[PATCHv2 1/3] hwmem: Add hwmem (part 1)

Add hardware memory driver, part 1.

The main purpose of hwmem is:

* To allocate buffers suitable for use with hardware. Currently this means contiguous buffers. * To synchronize the caches for the allocated buffers. This is achieved by keeping track of when the CPU uses a buffer and when other hardware uses the buffer, when we switch from CPU to other hardware or vice versa the caches are synchronized. * To handle sharing of allocated buffers between processes i.e. import, export.

Hwmem is available both through a user space API and through a kernel API.

Signed-off-by: Johan Mossberg johan.xx.mossberg@stericsson.com --- drivers/misc/Kconfig | 1 + drivers/misc/Makefile | 1 + drivers/misc/hwmem/Kconfig | 7 + drivers/misc/hwmem/Makefile | 3 + drivers/misc/hwmem/hwmem-ioctl.c | 455 ++++++++++++++++++++++ drivers/misc/hwmem/hwmem-main.c | 799 ++++++++++++++++++++++++++++++++++++++ include/linux/hwmem.h | 536 +++++++++++++++++++++++++ 7 files changed, 1802 insertions(+), 0 deletions(-) create mode 100644 drivers/misc/hwmem/Kconfig create mode 100644 drivers/misc/hwmem/Makefile create mode 100644 drivers/misc/hwmem/hwmem-ioctl.c create mode 100644 drivers/misc/hwmem/hwmem-main.c create mode 100644 include/linux/hwmem.h

diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig index cc8e49d..6d83fb8 100644 --- a/drivers/misc/Kconfig +++ b/drivers/misc/Kconfig @@ -457,5 +457,6 @@ source "drivers/misc/eeprom/Kconfig" source "drivers/misc/cb710/Kconfig" source "drivers/misc/iwmc3200top/Kconfig" source "drivers/misc/ti-st/Kconfig" +source "drivers/misc/hwmem/Kconfig"

endif # MISC_DEVICES diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile index 98009cc..698b4f6 100644 --- a/drivers/misc/Makefile +++ b/drivers/misc/Makefile @@ -42,3 +42,4 @@ obj-$(CONFIG_ARM_CHARLCD) += arm-charlcd.o obj-$(CONFIG_PCH_PHUB) += pch_phub.o obj-y += ti-st/ obj-$(CONFIG_AB8500_PWM) += ab8500-pwm.o +obj-$(CONFIG_HWMEM) += hwmem/ diff --git a/drivers/misc/hwmem/Kconfig b/drivers/misc/hwmem/Kconfig new file mode 100644 index 0000000..c161875 --- /dev/null +++ b/drivers/misc/hwmem/Kconfig @@ -0,0 +1,7 @@ +config HWMEM + bool "Hardware memory driver" + default n + help + This driver provides a way to allocate memory suitable for use with + both CPU and non-CPU hardware, handles the caches for allocated + memory and enables inter-process sharing of allocated memory. diff --git a/drivers/misc/hwmem/Makefile b/drivers/misc/hwmem/Makefile new file mode 100644 index 0000000..18da2ad --- /dev/null +++ b/drivers/misc/hwmem/Makefile @@ -0,0 +1,3 @@ +hwmem-objs := hwmem-main.o hwmem-ioctl.o cache_handler.o + +obj-$(CONFIG_HWMEM) += hwmem.o diff --git a/drivers/misc/hwmem/hwmem-ioctl.c b/drivers/misc/hwmem/hwmem-ioctl.c new file mode 100644 index 0000000..69a15a6 --- /dev/null +++ b/drivers/misc/hwmem/hwmem-ioctl.c @@ -0,0 +1,455 @@ +/* + * Copyright (C) ST-Ericsson SA 2010 + * + * Hardware memory driver, hwmem + * + * Author: Marcus Lorentzon marcus.xm.lorentzon@stericsson.com + * for ST-Ericsson. + * + * License terms: GNU General Public License (GPL), version 2. + */ + +#include <linux/kernel.h> +#include <linux/fs.h> +#include <linux/idr.h> +#include <linux/err.h> +#include <linux/slab.h> +#include <linux/miscdevice.h> +#include <linux/uaccess.h> +#include <linux/mm_types.h> +#include <linux/hwmem.h> +#include <linux/device.h> +#include <linux/sched.h> + +static int hwmem_open(struct inode *inode, struct file *file); +static int hwmem_ioctl_mmap(struct file *file, struct vm_area_struct *vma); +static int hwmem_release_fop(struct inode *inode, struct file *file); +static long hwmem_ioctl(struct file *file, unsigned int cmd, + unsigned long arg); +static unsigned long hwmem_get_unmapped_area(struct file *file, + unsigned long addr, unsigned long len, unsigned long pgoff, + unsigned long flags); + +static const struct file_operations hwmem_fops = { + .open = hwmem_open, + .mmap = hwmem_ioctl_mmap, + .unlocked_ioctl = hwmem_ioctl, + .release = hwmem_release_fop, + .get_unmapped_area = hwmem_get_unmapped_area, +}; + +static struct miscdevice hwmem_device = { + .minor = MISC_DYNAMIC_MINOR, + .name = "hwmem", + .fops = &hwmem_fops, +}; + +struct hwmem_file { + struct mutex lock; + struct idr idr; /* id -> struct hwmem_alloc*, ref counted */ + struct hwmem_alloc *fd_alloc; /* Ref counted */ +}; + +static s32 create_id(struct hwmem_file *hwfile, struct hwmem_alloc *alloc) +{ + int id, ret; + + while (true) { + if (idr_pre_get(&hwfile->idr, GFP_KERNEL) == 0) + return -ENOMEM; + + ret = idr_get_new_above(&hwfile->idr, alloc, 1, &id); + if (ret == 0) + break; + else if (ret != -EAGAIN) + return -ENOMEM; + } + + /* + * IDR always returns the lowest free id so there is no wrapping issue + * because of this. + */ + if (id >= (s32)1 << (31 - PAGE_SHIFT)) { + dev_err(hwmem_device.this_device, "Out of IDs!