Re: [PATCH RFC 03/15] drivers/base: Allocate/free platform-msi interrupts by group

[Dey, Megha]

Hi Thomas,

On 4/25/2020 2:23 PM, Thomas Gleixner wrote:
Dave Jiang <dave.ji...@intel.com> writes:
From: Megha Dey <megha....@linux.intel.com>
--- a/include/linux/msi.h
+++ b/include/linux/msi.h
@@ -135,6 +135,12 @@ enum platform_msi_type {
        GEN_PLAT_MSI = 1,
  };
  
+struct platform_msi_group_entry {
+       unsigned int group_id;
+       struct list_head group_list;
+       struct list_head entry_list;

I surely told you before that struct members want to be written tabular.

yep, you surely did :) I will use tabs henceforth!

+};
+
  /* Helpers to hide struct msi_desc implementation details */
  #define msi_desc_to_dev(desc)         ((desc)->dev)
  #define dev_to_msi_list(dev)          (&(dev)->msi_list)
@@ -145,21 +151,31 @@ enum platform_msi_type {
  #define for_each_msi_entry_safe(desc, tmp, dev)       \
        list_for_each_entry_safe((desc), (tmp), dev_to_msi_list((dev)), list)
  
-#define dev_to_platform_msi_list(dev)	(&(dev)->platform_msi_list)
-#define first_platform_msi_entry(dev)          \
-       list_first_entry(dev_to_platform_msi_list((dev)), struct msi_desc, list)
-#define for_each_platform_msi_entry(desc, dev) \
-       list_for_each_entry((desc), dev_to_platform_msi_list((dev)), list)
-#define for_each_platform_msi_entry_safe(desc, tmp, dev)       \
-       list_for_each_entry_safe((desc), (tmp), 
dev_to_platform_msi_list((dev)), list)
+#define dev_to_platform_msi_group_list(dev)    (&(dev)->platform_msi_list)
+
+#define first_platform_msi_group_entry(dev)                            \
+       list_first_entry(dev_to_platform_msi_group_list((dev)),         \
+                        struct platform_msi_group_entry, group_list)
  
-#define first_msi_entry_common(dev)	\
-       list_first_entry_select((dev)->platform_msi_type, 
dev_to_platform_msi_list((dev)),   \
+#define platform_msi_current_group_entry_list(dev)                     \
+       (&((list_last_entry(dev_to_platform_msi_group_list((dev)),  \
+                           struct platform_msi_group_entry,            \
+                           group_list))->entry_list))
+
+#define first_msi_entry_current_group(dev)                             \
+       list_first_entry_select((dev)->platform_msi_type,            \
+                               platform_msi_current_group_entry_list((dev)),   
\
                                dev_to_msi_list((dev)), struct msi_desc, list)
  
-#define for_each_msi_entry_common(desc, dev)	\
-       list_for_each_entry_select((dev)->platform_msi_type, desc, 
dev_to_platform_msi_list((dev)), \
-                                  dev_to_msi_list((dev)), list)        \
+#define for_each_msi_entry_current_group(desc, dev)                    \
+       list_for_each_entry_select((dev)->platform_msi_type, desc,   \
+                                  
platform_msi_current_group_entry_list((dev)),\
+                                  dev_to_msi_list((dev)), list)
+
+#define for_each_platform_msi_entry_in_group(desc, platform_msi_group, group, 
dev)     \
+       list_for_each_entry((platform_msi_group), 
dev_to_platform_msi_group_list((dev)), group_list)    \
+               if (((platform_msi_group)->group_id) == (group))                
     \
+                       list_for_each_entry((desc), 
(&(platform_msi_group)->entry_list), list)

Yet more unreadable macro maze to obfuscate what the code is actually
doing.

hmm I will i guess add some more documentation either in the commit 
message or somewhere in documentation to make it clearer about the 
purpose of these macros.


  /* When an MSI domain is used as an intermediate domain */
  int msi_domain_prepare_irqs(struct irq_domain *domain, struct device *dev,
diff --git a/kernel/irq/msi.c b/kernel/irq/msi.c
index bc5f9e32387f..899ade394ec8 100644
--- a/kernel/irq/msi.c
+++ b/kernel/irq/msi.c
@@ -320,7 +320,7 @@ int msi_domain_populate_irqs(struct irq_domain *domain, 
struct device *dev,
        struct msi_desc *desc;
        int ret = 0;
  
-	for_each_msi_entry_common(desc, dev) {
+       for_each_msi_entry_current_group(desc, dev) {

How is anyone supposed to figure out what the heck this means without
going through several layers of macro maze and some magic type/group
storage in struct device?


Point noted. I think I am better off committing smaller logical changes 
in each patch.

Again, function arguments exist for a reason.

ok makes sense, I will do this in the next version.


Thanks,

         tglx