ARM: Add arm_memblock_steal() to allocate memory away from the kernel

Several platforms are now using the memblock_alloc+memblock_free+ memblock_remove trick to obtain memory which won't be mapped in the kernel's page tables. Most platforms do this (correctly) in the ->reserve callback. However, OMAP has started to call these functions outside of this callback, and this is extremely unsafe - memory will not be unmapped, and could well be given out after memblock is no longer responsible for its management. So, provide arm_memblock_steal() to perform this function, and ensure that it panic()s if it is used inappropriately. Convert everyone over, including OMAP. As a result, OMAP with OMAP4_ERRATA_I688 enabled will panic on boot with this change. Mark this option as BROKEN and make it depend on BROKEN. OMAP needs to be fixed, or 137d105d50 (ARM: OMAP4: Fix errata i688 with MPU interconnect barriers.) reverted until such time it can be fixed correctly. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

ARM: Add arm_memblock_steal() to allocate memory away from the kernel
Several platforms are now using the memblock_alloc+memblock_free+ memblock_remove trick to obtain memory which won't be mapped in the kernel's page tables. Most platforms do this (correctly) in the ->reserve callback. However, OMAP has started to call these functions outside of this callback, and this is extremely unsafe - memory will not be unmapped, and could well be given out after memblock is no longer responsible for its management. So, provide arm_memblock_steal() to perform this function, and ensure that it panic()s if it is used inappropriately. Convert everyone over, including OMAP. As a result, OMAP with OMAP4_ERRATA_I688 enabled will panic on boot with this change. Mark this option as BROKEN and make it depend on BROKEN. OMAP needs to be fixed, or 137d105d50 (ARM: OMAP4: Fix errata i688 with MPU interconnect barriers.) reverted until such time it can be fixed correctly. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Russell King
1 parent 4de3a8e101
Showing 9 changed files with 34 additions and 32 deletions Side-by-side Diff
arch/arm/include/asm/memblock.h
arch/arm/mach-imx/mach-mx31_3ds.c
arch/arm/mach-imx/mach-mx31moboard.c
arch/arm/mach-imx/mach-pcm037.c
arch/arm/mach-omap2/Kconfig
arch/arm/mach-omap2/omap-secure.c
arch/arm/mach-omap2/omap4-common.c
arch/arm/mm/init.c
arch/arm/plat-omap/devices.c
@@ -6,5 +6,7 @@
  
 extern void arm_memblock_init(struct meminfo *, struct machine_desc *);
  
+phys_addr_t arm_memblock_steal(phys_addr_t size, phys_addr_t align);
+
 #endif
@@ -36,6 +36,7 @@
 #include <asm/mach/time.h>
 #include <asm/memory.h>
 #include <asm/mach/map.h>
+#include <asm/memblock.h>
 #include <mach/common.h>
 #include <mach/iomux-mx3.h>
 #include <mach/3ds_debugboard.h>
  
@@ -754,10 +755,8 @@
 static void __init mx31_3ds_reserve(void)
 {
 	/* reserve MX31_3DS_CAMERA_BUF_SIZE bytes for mx3-camera */
-	mx3_camera_base = memblock_alloc(MX31_3DS_CAMERA_BUF_SIZE,
+	mx3_camera_base = arm_memblock_steal(MX31_3DS_CAMERA_BUF_SIZE,
 					 MX31_3DS_CAMERA_BUF_SIZE);
-	memblock_free(mx3_camera_base, MX31_3DS_CAMERA_BUF_SIZE);
-	memblock_remove(mx3_camera_base, MX31_3DS_CAMERA_BUF_SIZE);
 }
  
 MACHINE_START(MX31_3DS, "Freescale MX31PDK (3DS)")
@@ -41,6 +41,7 @@
 #include <asm/mach/arch.h>
 #include <asm/mach/time.h>
 #include <asm/mach/map.h>
+#include <asm/memblock.h>
 #include <mach/board-mx31moboard.h>
 #include <mach/common.h>
 #include <mach/hardware.h>
  
@@ -584,10 +585,8 @@
 static void __init mx31moboard_reserve(void)
 {
 	/* reserve 4 MiB for mx3-camera */
-	mx3_camera_base = memblock_alloc(MX3_CAMERA_BUF_SIZE,
+	mx3_camera_base = arm_memblock_steal(MX3_CAMERA_BUF_SIZE,
 			MX3_CAMERA_BUF_SIZE);
-	memblock_free(mx3_camera_base, MX3_CAMERA_BUF_SIZE);
-	memblock_remove(mx3_camera_base, MX3_CAMERA_BUF_SIZE);
 }
  
