vc_mem: Add vc_mem driver for querying firmware memory addresses

Signed-off-by: popcornmix <popcornmix@gmail.com>

BCM270x: Move vc_mem

Make the vc_mem module available for ARCH_BCM2835 by moving it.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

char: vc_mem: Fix up compat ioctls for 64bit kernel

compat_ioctl wasn't defined, so 32bit user/64bit kernel
always failed.
VC_MEM_IOC_MEM_PHYS_ADDR was defined with parameter size
unsigned long, so the ioctl cmd changes between sizes.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

char: vc_mem: Fix all coding style issues.

Cleans up all checkpatch errors in vc_mem.c and vc_mem.h
No functional change to the code.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

char: vc_mem: Delete dead code

There are no error exists once device_create has succeeded, and
therefore no need to call device_destroy from vc_mem_init.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

char: broadcom: vc_mem: Fix preprocessor conditional

Signed-off-by: Alexander Winkowski <dereference23@outlook.com>

vc_mem: Add the DMA memcpy support from bcm2708_fb

bcm2708_fb is disabled by the vc4-kms-v3d overlay, which means that the
DMA memcpy support it provides is not available to allow vclog to read
the VC logs from the top 16MB on Pi 2 and Pi 3. Add the code to the
vc_mem driver, which will still be enabled.

It ought to be possible to do a proper DMA_MEM_TO_MEM copy via the
generic DMA customer API, but that can be a later step.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>
This commit is contained in:
popcornmix
2016-10-28 15:36:43 +01:00
committed by Dom Cobley
parent bba0ee42e5
commit 6201add5ee
4 changed files with 693 additions and 0 deletions

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@@ -0,0 +1,18 @@
#
# Broadcom char driver config
#
menuconfig BRCM_CHAR_DRIVERS
bool "Broadcom Char Drivers"
help
Broadcom's char drivers
if BRCM_CHAR_DRIVERS
config BCM2708_VCMEM
bool "Videocore Memory"
default y
help
Helper for videocore memory access and total size allocation.
endif

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@@ -0,0 +1 @@
obj-$(CONFIG_BCM2708_VCMEM) += vc_mem.o

