mirror of
https://github.com/gnif/LookingGlass.git
synced 2024-11-22 05:27:20 +00:00
[kvmfr] added the ability to obtain a dmabuf of the ivshmem memory
This is to enable the ability to use dri3 to create dmabuf backed pixmaps directly.
This commit is contained in:
Geoffrey McRae
parent
6aeafc6651
commit
788f885759
@ -3,14 +3,20 @@ USER := $(shell whoami)
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KVER ?= $(shell uname -r)
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KDIR ?= /lib/modules/$(KVER)/build
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all:
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all: test
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make -C $(KDIR) M=$(PWD) modules
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clean:
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make -C $(KDIR) M=$(PWD) clean
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test: all
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test:
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gcc test.c -Wall -Werror -g -Og -o test
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load: all
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grep -q '^uio' /proc/modules || sudo modprobe uio
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grep -q '^kvmfr' /proc/modules && sudo rmmod kvmfr || true
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sudo insmod ./kvmfr.ko
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sudo chown $(USER) /dev/uio0
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sudo chown $(USER) /dev/kvmfr0
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.PHONY: test
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396
module/kvmfr.c
396
module/kvmfr.c
@ -25,73 +25,367 @@ Place, Suite 330, Boston, MA 02111-1307 USA
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#include <linux/pci.h>
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#include <linux/slab.h>
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#include <linux/uio_driver.h>
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#include <linux/fs.h>
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#include <linux/dma-buf.h>
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#include <linux/highmem.h>
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#include <asm/io.h>
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#include "kvmfr.h"
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DEFINE_MUTEX(minor_lock);
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DEFINE_IDR(kvmfr_idr);
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#define KVMFR_UIO_NAME "KVMFR"
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#define KVMFR_UIO_VER "0.0.2"
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#define KVMFR_DEV_NAME "kvmfr"
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#define KVMFR_MAX_DEVICES 10
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struct kvmfr_info
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{
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int major;
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struct class * pClass;
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};
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static struct kvmfr_info *kvmfr;
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struct kvmfr_dev
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{
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struct pci_dev * dev;
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struct uio_info uio;
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int minor;
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dev_t devNo;
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struct device * pDev;
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void * addr;
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};
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struct kvmfrbuf
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{
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struct kvmfr_dev * kdev;
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pgoff_t pagecount;
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struct dev_pagemap * pgmap;
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struct page ** pages;
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};
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static vm_fault_t kvmfr_vm_fault(struct vm_fault *vmf)
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{
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struct vm_area_struct *vma = vmf->vma;
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struct kvmfrbuf *kbuf = (struct kvmfrbuf *)vma->vm_private_data;
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vmf->page = kbuf->pages[vmf->pgoff];
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get_page(vmf->page);
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return 0;
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}
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static const struct vm_operations_struct kvmfr_vm_ops =
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{
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.fault = kvmfr_vm_fault
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};
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static struct sg_table * map_kvmfrbuf(struct dma_buf_attachment *at,
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enum dma_data_direction direction)
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{
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struct kvmfrbuf *kbuf = at->dmabuf->priv;
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struct sg_table *sg;
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int ret;
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sg = kzalloc(sizeof(*sg), GFP_KERNEL);
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if (!sg)
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return ERR_PTR(-ENOMEM);
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ret = sg_alloc_table_from_pages(sg, kbuf->pages, kbuf->pagecount,
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0, kbuf->pagecount << PAGE_SHIFT, GFP_KERNEL);
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if (ret < 0)
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goto err;
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if (!dma_map_sg(at->dev, sg->sgl, sg->nents, direction))
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{
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ret = -EINVAL;
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goto err;
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}
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return sg;
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err:
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sg_free_table(sg);
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kfree(sg);
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return ERR_PTR(ret);
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}
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static void unmap_kvmfrbuf(struct dma_buf_attachment * at, struct sg_table * sg, enum dma_data_direction direction)
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{
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dma_unmap_sg(at->dev, sg->sgl, sg->nents, direction);
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sg_free_table(sg);
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kfree(sg);
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}
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static void release_kvmfrbuf(struct dma_buf * buf)
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{
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struct kvmfrbuf *kbuf = (struct kvmfrbuf *)buf->priv;
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pgoff_t pg;
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for (pg = 0; pg < kbuf->pagecount; pg++)
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put_page(kbuf->pages[pg]);