 MACHINE_START(MX31MOBOARD, "EPFL Mobots mx31moboard")
@@ -39,6 +39,7 @@
 #include <asm/mach/arch.h>
 #include <asm/mach/time.h>
 #include <asm/mach/map.h>
+#include <asm/memblock.h>
 #include <mach/common.h>
 #include <mach/hardware.h>
 #include <mach/iomux-mx3.h>
  
@@ -680,10 +681,8 @@
 static void __init pcm037_reserve(void)
 {
 	/* reserve 4 MiB for mx3-camera */
-	mx3_camera_base = memblock_alloc(MX3_CAMERA_BUF_SIZE,
+	mx3_camera_base = arm_memblock_steal(MX3_CAMERA_BUF_SIZE,
 			MX3_CAMERA_BUF_SIZE);
-	memblock_free(mx3_camera_base, MX3_CAMERA_BUF_SIZE);
-	memblock_remove(mx3_camera_base, MX3_CAMERA_BUF_SIZE);
 }
  
 MACHINE_START(PCM037, "Phytec Phycore pcm037")
@@ -366,8 +366,8 @@
 	  going on could result in system crashes;
  
 config OMAP4_ERRATA_I688
-	bool "OMAP4 errata: Async Bridge Corruption"
-	depends on ARCH_OMAP4
+	bool "OMAP4 errata: Async Bridge Corruption (BROKEN)"
+	depends on ARCH_OMAP4 && BROKEN
 	select ARCH_HAS_BARRIERS
 	help
 	  If a data is stalled inside asynchronous bridge because of back
@@ -16,6 +16,7 @@
 #include <linux/memblock.h>
  
 #include <asm/cacheflush.h>
+#include <asm/memblock.h>
  
 #include <mach/omap-secure.h>
  
  
@@ -57,20 +58,10 @@
 /* Allocate the memory to save secure ram */
 int __init omap_secure_ram_reserve_memblock(void)
 {
-	phys_addr_t paddr;
 	u32 size = OMAP_SECURE_RAM_STORAGE;
  
 	size = ALIGN(size, SZ_1M);
-	paddr = memblock_alloc(size, SZ_1M);
-	if (!paddr) {
-		pr_err("%s: failed to reserve %x bytes\n",
-				__func__, size);
-		return -ENOMEM;
-	}
-	memblock_free(paddr, size);
-	memblock_remove(paddr, size);
-
-	omap_secure_memblock_base = paddr;
+	omap_secure_memblock_base = arm_memblock_steal(size, SZ_1M);
  
 	return 0;
 }
@@ -20,6 +20,7 @@
 #include <asm/hardware/gic.h>
 #include <asm/hardware/cache-l2x0.h>
 #include <asm/mach/map.h>
+#include <asm/memblock.h>
  
 #include <plat/irqs.h>
 #include <plat/sram.h>
@@ -61,13 +62,8 @@
 		return -ENODEV;
  
 	size = ALIGN(PAGE_SIZE, SZ_1M);
-	paddr = memblock_alloc(size, SZ_1M);
-	if (!paddr) {
-		pr_err("%s: failed to reserve 4 Kbytes\n", __func__);
-		return -ENOMEM;
-	}
-	memblock_free(paddr, size);
-	memblock_remove(paddr, size);
+	paddr = arm_memblock_steal(size, SZ_1M);
+
 	dram_io_desc[0].virtual = OMAP4_DRAM_BARRIER_VA;
 	dram_io_desc[0].pfn = __phys_to_pfn(paddr);
 	dram_io_desc[0].length = size;
@@ -22,6 +22,7 @@
 #include <linux/memblock.h>
  
 #include <asm/mach-types.h>
+#include <asm/memblock.h>
 #include <asm/prom.h>
 #include <asm/sections.h>
 #include <asm/setup.h>
@@ -307,6 +308,21 @@
 }
 #endif
  
+static bool arm_memblock_steal_permitted = true;
+
+phys_addr_t arm_memblock_steal(phys_addr_t size, phys_addr_t align)
+{
+	phys_addr_t phys;
+
+	BUG_ON(!arm_memblock_steal_permitted);
+
+	phys = memblock_alloc(size, align);
+	memblock_free(phys, size);
+	memblock_remove(phys, size);
+
+	return phys;
+}
+
 void __init arm_memblock_init(struct meminfo *mi, struct machine_desc *mdesc)
 {
 	int i;
@@ -349,6 +365,7 @@
 	if (mdesc->reserve)
 		mdesc->reserve();
  
