| Message ID | 1389325833-16535-5-git-send-email-msalter@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, Jan 09, 2014 at 10:50:31PM -0500, Mark Salter wrote: > +#define FIXMAP_PAGE_NORMAL (L_PTE_MT_WRITEBACK | L_PTE_YOUNG | L_PTE_PRESENT) > +#define FIXMAP_PAGE_IO (L_PTE_MT_DEV_NONSHARED | L_PTE_YOUNG | L_PTE_PRESENT) Doesn't this also want L_PTE_XN for at least IO mappings - maybe for the normal too if no code is expected to be run from it.
On Fri, 2014-01-10 at 11:34 +0000, Russell King - ARM Linux wrote: > On Thu, Jan 09, 2014 at 10:50:31PM -0500, Mark Salter wrote: > > +#define FIXMAP_PAGE_NORMAL (L_PTE_MT_WRITEBACK | L_PTE_YOUNG | L_PTE_PRESENT) > > +#define FIXMAP_PAGE_IO (L_PTE_MT_DEV_NONSHARED | L_PTE_YOUNG | L_PTE_PRESENT) > > Doesn't this also want L_PTE_XN for at least IO mappings - maybe for the > normal too if no code is expected to be run from it. Yes is both cases. I also need to fix arm64 mem mapping for same reason. Thanks!
On Thu, Jan 9, 2014 at 9:50 PM, Mark Salter <msalter@redhat.com> wrote: > This patch uses the generic early_ioremap code to implement > early_ioremap for ARM. The ARM-specific bits come mostly from > an earlier patch from Leif Lindholm <leif.lindholm@linaro.org> > here: > > https://lkml.org/lkml/2013/10/3/279 I think this will be useful to implement an arm64 style earlycon for arm as the current DEBUG_LL doesn't really work with multi-platform kernels. I started on this and quickly realized I needed the fixmap support. > Signed-off-by: Mark Salter <msalter@redhat.com> > Tested-by: Leif Lindholm <leif.lindholm@linaro.org> > Acked-by: Catalin Marinas <catalin.marinas@arm.com> > CC: linux-arm-kernel@lists.infradead.org > CC: Russell King <linux@arm.linux.org.uk> > CC: Catalin Marinas <catalin.marinas@arm.com> > CC: Will Deacon <will.deacon@arm.com> > CC: Arnd Bergmann <arnd@arndb.de> > --- > arch/arm/Kconfig | 11 +++++ > arch/arm/include/asm/Kbuild | 1 + > arch/arm/include/asm/fixmap.h | 18 +++++++++ > arch/arm/include/asm/io.h | 1 + > arch/arm/kernel/setup.c | 3 ++ > arch/arm/mm/Makefile | 1 + > arch/arm/mm/early_ioremap.c | 93 +++++++++++++++++++++++++++++++++++++++++++ > arch/arm/mm/mmu.c | 2 + > 8 files changed, 130 insertions(+) > create mode 100644 arch/arm/mm/early_ioremap.c > > diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig > index c1f1a7e..78a79a6a 100644 > --- a/arch/arm/Kconfig > +++ b/arch/arm/Kconfig > @@ -1842,6 +1842,17 @@ config UACCESS_WITH_MEMCPY > However, if the CPU data cache is using a write-allocate mode, > this option is unlikely to provide any performance gain. > > +config EARLY_IOREMAP > + depends on MMU Is it possible to implement a !MMU version of early_ioremap that simply returns the phys address rather than have this dependency? > + bool "Provide early_ioremap() support for kernel initialization." > + select GENERIC_EARLY_IOREMAP > + help > + Provide a mechanism for kernel initialisation code to temporarily > + map, in a highmem-agnostic way, memory pages in before ioremap() > + and friends are available (before paging_init() has run). It uses > + the same virtual memory range as kmap so all early mappings must > + be unapped before paging_init() is called. > + > config SECCOMP > bool > prompt "Enable seccomp