[PATCH v2 10/16] stm: replace deprecated mmap hook with mmap_prepare

["Lorenzo Stoakes (Oracle)" <ljs@kernel.org>]

The f_op->mmap interface is deprecated, so update driver to use its
successor, mmap_prepare.

The driver previously used vm_iomap_memory(), so this change replaces it
with its mmap_prepare equivalent, mmap_action_simple_ioremap().

Also, in order to correctly maintain reference counting, add a
vm_ops->mapped callback to increment the reference count when successfully
mapped.

Signed-off-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org>
---
 drivers/hwtracing/stm/core.c | 31 +++++++++++++++++++++----------
 1 file changed, 21 insertions(+), 10 deletions(-)

diff --git a/drivers/hwtracing/stm/core.c b/drivers/hwtracing/stm/core.c
index 37584e786bb5..f48c6a8a0654 100644
--- a/drivers/hwtracing/stm/core.c
+++ b/drivers/hwtracing/stm/core.c
@@ -666,6 +666,16 @@ static ssize_t stm_char_write(struct file *file, const char __user *buf,
 	return count;
 }
 
+static int stm_mmap_mapped(unsigned long start, unsigned long end, pgoff_t pgoff,
+			   const struct file *file, void **vm_private_data)
+{
+	struct stm_file *stmf = file->private_data;
+	struct stm_device *stm = stmf->stm;
+
+	pm_runtime_get_sync(&stm->dev);
+	return 0;
+}
+
 static void stm_mmap_open(struct vm_area_struct *vma)
 {
 	struct stm_file *stmf = vma->vm_file->private_data;
@@ -684,12 +694,14 @@ static void stm_mmap_close(struct vm_area_struct *vma)
 }
 
 static const struct vm_operations_struct stm_mmap_vmops = {
+	.mapped = stm_mmap_mapped,
 	.open	= stm_mmap_open,
 	.close	= stm_mmap_close,
 };
 
-static int stm_char_mmap(struct file *file, struct vm_area_struct *vma)
+static int stm_char_mmap_prepare(struct vm_area_desc *desc)
 {
+	struct file *file = desc->file;
 	struct stm_file *stmf = file->private_data;
 	struct stm_device *stm = stmf->stm;
 	unsigned long size, phys;
@@ -697,10 +709,10 @@ static int stm_char_mmap(struct file *file, struct vm_area_struct *vma)
 	if (!stm->data->mmio_addr)
 		return -EOPNOTSUPP;
 
-	if (vma->vm_pgoff)
+	if (desc->pgoff)
 		return -EINVAL;
 
-	size = vma->vm_end - vma->vm_start;
+	size = vma_desc_size(desc);
 
 	if (stmf->output.nr_chans * stm->data->sw_mmiosz != size)
 		return -EINVAL;
@@ -712,13 +724,12 @@ static int stm_char_mmap(struct file *file, struct vm_area_struct *vma)
 	if (!phys)
 		return -EINVAL;
 
-	pm_runtime_get_sync(&stm->dev);
-
-	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
-	vm_flags_set(vma, VM_IO | VM_DONTEXPAND | VM_DONTDUMP);
-	vma->vm_ops = &stm_mmap_vmops;
-	vm_iomap_memory(vma, phys, size);
+	desc->page_prot = pgprot_noncached(desc->page_prot);
+	vma_desc_set_flags(desc, VMA_IO_BIT, VMA_DONTEXPAND_BIT,
+			   VMA_DONTDUMP_BIT);
+	desc->vm_ops = &stm_mmap_vmops;
 
+	mmap_action_simple_ioremap(desc, phys, size);
 	return 0;
 }
 
@@ -836,7 +847,7 @@ static const struct file_operations stm_fops = {
 	.open		= stm_char_open,
 	.release	= stm_char_release,
 	.write		= stm_char_write,
-	.mmap		= stm_char_mmap,
+	.mmap_prepare	= stm_char_mmap_prepare,
 	.unlocked_ioctl	= stm_char_ioctl,
 	.compat_ioctl	= compat_ptr_ioctl,
 };
-- 
2.53.0