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@@ -0,0 +1,635 @@
/*
* Copyright 2010 - 2011 Broadcom Corporation. All rights reserved.
*
* Unless you and Broadcom execute a separate written software license
* agreement governing use of this software, this software is licensed to you
* under the terms of the GNU General Public License version 2, available at
* http://www.broadcom.com/licenses/GPLv2.php (the "GPL").
*
* Notwithstanding the above, under no circumstances may you combine this
* software in any way with any other Broadcom software provided under a
* license other than the GPL, without Broadcom's express prior written
* consent.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/device.h>
#include <linux/cdev.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/debugfs.h>
#include <linux/uaccess.h>
#include <linux/dma-mapping.h>
#include <linux/broadcom/vc_mem.h>
#include <linux/compat.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/platform_data/dma-bcm2708.h>
#include <soc/bcm2835/raspberrypi-firmware.h>
#define DRIVER_NAME "vc-mem"
/* N.B. These use a different magic value for compatibility with bmc7208_fb */
#define VC_MEM_IOC_DMACOPY _IOW('z', 0x22, struct vc_mem_dmacopy)
#define VC_MEM_IOC_DMACOPY32 _IOW('z', 0x22, struct vc_mem_dmacopy32)
/* address with no aliases */
#define INTALIAS_NORMAL(x) ((x) & ~0xc0000000)
/* cache coherent but non-allocating in L1 and L2 */
#define INTALIAS_L1L2_NONALLOCATING(x) (((x) & ~0xc0000000) | 0x80000000)
/* Device (/dev) related variables */
static dev_t vc_mem_devnum;
static struct class *vc_mem_class;
static struct cdev vc_mem_cdev;
static int vc_mem_inited;
#ifdef CONFIG_DEBUG_FS
static struct dentry *vc_mem_debugfs_entry;
#endif
struct vc_mem_dmacopy {
void *dst;
__u32 src;
__u32 length;
};
#ifdef CONFIG_COMPAT
struct vc_mem_dmacopy32 {
compat_uptr_t dst;
__u32 src;
__u32 length;
};
#endif
/*
* Videocore memory addresses and size
*
* Drivers that wish to know the videocore memory addresses and sizes should
* use these variables instead of the MM_IO_BASE and MM_ADDR_IO defines in
* headers. This allows the other drivers to not be tied down to a a certain
* address/size at compile time.
*
* In the future, the goal is to have the videocore memory virtual address and
* size be calculated at boot time rather than at compile time. The decision of
* where the videocore memory resides and its size would be in the hands of the
* bootloader (and/or kernel). When that happens, the values of these variables
* would be calculated and assigned in the init function.
*/
/* In the 2835 VC in mapped above ARM, but ARM has full access to VC space */
unsigned long mm_vc_mem_phys_addr;
EXPORT_SYMBOL(mm_vc_mem_phys_addr);
unsigned int mm_vc_mem_size;
EXPORT_SYMBOL(mm_vc_mem_size);
unsigned int mm_vc_mem_base;
EXPORT_SYMBOL(mm_vc_mem_base);
static uint phys_addr;
static uint mem_size;
static uint mem_base;
struct vc_mem_dma {
struct device *dev;
int dma_chan;
int dma_irq;
void __iomem *dma_chan_base;
wait_queue_head_t dma_waitq;
void *cb_base; /* DMA control blocks */
dma_addr_t cb_handle;
};
struct { u32 base, length; } gpu_mem;
static struct mutex dma_mutex;
static struct vc_mem_dma vc_mem_dma;
static int
vc_mem_open(struct inode *inode, struct file *file)
{
(void)inode;
pr_debug("%s: called file = 0x%p\n", __func__, file);
return 0;
}
static int
vc_mem_release(struct inode *inode, struct file *file)
{
(void)inode;
pr_debug("%s: called file = 0x%p\n", __func__, file);
return 0;
}
static void
vc_mem_get_size(void)
{
}
static void
vc_mem_get_base(void)
{
}
int
vc_mem_get_current_size(void)
{
return mm_vc_mem_size;
}
EXPORT_SYMBOL_GPL(vc_mem_get_current_size);
static int
vc_mem_dma_init(void)
{
struct vc_mem_dma *vcdma = &vc_mem_dma;
struct platform_device *pdev;
struct device_node *fwnode;
struct rpi_firmware *fw;
struct device *dev;
u32 revision;
int rc;
if (vcdma->dev)
return 0;
fwnode = of_find_node_by_path("/system");
rc = of_property_read_u32(fwnode, "linux,revision", &revision);
revision = (revision >> 12) & 0xf;
if (revision != 1 && revision != 2) {
/* Only BCM2709 and BCM2710 may have logs where the ARMs
* can't see them.
*/
return -ENXIO;
}
fwnode = rpi_firmware_find_node();
if (!fwnode)
return -ENXIO;
pdev = of_find_device_by_node(fwnode);
dev = &pdev->dev;
rc = dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(32));
if (rc)
return rc;
fw = rpi_firmware_get(fwnode);
if (!fw)
return -ENXIO;
rc = rpi_firmware_property(fw, RPI_FIRMWARE_GET_VC_MEMORY,
&gpu_mem, sizeof(gpu_mem));
if (rc)
return rc;