to safely compute untrusted bytecode" > diff --git a/arch/arm/include/asm/Kbuild b/arch/arm/include/asm/Kbuild > index c38b58c..49ec506 100644 > --- a/arch/arm/include/asm/Kbuild > +++ b/arch/arm/include/asm/Kbuild > @@ -4,6 +4,7 @@ generic-y += auxvec.h > generic-y += bitsperlong.h > generic-y += cputime.h > generic-y += current.h > +generic-y += early_ioremap.h > generic-y += emergency-restart.h > generic-y += errno.h > generic-y += exec.h > diff --git a/arch/arm/include/asm/fixmap.h b/arch/arm/include/asm/fixmap.h > index 68ea615..e92b7a4 100644 > --- a/arch/arm/include/asm/fixmap.h > +++ b/arch/arm/include/asm/fixmap.h > @@ -21,8 +21,26 @@ enum fixed_addresses { > FIX_KMAP_BEGIN, > FIX_KMAP_END = (FIXADDR_TOP - FIXADDR_START) >> PAGE_SHIFT, > __end_of_fixed_addresses > +/* > + * 224 temporary boot-time mappings, used by early_ioremap(), > + * before ioremap() is functional. > + * > + * (P)re-using the FIXADDR region, which is used for highmem > + * later on, and statically aligned to 1MB. > + */ > +#define NR_FIX_BTMAPS 32 > +#define FIX_BTMAPS_SLOTS 7 > +#define TOTAL_FIX_BTMAPS (NR_FIX_BTMAPS * FIX_BTMAPS_SLOTS) > +#define FIX_BTMAP_END FIX_KMAP_BEGIN > +#define FIX_BTMAP_BEGIN (FIX_BTMAP_END + TOTAL_FIX_BTMAPS - 1) > }; > > +#define FIXMAP_PAGE_NORMAL (L_PTE_MT_WRITEBACK | L_PTE_YOUNG | L_PTE_PRESENT) > +#define FIXMAP_PAGE_IO (L_PTE_MT_DEV_NONSHARED | L_PTE_YOUNG | L_PTE_PRESENT) > + > +extern void __early_set_fixmap(enum fixed_addresses idx, > + phys_addr_t phys, pgprot_t flags); > + > #include <asm-generic/fixmap.h> > > #endif > diff --git a/arch/arm/include/asm/io.h b/arch/arm/include/asm/io.h > index fbeb39c..6b2cc53 100644 > --- a/arch/arm/include/asm/io.h > +++ b/arch/arm/include/asm/io.h > @@ -28,6 +28,7 @@ > #include <asm/byteorder.h> > #include <asm/memory.h> > #include <asm-generic/pci_iomap.h> > +#include <asm/early_ioremap.h> > #include <xen/xen.h> > > /* > diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c > index 987a7f5..038fb75 100644 > --- a/arch/arm/kernel/setup.c > +++ b/arch/arm/kernel/setup.c > @@ -36,6 +36,7 @@ > #include <asm/cpu.h> > #include <asm/cputype.h> > #include <asm/elf.h> > +#include <asm/io.h> Use linux/io.h? > #include <asm/procinfo.h> > #include <asm/psci.h> > #include <asm/sections.h> > @@ -887,6 +888,8 @@ void __init setup_arch(char **cmdline_p) > > parse_early_param(); > > + early_ioremap_init(); > + This call would need to be before parse_early_param for the earlycon to work. Rob
On Fri, Jan 10, 2014 at 04:11:03PM +0000, Rob Herring wrote: > On Thu, Jan 9, 2014 at 9:50 PM, Mark Salter <msalter@redhat.com> wrote: > > This patch uses the generic early_ioremap code to implement > > early_ioremap for ARM. The ARM-specific bits come mostly from > > an earlier patch from Leif Lindholm <leif.lindholm@linaro.org> > > here: > > > > https://lkml.org/lkml/2013/10/3/279 > > I think this will be useful to implement an arm64 style earlycon for > arm as the current DEBUG_LL doesn't really work with multi-platform > kernels. I started on this and quickly realized I needed the fixmap > support. It would be even better if you can make it more generic (drivers/tty/serial/) and keep DEBUG_LL as a specialised case for arch/arm (when !multi-platform).
