[v2,3/4] soc: qcom: smem: Support reserved-memory description

Practically all modern Qualcomm platforms has a single reserved-memory
region for SMEM. So rather than having to describe SMEM in the form of a
node with a reference to a reserved-memory node, allow the SMEM device
to be instantiated directly from the reserved-memory node.

The current means of falling back to dereferencing the "memory-region"
is kept as a fallback, if it's determined that the SMEM node is a
reserved-memory node.

The "qcom,smem" compatible is added to the reserved_mem_matches list, to
allow the reserved-memory device to be probed.

In order to retain the readability of the code, the resolution of
resources is split from the actual ioremapping.

Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

---

Changes since v1:
- None

 drivers/of/platform.c   |  1 +
 drivers/soc/qcom/smem.c | 57 ++++++++++++++++++++++++++++-------------
 2 files changed, 40 insertions(+), 18 deletions(-)

-- 
2.29.2

Hi Bjorn,

On 9/30/21 9:21 PM, Bjorn Andersson wrote:
> Practically all modern Qualcomm platforms has a single reserved-memory

> region for SMEM. So rather than having to describe SMEM in the form of a

> node with a reference to a reserved-memory node, allow the SMEM device

> to be instantiated directly from the reserved-memory node.

> 

> The current means of falling back to dereferencing the "memory-region"

> is kept as a fallback, if it's determined that the SMEM node is a

> reserved-memory node.

> 

> The "qcom,smem" compatible is added to the reserved_mem_matches list, to

> allow the reserved-memory device to be probed.

> 

> In order to retain the readability of the code, the resolution of

> resources is split from the actual ioremapping.

> 

> Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

> ---

> 

> Changes since v1:

> - None

> 

>   drivers/of/platform.c   |  1 +

>   drivers/soc/qcom/smem.c | 57 ++++++++++++++++++++++++++++-------------

>   2 files changed, 40 insertions(+), 18 deletions(-)

> 

> diff --git a/drivers/of/platform.c b/drivers/of/platform.c

> index 32d5ff8df747..07813fb1ef37 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 = "qcom,rmtfs-mem" },

>   	{ .compatible = "qcom,cmd-db" },

> +	{ .compatible = "qcom,smem" },

>   	{ .compatible = "ramoops" },

>   	{ .compatible = "nvmem-rmem" },

>   	{}

> diff --git a/drivers/soc/qcom/smem.c b/drivers/soc/qcom/smem.c

> index 4fb5aeeb0843..c7e519bfdc8a 100644

> --- a/drivers/soc/qcom/smem.c

> +++ b/drivers/soc/qcom/smem.c

> @@ -9,6 +9,7 @@

>   #include <linux/module.h>

>   #include <linux/of.h>

>   #include <linux/of_address.h>

> +#include <linux/of_reserved_mem.h>

>   #include <linux/platform_device.h>

>   #include <linux/sizes.h>

>   #include <linux/slab.h>

> @@ -240,7 +241,7 @@ static const u8 SMEM_INFO_MAGIC[] = { 0x53, 0x49, 0x49, 0x49 }; /* SIII */

>    * @size:	size of the memory region

>    */

>   struct smem_region {

> -	u32 aux_base;

> +	phys_addr_t aux_base;

>   	void __iomem *virt_base;

>   	size_t size;

>   };

> @@ -499,7 +500,7 @@ static void *qcom_smem_get_global(struct qcom_smem *smem,

>   	for (i = 0; i < smem->num_regions; i++) {

>   		region = &smem->regions[i];

>   

> -		if (region->aux_base == aux_base || !aux_base) {

> +		if ((u32)region->aux_base == aux_base || !aux_base) {

>   			if (size != NULL)

>   				*size = le32_to_cpu(entry->size);

>   			return region->virt_base + le32_to_cpu(entry->offset);

> @@ -664,7 +665,7 @@ phys_addr_t qcom_smem_virt_to_phys(void *p)

>   		if (p < region->virt_base + region->size) {

>   			u64 offset = p - region->virt_base;

>   

> -			return (phys_addr_t)region->aux_base + offset;

> +			return region->aux_base + offset;

>   		}

>   	}

>   

> @@ -863,12 +864,12 @@ qcom_smem_enumerate_partitions(struct qcom_smem *smem, u16 local_host)

>   	return 0;

>   }

>   

> -static int qcom_smem_map_memory(struct qcom_smem *smem, struct device *dev,

> -				const char *name, int i)

> +static int qcom_smem_resolve_mem(struct qcom_smem *smem, const char *name,

> +				 struct smem_region *region)