gpu_mem.base = INTALIAS_NORMAL(gpu_mem.base);
if (!gpu_mem.base || !gpu_mem.length) {
dev_err(dev, "%s: unable to determine gpu memory (%x,%x)\n",
__func__, gpu_mem.base, gpu_mem.length);
return -EFAULT;
}
vcdma->cb_base = dma_alloc_wc(dev, SZ_4K, &vcdma->cb_handle, GFP_KERNEL);
if (!vcdma->cb_base) {
dev_err(dev, "failed to allocate DMA CBs\n");
return -ENOMEM;
}
rc = bcm_dma_chan_alloc(BCM_DMA_FEATURE_BULK,
&vcdma->dma_chan_base,
&vcdma->dma_irq);
if (rc < 0) {
dev_err(dev, "failed to allocate a DMA channel\n");
goto free_cb;
}
vcdma->dma_chan = rc;
init_waitqueue_head(&vcdma->dma_waitq);
vcdma->dev = dev;
return 0;
free_cb:
dma_free_wc(dev, SZ_4K, vcdma->cb_base, vcdma->cb_handle);
return rc;
}
static void
vc_mem_dma_uninit(void)
{
struct vc_mem_dma *vcdma = &vc_mem_dma;
if (vcdma->dev) {
bcm_dma_chan_free(vcdma->dma_chan);
dma_free_wc(vcdma->dev, SZ_4K, vcdma->cb_base, vcdma->cb_handle);
vcdma->dev = NULL;
}
}
static int dma_memcpy(struct vc_mem_dma *vcdma, dma_addr_t dst, dma_addr_t src,
int size)
{
struct bcm2708_dma_cb *cb = vcdma->cb_base;
int burst_size = (vcdma->dma_chan == 0) ? 8 : 2;
cb->info = BCM2708_DMA_BURST(burst_size) | BCM2708_DMA_S_WIDTH |
BCM2708_DMA_S_INC | BCM2708_DMA_D_WIDTH |
BCM2708_DMA_D_INC;
cb->dst = dst;
cb->src = src;
cb->length = size;
cb->stride = 0;
cb->pad[0] = 0;
cb->pad[1] = 0;
cb->next = 0;
bcm_dma_start(vcdma->dma_chan_base, vcdma->cb_handle);
bcm_dma_wait_idle(vcdma->dma_chan_base);
return 0;
}
static long vc_mem_copy(struct vc_mem_dmacopy *ioparam)
{
struct vc_mem_dma *vcdma = &vc_mem_dma;
size_t size = PAGE_SIZE;
const u32 dma_xfer_chunk = 256;
u32 *buf = NULL;
dma_addr_t bus_addr;
long rc = 0;
size_t offset;
/* restrict this to root user */
if (!uid_eq(current_euid(), GLOBAL_ROOT_UID))
return -EFAULT;
if (mutex_lock_interruptible(&dma_mutex))
return -EINTR;
rc = vc_mem_dma_init();
if (rc)
goto out;
vcdma = &vc_mem_dma;
if (INTALIAS_NORMAL(ioparam->src) < gpu_mem.base ||
INTALIAS_NORMAL(ioparam->src) >= gpu_mem.base + gpu_mem.length) {
pr_err("%s: invalid memory access %x (%x-%x)", __func__,
INTALIAS_NORMAL(ioparam->src), gpu_mem.base,
gpu_mem.base + gpu_mem.length);
rc = -EFAULT;
goto out;
}
buf = dma_alloc_coherent(vcdma->dev, PAGE_ALIGN(size), &bus_addr,
GFP_ATOMIC);
if (!buf) {
rc = -ENOMEM;
goto out;
}
for (offset = 0; offset < ioparam->length; offset += size) {
size_t remaining = ioparam->length - offset;
size_t s = min(size, remaining);
u8 *p = (u8 *)((uintptr_t)ioparam->src + offset);
u8 *q = (u8 *)ioparam->dst + offset;
rc = dma_memcpy(vcdma, bus_addr,
INTALIAS_L1L2_NONALLOCATING((u32)(uintptr_t)p),
(s + dma_xfer_chunk - 1) & ~(dma_xfer_chunk - 1));
if (rc) {
dev_err(vcdma->dev, "dma_memcpy failed\n");
break;
}
if (copy_to_user(q, buf, s) != 0) {
pr_err("%s: copy_to_user failed\n", __func__);
rc = -EFAULT;
break;
}
}
out:
if (buf)
dma_free_coherent(vcdma->dev, PAGE_ALIGN(size), buf,
bus_addr);
mutex_unlock(&dma_mutex);
return rc;
}
static long
vc_mem_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
int rc = 0;
(void) cmd;
(void) arg;
pr_debug("%s: called file = 0x%p, cmd %08x\n", __func__, file, cmd);
switch (cmd) {
case VC_MEM_IOC_MEM_PHYS_ADDR:
{
pr_debug("%s: VC_MEM_IOC_MEM_PHYS_ADDR=0x%p\n",
__func__, (void *)mm_vc_mem_phys_addr);
if (copy_to_user((void *)arg, &mm_vc_mem_phys_addr,
sizeof(mm_vc_mem_phys_addr))) {
rc = -EFAULT;
}
break;
}
case VC_MEM_IOC_MEM_SIZE:
{
/* Get the videocore memory size first */
vc_mem_get_size();
pr_debug("%s: VC_MEM_IOC_MEM_SIZE=%x\n", __func__,
mm_vc_mem_size);
if (copy_to_user((void *)arg, &mm_vc_mem_size,
sizeof(mm_vc_mem_size))) {
rc = -EFAULT;
}
break;
}
case VC_MEM_IOC_MEM_BASE:
{
/* Get the videocore memory base */
vc_mem_get_base();
pr_debug("%s: VC_MEM_IOC_MEM_BASE=%x\n", __func__,
mm_vc_mem_base);
if (copy_to_user((void *)arg, &mm_vc_mem_base,
sizeof(mm_vc_mem_base))) {
rc = -EFAULT;
}
break;
}
case VC_MEM_IOC_MEM_LOAD:
{
/* Get the videocore memory base */
vc_mem_get_base();
pr_debug("%s: VC_MEM_IOC_MEM_LOAD=%x\n", __func__,
mm_vc_mem_base);
if (copy_to_user((void *)arg, &mm_vc_mem_base,
sizeof(mm_vc_mem_base))) {
rc = -EFAULT;
}
break;
}
case VC_MEM_IOC_DMACOPY:
{
struct vc_mem_dmacopy ioparam;
/* Get the parameter data.
*/
if (copy_from_user
(&ioparam, (void *)arg, sizeof(ioparam))) {
pr_err("%s: copy_from_user failed\n", __func__);
rc = -EFAULT;
break;
}
rc = vc_mem_copy(&ioparam);
break;
}
default:
{
return -ENOTTY;
}
}
pr_debug("%s: file = 0x%p returning %d\n", __func__, file, rc);
return rc;
}
#ifdef CONFIG_COMPAT
static long
vc_mem_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