\n"); + idr_remove(&hwfile->idr, id); + return -ENOMSG; + } + + return (s32)id << PAGE_SHIFT; +} + +static void remove_id(struct hwmem_file *hwfile, s32 id) +{ + idr_remove(&hwfile->idr, id >> PAGE_SHIFT); +} + +static struct hwmem_alloc *resolve_id(struct hwmem_file *hwfile, s32 id) +{ + struct hwmem_alloc *alloc; + + alloc = id ? idr_find(&hwfile->idr, id >> PAGE_SHIFT) : + hwfile->fd_alloc; + if (alloc == NULL) + alloc = ERR_PTR(-EINVAL); + + return alloc; +} + +static s32 alloc(struct hwmem_file *hwfile, struct hwmem_alloc_request *req) +{ + s32 ret = 0; + struct hwmem_alloc *alloc; + + alloc = hwmem_alloc(req->size, req->flags, req->default_access, + req->mem_type); + if (IS_ERR(alloc)) + return PTR_ERR(alloc); + + ret = create_id(hwfile, alloc); + if (ret < 0) + hwmem_release(alloc); + + return ret; +} + +static int alloc_fd(struct hwmem_file *hwfile, struct hwmem_alloc_request *req) +{ + struct hwmem_alloc *alloc; + + if (hwfile->fd_alloc) + return -EINVAL; + + alloc = hwmem_alloc(req->size, req->flags, req->default_access, + req->mem_type); + if (IS_ERR(alloc)) + return PTR_ERR(alloc); + + hwfile->fd_alloc = alloc; + + return 0; +} + +static int release(struct hwmem_file *hwfile, s32 id) +{ + struct hwmem_alloc *alloc; + + if (id == 0) + return -EINVAL; + + alloc = resolve_id(hwfile, id); + if (IS_ERR(alloc)) + return PTR_ERR(alloc); + + remove_id(hwfile, id); + hwmem_release(alloc); + + return 0; +} + +static int set_cpu_domain(struct hwmem_file *hwfile, + struct hwmem_set_domain_request *req) +{ + struct hwmem_alloc *alloc; + + alloc = resolve_id(hwfile, req->id); + if (IS_ERR(alloc)) + return PTR_ERR(alloc); + + return hwmem_set_domain(alloc, req->access, HWMEM_DOMAIN_CPU, + (struct hwmem_region *)&req->region); +} + +static int set_access(struct hwmem_file *hwfile, + struct hwmem_set_access_request *req) +{ + struct hwmem_alloc *alloc; + + alloc = resolve_id(hwfile, req->id); + if (IS_ERR(alloc)) + return PTR_ERR(alloc); + + return hwmem_set_access(alloc, req->access, req->pid); +} + +static int get_info(struct hwmem_file *hwfile, + struct hwmem_get_info_request *req) +{ + struct hwmem_alloc *alloc; + + alloc = resolve_id(hwfile, req->id); + if (IS_ERR(alloc)) + return PTR_ERR(alloc); + + hwmem_get_info(alloc, &req->size, &req->mem_type, &req->access); + + return 0; +} + +static s32 export(struct hwmem_file *hwfile, s32 id) +{ + s32 ret; + struct hwmem_alloc *alloc; + enum hwmem_access access; + + alloc = resolve_id(hwfile, id); + if (IS_ERR(alloc)) + return PTR_ERR(alloc); + + /* + * The user could be about to send the buffer to a driver but + * there is a chance the current thread group don't have import rights + * if it gained access to the buffer via a inter-process fd transfer + * (fork, Android binder), if this is the case the driver will not be + * able to resolve the buffer name. To avoid this situation we give the + * current thread group import rights. This will not breach the + * security as the process already has access to the buffer (otherwise + * it would not be able to get here). + */ + hwmem_get_info(alloc, NULL, NULL, &access); + + ret = hwmem_set_access(alloc, (access | HWMEM_ACCESS_IMPORT), + task_tgid_nr(current)); + if (ret < 0) + return ret; + + return hwmem_get_name(alloc); +} + +static s32 import(struct hwmem_file *hwfile, s32 name) +{ + s32 ret = 0; + struct hwmem_alloc *alloc; + enum hwmem_access access; + + alloc = hwmem_resolve_by_name(name); + if (IS_ERR(alloc)) + return PTR_ERR(alloc); + + /* Check access permissions for process */ + hwmem_get_info(alloc, NULL, NULL, &access); + if (!(access & HWMEM_ACCESS_IMPORT)) { + ret = -EPERM; + goto error; + } + + ret = create_id(hwfile, alloc); + if (ret < 0) + goto error; + + return ret; + +error: + hwmem_release(alloc); + + return ret; +} + +static int import_fd(struct hwmem_file *hwfile, s32 name) +{ + int ret; + struct hwmem_alloc *alloc; + enum hwmem_access access; + + if (hwfile->fd_alloc) + return -EINVAL; + + alloc = hwmem_resolve_by_name(name); + if (IS_ERR(alloc)) + return PTR_ERR(alloc); + + /* Check access permissions for process */ + hwmem_get_info(alloc, NULL, NULL, &access); + if (!(access & HWMEM_ACCESS_IMPORT)) { + ret = -EPERM; + goto error; + } + + hwfile->fd_alloc = alloc; + + return 0; + +error: + hwmem_release(alloc); + + return ret; +} + +static int hwmem_open(struct inode *inode, struct file *file) +{ + struct hwmem_file *hwfile; + + hwfile = kzalloc(sizeof(struct hwmem_file), GFP_KERNEL); + if (hwfile == NULL) + return -ENOMEM; + + idr_init(&hwfile->idr); + mutex_init(&hwfile->lock); + file->private_data = hwfile; + + return 0; +} + +static int hwmem_ioctl_mmap(struct file *file, struct vm_area_struct *vma) +{ + int ret; + struct hwmem_file *hwfile = (struct hwmem_file *)file->private_data; + struct hwmem_alloc *alloc; + + mutex_lock(&hwfile->lock); + + alloc = resolve_id(hwfile, (s32)vma->vm_pgoff << PAGE_SHIFT); + if (IS_ERR(alloc)) { + ret = PTR_ERR(alloc); + goto out; + } + + ret = hwmem_mmap(alloc, vma); + +out: + mutex_unlock(&hwfile->lock); + + return ret; +} + +static int hwmem_release_idr_for_each_wrapper(int id, void *ptr, void *data) +{ + hwmem_release((struct hwmem_alloc *)ptr); + + return 0; +} + +static int hwmem_release_fop(struct inode *inode, struct file *file) +{ + struct hwmem_file *hwfile = (struct hwmem_file *)file->private_data; + + idr_for_each(&hwfile->idr, hwmem_release_idr_for_each_wrapper, NULL); + idr_remove_all(&hwfile->idr); + idr_destroy(&hwfile->idr); + + if (hwfile->fd_alloc) + hwmem_release(hwfile->fd_alloc); + + mutex_destroy(&hwfile->lock); + + kfree(hwfile); + + return 0; +} + +static long hwmem_ioctl(struct file *file, unsigned int cmd, unsigned long arg) +{ + int ret = -ENOSYS; + struct hwmem_file *hwfile = (struct hwmem_file *)file->private_data; + + mutex_lock(&hwfile->lock); + + switch (cmd) { + case HWMEM_ALLOC_IOC: + { + struct hwmem_alloc_request req; + if (copy_from_user(&req, (void __user *)arg, + sizeof(struct hwmem_alloc_request))) + ret = -EFAULT; + else + ret = alloc(hwfile, &req); + } + break; + case HWMEM_ALLOC_FD_IOC: + { + struct hwmem_alloc_request req; + if (copy_from_user(&req, (void __user *)arg, + sizeof(struct hwmem_alloc_request))) + ret = -EFAULT; + else + ret = alloc_fd(hwfile, &req); + } + break; + case HWMEM_RELEASE_IOC: + ret = release(hwfile, (s32)arg); + break; + case