Currently, the kernel is automatically doing an IOMMU memory mapping. But we want to do it automatically for two reasons: - to reduce the overhead of each APU operation - to get the device address and use it as input for an operation This adds 2 IOCTL to manually IOMMU map and unmap memory.
Signed-off-by: Alexandre Bailon abailon@baylibre.com --- drivers/rpmsg/apu_rpmsg.c | 52 ++++++++++++++++++++++++++++++---- include/uapi/linux/apu_rpmsg.h | 7 +++++ 2 files changed, 53 insertions(+), 6 deletions(-)
diff --git a/drivers/rpmsg/apu_rpmsg.c b/drivers/rpmsg/apu_rpmsg.c index 343bd08a859a..4c064feddf5a 100644 --- a/drivers/rpmsg/apu_rpmsg.c +++ b/drivers/rpmsg/apu_rpmsg.c @@ -114,7 +114,7 @@ static int apu_rpmsg_callback(struct rpmsg_device *rpdev, void *data, int count, }
static struct apu_buffer *apu_device_memory_map(struct rpmsg_apu *apu, - uint32_t fd, struct rpmsg_request *rpmsg_req) + uint32_t fd) { struct rpmsg_device *rpdev = apu->rpdev; struct apu_buffer *buffer; @@ -129,10 +129,6 @@ static struct apu_buffer *apu_device_memory_map(struct rpmsg_apu *apu, list_for_each_entry(buffer, &apu->buffers, node) { if (buffer->fd == fd) { kref_get(&buffer->refcount); - if (rpmsg_req) - list_add(&buffer->req_node, - &rpmsg_req->buffers); - return buffer; } } @@ -230,6 +226,44 @@ static void apu_device_memory_unmap(struct kref *ref) kfree(buffer); }
+static int apu_iommu_mmap_ioctl(struct rpmsg_apu *apu, void __user *argp) +{ + struct apu_iommu_mmap apu_iommu_mmap; + struct apu_buffer *buffer; + int ret; + + if (copy_from_user(&apu_iommu_mmap, argp, sizeof(apu_iommu_mmap))) + return -EFAULT; + + buffer = apu_device_memory_map(apu, apu_iommu_mmap.fd); + if (!buffer) + return -ENOMEM; + + apu_iommu_mmap.da = buffer->iova; + if (copy_to_user(argp, &apu_iommu_mmap, sizeof(apu_iommu_mmap))) + ret = -EFAULT; + + return 0; +} + +static int apu_iommu_munmap_ioctl(struct rpmsg_apu *apu, void __user *argp) +{ + u32 fd; + struct apu_buffer *buffer, *tmp; + + if (copy_from_user(&fd, argp, sizeof(fd))) + return -EFAULT; + + list_for_each_entry_safe(buffer, tmp, &apu->buffers, node) { + if (buffer->fd == fd) { + kref_put(&buffer->refcount, apu_device_memory_unmap); + return 0; + } + } + + return -EINVAL; +} + static int apu_send_request(struct rpmsg_apu *apu, struct apu_request *req) { @@ -266,7 +300,7 @@ static int apu_send_request(struct rpmsg_apu *apu,
INIT_LIST_HEAD(&rpmsg_req->buffers); for (i = 0; i < req->count; i++) { - buffer = apu_device_memory_map(apu, fd[i], rpmsg_req); + buffer = apu_device_memory_map(apu, fd[i]); if (IS_ERR(buffer)) { ret = PTR_ERR(buffer); goto err_free_memory; @@ -417,6 +451,12 @@ static long rpmsg_eptdev_ioctl(struct file *fp, unsigned int cmd, } spin_unlock_irqrestore(&apu->ctx_lock, flags);
+ break; + case APU_IOMMU_MMAP: + ret = apu_iommu_mmap_ioctl(apu, argp); + break; + case APU_IOMMU_MUNMAP: + ret = apu_iommu_munmap_ioctl(apu, argp); break; default: ret = -EINVAL; diff --git a/include/uapi/linux/apu_rpmsg.h b/include/uapi/linux/apu_rpmsg.h index f61207520254..e9b841dcbcb4 100644 --- a/include/uapi/linux/apu_rpmsg.h +++ b/include/uapi/linux/apu_rpmsg.h @@ -31,10 +31,17 @@ struct apu_request { __u8 data[0]; };
+struct apu_iommu_mmap { + __u32 fd; + __u32 da; +}; + /* Send synchronous request to an APU */
#define APU_SEND_REQ_IOCTL _IOW(0xb7, 0x2, struct apu_request) #define APU_GET_NEXT_AVAILABLE_IOCTL _IOR(0xb7, 0x3, __u16) #define APU_GET_RESP _IOWR(0xb7, 0x4, struct apu_request) +#define APU_IOMMU_MMAP _IOWR(0xb7, 0x5, struct apu_iommu_mmap) +#define APU_IOMMU_MUNMAP _IOWR(0xb7, 0x6, __u32)
#endif