[PATCH 2/2] staging: media: atomisp: unify initialization flag usage in HMM

Abdelrahman Fekry
2025-07-07T14:10:19Z

Previously, the initialization state of the `hmm_bo_device` was tracked
in two places: a global `hmm_initialized` boolean in `hmm.c`, and a local
integer `flag` in the `hmm_bo_device` struct. This was redundant and could
lead to inconsistent state checks.

- Removes the global `hmm_initialized` variable and all checks against it.
- Replaces the `int flag` in `struct hmm_bo_device` with a strongly-typed
`enum hmm_bo_device_init_flag flag` (values: UNINITED = 0, INITED = 1).
- Initializes `flag` to `HMM_BO_DEVICE_UNINITED` at declaration to
ensure a well-defined starting state.
- Removes a redundant `hmm_init()` call inside `__hmm_alloc()` since its
always called after hmm_init()

This change improves type safety, consistency, and readability when
handling the HMM initialization state.

Signed-off-by: Abdelrahman Fekry <abdelrahmanfekry375@gmail.com>
---
.../staging/media/atomisp/include/hmm/hmm_bo.h | 9 +++++++--
drivers/staging/media/atomisp/pci/hmm/hmm.c | 16 ++++------------
2 files changed, 11 insertions(+), 14 deletions(-)

diff --git a/drivers/staging/media/atomisp/include/hmm/hmm_bo.h b/drivers/staging/media/atomisp/include/hmm/hmm_bo.h
index e09ac29ac43d..155f9d89b365 100644
--- a/drivers/staging/media/atomisp/include/hmm/hmm_bo.h
+++ b/drivers/staging/media/atomisp/include/hmm/hmm_bo.h
@@ -58,7 +58,10 @@
#define ISP_VM_SIZE (0x7FFFFFFF) /* 2G address space */
#define ISP_PTR_NULL NULL

-#define HMM_BO_DEVICE_INITED 0x1
+enum hmm_bo_device_init_flag {
+ HMM_BO_DEVICE_INITED = 0x1,
+ HMM_BO_DEVICE_UNINITED = 0x2,
+};

enum hmm_bo_type {
HMM_BO_PRIVATE,
@@ -86,7 +89,9 @@ struct hmm_bo_device {

/* list lock is used to protect the entire_bo_list */
spinlock_t list_lock;
- int flag;
+
+ /* flag to indicate whether the bo device is inited or not */
+ enum hmm_bo_device_init_flag flag;

/* linked list for entire buffer object */
struct list_head entire_bo_list;
diff --git a/drivers/staging/media/atomisp/pci/hmm/hmm.c b/drivers/staging/media/atomisp/pci/hmm/hmm.c
index c2ee9d2ec0d5..767a3a24f8e5 100644
--- a/drivers/staging/media/atomisp/pci/hmm/hmm.c
+++ b/drivers/staging/media/atomisp/pci/hmm/hmm.c
@@ -24,9 +24,10 @@
#include "mmu/isp_mmu.h"
#include "mmu/sh_mmu_mrfld.h"

-struct hmm_bo_device bo_device;
+struct hmm_bo_device bo_device = {
+ .flag = HMM_BO_DEVICE_UNINITED,
+};
static ia_css_ptr dummy_ptr = mmgr_EXCEPTION;
-static bool hmm_initialized;

int hmm_init(void)
{
@@ -38,8 +39,6 @@ int hmm_init(void)
dev_err(atomisp_dev, "hmm_bo_device_init failed.\n");
return ret;

- hmm_initialized = true;
-
/*
* As hmm use NULL to indicate invalid ISP virtual address,
* and ISP_VM_START is defined to 0 too, so we allocate
@@ -62,7 +61,7 @@ void hmm_cleanup(void)
dummy_ptr = 0;

hmm_bo_device_exit(&bo_device);
- hmm_initialized = false;
+ bo_device.flag = HMM_BO_DEVICE_UNINITED;
}

static ia_css_ptr __hmm_alloc(size_t bytes, enum hmm_bo_type type,
@@ -72,13 +71,6 @@ static ia_css_ptr __hmm_alloc(size_t bytes, enum hmm_bo_type type,
struct hmm_buffer_object *bo;
int ret;

- /*
- * Check if we are initialized. In the ideal world we wouldn't need
- * this but we can tackle it once the driver is a lot cleaner
- */
-
- if (!hmm_initialized)
- hmm_init();
/* Get page number from size */
pgnr = size_to_pgnr_ceil(bytes);

--
2.25.1