HWMEM_SET_CPU_DOMAIN_IOC: + { + struct hwmem_set_domain_request req; + if (copy_from_user(&req, (void __user *)arg, + sizeof(struct hwmem_set_domain_request))) + ret = -EFAULT; + else + ret = set_cpu_domain(hwfile, &req); + } + break; + case HWMEM_SET_ACCESS_IOC: + { + struct hwmem_set_access_request req; + if (copy_from_user(&req, (void __user *)arg, + sizeof(struct hwmem_set_access_request))) + ret = -EFAULT; + else + ret = set_access(hwfile, &req); + } + break; + case HWMEM_GET_INFO_IOC: + { + struct hwmem_get_info_request req; + if (copy_from_user(&req, (void __user *)arg, + sizeof(struct hwmem_get_info_request))) + ret = -EFAULT; + else + ret = get_info(hwfile, &req); + if (ret == 0 && copy_to_user((void __user *)arg, &req, + sizeof(struct hwmem_get_info_request))) + ret = -EFAULT; + } + break; + case HWMEM_EXPORT_IOC: + ret = export(hwfile, (s32)arg); + break; + case HWMEM_IMPORT_IOC: + ret = import(hwfile, (s32)arg); + break; + case HWMEM_IMPORT_FD_IOC: + ret = import_fd(hwfile, (s32)arg); + break; + } + + mutex_unlock(&hwfile->lock); + + return ret; +} + +static unsigned long hwmem_get_unmapped_area(struct file *file, + unsigned long addr, unsigned long len, unsigned long pgoff, + unsigned long flags) +{ + /* + * pgoff will not be valid as it contains a buffer id (right shifted + * PAGE_SHIFT bits). To not confuse get_unmapped_area we'll not pass + * on file or pgoff. + */ + return current->mm->get_unmapped_area(NULL, addr, len, 0, flags); +} + +int __init hwmem_ioctl_init(void) +{ + if (PAGE_SHIFT < 1 || PAGE_SHIFT > 30 || sizeof(size_t) != 4 || + sizeof(int) > 4 || sizeof(enum hwmem_alloc_flags) != 4 || + sizeof(enum hwmem_access) != 4 || + sizeof(enum hwmem_mem_type) != 4) { + dev_err(hwmem_device.this_device, "PAGE_SHIFT < 1 || PAGE_SHIFT" + " > 30 || sizeof(size_t) != 4 || sizeof(int) > 4 ||" + " sizeof(enum hwmem_alloc_flags) != 4 || sizeof(enum" + " hwmem_access) != 4 || sizeof(enum hwmem_mem_type)" + " != 4\n"); + return -ENOMSG; + } + if (PAGE_SHIFT > 15) + dev_warn(hwmem_device.this_device, "Due to the page size only" + " %u id:s per file instance are available\n", + ((u32)1 << (31 - PAGE_SHIFT)) - 1); + + return misc_register(&hwmem_device); +} + +void __exit hwmem_ioctl_exit(void) +{ + misc_deregister(&hwmem_device); +} diff --git a/drivers/misc/hwmem/hwmem-main.c b/drivers/misc/hwmem/hwmem-main.c new file mode 100644 index 0000000..e0f9b99 --- /dev/null +++ b/drivers/misc/hwmem/hwmem-main.c @@ -0,0 +1,799 @@ +/* + * Copyright (C) ST-Ericsson SA 2010 + * + * Hardware memory driver, hwmem + * + * Author: Marcus Lorentzon marcus.xm.lorentzon@stericsson.com, + * Johan Mossberg johan.xx.mossberg@stericsson.com for ST-Ericsson. + * + * License terms: GNU General Public License (GPL), version 2. + */ + +#include <linux/init.h> +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/device.h> +#include <linux/dma-mapping.h> +#include <linux/idr.h> +#include <linux/mm.h> +#include <linux/sched.h> +#include <linux/err.h> +#include <linux/platform_device.h> +#include <linux/slab.h> +#include <linux/pid.h> +#include <linux/list.h> +#include <linux/hwmem.h> +#include <linux/debugfs.h> +#include <linux/uaccess.h> +#include <linux/vmalloc.h> +#include <linux/io.h> +#include <asm/sizes.h> +#include "cache_handler.h" + +struct hwmem_alloc_threadg_info { + struct list_head list; + + struct pid *threadg_pid; /* Ref counted */ + + enum hwmem_access access; +}; + +struct hwmem_alloc { + struct list_head list; + + atomic_t ref_cnt; + enum hwmem_alloc_flags flags; + u32 paddr; + void *kaddr; + u32 size; + s32 name; + + /* Access control */ + enum hwmem_access default_access; + struct list_head threadg_info_list; + + /* Cache handling */ + struct cach_buf cach_buf; +}; + +static struct platform_device *hwdev; + +static u32 hwmem_paddr; +static u32 hwmem_size; + +static LIST_HEAD(alloc_list); +static DEFINE_IDR(global_idr); +static DEFINE_MUTEX(lock); + +static void vm_open(struct vm_area_struct *vma); +static void vm_close(struct vm_area_struct *vma); +static struct vm_operations_struct vm_ops = { + .open = vm_open, + .close = vm_close, +}; + +#ifdef CONFIG_DEBUG_FS + +static int debugfs_allocs_read(struct file *filp, char __user *buf, + size_t count, loff_t *f_pos); +static const struct file_operations debugfs_allocs_fops = { + .owner = THIS_MODULE, + .read = debugfs_allocs_read, +}; + +#endif /* #ifdef CONFIG_DEBUG_FS */ + +static void clean_alloc_list(void); +static void kunmap_alloc(struct hwmem_alloc *alloc); + +/* Helpers */ + +static u32 get_alloc_offset(struct hwmem_alloc *alloc) +{ + return alloc->paddr - hwmem_paddr; +} + +static void destroy_hwmem_alloc_threadg_info( + struct hwmem_alloc_threadg_info *info) +{ + if (info->threadg_pid) + put_pid(info->threadg_pid); + + kfree(info); +} + +static void clean_hwmem_alloc_threadg_info_list(struct hwmem_alloc *alloc) +{ + struct hwmem_alloc_threadg_info *info; + struct hwmem_alloc_threadg_info *tmp; + + list_for_each_entry_safe(info, tmp, &(alloc->threadg_info_list), list) { + list_del(&info->list); + destroy_hwmem_alloc_threadg_info(info); + } +} + +static enum hwmem_access get_access(struct hwmem_alloc *alloc) +{ + struct hwmem_alloc_threadg_info *info; + struct pid *my_pid; + bool found = false; + + my_pid = find_get_pid(task_tgid_nr(current)); + if (!my_pid) + return 0; + + list_for_each_entry(info, &(alloc->threadg_info_list), list) { + if (info->threadg_pid == my_pid) { + found = true; + break; + } + } + + put_pid(my_pid); + + if (found) + return info->access; + else + return alloc->default_access; +} + +static void clear_alloc_mem(struct hwmem_alloc *alloc) +{ + cach_set_domain(&alloc->cach_buf, HWMEM_ACCESS_WRITE, + HWMEM_DOMAIN_CPU, NULL); + + memset(alloc->kaddr, 0, alloc->size); +} + +static void clean_alloc(struct hwmem_alloc *alloc) +{ + if (alloc->name) { + idr_remove(&global_idr, alloc->name); + alloc->name = 0; + } + + alloc->flags = 0; + + clean_hwmem_alloc_threadg_info_list(alloc); + + kunmap_alloc(alloc); +} + +static void destroy_alloc(struct hwmem_alloc *alloc) +{ + clean_alloc(alloc); + + kfree(alloc); +} + +static void __hwmem_release(struct hwmem_alloc *alloc) +{ + struct hwmem_alloc *other; + + clean_alloc(alloc); + + other = list_entry(alloc->list.prev, struct hwmem_alloc, list); + if ((alloc->list.prev != &alloc_list) && + atomic_read(&other->ref_cnt) == 0) { + other->size += alloc->size; + list_del(&alloc->list); + destroy_alloc(alloc); + alloc = other; + } + other = list_entry(alloc->list.next, struct hwmem_alloc, list); + if ((alloc->list.next != &alloc_list) && + atomic_read(&other->ref_cnt) == 0) { + alloc->size += other->size; + list_del(&other->list); + destroy_alloc(other); + } +} + +static struct hwmem_alloc *find_free_alloc_bestfit(u32 size) +{ + u32 best_diff = ~0; + struct hwmem_alloc *alloc = NULL, *i; + + list_for_each_entry(i, &alloc_list, list) { + u32 diff = i->size - size; + if (atomic_read(&i->ref_cnt) > 0 || i->size < size) + continue; + if (diff < best_diff) { + alloc = i; + best_diff = diff; + } + } + + return alloc != NULL ? alloc : ERR_PTR(-ENOMEM); +} + +static struct hwmem_alloc *split_allocation(struct hwmem_alloc *alloc, + u32 new_alloc_size) +{ + struct hwmem_alloc *new_alloc; + + new_alloc = kzalloc(sizeof(struct hwmem_alloc), GFP_KERNEL); + if (new_alloc == NULL) + return ERR_PTR(-ENOMEM); + + atomic_inc(&new_alloc->ref_cnt); + INIT_LIST_HEAD(&new_alloc->threadg_info_list); + new_alloc->paddr = alloc->paddr; + new_alloc->size = new_alloc_size; + alloc->size -= new_alloc_size; + alloc->paddr += new_alloc_size; + + list_add_tail(&new_alloc->list, &alloc->list); + + return new_alloc; +} + +static int init_alloc_list(void) +{ + struct hwmem_alloc *alloc = kzalloc(sizeof(struct hwmem_alloc), + GFP_KERNEL); + if (alloc == NULL) + return -ENOMEM; + alloc->paddr = hwmem_paddr; + alloc->size = hwmem_size; + INIT_LIST_HEAD(&alloc->threadg_info_list); + list_add_tail(&alloc->list, &alloc_list); + + return 0; +} + +static void clean_alloc_list(void) +{ + while (list_empty(&alloc_list) == 0) { + struct hwmem_alloc *i = list_first_entry(&alloc_list, + struct hwmem_alloc, list); + + list_del(&i->list); + + destroy_alloc(i); + } +} + +static int kmap_alloc(struct hwmem_alloc *alloc) +{ + int ret; + pgprot_t pgprot; + + struct vm_struct *area = get_vm_area(alloc->size, VM_IOREMAP); + if (area == NULL) { + dev_info(&hwdev->dev, "Failed to allocate %u bytes virtual" + " memory", alloc->size); + return -ENOMSG; + } + + pgprot = PAGE_KERNEL; + cach_set_pgprot_cache_options(&alloc->cach_buf, &pgprot); + + ret = ioremap_page_range((unsigned long)area->addr, + (unsigned long)area->addr + alloc->size, alloc->paddr, pgprot); + if (ret < 0) { + dev_info(&hwdev->dev, "Failed to map %#x - %#x", alloc->paddr, + alloc->paddr + alloc->size); + goto failed_to_map; + } + + alloc->kaddr = area->addr; + + return 0; + +failed_to_map: + area = remove_vm_area(area->addr); + if (area == NULL) + dev_err(&hwdev->dev, + "Failed to unmap alloc, resource leak!\n"); + + kfree(area); + + return ret; +} + +static void kunmap_alloc(struct hwmem_alloc *alloc) +{ + struct vm_struct *area; + + if (alloc->kaddr == NULL) + return; + + area = remove_vm_area(alloc->kaddr); + if (area == NULL) { + dev_err(&hwdev->dev, + "Failed to unmap alloc, resource leak!\n"); + return; + } + + kfree(area); + + alloc->kaddr = NULL; +} + +/* HWMEM API */ + +struct hwmem_alloc *hwmem_alloc(u32 size, enum hwmem_alloc_flags flags, + enum hwmem_access def_access, enum hwmem_mem_type mem_type) +{ + struct hwmem_alloc *alloc; + int ret; + + if (!hwdev) { + printk(KERN_ERR "hwmem: Badly configured\n"); + return ERR_PTR(-EINVAL); + } + + if (size == 0) + return ERR_PTR(-EINVAL); + + mutex_lock(&lock); + + size = PAGE_ALIGN(size); + + alloc = find_free_alloc_bestfit(size); + if (IS_ERR(alloc)) { + dev_info(&hwdev->dev, "Allocation failed, no free slot\n"); + goto no_slot; + } + + if (size < alloc->size) { + alloc = split_allocation(alloc, size); + if (IS_ERR(alloc)) + goto split_alloc_failed; + } else { + atomic_inc(&alloc->ref_cnt); + } + + alloc->flags = flags; + alloc->default_access = def_access; + cach_init_buf(&alloc->cach_buf, alloc->flags, alloc->size); + ret = kmap_alloc(alloc); + if (ret < 0) + goto kmap_alloc_failed; + cach_set_buf_addrs(&alloc->cach_buf, alloc->kaddr, alloc->paddr); + + clear_alloc_mem(alloc); + + goto out; + +kmap_alloc_failed: + __hwmem_release(alloc); + alloc = ERR_PTR(ret); +split_alloc_failed: +no_slot: + +out: + mutex_unlock(&lock); + + return alloc; +} +EXPORT_SYMBOL(hwmem_alloc); + +void hwmem_release(struct hwmem_alloc *alloc) +{ + mutex_lock(&lock); + + if (atomic_dec_and_test(&alloc->ref_cnt)) + __hwmem_release(alloc); + + mutex_unlock(&lock); +} +EXPORT_SYMBOL(hwmem_release); + +int hwmem_set_domain(struct hwmem_alloc *alloc, enum hwmem_access access, + enum hwmem_domain domain, struct hwmem_region *region) +{ + mutex_lock(&lock); + + cach_set_domain(&alloc->cach_buf, access, domain, region); + + mutex_unlock(&lock); + + return 0; +} +EXPORT_SYMBOL(hwmem_set_domain); + +int hwmem_pin(struct hwmem_alloc *alloc, struct hwmem_mem_chunk *mem_chunks, + u32 *mem_chunks_length) +{ + if (*mem_chunks_length < 1) { + *mem_chunks_length = 1; + return -ENOSPC; + } + + mutex_lock(&lock); + + mem_chunks[0].paddr = alloc->paddr; + mem_chunks[0].size = alloc->size; + *mem_chunks_length = 1; + + mutex_unlock(&lock); + + return 0; +} +EXPORT_SYMBOL(hwmem_pin); + +void hwmem_unpin(struct hwmem_alloc *alloc) +{ +} +EXPORT_SYMBOL(hwmem_unpin); + +static void vm_open(struct vm_area_struct *vma) +{ + atomic_inc(&((struct hwmem_alloc *)vma->vm_private_data)->ref_cnt); +} + +static void vm_close(struct vm_area_struct *vma) +{ + hwmem_release((struct hwmem_alloc *)vma->vm_private_data); +} + +int hwmem_mmap(struct hwmem_alloc *alloc, struct vm_area_struct *vma) +{ + int ret = 0; + unsigned long vma_size = vma->vm_end - vma->vm_start; + enum hwmem_access access; + mutex_lock(&lock); + + access = get_access(alloc); + + /* Check permissions */ + if ((!