drm/msm/dpu: make the irq table size static

The size of the irq table is static, it has MDP_INTR_MAX * 32 interrupt
entries. Provide the fixed length and drop struct_size() statement.
Reviewed-by: Marijn Suijten <marijn.suijten@somainline.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/550927/
Link: https://lore.kernel.org/r/20230802100426.4184892-6-dmitry.baryshkov@linaro.org

drivers/gpu/drm/msm/disp/dpu1/dpu_hw_interrupts.c

@@ -200,10 +200,9 @@ static const struct dpu_intr_reg dpu_intr_set_7xxx[] = {
 #define DPU_IRQ_REG(irq_idx)	(irq_idx / 32)
 #define DPU_IRQ_MASK(irq_idx)	(BIT(irq_idx % 32))
 
-static inline bool dpu_core_irq_is_valid(struct dpu_hw_intr *intr,
-					 int irq_idx)
+static inline bool dpu_core_irq_is_valid(int irq_idx)
 {
-	return irq_idx >= 0 && irq_idx < intr->total_irqs;
+	return irq_idx >= 0 && irq_idx < DPU_NUM_IRQS;
 }
 
 static inline struct dpu_hw_intr_entry *dpu_core_irq_get_entry(struct dpu_hw_intr *intr,
@@ -305,7 +304,7 @@ static int dpu_hw_intr_enable_irq_locked(struct dpu_hw_intr *intr, int irq_idx)
 	if (!intr)
 		return -EINVAL;
 
-	if (!dpu_core_irq_is_valid(intr, irq_idx)) {
+	if (!dpu_core_irq_is_valid(irq_idx)) {
 		pr_err("invalid IRQ index: [%d]\n", irq_idx);
 		return -EINVAL;
 	}
@@ -358,7 +357,7 @@ static int dpu_hw_intr_disable_irq_locked(struct dpu_hw_intr *intr, int irq_idx)
 	if (!intr)
 		return -EINVAL;
 
-	if (!dpu_core_irq_is_valid(intr, irq_idx)) {
+	if (!dpu_core_irq_is_valid(irq_idx)) {
 		pr_err("invalid IRQ index: [%d]\n", irq_idx);
 		return -EINVAL;
 	}
@@ -443,7 +442,7 @@ u32 dpu_core_irq_read(struct dpu_kms *dpu_kms, int irq_idx)
 	if (!intr)
 		return 0;
 
-	if (!dpu_core_irq_is_valid(intr, irq_idx)) {
+	if (!dpu_core_irq_is_valid(irq_idx)) {
 		pr_err("invalid IRQ index: [%d]\n", irq_idx);
 		return 0;
 	}
@@ -470,13 +469,12 @@ struct dpu_hw_intr *dpu_hw_intr_init(void __iomem *addr,
 		const struct dpu_mdss_cfg *m)
 {
 	struct dpu_hw_intr *intr;
-	int nirq = MDP_INTR_MAX * 32;
 	unsigned int i;
 
 	if (!addr || !m)
 		return ERR_PTR(-EINVAL);
 
-	intr = kzalloc(struct_size(intr, irq_tbl, nirq), GFP_KERNEL);
+	intr = kzalloc(sizeof(*intr), GFP_KERNEL);
 	if (!intr)
 		return ERR_PTR(-ENOMEM);
 
@@ -487,8 +485,6 @@ struct dpu_hw_intr *dpu_hw_intr_init(void __iomem *addr,
 
 	intr->hw.blk_addr = addr + m->mdp[0].base;
 
-	intr->total_irqs = nirq;
-
 	intr->irq_mask = BIT(MDP_SSPP_TOP0_INTR) |
 			 BIT(MDP_SSPP_TOP0_INTR2) |
 			 BIT(MDP_SSPP_TOP0_HIST_INTR);
@@ -527,7 +523,7 @@ int dpu_core_irq_register_callback(struct dpu_kms *dpu_kms, int irq_idx,
 		return -EINVAL;
 	}
 
