Re: [PATCH net-next 1/8] net: ipa: maintain bitmap of suspend-enabled endpoints

From: Alex Elder
Date: Thu Apr 18 2024 - 20:46:57 EST


On 4/18/24 6:52 PM, Bryan O'Donoghue wrote:
On 18/04/2024 21:47, Alex Elder wrote:
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@xxxxxxxxxx>
---
  drivers/net/ipa/ipa_interrupt.c | 19 +++++++++++++++++--
  1 file changed, 17 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ipa/ipa_interrupt.c b/drivers/net/ipa/ipa_interrupt.c
index c44ec05f71e6f..0e8d4e43275ea 100644
--- a/drivers/net/ipa/ipa_interrupt.c
+++ b/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);
  }
@@ -246,7 +249,16 @@ 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);

why not use devm_bitmap_zalloc() instead and skip managing the cleanup ?

I don't use the devm_*() variants in the IPA driver.

I know I can, but if I'm make the switch I want to
do it everywhere. Not now.

Thanks for the review.

-Alex

+    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));
@@ -254,7 +266,7 @@ int ipa_interrupt_config(struct ipa *ipa)
                     "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);

You could also use devm_kzalloc() and do away with the kfree()s you have here on the probe path.

@@ -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 */

Just suggestions though.

Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@xxxxxxxxxx>