int rc = 0;
switch (cmd) {
case VC_MEM_IOC_MEM_PHYS_ADDR32:
pr_debug("%s: VC_MEM_IOC_MEM_PHYS_ADDR32=0x%p\n",
__func__, (void *)mm_vc_mem_phys_addr);
/* This isn't correct, but will cover us for now as
* VideoCore is 32bit only.
*/
if (copy_to_user((void *)arg, &mm_vc_mem_phys_addr,
sizeof(compat_ulong_t)))
rc = -EFAULT;
break;
case VC_MEM_IOC_DMACOPY32:
{
struct vc_mem_dmacopy32 param32;
struct vc_mem_dmacopy param;
/* Get the parameter data.
*/
if (copy_from_user(&param32, (void *)arg, sizeof(param32))) {
pr_err("%s: copy_from_user failed\n", __func__);
rc = -EFAULT;
break;
}
param.dst = compat_ptr(param32.dst);
param.src = param32.src;
param.length = param32.length;
rc = vc_mem_copy(&param);
break;
}
default:
rc = vc_mem_ioctl(file, cmd, arg);
break;
}
return rc;
}
#endif
static int
vc_mem_mmap(struct file *filp, struct vm_area_struct *vma)
{
int rc = 0;
unsigned long length = vma->vm_end - vma->vm_start;
unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
pr_debug("%s: vm_start = 0x%08lx vm_end = 0x%08lx vm_pgoff = 0x%08lx\n",
__func__, (long)vma->vm_start, (long)vma->vm_end,
(long)vma->vm_pgoff);
if (offset + length > mm_vc_mem_size) {
pr_err("%s: length %ld is too big\n", __func__, length);
return -EINVAL;
}
/* Do not cache the memory map */
vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
rc = remap_pfn_range(vma, vma->vm_start,
(mm_vc_mem_phys_addr >> PAGE_SHIFT) +
vma->vm_pgoff, length, vma->vm_page_prot);
if (rc)
pr_err("%s: remap_pfn_range failed (rc=%d)\n", __func__, rc);
return rc;
}
/* File Operations for the driver. */
static const struct file_operations vc_mem_fops = {
.owner = THIS_MODULE,
.open = vc_mem_open,
.release = vc_mem_release,
.unlocked_ioctl = vc_mem_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = vc_mem_compat_ioctl,
#endif
.mmap = vc_mem_mmap,
};
#ifdef CONFIG_DEBUG_FS
static void vc_mem_debugfs_deinit(void)
{
debugfs_remove_recursive(vc_mem_debugfs_entry);
vc_mem_debugfs_entry = NULL;
}
static int vc_mem_debugfs_init(
struct device *dev)
{
vc_mem_debugfs_entry = debugfs_create_dir(DRIVER_NAME, NULL);
if (!vc_mem_debugfs_entry) {
dev_warn(dev, "could not create debugfs entry\n");
return -EFAULT;
}
debugfs_create_x32("vc_mem_phys_addr",
0444,
vc_mem_debugfs_entry,
(u32 *)&mm_vc_mem_phys_addr);
debugfs_create_x32("vc_mem_size",
0444,
vc_mem_debugfs_entry,
(u32 *)&mm_vc_mem_size);
debugfs_create_x32("vc_mem_base",
0444,
vc_mem_debugfs_entry,
(u32 *)&mm_vc_mem_base);
return 0;
}
#endif /* CONFIG_DEBUG_FS */
/* Module load/unload functions */
static int __init
vc_mem_init(void)
{
int rc = -EFAULT;
struct device *dev;
pr_debug("%s: called\n", __func__);
mm_vc_mem_phys_addr = phys_addr;
mm_vc_mem_size = mem_size;
mm_vc_mem_base = mem_base;
vc_mem_get_size();
pr_info("vc-mem: phys_addr:0x%08lx mem_base=0x%08x mem_size:0x%08x(%u MiB)\n",
mm_vc_mem_phys_addr, mm_vc_mem_base, mm_vc_mem_size,
mm_vc_mem_size / (1024 * 1024));
rc = alloc_chrdev_region(&vc_mem_devnum, 0, 1, DRIVER_NAME);
if (rc < 0) {
pr_err("%s: alloc_chrdev_region failed (rc=%d)\n",
__func__, rc);
goto out_err;
}
cdev_init(&vc_mem_cdev, &vc_mem_fops);
rc = cdev_add(&vc_mem_cdev, vc_mem_devnum, 1);
if (rc) {
pr_err("%s: cdev_add failed (rc=%d)\n", __func__, rc);
goto out_unregister;
}
vc_mem_class = class_create(DRIVER_NAME);
if (IS_ERR(vc_mem_class)) {
rc = PTR_ERR(vc_mem_class);
pr_err("%s: class_create failed (rc=%d)\n", __func__, rc);
goto out_cdev_del;
}
dev = device_create(vc_mem_class, NULL, vc_mem_devnum, NULL,
DRIVER_NAME);
if (IS_ERR(dev)) {
rc = PTR_ERR(dev);
pr_err("%s: device_create failed (rc=%d)\n", __func__, rc);
goto out_class_destroy;
}
#ifdef CONFIG_DEBUG_FS
/* don't fail if the debug entries cannot be created */
vc_mem_debugfs_init(dev);
#endif
mutex_init(&dma_mutex);
vc_mem_inited = 1;
return 0;
out_class_destroy:
class_destroy(vc_mem_class);
vc_mem_class = NULL;
out_cdev_del:
cdev_del(&vc_mem_cdev);
out_unregister:
unregister_chrdev_region(vc_mem_devnum, 1);
out_err:
return -1;
}
static void __exit
vc_mem_exit(void)
{
pr_debug("%s: called\n", __func__);
vc_mem_dma_uninit();
if (vc_mem_inited) {
#ifdef CONFIG_DEBUG_FS
vc_mem_debugfs_deinit();
#endif
device_destroy(vc_mem_class, vc_mem_devnum);
class_destroy(vc_mem_class);
cdev_del(&vc_mem_cdev);
unregister_chrdev_region(vc_mem_devnum, 1);
vc_mem_inited = 0;
}
}
module_init(vc_mem_init);
module_exit(vc_mem_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Broadcom Corporation");
module_param(phys_addr, uint, 0644);
module_param(mem_size, uint, 0644);
module_param(mem_base, uint, 0644);

