linux/drivers/base/dma-coherent.c
Greg Kroah-Hartman b24413180f License cleanup: add SPDX GPL-2.0 license identifier to files with no license
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained >5
   lines of source
 - File already had some variant of a license header in it (even if <5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-02 11:10:55 +01:00

434 lines
11 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Coherent per-device memory handling.
* Borrowed from i386
*/
#include <linux/io.h>
#include <linux/slab.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/dma-mapping.h>
struct dma_coherent_mem {
void *virt_base;
dma_addr_t device_base;
unsigned long pfn_base;
int size;
int flags;
unsigned long *bitmap;
spinlock_t spinlock;
bool use_dev_dma_pfn_offset;
};
static struct dma_coherent_mem *dma_coherent_default_memory __ro_after_init;
static inline struct dma_coherent_mem *dev_get_coherent_memory(struct device *dev)
{
if (dev && dev->dma_mem)
return dev->dma_mem;
return NULL;
}
static inline dma_addr_t dma_get_device_base(struct device *dev,
struct dma_coherent_mem * mem)
{
if (mem->use_dev_dma_pfn_offset)
return (mem->pfn_base - dev->dma_pfn_offset) << PAGE_SHIFT;
else
return mem->device_base;
}
static int dma_init_coherent_memory(
phys_addr_t phys_addr, dma_addr_t device_addr, size_t size, int flags,
struct dma_coherent_mem **mem)
{
struct dma_coherent_mem *dma_mem = NULL;
void __iomem *mem_base = NULL;
int pages = size >> PAGE_SHIFT;
int bitmap_size = BITS_TO_LONGS(pages) * sizeof(long);
int ret;
if (!size) {
ret = -EINVAL;
goto out;
}
mem_base = memremap(phys_addr, size, MEMREMAP_WC);
if (!mem_base) {
ret = -EINVAL;
goto out;
}
dma_mem = kzalloc(sizeof(struct dma_coherent_mem), GFP_KERNEL);
if (!dma_mem) {
ret = -ENOMEM;
goto out;
}
dma_mem->bitmap = kzalloc(bitmap_size, GFP_KERNEL);
if (!dma_mem->bitmap) {
ret = -ENOMEM;
goto out;
}
dma_mem->virt_base = mem_base;
dma_mem->device_base = device_addr;
dma_mem->pfn_base = PFN_DOWN(phys_addr);
dma_mem->size = pages;
dma_mem->flags = flags;
spin_lock_init(&dma_mem->spinlock);
*mem = dma_mem;
return 0;
out:
kfree(dma_mem);
if (mem_base)
memunmap(mem_base);
return ret;
}
static void dma_release_coherent_memory(struct dma_coherent_mem *mem)
{
if (!mem)
return;
memunmap(mem->virt_base);
kfree(mem->bitmap);
kfree(mem);
}
static int dma_assign_coherent_memory(struct device *dev,
struct dma_coherent_mem *mem)
{
if (!dev)
return -ENODEV;
if (dev->dma_mem)
return -EBUSY;
dev->dma_mem = mem;
return 0;
}
int dma_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr,
dma_addr_t device_addr, size_t size, int flags)
{
struct dma_coherent_mem *mem;
int ret;
ret = dma_init_coherent_memory(phys_addr, device_addr, size, flags, &mem);
if (ret)
return ret;
ret = dma_assign_coherent_memory(dev, mem);
if (ret)
dma_release_coherent_memory(mem);
return ret;
}
EXPORT_SYMBOL(dma_declare_coherent_memory);
void dma_release_declared_memory(struct device *dev)
{
struct dma_coherent_mem *mem = dev->dma_mem;
if (!mem)
return;
dma_release_coherent_memory(mem);
dev->dma_mem = NULL;
}
EXPORT_SYMBOL(dma_release_declared_memory);
void *dma_mark_declared_memory_occupied(struct device *dev,
dma_addr_t device_addr, size_t size)
{
struct dma_coherent_mem *mem = dev->dma_mem;
unsigned long flags;
int pos, err;
size += device_addr & ~PAGE_MASK;
if (!mem)
return ERR_PTR(-EINVAL);
spin_lock_irqsave(&mem->spinlock, flags);
pos = PFN_DOWN(device_addr - dma_get_device_base(dev, mem));
err = bitmap_allocate_region(mem->bitmap, pos, get_order(size));
spin_unlock_irqrestore(&mem->spinlock, flags);
if (err != 0)
return ERR_PTR(err);
return mem->virt_base + (pos << PAGE_SHIFT);
}
EXPORT_SYMBOL(dma_mark_declared_memory_occupied);
static void *__dma_alloc_from_coherent(struct dma_coherent_mem *mem,
ssize_t size, dma_addr_t *dma_handle)
{
int order = get_order(size);
unsigned long flags;
int pageno;
void *ret;
spin_lock_irqsave(&mem->spinlock, flags);
if (unlikely(size > (mem->size << PAGE_SHIFT)))
goto err;
pageno = bitmap_find_free_region(mem->bitmap, mem->size, order);
if (unlikely(pageno < 0))
goto err;
/*
* Memory was found in the coherent area.