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devm_memunmap_pages(&kbuf->kdev->dev->dev, kbuf->pgmap);
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kfree(kbuf->pgmap);
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kfree(kbuf->pages);
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kfree(kbuf);
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}
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static void * kmap_kvmfrbuf(struct dma_buf * buf, unsigned long page_num)
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{
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struct kvmfrbuf * kbuf = (struct kvmfrbuf *)buf->priv;
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struct page * page = kbuf->pages[page_num];
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return kmap(page);
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}
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static void kunmap_kvmfrbuf(struct dma_buf * buf, unsigned long page_num, void * vaddr)
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{
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kunmap(vaddr);
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}
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static int mmap_kvmfrbuf(struct dma_buf * buf, struct vm_area_struct * vma)
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{
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if ((vma->vm_flags & (VM_SHARED | VM_MAYSHARE)) == 0)
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return -EINVAL;
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vma->vm_ops = &kvmfr_vm_ops;
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vma->vm_private_data = buf->priv;
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return 0;
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}
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static const struct dma_buf_ops kvmfrbuf_ops =
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{
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.map_dma_buf = map_kvmfrbuf,
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.unmap_dma_buf = unmap_kvmfrbuf,
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.release = release_kvmfrbuf,
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.map = kmap_kvmfrbuf,
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.unmap = kunmap_kvmfrbuf,
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.mmap = mmap_kvmfrbuf
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};
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inline static unsigned long get_min_align(void)
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{
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if (IS_ENABLED(CONFIG_SPARSEMEM_VMEMMAP))
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return PAGES_PER_SUBSECTION;
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else
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return PAGES_PER_SECTION;
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}
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static long kvmfr_dmabuf_create(struct kvmfr_dev * kdev, struct file * filp, unsigned long arg)
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{
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const unsigned long min_align = get_min_align();
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struct kvmfr_dmabuf_create create;
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DEFINE_DMA_BUF_EXPORT_INFO(exp_kdev);
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struct kvmfrbuf * kbuf;
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struct dma_buf * buf;
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u32 i;
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u8 *p;
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int ret = -EINVAL;
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if (copy_from_user(&create, (void __user *)arg,
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sizeof(create)))
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return -EFAULT;
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if (!IS_ALIGNED(create.offset, min_align) ||
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!IS_ALIGNED(create.size , min_align))
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{
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printk("kvmfr: buffer not aligned to 0x%lx bytes", min_align << PAGE_SHIFT);
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return -EINVAL;
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}
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if (create.offset + create.size > pci_resource_len(kdev->dev, 2))
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return -EINVAL;
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kbuf = kzalloc(sizeof(struct kvmfrbuf), GFP_KERNEL);
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if (!kbuf)
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return -ENOMEM;
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kbuf->kdev = kdev;
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kbuf->pagecount = (create.size - create.offset) >> PAGE_SHIFT;
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kbuf->pgmap = kzalloc(sizeof(*kbuf->pgmap), GFP_KERNEL);
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if (!kbuf->pgmap)
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{
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ret = -ENOMEM;
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goto err;
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}
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kbuf->pgmap->res.start = pci_resource_start(kdev->dev, 2) + create.offset;
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kbuf->pgmap->res.end = kbuf->pgmap->res.start + create.size - 1;
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kbuf->pgmap->res.flags = pci_resource_flags(kdev->dev, 2);
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kbuf->pgmap->type = MEMORY_DEVICE_DEVDAX;
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kdev->addr = devm_memremap_pages(&kdev->dev->dev, kbuf->pgmap);
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if (IS_ERR(kdev->addr))
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{
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ret = PTR_ERR(kdev->addr);
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goto err;
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}
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kbuf->pages = kmalloc_array(kbuf->pagecount, sizeof(*kbuf->pages), GFP_KERNEL);
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if (!kbuf->pages)
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{
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ret = -ENOMEM;
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goto err_unmap;
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}
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p = kdev->addr;
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for(i = 0; i < kbuf->pagecount; ++i)
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{
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kbuf->pages[i] = virt_to_page(p);
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p += PAGE_SIZE;
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}
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exp_kdev.ops = &kvmfrbuf_ops;
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exp_kdev.size = create.size;
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exp_kdev.priv = kbuf;
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exp_kdev.flags = O_RDWR;
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buf = dma_buf_export(&exp_kdev);
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if (IS_ERR(buf))
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{
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ret = PTR_ERR(buf);
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goto err;
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}
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printk("kvmfr_dmabuf_create: offset: %llu, size: %llu\n", create.offset, create.size);
