mm/cma: drop CONFIG_CMA_DEBUG

All pr_debug() prints in (mm/cma.c) could be enabled via standard Makefile
based method.  Besides cma_debug_show_areas() should always be called
during cma_alloc() failure path.  This seemingly redundant config,
CONFIG_CMA_DEBUG can be dropped without any problem.

[lukas.bulwahn@gmail.com: remove debug code to removed CONFIG_CMA_DEBUG]
  Link: https://lkml.kernel.org/r/20240207143825.986-1-lukas.bulwahn@gmail.com
Link: https://lkml.kernel.org/r/20240205031647.283510-1-anshuman.khandual@arm.comSigned-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

kernel/dma/contiguous.c

@@ -37,12 +37,6 @@
 
 #define pr_fmt(fmt) "cma: " fmt
 
-#ifdef CONFIG_CMA_DEBUG
-#ifndef DEBUG
-#  define DEBUG
-#endif
-#endif
-
 #include <asm/page.h>
 
 #include <linux/memblock.h>

mm/Kconfig

@@ -901,15 +901,6 @@ config CMA
 
 	  If unsure, say "n".
 
-config CMA_DEBUG
-	bool "CMA debug messages (DEVELOPMENT)"
-	depends on DEBUG_KERNEL && CMA
-	help
-	  Turns on debug messages in CMA.  This produces KERN_DEBUG
-	  messages for every CMA call as well as various messages while
-	  processing calls such as dma_alloc_from_contiguous().
-	  This option does not affect warning and error messages.
-
 config CMA_DEBUGFS
 	bool "CMA debugfs interface"
 	depends on CMA && DEBUG_FS

mm/cma.c

@@ -14,11 +14,6 @@
 
 #define pr_fmt(fmt) "cma: " fmt
 
-#ifdef CONFIG_CMA_DEBUG
-#ifndef DEBUG
-#  define DEBUG
-#endif
-#endif
 #define CREATE_TRACE_POINTS
 
 #include <linux/memblock.h>
@@ -387,7 +382,6 @@ int __init cma_declare_contiguous_nid(phys_addr_t base,
 	return ret;
 }
 
-#ifdef CONFIG_CMA_DEBUG
 static void cma_debug_show_areas(struct cma *cma)
 {
 	unsigned long next_zero_bit, next_set_bit, nr_zero;
@@ -412,9 +406,6 @@ static void cma_debug_show_areas(struct cma *cma)
 	pr_cont("=> %lu free of %lu total pages\n", nr_total, cma->count);
 	spin_unlock_irq(&cma->lock);
 }
-#else
-static inline void cma_debug_show_areas(struct cma *cma) { }
-#endif
 
 /**
  * cma_alloc() - allocate pages from contiguous area