On Fri, Jan 10, 2014 at 10:58 AM, Catalin Marinas <catalin.marinas@arm.com> wrote: > On Fri, Jan 10, 2014 at 04:11:03PM +0000, Rob Herring wrote: >> On Thu, Jan 9, 2014 at 9:50 PM, Mark Salter <msalter@redhat.com> wrote: >> > This patch uses the generic early_ioremap code to implement >> > early_ioremap for ARM. The ARM-specific bits come mostly from >> > an earlier patch from Leif Lindholm <leif.lindholm@linaro.org> >> > here: >> > >> > https://lkml.org/lkml/2013/10/3/279 >> >> I think this will be useful to implement an arm64 style earlycon for >> arm as the current DEBUG_LL doesn't really work with multi-platform >> kernels. I started on this and quickly realized I needed the fixmap >> support. > > It would be even better if you can make it more generic > (drivers/tty/serial/) and keep DEBUG_LL as a specialised case for > arch/arm (when !multi-platform). Y
On Fri, Jan 10, 2014 at 10:58 AM, Catalin Marinas <catalin.marinas@arm.com> wrote: > On Fri, Jan 10, 2014 at 04:11:03PM +0000, Rob Herring wrote: >> On Thu, Jan 9, 2014 at 9:50 PM, Mark Salter <msalter@redhat.com> wrote: >> > This patch uses the generic early_ioremap code to implement >> > early_ioremap for ARM. The ARM-specific bits come mostly from >> > an earlier patch from Leif Lindholm <leif.lindholm@linaro.org> >> > here: >> > >> > https://lkml.org/lkml/2013/10/3/279 >> >> I think this will be useful to implement an arm64 style earlycon for >> arm as the current DEBUG_LL doesn't really work with multi-platform >> kernels. I started on this and quickly realized I needed the fixmap >> support. > > It would be even better if you can make it more generic > (drivers/tty/serial/) and keep DEBUG_LL as a specialised case for > arch/arm (when !multi-platform). Yes, probably can do that. Perhaps DEBUG_LL can go back to just really early debug as Russell desires. Rob
Just some minor nitpicks On 01/09/14 19:50, Mark Salter wrote: > diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig > index c1f1a7e..78a79a6a 100644 > --- a/arch/arm/Kconfig > +++ b/arch/arm/Kconfig > @@ -1842,6 +1842,17 @@ config UACCESS_WITH_MEMCPY > However, if the CPU data cache is using a write-allocate mode, > this option is unlikely to provide any performance gain. > > +config EARLY_IOREMAP > + depends on MMU > + bool "Provide early_ioremap() support for kernel initialization." Please drop the full stop. > + select GENERIC_EARLY_IOREMAP > + help > + Provide a mechanism for kernel initialisation code to temporarily > + map, in a highmem-agnostic way, memory pages in before ioremap() > + and friends are available (before paging_init() has run). It uses > + the same virtual memory range as kmap so all early mappings must > + be unapped before paging_init() is called. s/unapped/unmapped/
On Fri, 2014-01-10 at 10:11 -0600, Rob Herring wrote: > On Thu, Jan 9, 2014 at 9:50 PM, Mark Salter <msalter@redhat.com> wrote: > > +config EARLY_IOREMAP > > + depends on MMU > > Is it possible to implement a !MMU version of early_ioremap that > simply returns the phys address rather than have this dependency? I don't think that would be too hard to do. > > > + bool "Provide early_ioremap() support for kernel initialization." > > + select GENERIC_EARLY_IOREMAP > > + help > > + Provide a mechanism for kernel initialisation code to temporarily > > + map, in a highmem-agnostic way, memory pages in before ioremap() > > + and friends are available (before paging_init() has run). It uses > > + the same virtual memory range as kmap so all early mappings must > > + be unapped before paging_init() is called. > > + > > config SECCOMP > > bool > > prompt "Enable seccomp to safely compute untrusted bytecode" > > diff --git a/arch/arm/include/asm/Kbuild b/arch/arm/include/asm/Kbuild > > index c38b58c..49ec506 100644 > > --- a/arch/arm/include/asm/Kbuild > > +++ b/arch/arm/include/asm/Kbuild > > @@ -4,6 +4,7 @@ generic-y += auxvec.h > > generic-y += bitsperlong.h > > generic-y += cputime.h > > generic-y += current.h > > +generic-y += early_ioremap.h > > generic-y += emergency-restart.h > > generic-y += errno.h > > generic-y += exec.h > > diff --git a/arch/arm/include/asm/fixmap.h b/arch/arm/include/asm/fixmap.h > > index 68ea615..e92b7a4 100644 > > --- a/arch/arm/include/asm/fixmap.h > > +++ b/arch/arm/include/asm/fixmap.h > > @@ -21,8 +21,26 @@ enum