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return dma_buf_fd(buf, create.flags & KVMFR_DMABUF_FLAG_CLOEXEC ? O_CLOEXEC : 0);
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err_unmap:
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devm_memunmap_pages(&kdev->dev->dev, kbuf->pgmap);
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err:
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kfree(kbuf->pgmap);
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kfree(kbuf->pages);
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kfree(kbuf);
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return ret;
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}
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static long device_ioctl(struct file * filp, unsigned int ioctl, unsigned long arg)
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{
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struct kvmfr_dev * kdev;
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long ret;
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kdev = (struct kvmfr_dev *)idr_find(&kvmfr_idr, iminor(filp->f_inode));
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if (!kdev)
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return -EINVAL;
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switch(ioctl)
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{
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case KVMFR_DMABUF_CREATE:
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ret = kvmfr_dmabuf_create(kdev, filp, arg);
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break;
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case KVMFR_DMABUF_GETALIGN:
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ret = get_min_align() << PAGE_SHIFT;
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break;
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case KVMFR_DMABUF_GETSIZE:
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ret = pci_resource_len(kdev->dev, 2);
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break;
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default:
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return -ENOTTY;
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}
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return ret;
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}
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static struct file_operations fops =
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{
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.owner = THIS_MODULE,
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.unlocked_ioctl = device_ioctl
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};
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static int kvmfr_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
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{
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struct uio_info *info;
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struct kvmfr_dev *kdev;
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info = kzalloc(sizeof(struct uio_info), GFP_KERNEL);
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if (!info)
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kdev = kzalloc(sizeof(struct kvmfr_dev), GFP_KERNEL);
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if (!kdev)
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return -ENOMEM;
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kdev->dev = dev;
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if (pci_enable_device(dev))
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goto out_free;
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if (pci_request_regions(dev, "kvmfr"))
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if (pci_request_regions(dev, KVMFR_DEV_NAME))
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goto out_disable;
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info->mem[0].addr = pci_resource_start(dev, 2);
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if (!info->mem[0].addr)
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kdev->uio.mem[0].addr = pci_resource_start(dev, 2);
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if (!kdev->uio.mem[0].addr)
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goto out_release;
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info->mem[0].internal_addr = ioremap_wt(
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kdev->uio.mem[0].internal_addr = ioremap_wt(
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pci_resource_start(dev, 2),
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pci_resource_len (dev, 2)
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);
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if (!info->mem[0].internal_addr)
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if (!kdev->uio.mem[0].internal_addr)
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goto out_release;
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info->mem[0].size = pci_resource_len(dev, 2);
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info->mem[0].memtype = UIO_MEM_PHYS;
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info->name = "KVMFR";
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info->version = "0.0.1";
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info->irq = 0;
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info->irq_flags = 0;
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info->handler = NULL;
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kdev->uio.mem[0].size = pci_resource_len(dev, 2);
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kdev->uio.mem[0].memtype = UIO_MEM_PHYS;
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kdev->uio.name = KVMFR_UIO_NAME;
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kdev->uio.version = KVMFR_UIO_VER;
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kdev->uio.irq = 0;
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kdev->uio.irq_flags = 0;
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kdev->uio.handler = NULL;
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if (uio_register_device(&dev->dev, info))
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if (uio_register_device(&dev->dev, &kdev->uio))
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goto out_unmap;
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pci_set_drvdata(dev, info);
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mutex_lock(&minor_lock);
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kdev->minor = idr_alloc(&kvmfr_idr, kdev, 0, KVMFR_MAX_DEVICES, GFP_KERNEL);
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if (kdev->minor < 0)
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{
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mutex_unlock(&minor_lock);
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goto out_unreg;
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}
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mutex_unlock(&minor_lock);
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kdev->devNo = MKDEV(kvmfr->major, kdev->minor);
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kdev->pDev = device_create(kvmfr->pClass, NULL, kdev->devNo, NULL, KVMFR_DEV_NAME "%d", kdev->minor);
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if (IS_ERR(kdev->pDev))
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goto out_unminor;
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pci_set_drvdata(dev, kdev);
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return 0;
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out_unminor:
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mutex_lock(&minor_lock);
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idr_remove(&kvmfr_idr, kdev->minor);
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mutex_unlock(&minor_lock);
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out_unreg:
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uio_unregister_device(&kdev->uio);
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out_unmap:
