Re: [PATCH -mm 0/3] i386 boot: replace boot_ioremap with enhanced bt_ioremap
Ingo Molnar wrote: * H. Peter Anvin <[EMAIL PROTECTED]> wrote: I did a quick scan over the patchset (not quite awake yet, so I may very well have missed something), but it looks like EFI (again!) is the only user of ioremapping before paging_init(). This makes me wonder if that code can't be restructured so that isn't necessary. i think that in general making access to unmapped memory a bit easier is generally a good robustness idea as ACPI could be impacted by it as well. Fundamentally, paging_init() has obvious dependency on "figuring out the memory setup" of the box, and "figuring out the memory setup" means interpreting various data structures passed in by the BIOS - some of which might be in not yet mapped areas or iommu areas (if we have to do some early quirk). So having a robust implementation of ioremap_early() sounds like a definitive plus. Fair enough. If it's generally useful, I certainly have no objections. -hpa -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH -mm 0/3] i386 boot: replace boot_ioremap with enhanced bt_ioremap
* H. Peter Anvin <[EMAIL PROTECTED]> wrote: > I did a quick scan over the patchset (not quite awake yet, so I may > very well have missed something), but it looks like EFI (again!) is > the only user of ioremapping before paging_init(). This makes me > wonder if that code can't be restructured so that isn't necessary. i think that in general making access to unmapped memory a bit easier is generally a good robustness idea as ACPI could be impacted by it as well. Fundamentally, paging_init() has obvious dependency on "figuring out the memory setup" of the box, and "figuring out the memory setup" means interpreting various data structures passed in by the BIOS - some of which might be in not yet mapped areas or iommu areas (if we have to do some early quirk). So having a robust implementation of ioremap_early() sounds like a definitive plus. Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH -mm 0/3] i386 boot: replace boot_ioremap with enhanced bt_ioremap
* Huang, Ying <[EMAIL PROTECTED]> wrote: > > in latest x86.git#mm there's an early_ioremap() introduced as part > > of the PAT series - available on both 32-bit and 64-bit. Could you > > take a look at it and use that if it's OK for your purposes? > > After checking the early_ioremap() implementation in > arch/x86/kernel/setup_32.c, I found that it is a duplication of > bt_ioremap() implementation in arch/x86/mm/ioremap_32.c. Both > implementations use set_fixmap(), so they can be used only after > paging_init(). > > The early_ioremap implementation provided in this patchset works as > follow: > > - Enhances bt_ioremap, make it usable before paging_init() via a > dedicated PTE page. > - Rename bt_ioremap to early_ioremap > > So I think maybe we should replace the early_ioremap() implementation > in PAT series with that of this series. yep, agreed, that would be nice. Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH -mm 0/3] i386 boot: replace boot_ioremap with enhanced bt_ioremap
Huang, Ying wrote: After checking the early_ioremap() implementation in arch/x86/kernel/setup_32.c, I found that it is a duplication of bt_ioremap() implementation in arch/x86/mm/ioremap_32.c. Both implementations use set_fixmap(), so they can be used only after paging_init(). The early_ioremap implementation provided in this patchset works as follow: - Enhances bt_ioremap, make it usable before paging_init() via a dedicated PTE page. - Rename bt_ioremap to early_ioremap So I think maybe we should replace the early_ioremap() implementation in PAT series with that of this series. I did a quick scan over the patchset (not quite awake yet, so I may very well have missed something), but it looks like EFI (again!) is the only user of ioremapping before paging_init(). This makes me wonder if that code can't be restructured so that isn't necessary. -hpa -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH -mm 0/3] i386 boot: replace boot_ioremap with enhanced bt_ioremap
