Blackfin: calculate on-chip lengths at link time rather than run time

Since the link sizes never change at runtime, push the calculation out to
the linker script to save some useless calculation costs.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

arch/blackfin/include/asm/sections.h

@@ -13,10 +13,18 @@ extern unsigned long memory_mtd_start, memory_mtd_end, mtd_size;
 extern unsigned long _ramstart, _ramend, _rambase;
 extern unsigned long memory_start, memory_end, physical_mem_end;
 
-extern char _stext_l1[], _etext_l1[], _sdata_l1[], _edata_l1[], _sbss_l1[],
-	_ebss_l1[], _l1_lma_start[], _sdata_b_l1[], _sbss_b_l1[], _ebss_b_l1[],
-	_stext_l2[], _etext_l2[], _sdata_l2[], _edata_l2[], _sbss_l2[],
-	_ebss_l2[], _l2_lma_start[];
+/*
+ * The weak markings on the lengths might seem weird, but this is required
+ * in order to make gcc accept the fact that these may actually have a value
+ * of 0 (since they aren't actually addresses, but sizes of sections).
+ */
+extern char _stext_l1[], _etext_l1[], _text_l1_lma[], __weak _text_l1_len[];
+extern char _sdata_l1[], _edata_l1[], _sbss_l1[], _ebss_l1[],
+	_data_l1_lma[], __weak _data_l1_len[];
+extern char _sdata_b_l1[], _edata_b_l1[], _sbss_b_l1[], _ebss_b_l1[],
+	_data_b_l1_lma[], __weak _data_b_l1_len[];
+extern char _stext_l2[], _etext_l2[], _sdata_l2[], _edata_l2[],
+	_sbss_l2[], _ebss_l2[], _l2_lma[], __weak _l2_len[];
 
 #include <asm/mem_map.h>
 

arch/blackfin/kernel/setup.c

@@ -178,10 +178,10 @@ void __init bfin_cache_init(void)
 
 void __init bfin_relocate_l1_mem(void)
 {
-	unsigned long l1_code_length;
-	unsigned long l1_data_a_length;
-	unsigned long l1_data_b_length;
-	unsigned long l2_length;
+	unsigned long text_l1_len = (unsigned long)_text_l1_len;
+	unsigned long data_l1_len = (unsigned long)_data_l1_len;
+	unsigned long data_b_l1_len = (unsigned long)_data_b_l1_len;
+	unsigned long l2_len = (unsigned long)_l2_len;
 
 	early_shadow_stamp();
 
@@ -201,30 +201,23 @@ void __init bfin_relocate_l1_mem(void)
 
 	blackfin_dma_early_init();
 
-	/* if necessary, copy _stext_l1 to _etext_l1 to L1 instruction SRAM */
-	l1_code_length = _etext_l1 - _stext_l1;
-	if (l1_code_length)
-		early_dma_memcpy(_stext_l1, _l1_lma_start, l1_code_length);
+	/* if necessary, copy L1 text to L1 instruction SRAM */
+	if (L1_CODE_LENGTH && text_l1_len)
+		early_dma_memcpy(_stext_l1, _text_l1_lma, text_l1_len);
 
-	/* if necessary, copy _sdata_l1 to _sbss_l1 to L1 data bank A SRAM */
-	l1_data_a_length = _sbss_l1 - _sdata_l1;
-	if (l1_data_a_length)
-		early_dma_memcpy(_sdata_l1, _l1_lma_start + l1_code_length, l1_data_a_length);
+	/* if necessary, copy L1 data to L1 data bank A SRAM */
+	if (L1_DATA_A_LENGTH && data_l1_len)
+		early_dma_memcpy(_sdata_l1, _data_l1_lma, data_l1_len);
 
-	/* if necessary, copy _sdata_b_l1 to _sbss_b_l1 to L1 data bank B SRAM */
-	l1_data_b_length = _sbss_b_l1 - _sdata_b_l1;
-	if (l1_data_b_length)
-		early_dma_memcpy(_sdata_b_l1, _l1_lma_start + l1_code_length +
-			l1_data_a_length, l1_data_b_length);
+	/* if necessary, copy L1 data B to L1 data bank B SRAM */
+	if (L1_DATA_B_LENGTH && data_b_l1_len)
+		early_dma_memcpy(_sdata_b_l1, _data_b_l1_lma, data_b_l1_len);
 
 	early_dma_memcpy_done();
 
