy) {
+ /*
+ * Zero copy buffer, so nothing to do.
+ * Copy buffer info and make callback.
+ */
+ msg_context->u.bulk.buffer_used =
+ msg->u.buffer_from_host.buffer_header.length;
+ msg_context->u.bulk.mmal_flags =
+ msg->u.buffer_from_host.buffer_header.flags;
+ msg_context->u.bulk.dts =
+ msg->u.buffer_from_host.buffer_header.dts;
+ msg_context->u.bulk.pts =
+ msg->u.buffer_from_host.buffer_header.pts;
+
} else if (msg->u.buffer_from_host.buffer_header.length == 0) {
/* empty buffer */
if (msg->u.buffer_from_host.buffer_header.flags &
@@ -1431,6 +1450,9 @@ int vchiq_mmal_port_parameter_set(struct vchiq_mmal_instance *instance,
mutex_unlock(&instance->vchiq_mutex);
+ if (parameter == MMAL_PARAMETER_ZERO_COPY && !ret)
+ port->zero_copy = !!(*(bool *)value);
+
return ret;
}
EXPORT_SYMBOL_GPL(vchiq_mmal_port_parameter_set);
@@ -1599,6 +1621,31 @@ int vchiq_mmal_submit_buffer(struct vchiq_mmal_instance *instance,
unsigned long flags = 0;
int ret;
+ /*
+ * We really want to do this in mmal_vchi_buffer_init but can't as
+ * videobuf2 won't let us have the dmabuf there.
+ */
+ if (port->zero_copy && buffer->dma_buf && !buffer->vcsm_handle) {
+ pr_debug("%s: import dmabuf %p\n", __func__, buffer->dma_buf);
+ ret = vc_sm_cma_import_dmabuf(buffer->dma_buf,
+ &buffer->vcsm_handle);
+ if (ret) {
+ pr_err("%s: vc_sm_import_dmabuf_fd failed, ret %d\n",
+ __func__, ret);
+ return ret;
+ }
+
+ buffer->vc_handle = vc_sm_cma_int_handle(buffer->vcsm_handle);
+ if (!buffer->vc_handle) {
+ pr_err("%s: vc_sm_int_handle failed %d\n",
+ __func__, ret);
+ vc_sm_cma_free(buffer->vcsm_handle);
+ return ret;
+ }
+ pr_debug("%s: import dmabuf %p - got vc handle %08X\n",
+ __func__, buffer->dma_buf, buffer->vc_handle);
+ }
+
ret = buffer_from_host(instance, port, buffer);
if (ret == -EINVAL) {
/* Port is disabled. Queue for when it is enabled. */
@@ -1632,6 +1679,16 @@ int mmal_vchi_buffer_cleanup(struct mmal_buffer *buf)
release_msg_context(msg_context);
buf->msg_context = NULL;
+ if (buf->vcsm_handle) {
+ int ret;
+
+ pr_debug("%s: vc_sm_cma_free on handle %p\n", __func__,
+ buf->vcsm_handle);
+ ret = vc_sm_cma_free(buf->vcsm_handle);
+ if (ret)
+ pr_err("%s: vcsm_free failed, ret %d\n", __func__, ret);
+ buf->vcsm_handle = 0;
+ }
return 0;
}
EXPORT_SYMBOL_GPL(mmal_vchi_buffer_cleanup);
diff --git a/drivers/platform/raspberrypi/vchiq-mmal/mmal-vchiq.h b/drivers/platform/raspberrypi/vchiq-mmal/mmal-vchiq.h
index 8c3959f6f97fb21bcaf2f21589ef291e754e7c19..9d31816f5be54d74bfdf42381b38e340279ffee4 100644
--- a/drivers/platform/raspberrypi/vchiq-mmal/mmal-vchiq.h
+++ b/drivers/platform/raspberrypi/vchiq-mmal/mmal-vchiq.h
@@ -49,6 +49,7 @@ typedef void (*vchiq_mmal_buffer_cb)(struct vchiq_mmal_instance *instance,
struct vchiq_mmal_port {
bool enabled;
+ u32 zero_copy:1;
u32 handle;
u32 type; /* port type, cached to use on port info set */
u32 index; /* port index, cached to use on port info set */
--
2.52.0
Powered by blists - more mailing lists