[PATCH 1/2] staging: ion: Add ion-physmem driver

[Andrew Andrianov <andrew@ncrmnt.org>]

Signed-off-by: Andrew Andrianov <andrew@ncrmnt.org>
---
 drivers/staging/android/ion/Kconfig       |    7 +
 drivers/staging/android/ion/Makefile      |    5 +-
 drivers/staging/android/ion/ion_physmem.c |  237 +++++++++++++++++++++++++++++
 3 files changed, 247 insertions(+), 2 deletions(-)
 create mode 100644 drivers/staging/android/ion/ion_physmem.c

diff --git a/drivers/staging/android/ion/Kconfig b/drivers/staging/android/ion/Kconfig
index 3452346..c558cf8 100644
--- a/drivers/staging/android/ion/Kconfig
+++ b/drivers/staging/android/ion/Kconfig
@@ -33,3 +33,10 @@ config ION_TEGRA
 	help
 	  Choose this option if you wish to use ion on an nVidia Tegra.
 
+config ION_PHYSMEM
+	bool "Generic PhysMem ION driver"
+	depends on ION
+	help
+	  Provides a generic ION driver that registers the
+	  /dev/ion device with heaps from devicetree entries.
+	  This heaps are made of chunks of physical memory
diff --git a/drivers/staging/android/ion/Makefile b/drivers/staging/android/ion/Makefile
index b56fd2b..ac9856d 100644
--- a/drivers/staging/android/ion/Makefile
+++ b/drivers/staging/android/ion/Makefile
@@ -5,6 +5,7 @@ ifdef CONFIG_COMPAT
 obj-$(CONFIG_ION) += compat_ion.o
 endif
 
-obj-$(CONFIG_ION_DUMMY) += ion_dummy_driver.o
-obj-$(CONFIG_ION_TEGRA) += tegra/
+obj-$(CONFIG_ION_DUMMY)   += ion_dummy_driver.o
+obj-$(CONFIG_ION_PHYSMEM) += ion_physmem.o
+obj-$(CONFIG_ION_TEGRA)   += tegra/
 
