Re: [PATCH v2 5/6] soc: qcom: add OCMEM driver

Brian Masney
2019-06-19T10:27:39Z

On Tue, Jun 18, 2019 at 10:32:08PM -0400, Brian Masney wrote:
> +++ b/include/soc/qcom/ocmem.h
> @@ -0,0 +1,62 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * The On Chip Memory (OCMEM) allocator allows various clients to allocate
> + * memory from OCMEM based on performance, latency and power requirements.
> + * This is typically used by the GPU, camera/video, and audio components on
> + * some Snapdragon SoCs.
> + *
> + * Copyright (C) 2019 Brian Masney <masneyb@onstation.org>
> + * Copyright (C) 2015 Red Hat. Author: Rob Clark <robdclark@gmail.com>
> + */
> +
> +#ifndef __OCMEM_H__
> +#define __OCMEM_H__
> +
> +enum ocmem_client {
> + /* GMEM clients */
> + OCMEM_GRAPHICS = 0x0,
> + /*
> + * TODO add more once ocmem_allocate() is clever enough to
> + * deal with multiple clients.
> + */
> + OCMEM_CLIENT_MAX,
> +};
> +
> +struct ocmem;
> +
> +struct ocmem_buf {
> + unsigned long offset;
> + unsigned long addr;
> + unsigned long len;
> +};
> +
> +#if IS_ENABLED(CONFIG_QCOM_OCMEM)
> +
> +struct ocmem *of_get_ocmem(struct device *dev);
> +struct ocmem_buf *ocmem_allocate(struct ocmem *ocmem, enum ocmem_client client,
> + unsigned long size);
> +void ocmem_free(struct ocmem *ocmem, enum ocmem_client client,
> + struct ocmem_buf *buf);
> +
> +#else /* IS_ENABLED(CONFIG_QCOM_OCMEM) */
> +
> +static inline struct ocmem *of_get_ocmem(struct device *dev)
> +{
> + return NULL;

This, along with ocmem_allocate() below, need to return ERR_PTR(-ENOSYS).
adreno_gpu_ocmem_init() needs to check for this error code:

ocmem = of_get_ocmem(dev);
if (IS_ERR(ocmem)) {
if (PTR_ERR(ocmem) == -ENXIO || PTR_ERR(ocmem) == -ENOSYS) {
/*
* Return success since either the ocmem property was
* not specified in device tree, or ocmem support is
* not compiled into the kernel.
*/
return 0;
}

return PTR_ERR(ocmem);
}

Brian

> +}
> +
> +static inline struct ocmem_buf *ocmem_allocate(struct ocmem *ocmem,
> + enum ocmem_client client,
> + unsigned long size)
> +{
> + return NULL;
> +}
> +
> +static inline void ocmem_free(struct ocmem *ocmem, enum ocmem_client client,
> + struct ocmem_buf *buf)
> +{
> +}
> +
> +#endif /* IS_ENABLED(CONFIG_QCOM_OCMEM) */
> +
> +#endif /* __OCMEM_H__ */
> --
> 2.20.1