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@@ -0,0 +1,39 @@
/*
* Copyright 2010 - 2011 Broadcom Corporation. All rights reserved.
*
* Unless you and Broadcom execute a separate written software license
* agreement governing use of this software, this software is licensed to you
* under the terms of the GNU General Public License version 2, available at
* http://www.broadcom.com/licenses/GPLv2.php (the "GPL").
*
* Notwithstanding the above, under no circumstances may you combine this
* software in any way with any other Broadcom software provided under a
* license other than the GPL, without Broadcom's express prior written
* consent.
*/
#ifndef _VC_MEM_H
#define _VC_MEM_H
#include <linux/ioctl.h>
#define VC_MEM_IOC_MAGIC 'v'
#define VC_MEM_IOC_MEM_PHYS_ADDR _IOR(VC_MEM_IOC_MAGIC, 0, unsigned long)
#define VC_MEM_IOC_MEM_SIZE _IOR(VC_MEM_IOC_MAGIC, 1, unsigned int)
#define VC_MEM_IOC_MEM_BASE _IOR(VC_MEM_IOC_MAGIC, 2, unsigned int)
#define VC_MEM_IOC_MEM_LOAD _IOR(VC_MEM_IOC_MAGIC, 3, unsigned int)
#ifdef __KERNEL__
#define VC_MEM_TO_ARM_ADDR_MASK 0x3FFFFFFF
extern unsigned long mm_vc_mem_phys_addr;
extern unsigned int mm_vc_mem_size;
extern int vc_mem_get_current_size(void);
#endif
#ifdef CONFIG_COMPAT
#define VC_MEM_IOC_MEM_PHYS_ADDR32 _IOR(VC_MEM_IOC_MAGIC, 0, compat_ulong_t)
#endif
#endif /* _VC_MEM_H */