ARM: move iotable mappings within the vmalloc region

In order to remove the build time variation between different SOCs with regards to VMALLOC_END, the iotable mappings are now allocated inside the vmalloc region. This allows for VMALLOC_END to be identical across all machines. The value for VMALLOC_END is now set to 0xff000000 which is right where the consistent DMA area starts. To accommodate all static mappings on machines with possible highmem usage, the default vmalloc area size is changed to 240 MB so that VMALLOC_START is no higher than 0xf0000000 by default. Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org> Tested-by: Stephen Warren <swarren@nvidia.com> Tested-by: Kevin Hilman <khilman@ti.com> Tested-by: Jamie Iles <jamie@jamieiles.com>

ARM: move iotable mappings within the vmalloc region
In order to remove the build time variation between different SOCs with regards to VMALLOC_END, the iotable mappings are now allocated inside the vmalloc region. This allows for VMALLOC_END to be identical across all machines. The value for VMALLOC_END is now set to 0xff000000 which is right where the consistent DMA area starts. To accommodate all static mappings on machines with possible highmem usage, the default vmalloc area size is changed to 240 MB so that VMALLOC_START is no higher than 0xf0000000 by default. Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org> Tested-by: Stephen Warren <swarren@nvidia.com> Tested-by: Kevin Hilman <khilman@ti.com> Tested-by: Jamie Iles <jamie@jamieiles.com>
Nicolas Pitre · Nicolas Pitre · Eric Lee · Eric Lee · Eric Lee · Eric Lee
1 parent be9b7335e7
Showing 3 changed files with 41 additions and 27 deletions Side-by-side Diff
Documentation/arm/memory.txt
arch/arm/include/asm/pgtable.h
arch/arm/mm/mmu.c
@@ -51,15 +51,14 @@
 ff000000	ffbfffff	Reserved for future expansion of DMA
 				mapping region.
  
-VMALLOC_END	feffffff	Free for platform use, recommended.
-				VMALLOC_END must be aligned to a 2MB
-				boundary.
-
 VMALLOC_START	VMALLOC_END-1	vmalloc() / ioremap() space.
 				Memory returned by vmalloc/ioremap will
 				be dynamically placed in this region.
-				VMALLOC_START may be based upon the value
-				of the high_memory variable.
+				Machine specific static mappings are also
+				located here through iotable_init().
+				VMALLOC_START is based upon the value
+				of the high_memory variable, and VMALLOC_END
+				is equal to 0xff000000.
  
 PAGE_OFFSET	high_memory-1	Kernel direct-mapped RAM region.
 				This maps the platforms RAM, and typically
@@ -21,7 +21,6 @@
 #else
  
 #include <asm/memory.h>
-#include <mach/vmalloc.h>
 #include <asm/pgtable-hwdef.h>
  
 #include <asm/pgtable-2level.h>
  
  
@@ -33,15 +32,10 @@
  * any out-of-bounds memory accesses will hopefully be caught.
  * The vmalloc() routines leaves a hole of 4kB between each vmalloced
  * area for the same reason. ;)
- *
- * Note that platforms may override VMALLOC_START, but they must provide
- * VMALLOC_END.  VMALLOC_END defines the (exclusive) limit of this space,
- * which may not overlap IO space.
  */
-#ifndef VMALLOC_START
 #define VMALLOC_OFFSET		(8*1024*1024)
 #define VMALLOC_START		(((unsigned long)high_memory + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1))
-#endif
+#define VMALLOC_END		0xff000000UL
  
 #define LIBRARY_TEXT_START	0x0c000000
  
@@ -15,6 +15,7 @@
 #include <linux/nodemask.h>
 #include <linux/memblock.h>
 #include <linux/fs.h>
+#include <linux/vmalloc.h>
  
 #include <asm/cputype.h>
 #include <asm/sections.h>
  
  
@@ -529,13 +530,18 @@
  
 #define vectors_base()	(vectors_high() ? 0xffff0000 : 0)
  
-static void __init *early_alloc(unsigned long sz)
+static void __init *early_alloc_aligned(unsigned long sz, unsigned long align)
 {
-	void *ptr = __va(memblock_alloc(sz, sz));
+	void *ptr = __va(memblock_alloc(sz, align));
 	memset(ptr, 0, sz);
 	return ptr;
 }
  
+static void __init *early_alloc(unsigned long sz)
+{
+	return early_alloc_aligned(sz, sz);
+}
+
 static pte_t * __init early_pte_alloc(pmd_t *pmd, unsigned long addr, unsigned long prot)
 {
 	if (pmd_none(*pmd)) {
  
@@ -685,9 +691,10 @@
 	}
  
 	if ((md->type == MT_DEVICE || md->type == MT_ROM) &&
-	    md->virtual >= PAGE_OFFSET && md->virtual < VMALLOC_END) {
+	    md->virtual >= PAGE_OFFSET &&
+	    (md->virtual < VMALLOC_START || md->virtual >= VMALLOC_END)) {
 		printk(KERN_WARNING "BUG: mapping for 0x%08llx"
-		       " at 0x%08lx overlaps vmalloc space\n",
+		       " at 0x%08lx out of vmalloc space\n",
 		       (long long)__pfn_to_phys((u64)md->pfn), md->virtual);
 	}
  