diff --git a/drivers/staging/android/ion/ion_physmem.c b/drivers/staging/android/ion/ion_physmem.c
new file mode 100644
index 0000000..e922d74
--- /dev/null
+++ b/drivers/staging/android/ion/ion_physmem.c
@@ -0,0 +1,237 @@
+/*
+ * Copyright (C) 2015 RC Module
+ * Andrew Andrianov <andrew@ncrmnt.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Generic devicetree physmem driver for ION Memory Manager
+ *
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/of_address.h>
+#include <linux/dma-mapping.h>
+#include <linux/io.h>
+#include "ion.h"
+#include "ion_priv.h"
+
+#define DRVNAME "ion-physmem"
+
+static struct ion_device *idev;
+
+static const struct of_device_id of_match_table[] = {
+	{ .compatible = "ion,physmem", },
+	{ /* end of list */ }
+};
+MODULE_DEVICE_TABLE(of, of_match_table);
+
+/*
+#define PHYSMAP_ION_DEBUG y
+*/
+
+struct physmem_ion_dev {
+	struct ion_platform_heap  data;
+	struct ion_heap          *heap;
+	int                       need_free_coherent;
+	void                     *freepage_ptr;
+};
+
+static long ion_physmem_custom_ioctl(struct ion_client *client,
+				     unsigned int cmd,
+				     unsigned long arg)
+{
+/* Just an ugly debugging hack. */
+#ifdef PHYSMAP_ION_DEBUG
+	if ((cmd == 0xff)) {
+		ion_phys_addr_t addr;
+		size_t len;
+		struct ion_handle *hndl;
+
+		printk(KERN_INFO "=== ION PHYSMEM DEBUG PRINTOUT ===\n");
+		printk(KERN_INFO "N.B. DO disable CONFIG_ION_PHYSMEM_DEBUG in production\n");
+		printk(KERN_INFO "Shared fd is %d\n", (int) arg);
+		hndl = ion_import_dma_buf(client, arg);
+		if (!hndl) {
+			printk(KERN_INFO "Failed to import shared descriptor.\n");
+			return 0;
+		}
+		ion_phys(client, hndl, &addr, &len);
+		printk(KERN_INFO "shared buffer: phys 0x%lx len %ul\n",
+		       addr, len);
+		printk(KERN_INFO "=== ION PHYSMEM DEBUG PRINTOUT ===\n");
+	}
+#endif
+	return 0;
+}
+
+static int ion_physmem_probe(struct platform_device *pdev)
+{
+	int ret;
+	u32 ion_heap_id, ion_heap_align, ion_heap_type;
+	ion_phys_addr_t addr;
+	size_t size = 0;
+	const char *ion_heap_name;
+	struct resource *res;
+	struct physmem_ion_dev *ipdev;
+
+	/*
+	   Looks like we can only have one ION device in our system.
+	   Therefore we call ion_device_create on first probe and only
+	   add heaps to it on subsequent probe calls.
+	   FixMe: Do we need to hold a spinlock here once device probing
+	   becomes async?
+	*/
+
+	if (!idev) {
+		idev = ion_device_create(ion_physmem_custom_ioctl);
+		dev_info(&pdev->dev, "ion-physmem: ION PhysMem Driver. (c) RC Module 2015\n");
+		if (!idev)
+			return -ENOMEM;
+	}
+
+	ipdev = kzalloc(sizeof(struct physmem_ion_dev), GFP_KERNEL);
+	if (!ipdev)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, ipdev);
+
+	ret =  of_property_read_u32(pdev->dev.of_node, "ion-heap-id",
+				    &ion_heap_id);
+	if (ret != 0)
+		goto errfreeipdev;
+
+	ret =  of_property_read_u32(pdev->dev.of_node, "ion-heap-type",
+				    &ion_heap_type);
+	if (ret != 0)
+		goto errfreeipdev;
+
+	ret =  of_property_read_u32(pdev->dev.of_node, "ion-heap-align",
+				    &ion_heap_align);
+	if (ret != 0)
+		goto errfreeipdev;
+
+	ret =  of_property_read_string(pdev->dev.of_node, "ion-heap-name",
+				       &ion_heap_name);
+	if (ret != 0)
+		goto errfreeipdev;
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "memory");
+	/* Not always needed, throw no error if missing */
+	if (res) {
+		/* Fill in some defaults */
+		addr = res->start;
+		size = resource_size(res);
+	}
+
+	switch (ion_heap_type) {
+	case ION_HEAP_TYPE_DMA:
+		if (res) {
+			ret = dma_declare_coherent_memory(&pdev->dev,
+							  res->start,
+							  res->start,
+							  resource_size(res),
+							  DMA_MEMORY_MAP |
+							  DMA_MEMORY_EXCLUSIVE);
+			if (ret == 0) {
+				ret = -ENODEV;
+				goto errfreeipdev;
+			}
+		}
+		/*
+		 *  If no memory region declared in dt we assume that
+		 *  the user is okay with plain dma_alloc_coherent.
+		 */
+		break;
+	case ION_HEAP_TYPE_CARVEOUT:
+	case ION_HEAP_TYPE_CHUNK:
+	{
+		if (size == 0) {
+			ret = -EIO;
+			goto errfreeipdev;
+		}
+		ipdev->freepage_ptr = alloc_pages_exact(size, GFP_KERNEL);
+		if (ipdev->freepage_ptr) {
+			addr = virt_to_phys(ipdev->freepage_ptr);
+		} else {
+			ret = -ENOMEM;
+			goto errfreeipdev;
+		}
+		break;
+	}
+	}
+
+	ipdev->data.id    = ion_heap_id;
+	ipdev->data.type  = ion_heap_type;
+	ipdev->data.name  = ion_heap_name;
+	ipdev->data.align = ion_heap_align;
+	ipdev->data.base  = addr;
+	ipdev->data.size  = size;
+	/* This one make dma_declare_coherent_memory actually work */
+	ipdev->data.priv  = &pdev->dev;
+
+
+	ipdev->heap = ion_heap_create(&ipdev->data);
+	if (!ipdev->heap)
+		goto errfreeipdev;
+
+	if (!try_module_get(THIS_MODULE))
+		goto errfreeheap;
+
+	ion_device_add_heap(idev, ipdev->heap);
+
+	dev_info(&pdev->dev, "ion-physmem: heap %s id %d type %d align 0x%x at phys 0x%lx len %lu KiB\n",
+	       ion_heap_name, ion_heap_id, ion_heap_type, ion_heap_align,
+	       (unsigned long int) addr, ((unsigned long int) size / 1024));
+
+	return 0;
+
+errfreeheap:
+	kfree(ipdev->heap);
+errfreeipdev:
+	kfree(ipdev);
+	return -ENOMEM;
+}
+
+static int ion_physmem_remove(struct platform_device *pdev)
+{
+	struct physmem_ion_dev *ipdev = platform_get_drvdata(pdev);
+
+	ion_heap_destroy(ipdev->heap);
+	if (ipdev->need_free_coherent)
+		dma_release_declared_memory(&pdev->dev);
+	if (ipdev->freepage_ptr)
+		free_pages_exact(ipdev->freepage_ptr, ipdev->data.size);
+	kfree(ipdev->heap);
+	kfree(ipdev);
+	module_put(THIS_MODULE);
+	return 0;
+}
+
+static void __exit ion_physmem_exit(void)
+{
+	if (idev)
+		ion_device_destroy(idev);
+}
+__exitcall(ion_physmem_exit);
+
+static struct platform_driver ion_physmem_driver = {
+	.probe		= ion_physmem_probe,
+	.remove		= ion_physmem_remove,
+	.driver		= {
+		.owner	= THIS_MODULE,
+		.name	= "ion-physmem",
+		.of_match_table = of_match_ptr(of_match_table),
+	},
+};
+module_platform_driver(ion_physmem_driver);
+
+MODULE_DESCRIPTION("Generic physmem driver for ION");
+MODULE_AUTHOR("Andrew Andrianov <andrew@ncrmnt.org>");
+MODULE_LICENSE("GPL");
-- 
1.7.10.4