On Tue, 2008-01-15 at 09:44 +0100, Ingo Molnar wrote: > * Huang, Ying <[EMAIL PROTECTED]> wrote: > > > This patchset replaces boot_ioremap with a enhanced version of > > bt_ioremap and renames the bt_ioremap to early_ioremap. This reduces > > 12k from .init.data segment and increases the size of memory that can > > be re-mapped before paging_init to 64k. > > in latest x86.git#mm there's an early_ioremap() introduced as part of > the PAT series - available on both 32-bit and 64-bit. Could you take a > look at it and use that if it's OK for your purposes? After checking the early_ioremap() implementation in arch/x86/kernel/setup_32.c, I found that it is a duplication of bt_ioremap() implementation in arch/x86/mm/ioremap_32.c. Both implementations use set_fixmap(), so they can be used only after paging_init(). The early_ioremap implementation provided in this patchset works as follow: - Enhances bt_ioremap, make it usable before paging_init() via a dedicated PTE page. - Rename bt_ioremap to early_ioremap So I think maybe we should replace the early_ioremap() implementation in PAT series with that of this series. Best Regards, Huang Ying -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH -mm 0/3] i386 boot: replace boot_ioremap with enhanced bt_ioremap
* Huang, Ying <[EMAIL PROTECTED]> wrote: > This patchset replaces boot_ioremap with a enhanced version of > bt_ioremap and renames the bt_ioremap to early_ioremap. This reduces > 12k from .init.data segment and increases the size of memory that can > be re-mapped before paging_init to 64k. in latest x86.git#mm there's an early_ioremap() introduced as part of the PAT series - available on both 32-bit and 64-bit. Could you take a look at it and use that if it's OK for your purposes? Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH -mm 0/3] i386 boot: replace boot_ioremap with enhanced bt_ioremap
* Huang, Ying [EMAIL PROTECTED] wrote: This patchset replaces boot_ioremap with a enhanced version of bt_ioremap and renames the bt_ioremap to early_ioremap. This reduces 12k from .init.data segment and increases the size of memory that can be re-mapped before paging_init to 64k. in latest x86.git#mm there's an early_ioremap() introduced as part of the PAT series - available on both 32-bit and 64-bit. Could you take a look at it and use that if it's OK for your purposes? Ingo -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH -mm 0/3] i386 boot: replace boot_ioremap with enhanced bt_ioremap
On Tue, 2008-01-15 at 09:44 +0100, Ingo Molnar wrote: * Huang, Ying [EMAIL PROTECTED] wrote: This patchset replaces boot_ioremap with a enhanced version of bt_ioremap and renames the bt_ioremap to early_ioremap. This reduces 12k from .init.data segment and increases the size of memory that can be re-mapped before paging_init to 64k. in latest x86.git#mm there's an early_ioremap() introduced as part of the PAT series - available on both 32-bit and 64-bit. Could you take a look at it and use that if it's OK for your purposes? After checking the early_ioremap() implementation in arch/x86/kernel/setup_32.c, I found that it is a duplication of bt_ioremap() implementation in arch/x86/mm/ioremap_32.c. Both implementations use set_fixmap(), so they can be used only after paging_init(). The early_ioremap implementation provided in this patchset works as follow: - Enhances bt_ioremap, make it usable before paging_init() via a dedicated PTE page. - Rename bt_ioremap to early_ioremap So I think maybe we should replace the early_ioremap() implementation in PAT series with that of this series. Best Regards, Huang Ying -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH -mm 0/3] i386 boot: replace boot_ioremap with enhanced bt_ioremap
Huang, Ying wrote: After checking the early_ioremap() implementation in arch/x86/kernel/setup_32.c, I found that it is a duplication of bt_ioremap() implementation in arch/x86/mm/ioremap_32.c. Both implementations use set_fixmap(), so they can be used only after paging_init(). The early_ioremap implementation provided in this patchset works as follow: - Enhances bt_ioremap, make it usable before paging_init() via a dedicated PTE page. - Rename bt_ioremap to early_ioremap So I think maybe we should replace the early_ioremap() implementation in PAT series with that of this series. I did a quick scan over the patchset (not quite awake yet, so I may very well have missed something), but it looks like EFI (again!) is the only user of ioremapping before paging_init(). This makes me wonder if that code can't be restructured so that isn't necessary. -hpa -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH -mm 0/3] i386 boot: replace boot_ioremap with enhanced bt_ioremap