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printk("unmap\n");
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iounmap(info->mem[0].internal_addr);
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iounmap(kdev->uio.mem[0].internal_addr);
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out_release:
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printk("release\n");
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pci_release_regions(dev);
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out_disable:
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printk("disable\n");
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pci_disable_device(dev);
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out_free:
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printk("free\n");
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kfree(info);
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kfree(kdev);
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return -ENODEV;
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}
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static void kvmfr_pci_remove(struct pci_dev *dev)
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{
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struct uio_info *info = pci_get_drvdata(dev);
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struct kvmfr_dev *kdev = pci_get_drvdata(dev);
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uio_unregister_device(info);
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device_destroy(kvmfr->pClass, kdev->devNo);
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mutex_lock(&minor_lock);
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idr_remove(&kvmfr_idr, kdev->minor);
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mutex_unlock(&minor_lock);
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uio_unregister_device(&kdev->uio);
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pci_release_regions(dev);
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pci_disable_device(dev);
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iounmap(info->mem[0].internal_addr);
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iounmap(kdev->uio.mem[0].internal_addr);
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kfree(info);
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kfree(kdev);
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}
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|
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static struct pci_device_id kvmfr_pci_ids[] =
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@ -107,13 +401,57 @@ static struct pci_device_id kvmfr_pci_ids[] =
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|
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static struct pci_driver kvmfr_pci_driver =
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{
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.name = "kvmfr",
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.name = KVMFR_DEV_NAME,
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.id_table = kvmfr_pci_ids,
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.probe = kvmfr_pci_probe,
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.remove = kvmfr_pci_remove
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};
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|
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module_pci_driver(kvmfr_pci_driver);
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static int __init kvmfr_module_init(void)
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{
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int ret;
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kvmfr = kzalloc(sizeof(struct kvmfr_info), GFP_KERNEL);
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if (!kvmfr)
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return -ENOMEM;
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|
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kvmfr->major = register_chrdev(0, KVMFR_DEV_NAME, &fops);
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if (kvmfr->major < 0)
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goto out_free;
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kvmfr->pClass = class_create(THIS_MODULE, KVMFR_DEV_NAME);
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if (IS_ERR(kvmfr->pClass))
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goto out_unreg;
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ret = pci_register_driver(&kvmfr_pci_driver);
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if (ret < 0)
|
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goto out_class_destroy;
|
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|
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return 0;
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|
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out_class_destroy:
|
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class_destroy(kvmfr->pClass);
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out_unreg:
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unregister_chrdev(kvmfr->major, KVMFR_DEV_NAME);
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out_free:
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kfree(kvmfr);
|
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kvmfr = NULL;
|
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return -ENODEV;
|
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}
|
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|
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static void __exit kvmfr_module_exit(void)
|
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{
|
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pci_unregister_driver(&kvmfr_pci_driver);
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class_destroy(kvmfr->pClass);
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unregister_chrdev(kvmfr->major, KVMFR_DEV_NAME);
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kfree(kvmfr);
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kvmfr = NULL;
|
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}
|
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|
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module_init(kvmfr_module_init);
|
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module_exit(kvmfr_module_exit);
|
||||
|
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MODULE_DEVICE_TABLE(pci, kvmfr_pci_ids);
|
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MODULE_LICENSE("GPL v2");
|
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MODULE_AUTHOR("Geoffrey McRae");
|
||||
52
module/test.c
Normal file
52
module/test.c
Normal file
@ -0,0 +1,52 @@
|
||||
#include <stdio.h>
|
||||
#include <stdlib.h>
|
||||
#include <unistd.h>
|
||||
#include <string.h>
|
||||
#include <fcntl.h>
|
||||
#include <unistd.h>
|
||||
#include <string.h>
|
||||
#include <sys/ioctl.h>
|
||||
#include <sys/syscall.h>
|
||||
#include <sys/mman.h>
|
||||
|
||||
#include "kvmfr.h"
|
||||
|
||||
int main()
|
||||
{
|
||||
int fd = open("/dev/kvmfr0", O_RDWR);
|
||||
if (fd < 0)
|
||||
{
|
||||
perror("open");
|
||||
return -1;
|
||||
}
|
||||
|
||||
unsigned long size = ioctl(fd, KVMFR_DMABUF_GETSIZE , 0);
|
||||
unsigned long alignment = ioctl(fd, KVMFR_DMABUF_GETALIGN, 0);
|
||||
|
||||
printf("Size: %lu MiB, Alignment: %lu MiB\n", size / 1024 / 1024, alignment / 1024 / 1024);
|
||||
|
||||
struct kvmfr_dmabuf_create create =
|
||||
{
|
||||
.flags = KVMFR_DMABUF_FLAG_CLOEXEC,
|
||||
.offset = 0x0,
|
||||
.size = size,
|
||||
};
|
||||
int dmaFd = ioctl(fd, KVMFR_DMABUF_CREATE, &create);
|
||||
if (dmaFd < 0)
|
||||
{
|
||||
perror("ioctl");
|
||||
return -1;
|
||||
}
|
||||
|
||||
void * mem = mmap(NULL, create.size, PROT_READ | PROT_WRITE, MAP_SHARED, dmaFd, 0);
|
||||
if (!mem)
|
||||
{
|
||||
perror("mmap");
|
||||
return -1;
|
||||
}
|
||||
|
||||
memset(mem, 0xAA, create.size);
|
||||
munmap(mem, create.size);
|
||||
close(fd);
|
||||
return 0;
|
||||
}
|
||||
Loading…
Reference in New Issue
Block a user