>   {

> +	struct device *dev = smem->dev;

>   	struct device_node *np;

>   	struct resource r;

> -	resource_size_t size;

>   	int ret;

>   

>   	np = of_parse_phandle(dev->of_node, name, 0);

> @@ -881,13 +882,9 @@ static int qcom_smem_map_memory(struct qcom_smem *smem, struct device *dev,

>   	of_node_put(np);

>   	if (ret)

>   		return ret;

> -	size = resource_size(&r);

>   

> -	smem->regions[i].virt_base = devm_ioremap_wc(dev, r.start, size);

> -	if (!smem->regions[i].virt_base)

> -		return -ENOMEM;

> -	smem->regions[i].aux_base = (u32)r.start;

> -	smem->regions[i].size = size;

> +	region->aux_base = r.start;

> +	region->size = resource_size(&r);

>   

>   	return 0;

>   }

> @@ -895,12 +892,14 @@ static int qcom_smem_map_memory(struct qcom_smem *smem, struct device *dev,

>   static int qcom_smem_probe(struct platform_device *pdev)

>   {

>   	struct smem_header *header;

> +	struct reserved_mem *rmem;

>   	struct qcom_smem *smem;

>   	size_t array_size;

>   	int num_regions;

>   	int hwlock_id;

>   	u32 version;

>   	int ret;

> +	int i;


Just a nitpicking, the index can be unsigned.

>   

>   	num_regions = 1;

>   	if (of_find_property(pdev->dev.of_node, "qcom,rpm-msg-ram", NULL))

> @@ -914,13 +913,35 @@ static int qcom_smem_probe(struct platform_device *pdev)

>   	smem->dev = &pdev->dev;

>   	smem->num_regions = num_regions;

>   

> -	ret = qcom_smem_map_memory(smem, &pdev->dev, "memory-region", 0);

> -	if (ret)

> -		return ret;

> +	rmem = of_reserved_mem_lookup(pdev->dev.of_node);

> +	if (rmem) {

> +		smem->regions[0].aux_base = rmem->base;

> +		smem->regions[0].size = rmem->size;

> +	} else {

> +		/*

> +		 * Fall back to the memory-region reference, if we're not a

> +		 * reserved-memory node.

> +		 */

> +		ret = qcom_smem_resolve_mem(smem, "memory-region", &smem->regions[0]);

> +		if (ret)

> +			return ret;

> +	}

>   

> -	if (num_regions > 1 && (ret = qcom_smem_map_memory(smem, &pdev->dev,

> -					"qcom,rpm-msg-ram", 1)))

> -		return ret;

> +	if (num_regions > 1) {

> +		ret = qcom_smem_resolve_mem(smem, "qcom,rpm-msg-ram", &smem->regions[1]);

> +		if (ret)

> +			return ret;

> +	}

> +

> +	for (i = 0; i < num_regions; i++) {

> +		smem->regions[i].virt_base = devm_ioremap_wc(&pdev->dev,

> +							     smem->regions[i].aux_base,

> +							     smem->regions[i].size);

> +		if (!smem->regions[i].virt_base) {

> +			dev_err(&pdev->dev, "failed to remap %pa\n", &smem->regions[i].aux_base);

> +			return -ENOMEM;

> +		}

> +	}

>   

>   	header = smem->regions[0].virt_base;

>   	if (le32_to_cpu(header->initialized) != 1 ||

> 


--
Best wishes,
Vladimir

On Thu, Sep 30, 2021 at 11:21:10AM -0700, Bjorn Andersson wrote:
> Practically all modern Qualcomm platforms has a single reserved-memory

> region for SMEM. So rather than having to describe SMEM in the form of a

> node with a reference to a reserved-memory node, allow the SMEM device

> to be instantiated directly from the reserved-memory node.

> 

> The current means of falling back to dereferencing the "memory-region"

> is kept as a fallback, if it's determined that the SMEM node is a

> reserved-memory node.

> 

> The "qcom,smem" compatible is added to the reserved_mem_matches list, to

> allow the reserved-memory device to be probed.

> 

> In order to retain the readability of the code, the resolution of

> resources is split from the actual ioremapping.

> 

> Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

> ---

> 

> Changes since v1:

> - None

> 

>  drivers/of/platform.c   |  1 +


Acked-by: Rob Herring <robh@kernel.org>


>  drivers/soc/qcom/smem.c | 57 ++++++++++++++++++++++++++++-------------

>  2 files changed, 40 insertions(+), 18 deletions(-)