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

Lorenzo Stoakes (Oracle)
2026-03-16T21:14:09Z

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