[PATCH v2 1/2] lmb: Fix LMB_MEMORY_REGIONS flag usage

[Patrick Delaunay]

Remove test on CONFIG_LMB_MEMORY_REGIONS introduced by commit
7c1860fce4e3 ("lmb: Fix lmb property's defination under struct lmb").

This code in lmb_init() is strange, because if CONFIG_LMB_USE_MAX_REGIONS
and CONFIG_LMB_MEMORY_REGIONS are not defined, the implicit #else is empty
and the required initialization is not done:
lmb->memory.max = ?
lmb->reserved.max = ?

But this setting is not possible:
- CONFIG_LMB_USE_MAX_REGIONS not defined
- CONFIG_LMB_MEMORY_REGIONS not defined
because CONFIG_LMB_MEMORY_REGIONS and CONFIG_LMB_RESERVED_REGIONS are
defined as soon as the CONFIG_LMB_USE_MAX_REGIONS is not defined.

This patch removes this impossible case #elif and I add some
explanation in lmb.h to explain why in the struct lmb {} the lmb
property is defined if CONFIG_LMB_MEMORY_REGIONS is NOT defined.

This patch also removes CONFIG_LMB_XXX dependency on CONFIG_LMB as these
defines are used in API file lmb.h and not only in library file.

Fixes: 5e2548c1d6e03 ("lmb: Fix LMB_MEMORY_REGIONS flag usage")
Reported-by: Mark Millard <marklmi at yahoo.com>
Signed-off-by: Patrick Delaunay <patrick.delaunay at foss.st.com>
---

Changes in v2:
- Remove CONFIG_LMB_XXX dependency on CONFIG_LMB as these defines are
  used in lmb.h file, include by default to export the LMB API
  and not only in LMB libary code. This modification is required to
  avoid issue in API definition when CONFIG_LMB is not set.
- Fix some typo in commit message and in comment

 include/lmb.h | 20 +++++++++++++++++++-
 lib/Kconfig   |  7 +++----
 lib/lmb.c     |  2 +-
 3 files changed, 23 insertions(+), 6 deletions(-)

diff --git a/include/lmb.h b/include/lmb.h
index 7298c2ccc403..07bf22144eac 100644
--- a/include/lmb.h
+++ b/include/lmb.h
@@ -35,6 +35,24 @@ struct lmb_property {
 	enum lmb_flags flags;
 };
 
+/*
+ * For regions size management, see LMB configuration in KConfig
+ * all the #if test are done with CONFIG_LMB_USE_MAX_REGIONS (boolean)
+ *
+ * case 1. CONFIG_LMB_USE_MAX_REGIONS is defined (legacy mode)
+ *         => CONFIG_LMB_MAX_REGIONS is used to configure the region size,
+ *         directly in the array lmb_region.region[], with the same
+ *         configuration for memory and reserved regions.
+ *
+ * case 2. CONFIG_LMB_USE_MAX_REGIONS is not defined, the size of each
+ *         region is configurated *independently* with
+ *         => CONFIG_LMB_MEMORY_REGIONS: struct lmb.memory_regions
+ *         => CONFIG_LMB_RESERVED_REGIONS: struct lmb.reserved_regions
+ *         lmb_region.region is only a pointer to the correct buffer,
+ *         initialized in lmb_init(). This configuration is useful to manage
+ *         more reserved memory regions with CONFIG_LMB_RESERVED_REGIONS.
+ */
+
 /**
  * struct lmb_region - Description of a set of region.
  *
@@ -68,7 +86,7 @@ struct lmb_region {
 struct lmb {
 	struct lmb_region memory;
 	struct lmb_region reserved;
-#ifdef CONFIG_LMB_MEMORY_REGIONS
+#if !IS_ENABLED(CONFIG_LMB_USE_MAX_REGIONS)
 	struct lmb_property memory_regions[CONFIG_LMB_MEMORY_REGIONS];
 	struct lmb_property reserved_regions[CONFIG_LMB_RESERVED_REGIONS];
 #endif
diff --git a/lib/Kconfig b/lib/Kconfig
index 83e5edd73b0e..da6c7cd5f628 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -1027,7 +1027,6 @@ config LMB
 
 config LMB_USE_MAX_REGIONS
 	bool "Use a common number of memory and reserved regions in lmb lib"
-	depends on LMB
 	default y
 	help
 	  Define the number of supported memory regions in the library logical
@@ -1037,7 +1036,7 @@ config LMB_USE_MAX_REGIONS
 
 config LMB_MAX_REGIONS
 	int "Number of memory and reserved regions in lmb lib"
-	depends on LMB && LMB_USE_MAX_REGIONS
+	depends on LMB_USE_MAX_REGIONS
 	default 16
 	help
 	  Define the number of supported regions, memory and reserved, in the
@@ -1045,7 +1044,7 @@ config LMB_MAX_REGIONS
 
 config LMB_MEMORY_REGIONS
 	int "Number of memory regions in lmb lib"
-	depends on LMB && !LMB_USE_MAX_REGIONS
+	depends on !LMB_USE_MAX_REGIONS
 	default 8
 	help
 	  Define the number of supported memory regions in the library logical
@@ -1054,7 +1053,7 @@ config LMB_MEMORY_REGIONS
 
 config LMB_RESERVED_REGIONS
 	int "Number of reserved regions in lmb lib"
-	depends on LMB && !LMB_USE_MAX_REGIONS
+	depends on !LMB_USE_MAX_REGIONS
 	default 8
 	help
 	  Define the number of supported reserved regions in the library logical
diff --git a/lib/lmb.c b/lib/lmb.c
index 2444b2a62121..8fbe453dfa9d 100644
--- a/lib/lmb.c
+++ b/lib/lmb.c
@@ -110,7 +110,7 @@ void lmb_init(struct lmb *lmb)
 #if IS_ENABLED(CONFIG_LMB_USE_MAX_REGIONS)
 	lmb->memory.max = CONFIG_LMB_MAX_REGIONS;
 	lmb->reserved.max = CONFIG_LMB_MAX_REGIONS;
-#elif defined(CONFIG_LMB_MEMORY_REGIONS)
+#else
 	lmb->memory.max = CONFIG_LMB_MEMORY_REGIONS;
 	lmb->reserved.max = CONFIG_LMB_RESERVED_REGIONS;
 	lmb->memory.region = lmb->memory_regions;
-- 
2.25.1