*/
*dma_handle = mem->device_base + (pageno << PAGE_SHIFT);
ret = mem->virt_base + (pageno << PAGE_SHIFT);
spin_unlock_irqrestore(&mem->spinlock, flags);
memset(ret, 0, size);
return ret;
err:
spin_unlock_irqrestore(&mem->spinlock, flags);
return NULL;
}
/**
* dma_alloc_from_dev_coherent() - allocate memory from device coherent pool
* @dev: device from which we allocate memory
* @size: size of requested memory area
* @dma_handle: This will be filled with the correct dma handle
* @ret: This pointer will be filled with the virtual address
* to allocated area.
*
* This function should be only called from per-arch dma_alloc_coherent()
* to support allocation from per-device coherent memory pools.
*
* Returns 0 if dma_alloc_coherent should continue with allocating from
* generic memory areas, or !0 if dma_alloc_coherent should return @ret.
*/
int dma_alloc_from_dev_coherent(struct device *dev, ssize_t size,
dma_addr_t *dma_handle, void **ret)
{
struct dma_coherent_mem *mem = dev_get_coherent_memory(dev);
if (!mem)
return 0;
*ret = __dma_alloc_from_coherent(mem, size, dma_handle);
if (*ret)
return 1;
/*
* In the case where the allocation can not be satisfied from the
* per-device area, try to fall back to generic memory if the
* constraints allow it.
*/
return mem->flags & DMA_MEMORY_EXCLUSIVE;
}
EXPORT_SYMBOL(dma_alloc_from_dev_coherent);
void *dma_alloc_from_global_coherent(ssize_t size, dma_addr_t *dma_handle)
{
if (!dma_coherent_default_memory)
return NULL;
return __dma_alloc_from_coherent(dma_coherent_default_memory, size,
dma_handle);
}
static int __dma_release_from_coherent(struct dma_coherent_mem *mem,
int order, void *vaddr)
{
if (mem && vaddr >= mem->virt_base && vaddr <
(mem->virt_base + (mem->size << PAGE_SHIFT))) {
int page = (vaddr - mem->virt_base) >> PAGE_SHIFT;
unsigned long flags;
spin_lock_irqsave(&mem->spinlock, flags);
bitmap_release_region(mem->bitmap, page, order);
spin_unlock_irqrestore(&mem->spinlock, flags);
return 1;
}
return 0;
}
/**
* dma_release_from_dev_coherent() - free memory to device coherent memory pool
* @dev: device from which the memory was allocated
* @order: the order of pages allocated
* @vaddr: virtual address of allocated pages
*
* This checks whether the memory was allocated from the per-device
* coherent memory pool and if so, releases that memory.
*
* Returns 1 if we correctly released the memory, or 0 if the caller should
* proceed with releasing memory from generic pools.
*/
int dma_release_from_dev_coherent(struct device *dev, int order, void *vaddr)
{
struct dma_coherent_mem *mem = dev_get_coherent_memory(dev);
return __dma_release_from_coherent(mem, order, vaddr);
}
EXPORT_SYMBOL(dma_release_from_dev_coherent);
int dma_release_from_global_coherent(int order, void *vaddr)
{
if (!dma_coherent_default_memory)
return 0;
return __dma_release_from_coherent(dma_coherent_default_memory, order,
vaddr);
}
static int __dma_mmap_from_coherent(struct dma_coherent_mem *mem,
struct vm_area_struct *vma, void *vaddr, size_t size, int *ret)
{
if (mem && vaddr >= mem->virt_base && vaddr + size <=
(mem->virt_base + (mem->size << PAGE_SHIFT))) {
unsigned long off = vma->vm_pgoff;
int start = (vaddr - mem->virt_base) >> PAGE_SHIFT;
int user_count = vma_pages(vma);
int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
*ret = -ENXIO;
if (off < count && user_count <= count - off) {
unsigned long pfn = mem->pfn_base + start + off;
*ret = remap_pfn_range(vma, vma->vm_start, pfn,
user_count << PAGE_SHIFT,
vma->vm_page_prot);
}
return 1;
}
return 0;
}
/**
* dma_mmap_from_dev_coherent() - mmap memory from the device coherent pool
* @dev: device from which the memory was allocated
* @vma: vm_area for the userspace memory
* @vaddr: cpu address returned by dma_alloc_from_dev_coherent
* @size: size of the memory buffer allocated
* @ret: result from remap_pfn_range()
*
* This checks whether the memory was allocated from the per-device
* coherent memory pool and if so, maps that memory to the provided vma.
