| Message ID | 1309923021-23487-1-git-send-email-nicolas.pitre@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
2011/7/6 Nicolas Pitre <nicolas.pitre@linaro.org>: > When the CONFIG_NO_MACH_MEMORY_H symbol is selected by a particular > machine class, the machine specific memory.h include file is no longer > used and can be removed. In that case the equivalent information can > be obtained dynamically at runtime by enabling CONFIG_ARM_PATCH_PHYS_VIRT > or by specifying the physical memory address at kernel configuration time. > > If/when all instances of mach/memory.h are removed then this symbol could > be removed. guess the main reason for this is that physical memory address should not be hard-coded in kernel. and it will cause issues while crossing platforms/boards. i noticed PLAT_PHYS_OFFSET is referred much early in head.S with CONFIG_XIP_KERNEL. #ifndef CONFIG_XIP_KERNEL adr r3, 2f ldmia r3, {r4, r8} sub r4, r3, r4 @ (PHYS_OFFSET - PAGE_OFFSET) add r8, r8, r4 @ PHYS_OFFSET #else ldr r8, =PLAT_PHYS_OFFSET #endif > > Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org> > --- > arch/arm/Kconfig | 15 ++++++++++++++- > arch/arm/include/asm/memory.h | 6 +++++- > 2 files changed, 19 insertions(+), 2 deletions(-) > > diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig > index 9adc278..9fc052c 100644 > --- a/arch/arm/Kconfig > +++ b/arch/arm/Kconfig > @@ -191,11 +191,17 @@ config VECTORS_BASE > help > The base address of exception vectors. > > +config NO_MACH_MEMORY_H > + bool > + help > + Select this when mach/memory.h is removed. > + > config ARM_PATCH_PHYS_VIRT > bool "Patch physical to virtual translations at runtime (EXPERIMENTAL)" > - depends on EXPERIMENTAL > + depends on EXPERIMENTAL || NO_MACH_MEMORY_H > depends on !XIP_KERNEL && MMU > depends on !ARCH_REALVIEW || !SPARSEMEM > + default y if NO_MACH_MEMORY_H > help > Patch phys-to-virt and virt-to-phys translation functions at > boot and module load time according to the position of the > @@ -213,6 +219,13 @@ config ARM_PATCH_PHYS_VIRT_16BIT > to allow physical memory down to a theoretical minimum of 64K > boundaries. > > +config PHYS_OFFSET > + hex "Physical address of main memory" > + depends on !ARM_PATCH_PHYS_VIRT && NO_MACH_MEMORY_H > + help > + Please provide the physical address corresponding to the > + location of main memory in your system. > + > source "init/Kconfig" > > source "kernel/Kconfig.freezer" > diff --git a/arch/arm/include/asm/memory.h b/arch/arm/include/asm/memory.h > index deb2eaa..2d21414 100644 > --- a/arch/arm/include/asm/memory.h > +++ b/arch/arm/include/asm/memory.h > @@ -16,7 +16,6 @@ > #include <linux/compiler.h> > #include <linux/const.h> > #include <linux/types.h> > -#include <mach/memory.h> > #include <asm/sizes.h> > > /* > @@ -200,8 +199,13 @@ static inline unsigned long __phys_to_virt(unsigned long x) > #endif > > #ifndef PHYS_OFFSET > +#ifdef CONFIG_NO_MACH_MEMORY_H > +#define PHYS_OFFSET UL(CONFIG_PHYS_OFFSET) > +#else > +#include <mach/memory.h> > #define PHYS_OFFSET PLAT_PHYS_OFFSET > #endif > +#endif > > /* > * The DMA mask corresponding to the maximum bus address allocatable > -- > 1.7.4 > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel >
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 9adc278..9fc052c 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -191,11 +191,17 @@ config VECTORS_BASE help The base address of exception vectors. +config NO_MACH_MEMORY_H + bool + help + Select this when mach/memory.h is removed. + config ARM_PATCH_PHYS_VIRT bool "Patch physical to virtual translations at runtime (EXPERIMENTAL)" - depends on EXPERIMENTAL + depends on EXPERIMENTAL || NO_MACH_MEMORY_H depends on !XIP_KERNEL && MMU depends on !ARCH_REALVIEW || !SPARSEMEM + default y if NO_MACH_MEMORY_H help Patch phys-to-virt and virt-to-phys translation functions at boot and module load time according to the position of the @@ -213,6 +219,13 @@ config ARM_PATCH_PHYS_VIRT_16BIT to allow physical memory down to a theoretical minimum of 64K boundaries. +config PHYS_OFFSET + hex "Physical address of main memory" + depends on !ARM_PATCH_PHYS_VIRT && NO_MACH_MEMORY_H + help + Please provide the physical address corresponding to the + location of main memory in your system. + source "init/Kconfig" source "kernel/Kconfig.freezer" diff --git a/arch/arm/include/asm/memory.h b/arch/arm/include/asm/memory.h index deb2eaa..2d21414 100644 --- a/arch/arm/include/asm/memory.h +++ b/arch/arm/include/asm/memory.h @@ -16,7 +16,6 @@ #include <linux/compiler.h> #include <linux/const.h> #include <linux/types.h> -#include <mach/memory.h> #include <asm/sizes.h> /* @@ -200,8 +199,13 @@ static inline unsigned long __phys_to_virt(unsigned long x) #endif #ifndef PHYS_OFFSET +#ifdef CONFIG_NO_MACH_MEMORY_H +#define PHYS_OFFSET UL(CONFIG_PHYS_OFFSET) +#else +#include <mach/memory.h> #define PHYS_OFFSET PLAT_PHYS_OFFSET #endif +#endif /* * The DMA mask corresponding to the maximum bus address allocatable
When the CONFIG_NO_MACH_MEMORY_H symbol is selected by a particular machine class, the machine specific memory.h include file is no longer used and can be removed. In that case the equivalent information can be obtained dynamically at runtime by enabling CONFIG_ARM_PATCH_PHYS_VIRT or by specifying the physical memory address at kernel configuration time. If/when all instances of mach/memory.h are removed then this symbol could be removed. Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org> --- arch/arm/Kconfig | 15 ++++++++++++++- arch/arm/include/asm/memory.h | 6 +++++- 2 files changed, 19 insertions(+), 2 deletions(-)