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SubjectRe: [PATCH v2 1/2] staging: ion: Add generic ion-physmem driver
On Sat, Apr 11, 2015 at 12:12:59AM +0300, Andrew Andrianov wrote:
> Signed-off-by: Andrew Andrianov <andrew@ncrmnt.org>

You need something here in the changelog entry, you just added a whole
new driver. Please give some information as to what it does, why we
need it, and how to use it.

> ---
> drivers/staging/android/ion/Kconfig | 7 +
> drivers/staging/android/ion/Makefile | 5 +-
> drivers/staging/android/ion/ion_physmem.c | 226 +++++++++++++++++++++++++++++
> include/dt-bindings/ion,physmem.h | 17 +++
> 4 files changed, 253 insertions(+), 2 deletions(-)
> create mode 100644 drivers/staging/android/ion/ion_physmem.c
> create mode 100644 include/dt-bindings/ion,physmem.h
>
> 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..5ebcd85
> --- /dev/null
> +++ b/drivers/staging/android/ion/ion_physmem.c
> @@ -0,0 +1,226 @@
> +/*
> + * 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/platform_device.h>
> +#include <linux/slab.h>
> +#include <linux/of.h>
> +#include <linux/of_platform.h>
> +#include <linux/of_address.h>
> +#include <linux/clk.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 int num_heaps_registered;
> +static uint32_t claimed_heap_ids;
> +
> +static const struct of_device_id of_match_table[] = {
> + { .compatible = "ion,physmem", },
> + { /* end of list */ }
> +};
> +
> +struct physmem_ion_dev {
> + struct ion_platform_heap data;
> + struct ion_heap *heap;
> + int need_free_coherent;
> + void *freepage_ptr;
> + struct clk *clk;
> +};
> +
> +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 = NULL;
> + 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:
> + 1. Do we need to hold a spinlock here?
> + 2. Can several probes race here on SMP?
> + */
> +
> + if (!idev) {
> + idev = ion_device_create(NULL);
> + dev_info(&pdev->dev, "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);
> +
> + /* Read out name first for the sake of sane error-reporting */
> + ret = of_property_read_string(pdev->dev.of_node, "ion-heap-name",
> + &ion_heap_name);
> + if (ret != 0)
> + goto errfreeipdev;
> +
> + ret = of_property_read_u32(pdev->dev.of_node, "ion-heap-id",
> + &ion_heap_id);
> + if (ret != 0)
> + goto errfreeipdev;
> +
> + /* Check id to be sane first */
> + if ((ion_heap_id < 0) || (ion_heap_id >= ION_NUM_HEAP_IDS)) {
> + dev_err(&pdev->dev, "bad heap id specified: %d\n",
> + ion_heap_id);
> + goto errfreeipdev;
> + }
> +
> + if ((1 << ion_heap_id) & claimed_heap_ids) {
> + dev_err(&pdev->dev, "heap id %d is already claimed\n",
> + ion_heap_id);
> + 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;
> +
> + 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:
> + {

Why this unneeded brace?

> + 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 it's needed - take care enable clocks */
> + ipdev->clk = devm_clk_get(&pdev->dev, NULL);
> + if (IS_ERR(ipdev->clk))
> + ipdev->clk = NULL;
> + else
> + clk_prepare_enable(ipdev->clk);
> +
> + ion_device_add_heap(idev, ipdev->heap);
> + num_heaps_registered++;
> + claimed_heap_ids |= (1 << ion_heap_id);
> +
> + dev_info(&pdev->dev, "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));

Don't be noisy for "normal" operations, this should be debug only as no
one really cares.

> + return 0;
> +
> +errfreeipdev:
> + kfree(ipdev);
> + dev_err(&pdev->dev, "Failed to register heap: %s\n",
> + ion_heap_name);
> + 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);
> + if (ipdev->clk)
> + clk_disable_unprepare(ipdev->clk);
> + kfree(ipdev);
> + num_heaps_registered--;
> + if (0 == num_heaps_registered) {
> + ion_device_destroy(idev);
> + idev = NULL;
> + }

We really have no other way to do allocation/cleanup than a simple
integer value? Shouldn't the ion device have reference counting in it?

thanks,

greg k-h


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