-	/* if necessary, copy _stext_l2 to _edata_l2 to L2 SRAM */
-	if (L2_LENGTH != 0) {
-		l2_length = _sbss_l2 - _stext_l2;
-		if (l2_length)
-			memcpy(_stext_l2, _l2_lma_start, l2_length);
-	}
+	/* if necessary, copy L2 text/data to L2 SRAM */
+	if (L2_LENGTH && l2_len)
+		memcpy(_stext_l2, _l2_lma, l2_len);
 }
 
 /* add_memory_region to memmap */

arch/blackfin/kernel/vmlinux.lds.S

@@ -123,8 +123,6 @@ SECTIONS
 		EXIT_DATA
 	}
 
-	__l1_lma_start = .;
-
 	.text_l1 L1_CODE_START : AT(LOADADDR(.exit.data) + SIZEOF(.exit.data))
 	{
 		. = ALIGN(4);
@@ -136,9 +134,11 @@ SECTIONS
 		. = ALIGN(4);
 		__etext_l1 = .;
 	}
-	ASSERT (SIZEOF(.text_l1) <= L1_CODE_LENGTH, "L1 text overflow!")
+	__text_l1_lma = LOADADDR(.text_l1);
+	__text_l1_len = SIZEOF(.text_l1);
+	ASSERT (__text_l1_len <= L1_CODE_LENGTH, "L1 text overflow!")
 
-	.data_l1 L1_DATA_A_START : AT(LOADADDR(.text_l1) + SIZEOF(.text_l1))
+	.data_l1 L1_DATA_A_START : AT(__text_l1_lma + __text_l1_len)
 	{
 		. = ALIGN(4);
 		__sdata_l1 = .;
@@ -154,9 +154,11 @@ SECTIONS
 		. = ALIGN(4);
 		__ebss_l1 = .;
 	}
-	ASSERT (SIZEOF(.data_l1) <= L1_DATA_A_LENGTH, "L1 data A overflow!")
+	__data_l1_lma = LOADADDR(.data_l1);
+	__data_l1_len = SIZEOF(.data_l1);
+	ASSERT (__data_l1_len <= L1_DATA_A_LENGTH, "L1 data A overflow!")
 
-	.data_b_l1 L1_DATA_B_START : AT(LOADADDR(.data_l1) + SIZEOF(.data_l1))
+	.data_b_l1 L1_DATA_B_START : AT(__data_l1_lma + __data_l1_len)
 	{
 		. = ALIGN(4);
 		__sdata_b_l1 = .;
@@ -169,11 +171,11 @@ SECTIONS
 		. = ALIGN(4);
 		__ebss_b_l1 = .;
 	}
-	ASSERT (SIZEOF(.data_b_l1) <= L1_DATA_B_LENGTH, "L1 data B overflow!")
-
-	__l2_lma_start = LOADADDR(.data_b_l1) + SIZEOF(.data_b_l1);
+	__data_b_l1_lma = LOADADDR(.data_b_l1);
+	__data_b_l1_len = SIZEOF(.data_b_l1);
+	ASSERT (__data_b_l1_len <= L1_DATA_B_LENGTH, "L1 data B overflow!")
 
-	.text_data_l2 L2_START : AT(LOADADDR(.data_b_l1) + SIZEOF(.data_b_l1))
+	.text_data_l2 L2_START : AT(__data_b_l1_lma + __data_b_l1_len)
 	{
 		. = ALIGN(4);
 		__stext_l2 = .;
@@ -195,12 +197,14 @@ SECTIONS
 		. = ALIGN(4);
 		__ebss_l2 = .;
 	}
-	ASSERT (SIZEOF(.text_data_l2) <= L2_LENGTH, "L2 overflow!")
+	__l2_lma = LOADADDR(.text_data_l2);
+	__l2_len = SIZEOF(.text_data_l2);
+	ASSERT (__l2_len <= L2_LENGTH, "L2 overflow!")
 
 	/* Force trailing alignment of our init section so that when we
 	 * free our init memory, we don't leave behind a partial page.
 	 */
-	. = LOADADDR(.text_data_l2) + SIZEOF(.text_data_l2);
+	. = __l2_lma + __l2_len;
 	. = ALIGN(PAGE_SIZE);
 	___init_end = .;