  
  
  
@@ -729,18 +736,32 @@
  */
 void __init iotable_init(struct map_desc *io_desc, int nr)
 {
-	int i;
+	struct map_desc *md;
+	struct vm_struct *vm;
  
-	for (i = 0; i < nr; i++)
-		create_mapping(io_desc + i);
+	if (!nr)
+		return;
+
+	vm = early_alloc_aligned(sizeof(*vm) * nr, __alignof__(*vm));
+
+	for (md = io_desc; nr; md++, nr--) {
+		create_mapping(md);
+		vm->addr = (void *)(md->virtual & PAGE_MASK);
+		vm->size = PAGE_ALIGN(md->length + (md->virtual & ~PAGE_MASK));
+		vm->phys_addr = __pfn_to_phys(md->pfn); 
+		vm->flags = VM_IOREMAP;
+		vm->caller = iotable_init;
+		vm_area_add_early(vm++);
+	}
 }
  
-static void * __initdata vmalloc_min = (void *)(VMALLOC_END - SZ_128M);
+static void * __initdata vmalloc_min =
+	(void *)(VMALLOC_END - (240 << 20) - VMALLOC_OFFSET);
  
 /*
  * vmalloc=size forces the vmalloc area to be exactly 'size'
  * bytes. This can be used to increase (or decrease) the vmalloc
- * area - the default is 128m.
+ * area - the default is 240m.
  */
 static int __init early_vmalloc(char *arg)
 {
  
@@ -891,10 +912,10 @@
  
 	/*
 	 * Clear out all the kernel space mappings, except for the first
-	 * memory bank, up to the end of the vmalloc region.
+	 * memory bank, up to the vmalloc region.
 	 */
 	for (addr = __phys_to_virt(end);
-	     addr < VMALLOC_END; addr += PMD_SIZE)
+	     addr < VMALLOC_START; addr += PMD_SIZE)
 		pmd_clear(pmd_off_k(addr));
 }
  
@@ -921,8 +942,8 @@
 }
  
 /*
- * Set up device the mappings.  Since we clear out the page tables for all
- * mappings above VMALLOC_END, we will remove any debug device mappings.
+ * Set up the device mappings.  Since we clear out the page tables for all
+ * mappings above VMALLOC_START, we will remove any debug device mappings.
  * This means you have to be careful how you debug this function, or any
  * called function.  This means you can't use any function or debugging
  * method which may touch any device, otherwise the kernel _will_ crash.
@@ -937,7 +958,7 @@
 	 */
 	vectors_page = early_alloc(PAGE_SIZE);
  
-	for (addr = VMALLOC_END; addr; addr += PMD_SIZE)
+	for (addr = VMALLOC_START; addr; addr += PMD_SIZE)
 		pmd_clear(pmd_off_k(addr));
  
