[v2,2/2] soc: qcom: add MDSS DSM memory driver

Add a driver for the Qualcomm Modem Processing SubSystem DSM memory
used to assign such regions of memory with remote MPSS processors.

This memory zone is shared between the APPS and the MPSS subsystem,
and must be configured during the whole lifetime of the system.

Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
---
 drivers/of/platform.c           |  1 +
 drivers/soc/qcom/Kconfig        | 10 +++++
 drivers/soc/qcom/Makefile       |  1 +
 drivers/soc/qcom/mpss_dsm_mem.c | 95 +++++++++++++++++++++++++++++++++++++++++
 4 files changed, 107 insertions(+)

On 18/11/2022 08:53, Neil Armstrong wrote:
> Add a driver for the Qualcomm Modem Processing SubSystem DSM memory
> used to assign such regions of memory with remote MPSS processors.
> 
> This memory zone is shared between the APPS and the MPSS subsystem,
> and must be configured during the whole lifetime of the system.
> 
> Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
> ---
>   drivers/of/platform.c           |  1 +
>   drivers/soc/qcom/Kconfig        | 10 +++++
>   drivers/soc/qcom/Makefile       |  1 +
>   drivers/soc/qcom/mpss_dsm_mem.c | 95 +++++++++++++++++++++++++++++++++++++++++
>   4 files changed, 107 insertions(+)
> 
> diff --git a/drivers/of/platform.c b/drivers/of/platform.c
> index 3507095a69f6..d4bb03292f45 100644
> --- a/drivers/of/platform.c
> +++ b/drivers/of/platform.c
> @@ -505,6 +505,7 @@ EXPORT_SYMBOL_GPL(of_platform_default_populate);
>   
>   static const struct of_device_id reserved_mem_matches[] = {
>   	{ .compatible = "phram" },
> +	{ .compatible = "qcom,mpss-dsm-mem" },
>   	{ .compatible = "qcom,rmtfs-mem" },
>   	{ .compatible = "qcom,cmd-db" },
>   	{ .compatible = "qcom,smem" },
> diff --git a/drivers/soc/qcom/Kconfig b/drivers/soc/qcom/Kconfig
> index 024e420f1bb7..7624a8af56bf 100644
> --- a/drivers/soc/qcom/Kconfig
> +++ b/drivers/soc/qcom/Kconfig
> @@ -95,6 +95,16 @@ config QCOM_QMI_HELPERS
>   	tristate
>   	depends on NET
>   
> +config QCOM_MPSS_DSM_MEM
> +	tristate "Qualcomm Modem Processing SubSystem DSM memory driver"
> +	depends on ARCH_QCOM
> +	select QCOM_SCM
> +	help
> +	  The Qualcomm Modem Processing SubSystem DSM memory driver is used to
> +	  assign regions of DSM memory with remote MPSS processors.
> +
> +	  Say y here if you intend to boot the modem remoteproc.
> +
>   config QCOM_RMTFS_MEM
>   	tristate "Qualcomm Remote Filesystem memory driver"
>   	depends on ARCH_QCOM
> diff --git a/drivers/soc/qcom/Makefile b/drivers/soc/qcom/Makefile
> index d66604aff2b0..0d0e850f1a18 100644
> --- a/drivers/soc/qcom/Makefile
> +++ b/drivers/soc/qcom/Makefile
> @@ -16,6 +16,7 @@ qcom_rpmh-y			+= rpmh-rsc.o
>   qcom_rpmh-y			+= rpmh.o
>   obj-$(CONFIG_QCOM_SMD_RPM)	+= smd-rpm.o
>   obj-$(CONFIG_QCOM_SMEM) +=	smem.o
> +obj-$(CONFIG_QCOM_MPSS_DSM_MEM) += mpss_dsm_mem.o
>   obj-$(CONFIG_QCOM_SMEM_STATE) += smem_state.o
>   obj-$(CONFIG_QCOM_SMP2P)	+= smp2p.o
>   obj-$(CONFIG_QCOM_SMSM)	+= smsm.o
> diff --git a/drivers/soc/qcom/mpss_dsm_mem.c b/drivers/soc/qcom/mpss_dsm_mem.c
> new file mode 100644
> index 000000000000..5584bd101aee
> --- /dev/null
> +++ b/drivers/soc/qcom/mpss_dsm_mem.c
> @@ -0,0 +1,95 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (c) 2022 Linaro Ltd.
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/err.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/of.h>
> +#include <linux/of_reserved_mem.h>
> +#include <linux/slab.h>
> +#include <linux/qcom_scm.h>
> +
> +struct qcom_mpss_dsm_mem {
> +	phys_addr_t addr;
> +	phys_addr_t size;
> +
> +	unsigned int perms;
> +};
> +
> +static int qcom_mpss_dsm_mem_probe(struct platform_device *pdev)
> +{
> +	struct device_node *node = pdev->dev.of_node;
> +	struct qcom_scm_vmperm perm;
> +	struct reserved_mem *rmem;
> +	struct qcom_mpss_dsm_mem *mpss_dsm_mem;
> +	int ret;
> +
> +	if (!qcom_scm_is_available())
> +		return -EPROBE_DEFER;
> +
> +	rmem = of_reserved_mem_lookup(node);
> +	if (!rmem) {
> +		dev_err(&pdev->dev, "failed to acquire memory region\n");
> +		return -EINVAL;
> +	}
> +
> +	mpss_dsm_mem = kzalloc(sizeof(*mpss_dsm_mem), GFP_KERNEL);
> +	if (!mpss_dsm_mem)
> +		return -ENOMEM;
> +
> +	mpss_dsm_mem->addr = rmem->base;
> +	mpss_dsm_mem->size = rmem->size;
> +
> +	perm.vmid = QCOM_SCM_VMID_MSS_MSA;
> +	perm.perm = QCOM_SCM_PERM_RW;
> +
> +	mpss_dsm_mem->perms = BIT(QCOM_SCM_VMID_HLOS);
> +	ret = qcom_scm_assign_mem(mpss_dsm_mem->addr, mpss_dsm_mem->size,
> +				  &mpss_dsm_mem->perms, &perm, 1);
> +	if (ret < 0) {
> +		dev_err(&pdev->dev, "assign memory failed\n");