(access & HWMEM_ACCESS_WRITE) && + (vma->vm_flags & VM_WRITE)) || + (!(access & HWMEM_ACCESS_READ) && + (vma->vm_flags & VM_READ))) { + ret = -EPERM; + goto illegal_access; + } + + if (vma_size > alloc->size) { + ret = -EINVAL; + goto illegal_size; + } + + /* + * We don't want Linux to do anything (merging etc) with our VMAs as + * the offset is not necessarily valid + */ + vma->vm_flags |= VM_SPECIAL; + cach_set_pgprot_cache_options(&alloc->cach_buf, &vma->vm_page_prot); + vma->vm_private_data = (void *)alloc; + atomic_inc(&alloc->ref_cnt); + vma->vm_ops = &vm_ops; + + ret = remap_pfn_range(vma, vma->vm_start, alloc->paddr >> PAGE_SHIFT, + min(vma_size, (unsigned long)alloc->size), vma->vm_page_prot); + if (ret < 0) + goto map_failed; + + goto out; + +map_failed: + atomic_dec(&alloc->ref_cnt); +illegal_size: +illegal_access: + +out: + mutex_unlock(&lock); + + return ret; +} +EXPORT_SYMBOL(hwmem_mmap); + +void *hwmem_kmap(struct hwmem_alloc *alloc) +{ + void *ret; + + mutex_lock(&lock); + + ret = alloc->kaddr; + + mutex_unlock(&lock); + + return ret; +} +EXPORT_SYMBOL(hwmem_kmap); + +void hwmem_kunmap(struct hwmem_alloc *alloc) +{ +} +EXPORT_SYMBOL(hwmem_kunmap); + +int hwmem_set_access(struct hwmem_alloc *alloc, + enum hwmem_access access, pid_t pid_nr) +{ + int ret; + struct hwmem_alloc_threadg_info *info; + struct pid *pid; + bool found = false; + + pid = find_get_pid(pid_nr); + if (!pid) { + ret = -EINVAL; + goto error_get_pid; + } + + list_for_each_entry(info, &(alloc->threadg_info_list), list) { + if (info->threadg_pid == pid) { + found = true; + break; + } + } + + if (!found) { + info = kmalloc(sizeof(*info), GFP_KERNEL); + if (!info) { + ret = -ENOMEM; + goto error_alloc_info; + } + + info->threadg_pid = pid; + info->access = access; + + list_add_tail(&(info->list), &(alloc->threadg_info_list)); + } else { + info->access = access; + } + + return 0; + +error_alloc_info: + put_pid(pid); +error_get_pid: + return ret; +} +EXPORT_SYMBOL(hwmem_set_access); + +void hwmem_get_info(struct hwmem_alloc *alloc, u32 *size, + enum hwmem_mem_type *mem_type, enum hwmem_access *access) +{ + mutex_lock(&lock); + + if (size != NULL) + *size = alloc->size; + if (mem_type != NULL) + *mem_type = HWMEM_MEM_CONTIGUOUS_SYS; + if (access != NULL) + *access = get_access(alloc); + + mutex_unlock(&lock); +} +EXPORT_SYMBOL(hwmem_get_info); + +int hwmem_get_name(struct hwmem_alloc *alloc) +{ + int ret = 0, name; + + mutex_lock(&lock); + + if (alloc->name != 0) { + ret = alloc->name; + goto out; + } + + while (true) { + if (idr_pre_get(&global_idr, GFP_KERNEL) == 0) { + ret = -ENOMEM; + goto pre_get_id_failed; + } + + ret = idr_get_new_above(&global_idr, alloc, 1, &name); + if (ret == 0) + break; + else if (ret != -EAGAIN) + goto get_id_failed; + } + + alloc->name = name; + + ret = name; + goto out; + +get_id_failed: +pre_get_id_failed: + +out: + mutex_unlock(&lock); + + return ret; +} +EXPORT_SYMBOL(hwmem_get_name); + +struct hwmem_alloc *hwmem_resolve_by_name(s32 name) +{ + struct hwmem_alloc *alloc; + + mutex_lock(&lock); + + alloc = idr_find(&global_idr, name); + if (alloc == NULL) { + alloc = ERR_PTR(-EINVAL); + goto find_failed; + } + atomic_inc(&alloc->ref_cnt); + + goto out; + +find_failed: + +out: + mutex_unlock(&lock); + + return alloc; +} +EXPORT_SYMBOL(hwmem_resolve_by_name); + +/* Debug */ + +static int print_alloc(struct hwmem_alloc *alloc, char **buf, size_t buf_size) +{ + int ret; + + if (buf_size < 134) + return -EINVAL; + + ret = sprintf(*buf, "paddr: %#10x\tsize: %10u\tref cnt: %2i\t" + "name: %#10x\tflags: %#4x\t$ settings: %#4x\t" + "def acc: %#3x\n", alloc->paddr, alloc->size, + atomic_read(&alloc->ref_cnt), alloc->name, + alloc->flags, alloc->cach_buf.cache_settings, + alloc->default_access); + if (ret < 0) + return -ENOMSG; + + *buf += ret; + + return 0; +} + +#ifdef CONFIG_DEBUG_FS + +static int debugfs_allocs_read(struct file *file, char __user *buf, + size_t count, loff_t *f_pos) +{ + /* + * We assume the supplied buffer and PAGE_SIZE is large enough to hold + * information about at least one alloc, if not no data will be + * returned. + */ + + int ret; + struct hwmem_alloc *curr_alloc; + char *local_buf = kmalloc(PAGE_SIZE, GFP_KERNEL); + char *local_buf_pos = local_buf; + size_t available_space = min((size_t)PAGE_SIZE, count); + /* private_data is intialized to NULL in open which I assume is 0. */ + u32 *curr_pos = (u32 *)&file->private_data; + size_t bytes_read; + + if (local_buf == NULL) + return -ENOMEM; + + mutex_lock(&lock); + + list_for_each_entry(curr_alloc, &alloc_list, list) { + u32 alloc_offset = get_alloc_offset(curr_alloc); + + if (alloc_offset < *curr_pos) + continue; + + ret = print_alloc(curr_alloc, &local_buf_pos, available_space - + (size_t)(local_buf_pos - local_buf)); + if (ret == -EINVAL) /* No more room */ + break; + else if (ret < 0) + goto