* H. Peter Anvin [EMAIL PROTECTED] wrote: I did a quick scan over the patchset (not quite awake yet, so I may very well have missed something), but it looks like EFI (again!) is the only user of ioremapping before paging_init(). This makes me wonder if that code can't be restructured so that isn't necessary. i think that in general making access to unmapped memory a bit easier is generally a good robustness idea as ACPI could be impacted by it as well. Fundamentally, paging_init() has obvious dependency on figuring out the memory setup of the box, and figuring out the memory setup means interpreting various data structures passed in by the BIOS - some of which might be in not yet mapped areas or iommu areas (if we have to do some early quirk). So having a robust implementation of ioremap_early() sounds like a definitive plus. Ingo -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH -mm 0/3] i386 boot: replace boot_ioremap with enhanced bt_ioremap
Ingo Molnar wrote: * H. Peter Anvin [EMAIL PROTECTED] wrote: I did a quick scan over the patchset (not quite awake yet, so I may very well have missed something), but it looks like EFI (again!) is the only user of ioremapping before paging_init(). This makes me wonder if that code can't be restructured so that isn't necessary. i think that in general making access to unmapped memory a bit easier is generally a good robustness idea as ACPI could be impacted by it as well. Fundamentally, paging_init() has obvious dependency on figuring out the memory setup of the box, and figuring out the memory setup means interpreting various data structures passed in by the BIOS - some of which might be in not yet mapped areas or iommu areas (if we have to do some early quirk). So having a robust implementation of ioremap_early() sounds like a definitive plus. Fair enough. If it's generally useful, I certainly have no objections. -hpa -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH -mm 0/3] i386 boot: replace boot_ioremap with enhanced bt_ioremap
* Huang, Ying [EMAIL PROTECTED] wrote: in latest x86.git#mm there's an early_ioremap() introduced as part of the PAT series - available on both 32-bit and 64-bit. Could you take a look at it and use that if it's OK for your purposes? After checking the early_ioremap() implementation in arch/x86/kernel/setup_32.c, I found that it is a duplication of bt_ioremap() implementation in arch/x86/mm/ioremap_32.c. Both implementations use set_fixmap(), so they can be used only after paging_init(). The early_ioremap implementation provided in this patchset works as follow: - Enhances bt_ioremap, make it usable before paging_init() via a dedicated PTE page. - Rename bt_ioremap to early_ioremap So I think maybe we should replace the early_ioremap() implementation in PAT series with that of this series. yep, agreed, that would be nice. Ingo -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[PATCH -mm 0/3] i386 boot: replace boot_ioremap with enhanced bt_ioremap
This patchset replaces boot_ioremap with a enhanced version of bt_ioremap and renames the bt_ioremap to early_ioremap. This reduces 12k from .init.data segment and increases the size of memory that can be re-mapped before paging_init to 64k. This patchset is based on linux-2.6.24-rc5-mm1 + efi-split-efi-tables-parsing-code-from-efi-runtime-service-support-code.patch. It has been tested on i386 with PAE on/off. Best Regards, Huang Ying -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[PATCH -mm 0/3] i386 boot: replace boot_ioremap with enhanced bt_ioremap
This patchset replaces boot_ioremap with a enhanced version of bt_ioremap and renames the bt_ioremap to early_ioremap. This reduces 12k from .init.data segment and increases the size of memory that can be re-mapped before paging_init to 64k. This patchset is based on linux-2.6.24-rc5-mm1 + efi-split-efi-tables-parsing-code-from-efi-runtime-service-support-code.patch. It has been tested on i386 with PAE on/off. Best Regards, Huang Ying -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