+	arm_memblock_steal_permitted = false;
 	memblock_allow_resize();
 	memblock_dump_all();
 }
@@ -20,6 +20,7 @@
 #include <mach/hardware.h>
 #include <asm/mach-types.h>
 #include <asm/mach/map.h>
+#include <asm/memblock.h>
  
 #include <plat/tc.h>
 #include <plat/board.h>
  
@@ -164,14 +165,12 @@
 	if (!size)
 		return;
  
-	paddr = memblock_alloc(size, SZ_1M);
+	paddr = arm_memblock_steal(size, SZ_1M);
 	if (!paddr) {
 		pr_err("%s: failed to reserve %x bytes\n",
 				__func__, size);
 		return;
 	}
-	memblock_free(paddr, size);
-	memblock_remove(paddr, size);
  
 	omap_dsp_phys_mempool_base = paddr;
 }
...	...	@@ -6,5 +6,7 @@
6	6
7	7	extern void arm_memblock_init(struct meminfo , struct machine_desc );
8	8
	9	+phys_addr_t arm_memblock_steal(phys_addr_t size, phys_addr_t align);
	10	+
9	11	#endif
...	...	@@ -36,6 +36,7 @@
36	36	#include <asm/mach/time.h>
37	37	#include <asm/memory.h>
38	38	#include <asm/mach/map.h>
	39	+#include <asm/memblock.h>
39	40	#include <mach/common.h>
40	41	#include <mach/iomux-mx3.h>
41	42	#include <mach/3ds_debugboard.h>
42	43
...	...	@@ -754,10 +755,8 @@
754	755	static void __init mx31_3ds_reserve(void)
755	756	{
756	757	/* reserve MX31_3DS_CAMERA_BUF_SIZE bytes for mx3-camera */
757		- mx3_camera_base = memblock_alloc(MX31_3DS_CAMERA_BUF_SIZE,
	758	+ mx3_camera_base = arm_memblock_steal(MX31_3DS_CAMERA_BUF_SIZE,
758	759	MX31_3DS_CAMERA_BUF_SIZE);
759		- memblock_free(mx3_camera_base, MX31_3DS_CAMERA_BUF_SIZE);
760		- memblock_remove(mx3_camera_base, MX31_3DS_CAMERA_BUF_SIZE);
761	760	}
762	761
763	762	MACHINE_START(MX31_3DS, "Freescale MX31PDK (3DS)")
...	...	@@ -41,6 +41,7 @@
41	41	#include <asm/mach/arch.h>
42	42	#include <asm/mach/time.h>
43	43	#include <asm/mach/map.h>
	44	+#include <asm/memblock.h>
44	45	#include <mach/board-mx31moboard.h>
45	46	#include <mach/common.h>
46	47	#include <mach/hardware.h>
47	48
...	...	@@ -584,10 +585,8 @@
584	585	static void __init mx31moboard_reserve(void)
585	586	{
586	587	/* reserve 4 MiB for mx3-camera */
587		- mx3_camera_base = memblock_alloc(MX3_CAMERA_BUF_SIZE,
	588	+ mx3_camera_base = arm_memblock_steal(MX3_CAMERA_BUF_SIZE,
588	589	MX3_CAMERA_BUF_SIZE);
589		- memblock_free(mx3_camera_base, MX3_CAMERA_BUF_SIZE);
590		- memblock_remove(mx3_camera_base, MX3_CAMERA_BUF_SIZE);
591	590	}
592	591
593	592	MACHINE_START(MX31MOBOARD, "EPFL Mobots mx31moboard")
...	...	@@ -39,6 +39,7 @@
39	39	#include <asm/mach/arch.h>
40	40	#include <asm/mach/time.h>
41	41	#include <asm/mach/map.h>
	42	+#include <asm/memblock.h>
42	43	#include <mach/common.h>
43	44	#include <mach/hardware.h>
44	45	#include <mach/iomux-mx3.h>
45	46
...	...	@@ -680,10 +681,8 @@
680	681	static void __init pcm037_reserve(void)
681	682	{
682	683	/* reserve 4 MiB for mx3-camera */
683		- mx3_camera_base = memblock_alloc(MX3_CAMERA_BUF_SIZE,
	684	+ mx3_camera_base = arm_memblock_steal(MX3_CAMERA_BUF_SIZE,
684	685	MX3_CAMERA_BUF_SIZE);
685		- memblock_free(mx3_camera_base, MX3_CAMERA_BUF_SIZE);
686		- memblock_remove(mx3_camera_base, MX3_CAMERA_BUF_SIZE);