out; + + *curr_pos = alloc_offset + 1; + } + + bytes_read = (size_t)(local_buf_pos - local_buf); + + ret = copy_to_user(buf, local_buf, bytes_read); + if (ret < 0) + goto out; + + ret = bytes_read; + +out: + kfree(local_buf); + + mutex_unlock(&lock); + + return ret; +} + +static void init_debugfs(void) +{ + /* Hwmem is never unloaded so dropping the dentrys is ok. */ + struct dentry *debugfs_root_dir = debugfs_create_dir("hwmem", NULL); + (void)debugfs_create_file("allocs", 0444, debugfs_root_dir, 0, + &debugfs_allocs_fops); +} + +#endif /* #ifdef CONFIG_DEBUG_FS */ + +/* Module */ + +extern int hwmem_ioctl_init(void); +extern void hwmem_ioctl_exit(void); + +static int __devinit hwmem_probe(struct platform_device *pdev) +{ + int ret = 0; + struct hwmem_platform_data *platform_data = pdev->dev.platform_data; + + if (sizeof(int) != 4 || sizeof(phys_addr_t) < 4 || + sizeof(void *) < 4 || sizeof(size_t) != 4) { + dev_err(&pdev->dev, "sizeof(int) != 4 || sizeof(phys_addr_t)" + " < 4 || sizeof(void *) < 4 || sizeof(size_t) !=" + " 4\n"); + return -ENOMSG; + } + + if (hwdev || platform_data->size == 0 || + platform_data->start != PAGE_ALIGN(platform_data->start) || + platform_data->size != PAGE_ALIGN(platform_data->size)) { + dev_err(&pdev->dev, "hwdev || platform_data->size == 0 ||" + "platform_data->start !=" + " PAGE_ALIGN(platform_data->start) ||" + "platform_data->size !=" + " PAGE_ALIGN(platform_data->size)\n"); + return -EINVAL; + } + + hwdev = pdev; + hwmem_paddr = platform_data->start; + hwmem_size = platform_data->size; + + /* + * No need to flush the caches here. If we can keep track of the cache + * content then none of our memory will be in the caches, if we can't + * keep track of the cache content we always assume all our memory is + * in the caches. + */ + + ret = init_alloc_list(); + if (ret < 0) + goto init_alloc_list_failed; + + ret = hwmem_ioctl_init(); + if (ret) + goto ioctl_init_failed; + +#ifdef CONFIG_DEBUG_FS + init_debugfs(); +#endif + + dev_info(&pdev->dev, "Hwmem probed, device contains %#x bytes\n", + hwmem_size); + + goto out; + +ioctl_init_failed: + clean_alloc_list(); +init_alloc_list_failed: + hwdev = NULL; + +out: + return ret; +} + +static struct platform_driver hwmem_driver = { + .probe = hwmem_probe, + .driver = { + .name = "hwmem", + }, +}; + +static int __init hwmem_init(void) +{ + return platform_driver_register(&hwmem_driver); +} +subsys_initcall(hwmem_init); + +MODULE_AUTHOR("Marcus Lorentzon marcus.xm.lorentzon@stericsson.com"); +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("Hardware memory driver"); diff --git a/include/linux/hwmem.h b/include/linux/hwmem.h new file mode 100644 index 0000000..dd99c44 --- /dev/null +++ b/include/linux/hwmem.h @@ -0,0 +1,536 @@ +/* + * Copyright (C) ST-Ericsson SA 2010 + * + * Hardware memory driver, hwmem + * + * Author: Marcus Lorentzon marcus.xm.lorentzon@stericsson.com + * for ST-Ericsson. + * + * License terms: GNU General Public License (GPL), version 2. + */ + +#ifndef _HWMEM_H_ +#define _HWMEM_H_ + +#if !defined(__KERNEL__) && !defined(_KERNEL) +#include <stdint.h> +#include <sys/types.h> +#else +#include <linux/types.h> +#include <linux/mm_types.h> +#endif + +#define HWMEM_DEFAULT_DEVICE_NAME "hwmem" + +/** + * @brief Flags defining behavior of allocation + */ +enum hwmem_alloc_flags { + /** + * @brief Buffered + */ + HWMEM_ALLOC_HINT_WRITE_COMBINE = (1 << 0), + /** + * @brief Non-buffered + */ + HWMEM_ALLOC_HINT_NO_WRITE_COMBINE = (1 << 1), + /** + * @brief Cached + */ + HWMEM_ALLOC_HINT_CACHED = (1 << 2), + /** + * @brief Uncached + */ + HWMEM_ALLOC_HINT_UNCACHED = (1 << 3), + /** + * @brief Write back + */ + HWMEM_ALLOC_HINT_CACHE_WB = (1 << 4), + /** + * @brief Write through + */ + HWMEM_ALLOC_HINT_CACHE_WT = (1 << 5), + /** + * @brief No alloc on write + */ + HWMEM_ALLOC_HINT_CACHE_NAOW = (1 << 6), + /** + * @brief Alloc on write + */ + HWMEM_ALLOC_HINT_CACHE_AOW = (1 << 7), + /** + * @brief Inner and outer cache + */ + HWMEM_ALLOC_HINT_INNER_AND_OUTER_CACHE = (1 << 8), + /** + * @brief Inner cache only + */ + HWMEM_ALLOC_HINT_INNER_CACHE_ONLY = (1 << 9), + /** + * @brief Reserved for use by the cache handler integration + */ + HWMEM_ALLOC_RESERVED_CHI = (1 << 31), +}; + +/** + * @brief Flags defining buffer access mode. + */ +enum hwmem_access { + /** + * @brief Buffer will be read from. + */ + HWMEM_ACCESS_READ = (1 << 0), + /** + * @brief Buffer will be written to. + */ + HWMEM_ACCESS_WRITE = (1 << 1), + /** + * @brief Buffer will be imported. + */ + HWMEM_ACCESS_IMPORT = (1 << 2), +}; + +/** + * @brief Values defining memory types. + */ +enum hwmem_mem_type { + /** + * @brief Scattered system memory. + */ + HWMEM_MEM_SCATTERED_SYS, + /** + * @brief Contiguous system memory. + */ + HWMEM_MEM_CONTIGUOUS_SYS, +}; + +/* User space API */ + +/** + * @see struct hwmem_region. + */ +struct hwmem_region_us { + __u32 offset; + __u32 count; + __u32 start; + __u32 end; + __u32 size; +}; + +/** + * @brief Alloc request data. + */ +struct hwmem_alloc_request { + /** + * @brief [in] Size of requested allocation in bytes. Size will be + * aligned to PAGE_SIZE bytes. + */ + __u32 size; + /** + * @brief [in] Flags describing requested allocation options. + */ + __u32 flags; /* enum hwmem_alloc_flags */ + /** + * @brief [in] Default access rights for buffer. + */ + __u32 default_access; /* enum hwmem_access */ + /** + * @brief [in] Memory type of the buffer. + */ + __u32 mem_type; /* enum hwmem_mem_type */ +}; + +/** + * @brief Set domain request data. + */ +struct hwmem_set_domain_request { + /** + * @brief [in] Identifier of buffer to be prepared. If 