| Message ID | 20140226135352.GY21483@n2100.arm.linux.org.uk (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wednesday 26 February 2014 13:53:52 Russell King - ARM Linux wrote: > It's more to the point. The first hunk hides the "Memory split" option > which is irrelevent on !MMU. We already know that PAGE_OFFSET should > be the same as PHYS_OFFSET for noMMU, so let's make that explicit. > Note that it already is by way of the bit in the last hunk - which as > a result of this change can now be removed... especially so as we have > nothing defining PAGE_OFFSET in arch/arm/*/include... Looks good to me as well. I first wasn't sure about what this would do for platforms that define their own PLAT_PHYS_OFFSET, but we they are broken anyway if you set a DRAM_BASE that is not the same as PLAT_PHYS_OFFSET. Arnd
On Wed, Feb 26, 2014 at 01:53:52PM +0000, Russell King - ARM Linux wrote: > On Wed, Feb 26, 2014 at 02:46:05PM +0100, Uwe Kleine-König wrote: > > diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig > > --- a/arch/arm/Kconfig > > +++ b/arch/arm/Kconfig > > @@ -1595,6 +1595,7 @@ endchoice > > > > config PAGE_OFFSET > > hex > > + default DRAM_BASE if !MMU > > default 0x40000000 if VMSPLIT_1G > > default 0x80000000 if VMSPLIT_2G > > default 0xC0000000 > > I'd prefer this actually: > > diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig > index 24d65aae0491..09289d7b7f68 100644 > --- a/arch/arm/Kconfig > +++ b/arch/arm/Kconfig > @@ -1593,6 +1593,7 @@ config BL_SWITCHER_DUMMY_IF > > choice > prompt "Memory split" > + depends on MMU > default VMSPLIT_3G > help > Select the desired split between kernel and user memory. This hunk is already in my working copy, too :-) > @@ -1610,6 +1611,7 @@ endchoice > > config PAGE_OFFSET > hex > + default PHYS_OFFSET if !MMU > default 0x40000000 if VMSPLIT_1G > default 0x80000000 if VMSPLIT_2G > default 0xC0000000 > diff --git a/arch/arm/include/asm/memory.h b/arch/arm/include/asm/memory.h > index 8756e4bcdba0..5ccc4a627192 100644 > --- a/arch/arm/include/asm/memory.h > +++ b/arch/arm/include/asm/memory.h > @@ -104,10 +104,6 @@ > #define END_MEM (UL(CONFIG_DRAM_BASE) + CONFIG_DRAM_SIZE) > #endif > > -#ifndef PAGE_OFFSET > -#define PAGE_OFFSET PLAT_PHYS_OFFSET > -#endif > - > /* > * The module can be at any place in ram in nommu mode. > */ > > It's more to the point. The first hunk hides the "Memory split" option > which is irrelevent on !MMU. We already know that PAGE_OFFSET should > be the same as PHYS_OFFSET for noMMU, so let's make that explicit. > Note that it already is by way of the bit in the last hunk - which as > a result of this change can now be removed... especially so as we have > nothing defining PAGE_OFFSET in arch/arm/*/include... Looks reasonable. Maybe we can also get rid of PLAT_PHYS_OFFSET then. Best regards Uwe
On Wednesday 26 February 2014 15:06:32 Uwe Kleine-König wrote: > > It's more to the point. The first hunk hides the "Memory split" option > > which is irrelevent on !MMU. We already know that PAGE_OFFSET should > > be the same as PHYS_OFFSET for noMMU, so let's make that explicit. > > Note that it already is by way of the bit in the last hunk - which as > > a result of this change can now be removed... especially so as we have > > nothing defining PAGE_OFFSET in arch/arm/*/include... > > Looks reasonable. Maybe we can also get rid of PLAT_PHYS_OFFSET then. I think we still need PLAT_PHYS_OFFSET for the configurations that cannot use ARM_PATCH_PHYS_VIRT, which are: * Anything using XIP_KERNEL with MMU=y * mach-realview with the custom __phys_to_virt hack * ZBOOT_ROM Arnd
On Wednesday 26 February 2014 15:16:40 Arnd Bergmann wrote: > On Wednesday 26 February 2014 15:06:32 Uwe Kleine-König wrote: > > > It's more to the point. The first hunk hides the "Memory split" option > > > which is irrelevent on !MMU. We already know that PAGE_OFFSET should > > > be the same as PHYS_OFFSET for noMMU, so let's make that explicit. > > > Note that it already is by way of the bit in the last hunk - which as > > > a result of this change can now be removed... especially so as we have > > > nothing defining PAGE_OFFSET in arch/arm/*/include... > > > > Looks reasonable. Maybe we can also get rid of PLAT_PHYS_OFFSET then. > > I think we still need PLAT_PHYS_OFFSET for the configurations that cannot > use ARM_PATCH_PHYS_VIRT, which are: > > * Anything using XIP_KERNEL with MMU=y > * mach-realview with the custom __phys_to_virt hack > * ZBOOT_ROM Ah, nevermind. We need either PLAT_PHYS_OFFSET /or/ CONFIG_PHYS_OFFSET for these case, but we could in theory drop the former. Arnd
On Wed, Feb 26, 2014 at 03:06:32PM +0100, Uwe Kleine-König wrote:
> Looks reasonable. Maybe we can also get rid of PLAT_PHYS_OFFSET then.
I don't think so - try grep.
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 24d65aae0491..09289d7b7f68 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -1593,6 +1593,7 @@ config BL_SWITCHER_DUMMY_IF choice prompt "Memory split" + depends on MMU default VMSPLIT_3G help Select the desired split between kernel and user memory. @@ -1610,6 +1611,7 @@ endchoice config PAGE_OFFSET hex + default PHYS_OFFSET if !MMU default 0x40000000 if VMSPLIT_1G default 0x80000000 if VMSPLIT_2G default 0xC0000000 diff --git a/arch/arm/include/asm/memory.h b/arch/arm/include/asm/memory.h index 8756e4bcdba0..5ccc4a627192 100644 --- a/arch/arm/include/asm/memory.h +++ b/arch/arm/include/asm/memory.h @@ -104,10 +104,6 @@ #define END_MEM (UL(CONFIG_DRAM_BASE) + CONFIG_DRAM_SIZE) #endif -#ifndef PAGE_OFFSET -#define PAGE_OFFSET PLAT_PHYS_OFFSET -#endif - /* * The module can be at any place in ram in nommu mode. */