-	if (!dpu_core_irq_is_valid(dpu_kms->hw_intr, irq_idx)) {
+	if (!dpu_core_irq_is_valid(irq_idx)) {
 		DPU_ERROR("invalid IRQ index: [%d]\n", irq_idx);
 		return -EINVAL;
 	}
@@ -566,7 +562,7 @@ int dpu_core_irq_unregister_callback(struct dpu_kms *dpu_kms, int irq_idx)
 	unsigned long irq_flags;
 	int ret;
 
-	if (!dpu_core_irq_is_valid(dpu_kms->hw_intr, irq_idx)) {
+	if (!dpu_core_irq_is_valid(irq_idx)) {
 		DPU_ERROR("invalid IRQ index: [%d]\n", irq_idx);
 		return -EINVAL;
 	}
@@ -601,7 +597,7 @@ static int dpu_debugfs_core_irq_show(struct seq_file *s, void *v)
 	int i, irq_count;
 	void *cb;
 
-	for (i = 0; i < dpu_kms->hw_intr->total_irqs; i++) {
+	for (i = 0; i < DPU_NUM_IRQS; i++) {
 		spin_lock_irqsave(&dpu_kms->hw_intr->irq_lock, irq_flags);
 		irq_entry = dpu_core_irq_get_entry(dpu_kms->hw_intr, i);
 		irq_count = atomic_read(&irq_entry->count);
@@ -636,7 +632,7 @@ void dpu_core_irq_preinstall(struct msm_kms *kms)
 	dpu_disable_all_irqs(dpu_kms);
 	pm_runtime_put_sync(&dpu_kms->pdev->dev);
 
-	for (i = 0; i < dpu_kms->hw_intr->total_irqs; i++) {
+	for (i = 0; i < DPU_NUM_IRQS; i++) {
 		irq_entry = dpu_core_irq_get_entry(dpu_kms->hw_intr, i);
 		atomic_set(&irq_entry->count, 0);
 	}
@@ -652,7 +648,7 @@ void dpu_core_irq_uninstall(struct msm_kms *kms)
 		return;
 
 	pm_runtime_get_sync(&dpu_kms->pdev->dev);
-	for (i = 0; i < dpu_kms->hw_intr->total_irqs; i++) {
+	for (i = 0; i < DPU_NUM_IRQS; i++) {
 		irq_entry = dpu_core_irq_get_entry(dpu_kms->hw_intr, i);
 		if (irq_entry->cb)
 			DPU_ERROR("irq_idx=%d still enabled/registered\n", i);

drivers/gpu/drm/msm/disp/dpu1/dpu_hw_interrupts.h

@@ -38,6 +38,8 @@ enum dpu_hw_intr_reg {
 
 #define DPU_IRQ_IDX(reg_idx, offset)	(reg_idx * 32 + offset)
 
+#define DPU_NUM_IRQS		(MDP_INTR_MAX * 32)
+
 struct dpu_hw_intr_entry {
 	void (*cb)(void *arg);
 	void *arg;
@@ -50,7 +52,6 @@ struct dpu_hw_intr_entry {
  * @ops:              function pointer mapping for IRQ handling
  * @cache_irq_mask:   array of IRQ enable masks reg storage created during init
  * @save_irq_status:  array of IRQ status reg storage created during init
- * @total_irqs: total number of irq_idx mapped in the hw_interrupts
  * @irq_lock:         spinlock for accessing IRQ resources
  * @irq_cb_tbl:       array of IRQ callbacks
  */
@@ -58,12 +59,11 @@ struct dpu_hw_intr {
 	struct dpu_hw_blk_reg_map hw;
 	u32 cache_irq_mask[MDP_INTR_MAX];
 	u32 *save_irq_status;
-	u32 total_irqs;
 	spinlock_t irq_lock;
 	unsigned long irq_mask;
 	const struct dpu_intr_reg *intr_set;
 
-	struct dpu_hw_intr_entry irq_tbl[];
+	struct dpu_hw_intr_entry irq_tbl[DPU_NUM_IRQS];
 };
 
 /**