687	686	}
688	687
689	688	MACHINE_START(PCM037, "Phytec Phycore pcm037")
...	...	@@ -366,8 +366,8 @@
366	366	going on could result in system crashes;
367	367
368	368	config OMAP4_ERRATA_I688
369		- bool "OMAP4 errata: Async Bridge Corruption"
370		- depends on ARCH_OMAP4
	369	+ bool "OMAP4 errata: Async Bridge Corruption (BROKEN)"
	370	+ depends on ARCH_OMAP4 && BROKEN
371	371	select ARCH_HAS_BARRIERS
372	372	help
373	373	If a data is stalled inside asynchronous bridge because of back
...	...	@@ -16,6 +16,7 @@
16	16	#include <linux/memblock.h>
17	17
18	18	#include <asm/cacheflush.h>
	19	+#include <asm/memblock.h>
19	20
20	21	#include <mach/omap-secure.h>
21	22
22	23
...	...	@@ -57,20 +58,10 @@
57	58	/* Allocate the memory to save secure ram */
58	59	int __init omap_secure_ram_reserve_memblock(void)
59	60	{
60		- phys_addr_t paddr;
61	61	u32 size = OMAP_SECURE_RAM_STORAGE;
62	62
63	63	size = ALIGN(size, SZ_1M);
64		- paddr = memblock_alloc(size, SZ_1M);
65		- if (!paddr) {
66		- pr_err("%s: failed to reserve %x bytes\n",
67		- __func__, size);
68		- return -ENOMEM;
69		- }
70		- memblock_free(paddr, size);
71		- memblock_remove(paddr, size);
72		-
73		- omap_secure_memblock_base = paddr;
	64	+ omap_secure_memblock_base = arm_memblock_steal(size, SZ_1M);
74	65
75	66	return 0;
76	67	}
...	...	@@ -20,6 +20,7 @@
20	20	#include <asm/hardware/gic.h>
21	21	#include <asm/hardware/cache-l2x0.h>
22	22	#include <asm/mach/map.h>
	23	+#include <asm/memblock.h>
23	24
24	25	#include <plat/irqs.h>
25	26	#include <plat/sram.h>
...	...	@@ -61,13 +62,8 @@
61	62	return -ENODEV;
62	63
63	64	size = ALIGN(PAGE_SIZE, SZ_1M);
64		- paddr = memblock_alloc(size, SZ_1M);
65		- if (!paddr) {
66		- pr_err("%s: failed to reserve 4 Kbytes\n", __func__);
67		- return -ENOMEM;
68		- }
69		- memblock_free(paddr, size);
70		- memblock_remove(paddr, size);
	65	+ paddr = arm_memblock_steal(size, SZ_1M);
	66	+
71	67	dram_io_desc[0].virtual = OMAP4_DRAM_BARRIER_VA;
72	68	dram_io_desc[0].pfn = __phys_to_pfn(paddr);
73	69	dram_io_desc[0].length = size;
...	...	@@ -22,6 +22,7 @@
22	22	#include <linux/memblock.h>
23	23
24	24	#include <asm/mach-types.h>
	25	+#include <asm/memblock.h>
25	26	#include <asm/prom.h>
26	27	#include <asm/sections.h>
27	28	#include <asm/setup.h>
...	...	@@ -307,6 +308,21 @@
307	308	}
308	309	#endif
309	310
	311	+static bool arm_memblock_steal_permitted = true;
	312	+
	313	+phys_addr_t arm_memblock_steal(phys_addr_t size, phys_addr_t align)
	314	+{
	315	+ phys_addr_t phys;
	316	+
	317	+ BUG_ON(!arm_memblock_steal_permitted);
	318	+
	319	+ phys = memblock_alloc(size, align);
	320	+ memblock_free(phys, size);
	321	+ memblock_remove(phys, size);
	322	+
	323	+ return phys;
	324	+}
	325	+
310	326	void __init arm_memblock_init(struct meminfo mi, struct machine_desc mdesc)
311	327	{
312	328	int i;
...	...	@@ -349,6 +365,7 @@
349	365	if (mdesc->reserve)
350	366	mdesc->reserve();
351	367
	368	+ arm_memblock_steal_permitted = false;
352	369	memblock_allow_resize();
353	370	memblock_dump_all();
354	371	}