memory leak here?


> +		return ret;
> +	}
> +
> +	dev_set_drvdata(&pdev->dev, mpss_dsm_mem);
> +
> +	return 0;
> +}
> +
> +static int qcom_mpss_dsm_mem_remove(struct platform_device *pdev)
> +{
> +	struct qcom_mpss_dsm_mem *mpss_dsm_mem = dev_get_drvdata(&pdev->dev);
> +	struct qcom_scm_vmperm perm;
> +
> +	perm.vmid = QCOM_SCM_VMID_HLOS;
> +	perm.perm = QCOM_SCM_PERM_RW;
> +
> +	qcom_scm_assign_mem(mpss_dsm_mem->addr, mpss_dsm_mem->size,
> +			    &mpss_dsm_mem->perms, &perm, 1);
> +

same here.

> +	return 0;
> +}
> +
> +static const struct of_device_id qcom_mpss_dsm_mem_of_match[] = {
> +	{ .compatible = "qcom,mpss-dsm-mem" },
> +	{}
> +};
> +MODULE_DEVICE_TABLE(of, qcom_mpss_dsm_mem_of_match);
> +
> +static struct platform_driver qcom_mpss_dsm_mem_driver = {
> +	.probe = qcom_mpss_dsm_mem_probe,
> +	.remove = qcom_mpss_dsm_mem_remove,
> +	.driver  = {
> +		.name  = "qcom_mpss_dsm_mem",
> +		.of_match_table = qcom_mpss_dsm_mem_of_match,
> +	},
> +};
> +
> +module_platform_driver(qcom_mpss_dsm_mem_driver);
> +
> +MODULE_AUTHOR("Linaro Ltd");
> +MODULE_DESCRIPTION("Qualcomm DSM memory driver");
> +MODULE_LICENSE("GPL");
>