 	/*
...	...	@@ -51,15 +51,14 @@
51	51	ff000000 ffbfffff Reserved for future expansion of DMA
52	52	mapping region.
53	53
54		-VMALLOC_END feffffff Free for platform use, recommended.
55		- VMALLOC_END must be aligned to a 2MB
56		- boundary.
57		-
58	54	VMALLOC_START VMALLOC_END-1 vmalloc() / ioremap() space.
59	55	Memory returned by vmalloc/ioremap will
60	56	be dynamically placed in this region.
61		- VMALLOC_START may be based upon the value
62		- of the high_memory variable.
	57	+ Machine specific static mappings are also
	58	+ located here through iotable_init().
	59	+ VMALLOC_START is based upon the value
	60	+ of the high_memory variable, and VMALLOC_END
	61	+ is equal to 0xff000000.
63	62
64	63	PAGE_OFFSET high_memory-1 Kernel direct-mapped RAM region.
65	64	This maps the platforms RAM, and typically
...	...	@@ -21,7 +21,6 @@
21	21	#else
22	22
23	23	#include <asm/memory.h>
24		-#include <mach/vmalloc.h>
25	24	#include <asm/pgtable-hwdef.h>
26	25
27	26	#include <asm/pgtable-2level.h>
28	27
29	28
...	...	@@ -33,15 +32,10 @@
33	32	* any out-of-bounds memory accesses will hopefully be caught.
34	33	* The vmalloc() routines leaves a hole of 4kB between each vmalloced
35	34	* area for the same reason. ;)
36		- *
37		- * Note that platforms may override VMALLOC_START, but they must provide
38		- * VMALLOC_END. VMALLOC_END defines the (exclusive) limit of this space,
39		- * which may not overlap IO space.
40	35	*/
41		-#ifndef VMALLOC_START
42	36	#define VMALLOC_OFFSET (810241024)
43	37	#define VMALLOC_START (((unsigned long)high_memory + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1))
44		-#endif
	38	+#define VMALLOC_END 0xff000000UL
45	39
46	40	#define LIBRARY_TEXT_START 0x0c000000
47	41
...	...	@@ -15,6 +15,7 @@
15	15	#include <linux/nodemask.h>
16	16	#include <linux/memblock.h>
17	17	#include <linux/fs.h>
	18	+#include <linux/vmalloc.h>
18	19
19	20	#include <asm/cputype.h>
20	21	#include <asm/sections.h>
21	22
22	23
...	...	@@ -529,13 +530,18 @@
529	530
530	531	#define vectors_base() (vectors_high() ? 0xffff0000 : 0)
531	532
532		-static void __init *early_alloc(unsigned long sz)
	533	+static void __init *early_alloc_aligned(unsigned long sz, unsigned long align)
533	534	{
534		- void *ptr = __va(memblock_alloc(sz, sz));
	535	+ void *ptr = __va(memblock_alloc(sz, align));
535	536	memset(ptr, 0, sz);
536	537	return ptr;
537	538	}
538	539
	540	+static void __init *early_alloc(unsigned long sz)
	541	+{
	542	+ return early_alloc_aligned(sz, sz);
	543	+}
	544	+
539	545	static pte_t * __init early_pte_alloc(pmd_t *pmd, unsigned long addr, unsigned long prot)
540	546	{
541	547	if (pmd_none(*pmd)) {
542	548
...	...	@@ -685,9 +691,10 @@
685	691	}
686	692
687	693	if ((md->type == MT_DEVICE \|\| md->type == MT_ROM) &&
688		- md->virtual >= PAGE_OFFSET && md->virtual < VMALLOC_END) {
	694	+ md->virtual >= PAGE_OFFSET &&
	695	+ (md->virtual < VMALLOC_START \|\| md->virtual >= VMALLOC_END)) {
689	696	printk(KERN_WARNING "BUG: mapping for 0x%08llx"
690		- " at 0x%08lx overlaps vmalloc space\n",
	697	+ " at 0x%08lx out of vmalloc space\n",
691	698	(long long)__pfn_to_phys((u64)md->pfn), md->virtual);
692	699	}
693	700
694	701
695	702
696	703
...	...	@@ -729,18 +736,32 @@
729	736	*/
730	737	void __init iotable_init(struct map_desc *io_desc, int nr)
731	738	{
732		- int i;
	739	+ struct map_desc *md;
	740	+ struct vm_struct *vm;
733	741
734		- for (i = 0; i < nr; i++)
735		- create_mapping(io_desc + i);
	742	+ if (!nr)
	743	+ return;
	744	+
	745	+ vm = early_alloc_aligned(sizeof(vm) nr, __alignof__(*vm));
	746	+
	747	+ for (md = io_desc; nr; md++, nr--) {
	748	+ create_mapping(md);
	749	+ vm->addr = (void *)(md->virtual & PAGE_MASK);
	750	+ vm->size = PAGE_ALIGN(md->length + (md->virtual & ~PAGE_MASK));
	751	+ vm->phys_addr = __pfn_to_phys(md->pfn);
	752	+ vm->flags = VM_IOREMAP;
	753	+ vm->caller = iotable_init;
	754	+ vm_area_add_early(vm++);
	755	+ }
736	756	}
737	757
738		-static void * __initdata vmalloc_min = (void *)(VMALLOC_END - SZ_128M);
	758	+static void * __initdata vmalloc_min =
	759	+ (void *)(VMALLOC_END - (240 << 20) - VMALLOC_OFFSET);
739	760
740	761	/*
741	762	* vmalloc=size forces the vmalloc area to be exactly 'size'
742	763	* bytes. This can be used to increase (or decrease) the vmalloc
743		- * area - the default is 128m.
	764	+ * area - the default is 240m.
744	765	*/
745	766	static int __init early_vmalloc(char *arg)
746	767	{
747	768
...	...	@@ -891,10 +912,10 @@
891	912
892	913	/*
893	914	* Clear out all the kernel space mappings, except for the first
894		- * memory bank, up to the end of the vmalloc region.
	915	+ * memory bank, up to the vmalloc region.
895	916	*/
896	917	for (addr = __phys_to_virt(end);
897		- addr < VMALLOC_END; addr += PMD_SIZE)
	918	+ addr < VMALLOC_START; addr += PMD_SIZE)
898	919	pmd_clear(pmd_off_k(addr));
899	920	}
900	921
...	...	@@ -921,8 +942,8 @@
921	942	}
922	943
923	944	/*
924		- * Set up device the mappings. Since we clear out the page tables for all
925		- * mappings above VMALLOC_END, we will remove any debug device mappings.
	945	+ * Set up the device mappings. Since we clear out the page tables for all
	946	+ * mappings above VMALLOC_START, we will remove any debug device mappings.
926	947	* This means you have to be careful how you debug this function, or any
927	948	* called function. This means you can't use any function or debugging
928	949	* method which may touch any device, otherwise the kernel _will_ crash.
...	...	@@ -937,7 +958,7 @@
937	958	*/
938	959	vectors_page = early_alloc(PAGE_SIZE);
939	960
940		- for (addr = VMALLOC_END; addr; addr += PMD_SIZE)
	961	+ for (addr = VMALLOC_START; addr; addr += PMD_SIZE)
941	962	pmd_clear(pmd_off_k(addr));
942	963
943	964	/*