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Commit 9107be2a authored by Nikhilesh Reddy's avatar Nikhilesh Reddy Committed by Ritesh Harjani
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uio: Add snapshot of MSM sharedmem driver 



This is a snapshot of the MSM sharedmem driver as of msm-3.14
commit:
commit 149717c082aab81 ("uio: msm_sharedmem: Add custom mmap") +
sharedmem qmi logic is removed.

The following changes are included:
02d55287 uio: msm_sharedmem: Restrict debugfs write to root.
de961fc7 uio: msm_sharedmem: Return ENOMEM if the shared mem addr
	 is zero.
b974ce64 uio: msm_sharedmem: Add addtional information to debugfs
c46af547 uio: msm_sharedmem: Add support for dynamic shared memory
	 allocation

Change-Id: I49902f018bde1d59d41027b7e46268cc17231a3e
Signed-off-by: default avatarNikhilesh Reddy <reddyn@codeaurora.org>
Signed-off-by: default avatarRitesh Harjani <riteshh@codeaurora.org>
parent fd32b3b7

Documentation/devicetree/bindings/uio/msm_sharedmem.txt

0 → 100644
+18 −0
Original line number Original line Diff line number Diff line 
msm_sharedmem provides the shared memory addresses for various clients in user-space



Required properties:

- compatible:		Must be "qcom,sharedmem-uio"

- reg : The address and size of the shared memory. The address/sizes may vary.

	A reg address of Zero indicates that the shared memory is dynamically

	allocated using dma_alloc_coherent. A non zero reg address is used

	directly.

- reg-names : Indicates various client-names.

- qcom,client-id : The client id for the QMI clients.



Example:

	qcom,msm_sharedmem@0dc80000 {

		compatible = "qcom,sharedmem-uio";

		reg = <0x0dc80000 0x00180000>,

		reg-names = "rmtfs";

		qcom,client-id = <0x00000001>;

	};

drivers/uio/Kconfig

+7 −0
Original line number Original line Diff line number Diff line
@@ -164,4 +164,11 @@ config UIO_HV_GENERIC 
	  to network and storage devices from userspace.

	  to network and storage devices from userspace.





	  If you compile this as a module, it will be called uio_hv_generic.

	  If you compile this as a module, it will be called uio_hv_generic.

config UIO_MSM_SHAREDMEM

	bool "MSM shared memory driver"

	default n

	help

	  Provides the clients with their respective alloted shared memory

	  addresses which are used as transport buffer.



endif
 
endif

drivers/uio/Makefile

+1 −0
Original line number Original line Diff line number Diff line
@@ -11,3 +11,4 @@ obj-$(CONFIG_UIO_PRUSS) += uio_pruss.o 
obj-$(CONFIG_UIO_MF624)         += uio_mf624.o

obj-$(CONFIG_UIO_MF624)         += uio_mf624.o

obj-$(CONFIG_UIO_FSL_ELBC_GPCM)	+= uio_fsl_elbc_gpcm.o

obj-$(CONFIG_UIO_FSL_ELBC_GPCM)	+= uio_fsl_elbc_gpcm.o

obj-$(CONFIG_UIO_HV_GENERIC)	+= uio_hv_generic.o

obj-$(CONFIG_UIO_HV_GENERIC)	+= uio_hv_generic.o

obj-$(CONFIG_UIO_MSM_SHAREDMEM) += msm_sharedmem/

drivers/uio/msm_sharedmem/Makefile

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+1 −0
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obj-$(CONFIG_UIO_MSM_SHAREDMEM) := msm_sharedmem.o

drivers/uio/msm_sharedmem/msm_sharedmem.c

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+191 −0
Original line number Original line Diff line number Diff line 
/* Copyright (c) 2013-2018, The Linux Foundation. All rights reserved.

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 and

 * only version 2 as published by the Free Software Foundation.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 */



#define DRIVER_NAME "msm_sharedmem"

#define pr_fmt(fmt) DRIVER_NAME ": %s: " fmt, __func__



#include <linux/uio_driver.h>

#include <linux/module.h>

#include <linux/platform_device.h>

#include <linux/err.h>

#include <linux/of.h>

#include <linux/dma-mapping.h>



#define CLIENT_ID_PROP "qcom,client-id"



static int uio_get_mem_index(struct uio_info *info, struct vm_area_struct *vma)

{

	if (vma->vm_pgoff >= MAX_UIO_MAPS)

		return -EINVAL;



	if (info->mem[vma->vm_pgoff].size == 0)

		return -EINVAL;



	return (int)vma->vm_pgoff;

}



static int sharedmem_mmap(struct uio_info *info, struct vm_area_struct *vma)

