This patch adds a mismatch between the Kconfig symbol (a bool) and the
code (which suggests it could be built modular too).
On Mon, 2015-04-06 at 18:58 +0300, Andrew Andrianov wrote:
+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
--- a/drivers/staging/android/ion/Makefile
+++ b/drivers/staging/android/ion/Makefile
-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/
To make absolutely sure I'm reading this correctly: there's no way
ion_physmem.o can ever be part of a module, right?
(If I'm not reading this correctly you can stop reading here.)
--- /dev/null
+++ b/drivers/staging/android/ion/ion_physmem.c
@@ -0,0 +1,237 @@
+/*
+ * Copyright (C) 2015 RC Module
+ * Andrew Andrianov <andrew@xxxxxxxxxx>
+ *
+ * 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/module.h>
If this file can only be built-in this include might not be needed.
+MODULE_DEVICE_TABLE(of, of_match_table);
MODULE_DEVICE_TABLE will always be preprocessed away for built-in code
(see include/linux/module.h).
+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;
For built-in only code THIS_MODULE will be, basically, always NULL. So,
I think try_module_get() will always return true.
+ 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);
Again, THIS_MODULE will be, basically, always NULL.
+ return 0;
+}
+
+static struct platform_driver ion_physmem_driver = {
+ .probe = ion_physmem_probe,
+ .remove = ion_physmem_remove,
+ .driver = {
+ .owner = THIS_MODULE,
Ditto.
+ .name = "ion-physmem",
+ .of_match_table = of_match_ptr(of_match_table),
+ },
+};
+module_platform_driver(ion_physmem_driver);
For built-in only code this is equivalent to, if I remember correctly,
having a small wrapper call
platform_driver_register(&ion_physmem_driver);
and mark that wrapper with device_initcall().
+MODULE_DESCRIPTION("Generic physmem driver for ION");
+MODULE_AUTHOR("Andrew Andrianov <andrew@xxxxxxxxxx>");
+MODULE_LICENSE("GPL");
These macros will always be effectively preprocessed away for built-in
only code.
(If you plan to make ION_PHYSMEM tristate, you should note that "GPL"
doesn't match the license stated in the comment at the top of this file,
see include/linux/module.h.)
Paul Bolle