Commit 483050c0 authored by Scott Branden's avatar Scott Branden Committed by Greg Kroah-Hartman
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misc: bcm-vk: add mmap function for exposing BAR2 



Add mmap function that allows host application to open up BAR2 memory
for remote spooling out messages from the VK logger.

Co-developed-by: default avatarDesmond Yan <desmond.yan@broadcom.com>
Acked-by: default avatarOlof Johansson <olof@lixom.net>
Signed-off-by: default avatarDesmond Yan <desmond.yan@broadcom.com>
Signed-off-by: default avatarScott Branden <scott.branden@broadcom.com>
Link: https://lore.kernel.org/r/20210120175827.14820-12-scott.branden@broadcom.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent d63d658f

drivers/misc/bcm-vk/bcm_vk_dev.c

+24 −0
Original line number Diff line number Diff line
@@ -1199,6 +1199,29 @@ static long bcm_vk_reset(struct bcm_vk *vk, struct vk_reset __user *arg) 
	return ret;

}



static int bcm_vk_mmap(struct file *file, struct vm_area_struct *vma)

{

	struct bcm_vk_ctx *ctx = file->private_data;

	struct bcm_vk *vk = container_of(ctx->miscdev, struct bcm_vk, miscdev);

	unsigned long pg_size;



	/* only BAR2 is mmap possible, which is bar num 4 due to 64bit */

#define VK_MMAPABLE_BAR 4



	pg_size = ((pci_resource_len(vk->pdev, VK_MMAPABLE_BAR) - 1)

		    >> PAGE_SHIFT) + 1;

	if (vma->vm_pgoff + vma_pages(vma) > pg_size)

		return -EINVAL;



	vma->vm_pgoff += (pci_resource_start(vk->pdev, VK_MMAPABLE_BAR)

			  >> PAGE_SHIFT);

	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);



	return io_remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,

				  vma->vm_end - vma->vm_start,

				  vma->vm_page_prot);

}



static long bcm_vk_ioctl(struct file *file, unsigned int cmd, unsigned long arg)

{

	long ret = -EINVAL;
@@ -1237,6 +1260,7 @@ static const struct file_operations bcm_vk_fops = { 
	.write = bcm_vk_write,

	.poll = bcm_vk_poll,

	.release = bcm_vk_release,

	.mmap = bcm_vk_mmap,

	.unlocked_ioctl = bcm_vk_ioctl,

};