0 is specified + * the buffer associated with the current file instance will be used. + */ + __s32 id; + /** + * @brief [in] Flags specifying access mode of the operation. + * + * One of HWMEM_ACCESS_READ and HWMEM_ACCESS_WRITE is required. + * For details, @see enum hwmem_access. + */ + __u32 access; /* enum hwmem_access */ + /** + * @brief [in] The region of bytes to be prepared. + * + * For details, @see struct hwmem_region. + */ + struct hwmem_region_us region; +}; + +/** + * @brief Set access rights request data. + */ +struct hwmem_set_access_request { + /** + * @brief [in] Identifier of buffer to set access rights for. If 0 is + * specified, the buffer associated with the current file instance will + * be used. + */ + __s32 id; + /** + * @param access Access value indicating what is allowed. + */ + __u32 access; /* enum hwmem_access */ + /** + * @param pid Process ID to set rights for. + */ + pid_t pid; +}; + +/** + * @brief Get info request data. + */ +struct hwmem_get_info_request { + /** + * @brief [in] Identifier of buffer to get info about. If 0 is specified, + * the buffer associated with the current file instance will be used. + */ + __s32 id; + /** + * @brief [out] Size in bytes of buffer. + */ + __u32 size; + /** + * @brief [out] Memory type of buffer. + */ + __u32 mem_type; /* enum hwmem_mem_type */ + /** + * @brief [out] Access rights for buffer. + */ + __u32 access; /* enum hwmem_access */ +}; + +/** + * @brief Allocates <size> number of bytes and returns a buffer identifier. + * + * Input is a pointer to a hwmem_alloc_request struct. + * + * @return A buffer identifier on success, or a negative error code. + */ +#define HWMEM_ALLOC_IOC _IOW('W', 1, struct hwmem_alloc_request) + +/** + * @brief Allocates <size> number of bytes and associates the created buffer + * with the current file instance. + * + * If the current file instance is already associated with a buffer the call + * will fail. Buffers referenced through files instances shall not be released + * with HWMEM_RELEASE_IOC, instead the file instance shall be closed. + * + * Input is a pointer to a hwmem_alloc_request struct. + * + * @return Zero on success, or a negative error code. + */ +#define HWMEM_ALLOC_FD_IOC _IOW('W', 2, struct hwmem_alloc_request) + +/** + * @brief Releases buffer. + * + * Buffers are reference counted and will not be destroyed until the last + * reference is released. Buffers allocated with ALLOC_FD_IOC shall not be + * released with this IOC, @see HWMEM_ALLOC_FD_IOC. + * + * Input is the buffer identifier. + * + * @return Zero on success, or a negative error code. + */ +#define HWMEM_RELEASE_IOC _IO('W', 3) + +/** + * Memory Mapping + * + * To map a hwmem buffer mmap the hwmem fd and supply the buffer identifier as + * the offset. If the buffer is linked to the fd and thus have no buffer + * identifier supply 0 as the offset. Note that the offset feature of mmap is + * disabled in both cases, you can only mmap starting a position 0. + */ + +/** + * @brief Prepares the buffer for CPU access. + * + * Input is a pointer to a hwmem_set_domain_request struct. + * + * @return Zero on success, or a negative error code. + */ +#define HWMEM_SET_CPU_DOMAIN_IOC _IOW('W', 4, struct hwmem_set_domain_request) + +/** + * @brief Set access rights for buffer. + * + * Input is a pointer to a hwmem_set_access_request struct. + * + * @return Zero on success, or a negative error code. + */ +#define HWMEM_SET_ACCESS_IOC _IOW('W', 8, struct hwmem_set_access_request) + +/** + * @brief Get buffer information. + * + * Input is a pointer to a hwmem_get_info_request struct. + * + * @return Zero on success, or a negative error code. + */ +#define HWMEM_GET_INFO_IOC _IOWR('W', 9, struct hwmem_get_info_request) + +/** + * @brief Export the buffer identifier for use in another process. + * + * The global name will not increase the buffers reference count and will + * therefore not keep the buffer alive. + * + * Input is the buffer identifier. If 0 is specified the buffer associated with + * the current file instance will be exported. + * + * @return A global buffer name on success, or a negative error code. + */ +#define HWMEM_EXPORT_IOC _IO('W', 10) + +/** + * @brief Import a buffer to allow local access to the buffer. + * + * Input is the buffer's global name. + * + * @return The imported buffer's identifier on success, or a negative error + * code. + */ +#define HWMEM_IMPORT_IOC _IO('W', 11) + +/** + * @brief Import a buffer to allow local access to the buffer using the current + * fd. + * + * Input is the buffer's global name. + * + * @return Zero on success, or a negative error code. + */ +#define HWMEM_IMPORT_FD_IOC _IO('W', 12) + +#ifdef __KERNEL__ + +/* Kernel API */ + +/** + * @brief Values defining memory domain. + */ +enum hwmem_domain { + /** + * @brief This value specifies the neutral memory domain. Setting this + * domain will syncronize all supported memory domains. + */ + HWMEM_DOMAIN_SYNC = 0, + /** + * @brief This value specifies the CPU memory domain. + */ + HWMEM_DOMAIN_CPU, +}; + +struct hwmem_alloc; + +/** + * @brief Structure defining a region of a memory buffer. + * + * A buffer is defined to contain a number of equally sized blocks. Each block + * has a part of it included in the region [<start>-<end>). That is + * <end>-<start> bytes. Each block is <size> bytes long. Total number of bytes + * in the region is (<end> - <start>) * <count>. First byte of the region is + * <offset> + <start> bytes into the buffer. + * + * Here's an example of a region in a graphics buffer (X = buffer, R = region): + * + * XXXXXXXXXXXXXXXXXXXX \ + * XXXXXXXXXXXXXXXXXXXX |-- offset = 60 + * XXXXXXXXXXXXXXXXXXXX / + * XXRRRRRRRRXXXXXXXXXX \ + * XXRRRRRRRRXXXXXXXXXX |-- count = 4 + * XXRRRRRRRRXXXXXXXXXX | + * XXRRRRRRRRXXXXXXXXXX / + * XXXXXXXXXXXXXXXXXXXX + * --| start = 2 + * ----------| end = 10 + * --------------------| size = 20 + */ +struct hwmem_region { + /** + * @brief The first block's offset from beginning of buffer. + */ + size_t offset; + /** + * @brief The number of blocks included in this region. + */ + size_t count; + /** + * @brief The index of the first byte included in this block. + */ + size_t start; + /** + * @brief The index of the last byte included in this block plus one. + */ + size_t end; + /** + * @brief The size in bytes of each block. + */ + size_t size; +}; + +struct hwmem_mem_chunk { + phys_addr_t paddr; + size_t size; +}; + +/** + * @brief Allocates <size> number of bytes. + * + * @param size Number of bytes to allocate. All allocations are page aligned. + * @param flags Allocation options. + * @param def_access Default buffer access rights. + * @param mem_type Memory type. + * + * @return Pointer to allocation, or a negative error code. + */ +struct hwmem_alloc *hwmem_alloc(size_t size, enum hwmem_alloc_flags flags, + enum hwmem_access def_access, enum hwmem_mem_type mem_type); + +/** + * @brief Release a previously allocated buffer. + * When last reference is released, the buffer will be freed. + * + * @param alloc Buffer to be released. + */ +void hwmem_release(struct hwmem_alloc *alloc); + +/** + * @brief Set the buffer domain and prepare it for access. + * + * @param alloc Buffer to be prepared. + * @param access Flags defining memory access mode of the call. + * @param domain Value specifying the memory domain. + * @param region Structure defining the minimum area of the buffer to be + * prepared. + * + * @return Zero on success, or a negative error code. + */ +int hwmem_set_domain(struct hwmem_alloc *alloc, enum hwmem_access access, + enum hwmem_domain domain, struct hwmem_region *region); + +/** + * @brief Pins the buffer. + * + * Notice that the number of mem chunks a buffer consists of can change at any + * time if the buffer is not pinned. Because of this one can not assume that + * pin will succeed if <mem_chunks> has the length specified by a previous call + * to pin as the buffer layout may have changed between the calls. There are + * two ways of handling this situation, keep redoing the pin procedure till it + * succeeds or allocate enough mem chunks for the worst case ("buffer size" / + * "page size" mem chunks). Contiguous buffers always require only one mem + * chunk. + * + * @param alloc Buffer to be pinned. + * @param mem_chunks Pointer to array of mem chunks. + * @param mem_chunks_length Pointer to variable that contains the length of + * <mem_chunks> array. On success the number of written mem chunks will be + * stored in this variable. If the call fails with -ENOSPC the required length + * of <mem_chunks> will be stored in this variable. + * + * @return Zero on success, or a negative error code. + */ +int hwmem_pin(struct hwmem_alloc *alloc, struct hwmem_mem_chunk *mem_chunks, + size_t *mem_chunks_length); + +/** + * @brief Unpins the buffer. + * + * @param alloc Buffer to be unpinned. + */ +void hwmem_unpin(struct hwmem_alloc *alloc); + +/** + * @brief Map the buffer to user space. + * + * @param alloc Buffer to be mapped. + * + * @return Zero on success, or a negative error code. + */ +int hwmem_mmap(struct hwmem_alloc *alloc, struct vm_area_struct *vma); + +/** + * @brief Map the buffer for use in the kernel. + * + * This function implicitly pins the buffer. + * + * @param alloc Buffer to be mapped. + * + * @return Pointer to buffer, or a negative error code. + */ +void *hwmem_kmap(struct hwmem_alloc *alloc); + +/** + * @brief Un-map a buffer previously mapped with hwmem_kmap. + * + * This function implicitly unpins the buffer. + * + * @param alloc Buffer to be un-mapped. + */ +void hwmem_kunmap(struct hwmem_alloc *alloc); + +/** + * @brief Set access rights for buffer. + * + * @param alloc Buffer to set rights for. + * @param access Access value indicating what is allowed. + * @param pid Process ID to set rights for. + */ +int hwmem_set_access(struct hwmem_alloc *alloc, enum hwmem_access access, + pid_t pid); + +/** + * @brief Get buffer information. + * + * @param alloc Buffer to get information about. + * @param size Pointer to size output variable. Can be NULL. + * @param size Pointer to memory type output variable. Can be NULL. + * @param size Pointer to access rights output variable. Can be NULL. + */ +void hwmem_get_info(struct hwmem_alloc *alloc, size_t *size, + enum hwmem_mem_type *mem_type, enum hwmem_access *access); + +/** + * @brief Allocate a global buffer name. + * Generated buffer name is valid in all processes. Consecutive calls will get + * the same name for the same buffer. + * + * @param alloc Buffer to be made public. + * + * @return Positive global name on success, or a negative error code. + */ +s32 hwmem_get_name(struct hwmem_alloc *alloc); + +/** + * @brief Import the global buffer name to allow local access to the buffer. + * This call will add a buffer reference. Resulting buffer should be + * released with a call to hwmem_release. + * + * @param name A valid global buffer name. + * + * @return Pointer to allocation, or a negative error code. + */ +struct hwmem_alloc *hwmem_resolve_by_name(s32 name); + +/* Internal */ + +struct hwmem_platform_data { + /* Physical address of memory region */ + u32 start; + /* Size of memory region */ + u32 size; +}; + +#endif + +#endif /* _HWMEM_H_ */