[PATCH] ARM: Set proper TEXT_OFFSET for newer MSMs

Stephen Boyd sboyd at codeaurora.org
Sun Jul 24 13:39:09 EDT 2011


MSMs post 8x50 have 2Mb at the beginning of RAM reserved for
shared memory. Since the kernel hasn't typically been told this
RAM exists, PHYS_OFFSET has been set to 0xN0200000 and the memory
atags passed to the kernel have matched. This doesn't play nicely
with things such as AUTO_ZRELADDR, which doesn't work at all, and
dynamic phys to virt, which requires an MSM specific workaround.

Work around these issues by telling the kernel RAM starts at
0xN0000000 (it actually does) and fixup the atags from the
bootloader (if necessary) to say the same. In addition, make sure
to set TEXT_OFFSET at least 2Mb beyond the start of RAM so that
the kernel doesn't end up being decompressed into shared memory.

After doing this, AUTO_ZRELADDR should work on MSM with no
problems and ARM_PATCH_PHYS_VIRT_16BIT should no longer be
necessary.

Signed-off-by: Stephen Boyd <sboyd at codeaurora.org>
Cc: Nicolas Pitre <nico at fluxnic.net>
---

> On Mon, Jul 11, 2011 at 06:14:38PM -0400, Nicolas Pitre wrote:
> 
> > > Anyway, maybe we've been going about this the wrong way. Couldn't we
> > > just make TEXT_OFFSET be 0x00208000 and then make sure to remove the
> > > first 2MB of memory in a machine->reserve() routine if we're MSM?
> > 
> > I think that would certainly be a worthwhile thing to do.  This would 
> > even make ARM_PATCH_PHYS_VIRT more efficient as you won't have to enable 
> > ARM_PATCH_PHYS_VIRT_16BIT anymore.  And even without 
> > ARM_PATCH_PHYS_VIRT, the compiled code for virt_to_phys() and 
> > phys_to_virt() would be more efficient.
> > 
> > Whether or not we would like to still keep the ARM_PATCH_PHYS_VIRT_16BIT 
> > code around is a separate question.

Here is the patch. It seems to work.

 arch/arm/Makefile                       |    3 +++
 arch/arm/mach-msm/board-msm7x30.c       |   20 ++++++++++++++++++++
 arch/arm/mach-msm/board-msm8960.c       |   19 +++++++++++++++++++
 arch/arm/mach-msm/board-msm8x60.c       |   22 ++++++++++++++++++++++
 arch/arm/mach-msm/include/mach/memory.h |    6 +++---
 5 files changed, 67 insertions(+), 3 deletions(-)

diff --git a/arch/arm/Makefile b/arch/arm/Makefile
index 3a4a04b..8c35e19 100644
--- a/arch/arm/Makefile
+++ b/arch/arm/Makefile
@@ -128,6 +128,9 @@ textofs-$(CONFIG_PM_H1940)      := 0x00108000
 ifeq ($(CONFIG_ARCH_SA1100),y)
 textofs-$(CONFIG_SA1111) := 0x00208000
 endif
+textofs-$(CONFIG_ARCH_MSM7X30) := 0x00208000
+textofs-$(CONFIG_ARCH_MSM8X60) := 0x00208000
+textofs-$(CONFIG_ARCH_MSM8960) := 0x00208000
 
 # Machine directory name.  This list is sorted alphanumerically
 # by CONFIG_* macro name.
diff --git a/arch/arm/mach-msm/board-msm7x30.c b/arch/arm/mach-msm/board-msm7x30.c
index 8d21769..b809dc6 100644
--- a/arch/arm/mach-msm/board-msm7x30.c
+++ b/arch/arm/mach-msm/board-msm7x30.c
@@ -24,6 +24,7 @@
 #include <linux/smsc911x.h>
 #include <linux/usb/msm_hsusb.h>
 #include <linux/clkdev.h>
+#include <linux/memblock.h>
 
 #include <asm/mach-types.h>
 #include <asm/mach/arch.h>
@@ -42,6 +43,19 @@
 
 extern struct sys_timer msm_timer;
 
