net: ipa: maintain bitmap of suspend-enabled endpoints

Keep track of which endpoints have the SUSPEND IPA interrupt enabled
in a variable-length bitmap.  This will be used in the next patch to
allow the SUSPEND interrupt type to be disabled except when needed.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

drivers/net/ipa/ipa_interrupt.c

@@ -37,11 +37,13 @@
  * @ipa:		IPA pointer
  * @irq:		Linux IRQ number used for IPA interrupts
  * @enabled:		Mask indicating which interrupts are enabled
+ * @suspend_enabled:	Bitmap of endpoints with the SUSPEND interrupt enabled
  */
 struct ipa_interrupt {
 	struct ipa *ipa;
 	u32 irq;
 	u32 enabled;
+	unsigned long *suspend_enabled;
 };
 
 /* Clear the suspend interrupt for all endpoints that signaled it */
@@ -211,6 +213,7 @@ static void ipa_interrupt_suspend_control(struct ipa_interrupt *interrupt,
 		val |= mask;
 	else
 		val &= ~mask;
+	__change_bit(endpoint_id, interrupt->suspend_enabled);
 
 	iowrite32(val, ipa->reg_virt + offset);
 }
@@ -246,15 +249,24 @@ int ipa_interrupt_config(struct ipa *ipa)
 
 	interrupt->ipa = ipa;
 
-	/* Disable all IPA interrupt types */
+	/* Initially all IPA interrupt types are disabled */
+	interrupt->enabled = 0;
+	interrupt->suspend_enabled = bitmap_zalloc(ipa->endpoint_count,
+						   GFP_KERNEL);
+	if (!interrupt->suspend_enabled) {
+		ret = -ENOMEM;
+		goto err_kfree;
+	}
+
+	/* Disable IPA interrupt types */
 	reg = ipa_reg(ipa, IPA_IRQ_EN);
 	iowrite32(0, ipa->reg_virt + reg_offset(reg));
 
 	ret = request_threaded_irq(irq, NULL, ipa_isr_thread, IRQF_ONESHOT,
 				   "ipa", interrupt);
 	if (ret) {
 		dev_err(dev, "error %d requesting \"ipa\" IRQ\n", ret);
-		goto err_kfree;
+		goto err_free_bitmap;
 	}
 
 	ret = dev_pm_set_wake_irq(dev, irq);
@@ -270,6 +282,8 @@ int ipa_interrupt_config(struct ipa *ipa)
 
 err_free_irq:
 	free_irq(interrupt->irq, interrupt);
+err_free_bitmap:
+	bitmap_free(interrupt->suspend_enabled);
 err_kfree:
 	kfree(interrupt);
 
@@ -286,6 +300,7 @@ void ipa_interrupt_deconfig(struct ipa *ipa)
 
 	dev_pm_clear_wake_irq(dev);
 	free_irq(interrupt->irq, interrupt);
+	bitmap_free(interrupt->suspend_enabled);
 }
 
 /* Initialize the IPA interrupt structure */