uio: Add snapshot of MSM sharedmem driver (056279eb) · Commits · e / devices / android_kernel_fairphone_FP4

drivers/uio/Kconfig

+10 −0

Original line number	Diff line number	Diff line
		@@ -164,4 +164,14 @@ config UIO_HV_GENERIC
		to network and storage devices from userspace.

		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.

		If you don't know what to do here, say N.

		endif

drivers/uio/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -11,3 +11,4 @@ obj-$(CONFIG_UIO_PRUSS) += uio_pruss.o
		obj-$(CONFIG_UIO_MF624) += uio_mf624.o
		obj-$(CONFIG_UIO_FSL_ELBC_GPCM) += uio_fsl_elbc_gpcm.o
		obj-$(CONFIG_UIO_HV_GENERIC) += uio_hv_generic.o
		obj-$(CONFIG_UIO_MSM_SHAREDMEM) += msm_sharedmem/

drivers/uio/msm_sharedmem/Makefile

0 → 100644

+2 −0

Original line number	Diff line number	Diff line
		# SPDX-License-Identifier: GPL-2.0-only
		obj-$(CONFIG_UIO_MSM_SHAREDMEM) := msm_sharedmem.o

drivers/uio/msm_sharedmem/msm_sharedmem.c

0 → 100644

+183 −0

Original line number	Diff line number	Diff line
		// SPDX-License-Identifier: GPL-2.0-only
		/*
		* Copyright (c) 2015-2019, The Linux Foundation. All rights reserved.
		*/

		#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,
		.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");