From 47c1d1988df17bf39bbf3a188d78792eaa693068 Mon Sep 17 00:00:00 2001 From: popcornmix Date: Fri, 28 Oct 2016 15:36:43 +0100 Subject: [PATCH] vc_mem: Add vc_mem driver for querying firmware memory addresses MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Signed-off-by: popcornmix BCM270x: Move vc_mem Make the vc_mem module available for ARCH_BCM2835 by moving it. Signed-off-by: Noralf Trønnes 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 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 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 --- drivers/char/broadcom/Kconfig | 18 ++ drivers/char/broadcom/Makefile | 1 + drivers/char/broadcom/vc_mem.c | 373 ++++++++++++++++++++++++++++++++ include/linux/broadcom/vc_mem.h | 39 ++++ 4 files changed, 431 insertions(+) create mode 100644 drivers/char/broadcom/Kconfig create mode 100644 drivers/char/broadcom/Makefile create mode 100644 drivers/char/broadcom/vc_mem.c create mode 100644 include/linux/broadcom/vc_mem.h --- /dev/null +++ b/drivers/char/broadcom/Kconfig @@ -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 --- /dev/null +++ b/drivers/char/broadcom/Makefile @@ -0,0 +1 @@ +obj-$(CONFIG_BCM2708_VCMEM) += vc_mem.o --- /dev/null +++ b/drivers/char/broadcom/vc_mem.c @@ -0,0 +1,373 @@ +/* + * 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 +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define DRIVER_NAME "vc-mem" + +/* 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 + +/* + * 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; + +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 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; + } + 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; + + 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(THIS_MODULE, 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 + + 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__); + + if (vc_mem_inited) { +#if 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); + } +} + +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); --- /dev/null +++ b/include/linux/broadcom/vc_mem.h @@ -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 + +#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 */