+static void __init msm7x30_fixup(struct machine_desc *desc, struct tag *tag,
+			 char **cmdline, struct meminfo *mi)
+{
+	for (; tag->hdr.size; tag = tag_next(tag))
+		if (tag->hdr.tag == ATAG_MEM && tag->u.mem.start == 0x200000)
+			tag->u.mem.start = 0;
+}
+
+static void __init msm7x30_reserve(void)
+{
+	memblock_remove(0x0, SZ_2M);
+}
+
 static int hsusb_phy_init_seq[] = {
 	0x30, 0x32,	/* Enable and set Pre-Emphasis Depth to 20% */
 	0x02, 0x36,	/* Disable CDR Auto Reset feature */
@@ -108,6 +122,8 @@ static void __init msm7x30_map_io(void)
 
 MACHINE_START(MSM7X30_SURF, "QCT MSM7X30 SURF")
 	.boot_params = PLAT_PHYS_OFFSET + 0x100,
+	.fixup = msm7x30_fixup,
+	.reserve = msm7x30_reserve,
 	.map_io = msm7x30_map_io,
 	.init_irq = msm7x30_init_irq,
 	.init_machine = msm7x30_init,
@@ -116,6 +132,8 @@ MACHINE_END
 
 MACHINE_START(MSM7X30_FFA, "QCT MSM7X30 FFA")
 	.boot_params = PLAT_PHYS_OFFSET + 0x100,
+	.fixup = msm7x30_fixup,
+	.reserve = msm7x30_reserve,
 	.map_io = msm7x30_map_io,
 	.init_irq = msm7x30_init_irq,
 	.init_machine = msm7x30_init,
@@ -124,6 +142,8 @@ MACHINE_END
 
 MACHINE_START(MSM7X30_FLUID, "QCT MSM7X30 FLUID")
 	.boot_params = PLAT_PHYS_OFFSET + 0x100,
+	.fixup = msm7x30_fixup,
+	.reserve = msm7x30_reserve,
 	.map_io = msm7x30_map_io,
 	.init_irq = msm7x30_init_irq,
 	.init_machine = msm7x30_init,
diff --git a/arch/arm/mach-msm/board-msm8960.c b/arch/arm/mach-msm/board-msm8960.c
index 8294692..db835ef 100644
--- a/arch/arm/mach-msm/board-msm8960.c
+++ b/arch/arm/mach-msm/board-msm8960.c
@@ -20,16 +20,31 @@
 #include <linux/io.h>
 #include <linux/irq.h>
 #include <linux/clkdev.h>
+#include <linux/memblock.h>
 
 #include <asm/mach-types.h>
 #include <asm/mach/arch.h>
 #include <asm/hardware/gic.h>
+#include <asm/setup.h>
 
 #include <mach/board.h>
 #include <mach/msm_iomap.h>
 
 #include "devices.h"
 
+static void __init msm8960_fixup(struct machine_desc *desc, struct tag *tag,
+			 char **cmdline, struct meminfo *mi)
+{
+	for (; tag->hdr.size; tag = tag_next(tag))
+		if (tag->hdr.tag == ATAG_MEM && tag->u.mem.start == 0x40200000)
+			tag->u.mem.start = 0x40000000;
+}
+
+static void __init msm8960_reserve(void)
+{
+	memblock_remove(0x40000000, SZ_2M);
+}
+
 static void __init msm8960_map_io(void)
 {
 	msm_map_msm8960_io();
@@ -92,6 +107,8 @@ static void __init msm8960_rumi3_init(void)
 }
 
 MACHINE_START(MSM8960_SIM, "QCT MSM8960 SIMULATOR")
+	.fixup = msm8960_fixup,
+	.reserve = msm8960_reserve,
 	.map_io = msm8960_map_io,
 	.init_early = msm8960_init_early,
 	.init_irq = msm8960_init_irq,
@@ -100,6 +117,8 @@ MACHINE_START(MSM8960_SIM, "QCT MSM8960 SIMULATOR")
 MACHINE_END
 
 MACHINE_START(MSM8960_RUMI3, "QCT MSM8960 RUMI3")
+	.fixup = msm8960_fixup,
+	.reserve = msm8960_reserve,
 	.map_io = msm8960_map_io,
 	.init_early = msm8960_init_early,
 	.init_irq = msm8960_init_irq,
diff --git a/arch/arm/mach-msm/board-msm8x60.c b/arch/arm/mach-msm/board-msm8x60.c
index 98c47ce..39a3c0b 100644
--- a/arch/arm/mach-msm/board-msm8x60.c
+++ b/arch/arm/mach-msm/board-msm8x60.c
@@ -20,15 +20,29 @@
 #include <linux/platform_device.h>
 #include <linux/io.h>
 #include <linux/irq.h>
+#include <linux/memblock.h>
 
