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authorScott Branden2021-01-20 09:58:25 -0800
committerGreg Kroah-Hartman2021-01-25 18:44:45 +0100
commit483050c04738c685e3982c1baec202d0cc1beb0d (patch)
tree43783ab5321d9cd85b1ea31415a06d2270ab2f0d /drivers/misc/bcm-vk
parentd63d658f74727749088bfe436230b810f3880b0a (diff)
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: Desmond Yan <desmond.yan@broadcom.com> Acked-by: Olof Johansson <olof@lixom.net> Signed-off-by: Desmond Yan <desmond.yan@broadcom.com> Signed-off-by: Scott Branden <scott.branden@broadcom.com> Link: https://lore.kernel.org/r/20210120175827.14820-12-scott.branden@broadcom.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/misc/bcm-vk')
-rw-r--r--drivers/misc/bcm-vk/bcm_vk_dev.c24
1 files changed, 24 insertions, 0 deletions
diff --git a/drivers/misc/bcm-vk/bcm_vk_dev.c b/drivers/misc/bcm-vk/bcm_vk_dev.c
index e572a7b18fab..cac07419f041 100644
--- a/drivers/misc/bcm-vk/bcm_vk_dev.c
+++ b/drivers/misc/bcm-vk/bcm_vk_dev.c
@@ -1199,6 +1199,29 @@ err_exit:
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,
};