[PATCH] Replacement for Arm initrd memblock reserve and free inconsistency.

[Russell King - ARM Linux]

On Tue, Nov 15, 2016 at 03:45:55PM +0000, william.helsby at stfc.ac.uk wrote:
> The option of moving the initrd code later (after
> 	early_init_fdt_reserve_self();
> 	early_init_fdt_scan_reserved_mem() ) 
> was tested.

Moving stuff around tends to break...

I'd prefer to do it this way, as it's much more readable (and we prize
readability... see Documentation/CodingStyle.)

 arch/arm/mm/init.c | 71 +++++++++++++++++++++++++++++++++---------------------
 1 file changed, 43 insertions(+), 28 deletions(-)

diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c
index 370581aeb871..ffae20b25929 100644
--- a/arch/arm/mm/init.c
+++ b/arch/arm/mm/init.c
@@ -227,6 +227,48 @@ phys_addr_t __init arm_memblock_steal(phys_addr_t size, phys_addr_t align)
 	return phys;
 }
 
+static void __init arm_initrd_init(void)
+{
+#ifdef CONFIG_BLK_DEV_INITRD
+	unsigned long size;
+	phys_addr_t start;
+
+	/* FDT scan will populate initrd_start */
+	if (initrd_start && !phys_initrd_size) {
+		phys_initrd_start = __virt_to_phys(initrd_start);
+		phys_initrd_size = initrd_end - initrd_start;
+	}
+
+	initrd_start = initrd_end = 0;
+
+	if (!phys_initrd_size)
+		return;
+
+	start = phys_initrd_start & PAGE_MASK;
+	size = PAGE_ALIGN(phys_initrd_size + phys_initrd_start - start);
+
+	if (!memblock_is_region_memory(start, size)) {
+		pr_err("INITRD: 0x%08llx+0x%08lx is not a memory region - disabling initrd\n",
+		       (u64)start, size);
+		phys_initrd_start = phys_initrd_size = 0;
+		return;
+	}
+
+	if (memblock_is_region_reserved(start, size)) {
+		pr_err("INITRD: 0x%08llx+0x%08lx overlaps in-use memory region - disabling initrd\n",
+		       (u64)start, size);
+		phys_initrd_start = phys_initrd_size = 0;
+		return;
+	}
+
+	memblock_reserve(start, size);
+
+	/* Now convert initrd to virtual addresses */
+	initrd_start = __phys_to_virt(phys_initrd_start);
+	initrd_end = initrd_start + phys_initrd_size;
+#endif
+}
+
 void __init arm_memblock_init(const struct machine_desc *mdesc)
 {
 	/* Register the kernel text, kernel data and initrd with memblock. */
@@ -235,34 +277,7 @@ void __init arm_memblock_init(const struct machine_desc *mdesc)
 #else
 	memblock_reserve(__pa(_stext), _end - _stext);
 #endif
-#ifdef CONFIG_BLK_DEV_INITRD
-	/* FDT scan will populate initrd_start */
-	if (initrd_start && !phys_initrd_size) {
-		phys_initrd_start = __virt_to_phys(initrd_start);
-		phys_initrd_size = initrd_end - initrd_start;
-	}
-	initrd_start = initrd_end = 0;
-	if (phys_initrd_size &&
-	    !memblock_is_region_memory(phys_initrd_start, phys_initrd_size)) {
-		pr_err("INITRD: 0x%08llx+0x%08lx is not a memory region - disabling initrd\n",
-		       (u64)phys_initrd_start, phys_initrd_size);
-		phys_initrd_start = phys_initrd_size = 0;
-	}
-	if (phys_initrd_size &&
-	    memblock_is_region_reserved(phys_initrd_start, phys_initrd_size)) {
-		pr_err("INITRD: 0x%08llx+0x%08lx overlaps in-use memory region - disabling initrd\n",
-		       (u64)phys_initrd_start, phys_initrd_size);
-		phys_initrd_start = phys_initrd_size = 0;
-	}
-	if (phys_initrd_size) {
-		memblock_reserve(phys_initrd_start, phys_initrd_size);
-
-		/* Now convert initrd to virtual addresses */
-		initrd_start = __phys_to_virt(phys_initrd_start);
-		initrd_end = initrd_start + phys_initrd_size;
-	}
-#endif
-
+	arm_initrd_init();
 	arm_mm_memblock_reserve();
 
 	/* reserve any platform specific memblock areas */

-- 
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