 #include <asm/mach-types.h>
 #include <asm/mach/arch.h>
 #include <asm/hardware/gic.h>
+#include <asm/setup.h>
 
 #include <mach/board.h>
 #include <mach/msm_iomap.h>
 #include "devices.h"
 
+static void __init msm8x60_fixup(struct machine_desc *desc, struct tag *tag,
+			 char **cmdline, struct meminfo *mi)
+{
+	for (; tag->hdr.size; tag = tag_next(tag))
+		if (tag->hdr.tag == ATAG_MEM && tag->u.mem.start == 0x40200000)
+			tag->u.mem.start = 0x40000000;
+}
+
+static void __init msm8x60_reserve(void)
+{
+	memblock_remove(0x40000000, SZ_2M);
+}
 
 static void __init msm8x60_map_io(void)
 {
@@ -72,6 +86,8 @@ static void __init msm8x60_init(void)
 }
 
 MACHINE_START(MSM8X60_RUMI3, "QCT MSM8X60 RUMI3")
+	.fixup = msm8x60_fixup,
+	.reserve = msm8x60_reserve,
 	.map_io = msm8x60_map_io,
 	.init_irq = msm8x60_init_irq,
 	.init_machine = msm8x60_init,
@@ -79,6 +95,8 @@ MACHINE_START(MSM8X60_RUMI3, "QCT MSM8X60 RUMI3")
 MACHINE_END
 
 MACHINE_START(MSM8X60_SURF, "QCT MSM8X60 SURF")
+	.fixup = msm8x60_fixup,
+	.reserve = msm8x60_reserve,
 	.map_io = msm8x60_map_io,
 	.init_irq = msm8x60_init_irq,
 	.init_machine = msm8x60_init,
@@ -86,6 +104,8 @@ MACHINE_START(MSM8X60_SURF, "QCT MSM8X60 SURF")
 MACHINE_END
 
 MACHINE_START(MSM8X60_SIM, "QCT MSM8X60 SIMULATOR")
+	.fixup = msm8x60_fixup,
+	.reserve = msm8x60_reserve,
 	.map_io = msm8x60_map_io,
 	.init_irq = msm8x60_init_irq,
 	.init_machine = msm8x60_init,
@@ -93,6 +113,8 @@ MACHINE_START(MSM8X60_SIM, "QCT MSM8X60 SIMULATOR")
 MACHINE_END
 
 MACHINE_START(MSM8X60_FFA, "QCT MSM8X60 FFA")
+	.fixup = msm8x60_fixup,
+	.reserve = msm8x60_reserve,
 	.map_io = msm8x60_map_io,
 	.init_irq = msm8x60_init_irq,
 	.init_machine = msm8x60_init,
diff --git a/arch/arm/mach-msm/include/mach/memory.h b/arch/arm/mach-msm/include/mach/memory.h
index f2f8d29..58d5e7e 100644
--- a/arch/arm/mach-msm/include/mach/memory.h
+++ b/arch/arm/mach-msm/include/mach/memory.h
@@ -22,11 +22,11 @@
 #elif defined(CONFIG_ARCH_QSD8X50)
 #define PLAT_PHYS_OFFSET		UL(0x20000000)
 #elif defined(CONFIG_ARCH_MSM7X30)
-#define PLAT_PHYS_OFFSET		UL(0x00200000)
+#define PLAT_PHYS_OFFSET		UL(0x00000000)
 #elif defined(CONFIG_ARCH_MSM8X60)
-#define PLAT_PHYS_OFFSET		UL(0x40200000)
+#define PLAT_PHYS_OFFSET		UL(0x40000000)
 #elif defined(CONFIG_ARCH_MSM8960)
-#define PLAT_PHYS_OFFSET		UL(0x40200000)
+#define PLAT_PHYS_OFFSET		UL(0x40000000)
 #else
 #define PLAT_PHYS_OFFSET		UL(0x10000000)
 #endif
-- 
Sent by an employee of the Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.




More information about the linux-arm-kernel mailing list