Re: [PATCH v1] misc: fastrpc: Fix remote heap allocation request

[Srinivas Kandagatla]

On 05/06/2023 15:11, Ekansh Gupta wrote:
> Remote heap is used by DSP audioPD on need basis. This memory is
> allocated from reserved CMA memory region and is then shared with
> audioPD to use it for it's functionality.
>
> Current implementation of remote heap is not allocating the memory
> from CMA region, instead it is allocating the memory from SMMU
> context bank. The arguments passed to scm call for the reassignment
> of ownership is also not correct. Added changes to allocate CMA
> memory and have a proper ownership reassignment.
>
> Fixes: 532ad70c6d44 ("misc: fastrpc: Add mmap request assigning for static PD pool")
> Cc: stable <stable@xxxxxxxxxx>
> Tested-by: Ekansh Gupta <quic_ekangupt@xxxxxxxxxxx>
> Signed-off-by: Ekansh Gupta <quic_ekangupt@xxxxxxxxxxx>
> ---
>   drivers/misc/fastrpc.c | 26 ++++++++++++++++++++------
>   1 file changed, 20 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c
> index 30d4d04..f5fc2de 100644
> --- a/drivers/misc/fastrpc.c
> +++ b/drivers/misc/fastrpc.c
> @@ -1866,7 +1866,11 @@ static int fastrpc_req_mmap(struct fastrpc_user *fl, char __user *argp)
>   		return -EINVAL;
>   	}
>   
> -	err = fastrpc_buf_alloc(fl, fl->sctx->dev, req.size, &buf);
> +	if (req.flags == ADSP_MMAP_REMOTE_HEAP_ADDR)
> +		err = fastrpc_remote_heap_alloc(fl, dev, req.size, &buf);
> +	else
> +		err = fastrpc_buf_alloc(fl, dev, req.size, &buf);
> +
>   	if (err) {
>   		dev_err(dev, "failed to allocate buffer\n");
>   		return err;
> @@ -1905,12 +1909,22 @@ static int fastrpc_req_mmap(struct fastrpc_user *fl, char __user *argp)
>   
>   	/* Add memory to static PD pool, protection thru hypervisor */
>   	if (req.flags == ADSP_MMAP_REMOTE_HEAP_ADDR && fl->cctx->vmcount) {
> -		struct qcom_scm_vmperm perm;
> +		u64 src_perms = BIT(QCOM_SCM_VMID_HLOS);
> +		struct qcom_scm_vmperm *dst_perms;
> +		u32 i;
>   
> -		perm.vmid = QCOM_SCM_VMID_HLOS;
> -		perm.perm = QCOM_SCM_PERM_RWX;
> -		err = qcom_scm_assign_mem(buf->phys, buf->size,
> -			&fl->cctx->perms, &perm, 1);
> +		dst_perms = kcalloc(fl->cctx->vmcount,
> +			sizeof(struct qcom_scm_vmperm), GFP_KERNEL);
> +		if (!dst_perms)
> +			return -ENOMEM;
> +		for (i = 0; i < fl->cctx->vmcount; i++) {
> +			dst_perms[i].vmid = fl->cctx->vmperms[i].vmid;
> +			dst_perms[i].perm = fl->cctx->vmperms[i].perm;
> +		}
> +
Why not use fl->cctx->vmperms instead of allocating a new dst_perms?

--srini

> +		err = qcom_scm_assign_mem(buf->phys,(u64)buf->size,
> +			&src_perms, dst_perms, fl->cctx->vmcount);
> +		kfree(dst_perms);
>   		if (err) {
>   			dev_err(fl->sctx->dev, "Failed to assign memory phys 0x%llx size 0x%llx err %d",
>   					buf->phys, buf->size, err);