*
* Returns 1 if we correctly mapped the memory, or 0 if the caller should
* proceed with mapping memory from generic pools.
*/
int dma_mmap_from_dev_coherent(struct device *dev, struct vm_area_struct *vma,
void *vaddr, size_t size, int *ret)
{
struct dma_coherent_mem *mem = dev_get_coherent_memory(dev);
return __dma_mmap_from_coherent(mem, vma, vaddr, size, ret);
}
EXPORT_SYMBOL(dma_mmap_from_dev_coherent);
int dma_mmap_from_global_coherent(struct vm_area_struct *vma, void *vaddr,
size_t size, int *ret)
{
if (!dma_coherent_default_memory)
return 0;
return __dma_mmap_from_coherent(dma_coherent_default_memory, vma,
vaddr, size, ret);
}
/*
* Support for reserved memory regions defined in device tree
*/
#ifdef CONFIG_OF_RESERVED_MEM
#include <linux/of.h>
#include <linux/of_fdt.h>
#include <linux/of_reserved_mem.h>
static struct reserved_mem *dma_reserved_default_memory __initdata;
static int rmem_dma_device_init(struct reserved_mem *rmem, struct device *dev)
{
struct dma_coherent_mem *mem = rmem->priv;
int ret;
if (!mem) {
ret = dma_init_coherent_memory(rmem->base, rmem->base,
rmem->size,
DMA_MEMORY_EXCLUSIVE, &mem);
if (ret) {
pr_err("Reserved memory: failed to init DMA memory pool at %pa, size %ld MiB\n",
&rmem->base, (unsigned long)rmem->size / SZ_1M);
return ret;
}
}
mem->use_dev_dma_pfn_offset = true;
rmem->priv = mem;
dma_assign_coherent_memory(dev, mem);
return 0;
}
static void rmem_dma_device_release(struct reserved_mem *rmem,
struct device *dev)
{
if (dev)
dev->dma_mem = NULL;
}
static const struct reserved_mem_ops rmem_dma_ops = {
.device_init = rmem_dma_device_init,
.device_release = rmem_dma_device_release,
};
static int __init rmem_dma_setup(struct reserved_mem *rmem)
{
unsigned long node = rmem->fdt_node;
if (of_get_flat_dt_prop(node, "reusable", NULL))
return -EINVAL;
#ifdef CONFIG_ARM
if (!of_get_flat_dt_prop(node, "no-map", NULL)) {
pr_err("Reserved memory: regions without no-map are not yet supported\n");
return -EINVAL;
}
if (of_get_flat_dt_prop(node, "linux,dma-default", NULL)) {
WARN(dma_reserved_default_memory,
"Reserved memory: region for default DMA coherent area is redefined\n");
dma_reserved_default_memory = rmem;
}
#endif
rmem->ops = &rmem_dma_ops;
pr_info("Reserved memory: created DMA memory pool at %pa, size %ld MiB\n",
&rmem->base, (unsigned long)rmem->size / SZ_1M);
return 0;
}
static int __init dma_init_reserved_memory(void)
{
const struct reserved_mem_ops *ops;
int ret;
if (!dma_reserved_default_memory)
return -ENOMEM;
ops = dma_reserved_default_memory->ops;
/*
* We rely on rmem_dma_device_init() does not propagate error of
* dma_assign_coherent_memory() for "NULL" device.
*/
ret = ops->device_init(dma_reserved_default_memory, NULL);
if (!ret) {
dma_coherent_default_memory = dma_reserved_default_memory->priv;
pr_info("DMA: default coherent area is set\n");
}
return ret;
}
core_initcall(dma_init_reserved_memory);
RESERVEDMEM_OF_DECLARE(dma, "shared-dma-pool", rmem_dma_setup);
#endif