{

	int result;

	struct uio_mem *mem;

	int mem_index = uio_get_mem_index(info, vma);



	if (mem_index < 0) {

		pr_err("mem_index is invalid errno %d\n", mem_index);

		return mem_index;

	}



	mem = info->mem + mem_index;



	if (vma->vm_end - vma->vm_start > mem->size) {

		pr_err("vm_end[%lu] - vm_start[%lu] [%lu] > mem->size[%lu]\n",

			vma->vm_end, vma->vm_start,

			(vma->vm_end - vma->vm_start), mem->size);

		return -EINVAL;

	}

	pr_debug("Attempting to setup mmap.\n");



	vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);



	result = remap_pfn_range(vma,

				 vma->vm_start,

				 mem->addr >> PAGE_SHIFT,

				 vma->vm_end - vma->vm_start,

				 vma->vm_page_prot);

	if (result != 0)

		pr_err("mmap Failed with errno %d\n", result);

	else

		pr_debug("mmap success\n");



	return result;

}



static int msm_sharedmem_probe(struct platform_device *pdev)

{

	int ret = 0;

	struct uio_info *info = NULL;

	struct resource *clnt_res = NULL;

	u32 client_id = ((u32)~0U);

	u32 shared_mem_size = 0;

	void *shared_mem = NULL;

	phys_addr_t shared_mem_pyhsical = 0;

	bool is_addr_dynamic = false;



	/* Get the addresses from platform-data */

	if (!pdev->dev.of_node) {

		pr_err("Node not found\n");

		ret = -ENODEV;

		goto out;

	}

	clnt_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

	if (!clnt_res) {

		pr_err("resource not found\n");

		return -ENODEV;

	}



	ret = of_property_read_u32(pdev->dev.of_node, CLIENT_ID_PROP,

				   &client_id);

	if (ret) {

		client_id = ((u32)~0U);

		pr_warn("qcom,client-id property not found\n");

	}



	info = devm_kzalloc(&pdev->dev, sizeof(struct uio_info), GFP_KERNEL);

	if (!info)

		return -ENOMEM;



	shared_mem_size = resource_size(clnt_res);

	shared_mem_pyhsical = clnt_res->start;



	if (shared_mem_size == 0) {

		pr_err("Shared memory size is zero\n");

		return -EINVAL;

	}



	if (shared_mem_pyhsical == 0) {

		is_addr_dynamic = true;

		shared_mem = dma_alloc_coherent(&pdev->dev, shared_mem_size,

					&shared_mem_pyhsical, GFP_KERNEL);

		if (shared_mem == NULL) {

			pr_err("Shared mem alloc client=%s, size=%u\n",

				clnt_res->name, shared_mem_size);

			return -ENOMEM;

		}

	}



	/* Setup device */

	info->mmap = sharedmem_mmap; /* Custom mmap function. */

	info->name = clnt_res->name;

	info->version = "1.0";

	info->mem[0].addr = shared_mem_pyhsical;

	info->mem[0].size = shared_mem_size;

	info->mem[0].memtype = UIO_MEM_PHYS;



	ret = uio_register_device(&pdev->dev, info);

	if (ret) {

		pr_err("uio register failed ret=%d\n", ret);

		goto out;

	}

	dev_set_drvdata(&pdev->dev, info);



	pr_info("Device created for client '%s'\n", clnt_res->name);

out:

	return ret;

}



static int msm_sharedmem_remove(struct platform_device *pdev)

{

	struct uio_info *info = dev_get_drvdata(&pdev->dev);



	uio_unregister_device(info);



	return 0;

}



static const struct of_device_id msm_sharedmem_of_match[] = {

	{.compatible = "qcom,sharedmem-uio",},

	{},

};

MODULE_DEVICE_TABLE(of, msm_sharedmem_of_match);



static struct platform_driver msm_sharedmem_driver = {

	.probe          = msm_sharedmem_probe,

	.remove         = msm_sharedmem_remove,

	.driver         = {

		.name   = DRIVER_NAME,

		.owner	= THIS_MODULE,

		.of_match_table = msm_sharedmem_of_match,

	},

};





static int __init msm_sharedmem_init(void)

{

	int result;



	result = platform_driver_register(&msm_sharedmem_driver);

	if (result != 0) {

		pr_err("Platform driver registration failed\n");

		return result;

	}

	return 0;

}



static void __exit msm_sharedmem_exit(void)

{

	platform_driver_unregister(&msm_sharedmem_driver);

}



module_init(msm_sharedmem_init);

module_exit(msm_sharedmem_exit);



MODULE_LICENSE("GPL v2");