fixed_addresses { > > FIX_KMAP_BEGIN, > > FIX_KMAP_END = (FIXADDR_TOP - FIXADDR_START) >> PAGE_SHIFT, > > __end_of_fixed_addresses > > +/* > > + * 224 temporary boot-time mappings, used by early_ioremap(), > > + * before ioremap() is functional. > > + * > > + * (P)re-using the FIXADDR region, which is used for highmem > > + * later on, and statically aligned to 1MB. > > + */ > > +#define NR_FIX_BTMAPS 32 > > +#define FIX_BTMAPS_SLOTS 7 > > +#define TOTAL_FIX_BTMAPS (NR_FIX_BTMAPS * FIX_BTMAPS_SLOTS) > > +#define FIX_BTMAP_END FIX_KMAP_BEGIN > > +#define FIX_BTMAP_BEGIN (FIX_BTMAP_END + TOTAL_FIX_BTMAPS - 1) > > }; > > > > +#define FIXMAP_PAGE_NORMAL (L_PTE_MT_WRITEBACK | L_PTE_YOUNG | L_PTE_PRESENT) > > +#define FIXMAP_PAGE_IO (L_PTE_MT_DEV_NONSHARED | L_PTE_YOUNG | L_PTE_PRESENT) > > + > > +extern void __early_set_fixmap(enum fixed_addresses idx, > > + phys_addr_t phys, pgprot_t flags); > > + > > #include <asm-generic/fixmap.h> > > > > #endif > > diff --git a/arch/arm/include/asm/io.h b/arch/arm/include/asm/io.h > > index fbeb39c..6b2cc53 100644 > > --- a/arch/arm/include/asm/io.h > > +++ b/arch/arm/include/asm/io.h > > @@ -28,6 +28,7 @@ > > #include <asm/byteorder.h> > > #include <asm/memory.h> > > #include <asm-generic/pci_iomap.h> > > +#include <asm/early_ioremap.h> > > #include <xen/xen.h> > > > > /* > > diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c > > index 987a7f5..038fb75 100644 > > --- a/arch/arm/kernel/setup.c > > +++ b/arch/arm/kernel/setup.c > > @@ -36,6 +36,7 @@ > > #include <asm/cpu.h> > > #include <asm/cputype.h> > > #include <asm/elf.h> > > +#include <asm/io.h> > > Use linux/io.h? Yes. > > > #include <asm/procinfo.h> > > #include <asm/psci.h> > > #include <asm/sections.h> > > @@ -887,6 +888,8 @@ void __init setup_arch(char **cmdline_p) > > > > parse_early_param(); > > > > + early_ioremap_init(); > > + > > This call would need to be before parse_early_param for the earlycon to work. Yes, like arm64 does it.
On Fri, 2014-01-10 at 12:40 -0800, Stephen Boyd wrote: > Just some minor nitpicks > > On 01/09/14 19:50, Mark Salter wrote: > > diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig > > index c1f1a7e..78a79a6a 100644 > > --- a/arch/arm/Kconfig > > +++ b/arch/arm/Kconfig > > @@ -1842,6 +1842,17 @@ config UACCESS_WITH_MEMCPY > > However, if the CPU data cache is using a write-allocate mode, > > this option is unlikely to provide any performance gain. > > > > +config EARLY_IOREMAP > > + depends on MMU > > + bool "Provide early_ioremap() support for kernel initialization." > > Please drop the full stop. > > > + select GENERIC_EARLY_IOREMAP > > + help > > + Provide a mechanism for kernel initialisation code to temporarily > > + map, in a highmem-agnostic way, memory pages in before ioremap() > > + and friends are available (before paging_init() has run). It uses > > + the same virtual memory range as kmap so all early mappings must > > + be unapped before paging_init() is called. > > s/unapped/unmapped/ > Will do. Thanks!
On 1/9/2014 7:50 PM, Mark Salter wrote: .... > diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c > index 987a7f5..038fb75 100644 > --- a/arch/arm/kernel/setup.c > +++ b/arch/arm/kernel/setup.c > @@ -36,6 +36,7 @@ > #include <asm/cpu.h> > #include <asm/cputype.h> > #include <asm/elf.h> > +#include <asm/io.h> > #include <asm/procinfo.h> > #include <asm/psci.h> > #include <asm/sections.h> > @@ -887,6 +888,8 @@ void __init setup_arch(char **cmdline_p) > > parse_early_param(); > > + early_ioremap_init(); > + > sort(&meminfo.bank, meminfo.nr_banks, sizeof(meminfo.bank[0]), meminfo_cmp, NULL); > > early_paging_init(mdesc, lookup_processor_type(read_cpuid_id())); Any chance we could do this even earlier, say right after setup_processor? It would be nice to be able to do this while FDT scanning (I have a use case in mind, potential patches are in the works) <snip> > diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c > index 580ef2d..bef59b9 100644 > --- a/arch/arm/mm/mmu.c > +++ b/arch/arm/mm/mmu.c > @@ -34,6 +34,7 @@ > #include <asm/mach/arch.h> > #include <asm/mach/map.h> > #include <asm/mach/pci.h> > +#include <asm/early_ioremap.h> > > #include "mm.h" > #include "tcm.h" > @@ -1405,6 +1406,7 @@ void __init paging_init(const struct machine_desc *mdesc) > { > void *zero_page; > > + early_ioremap_reset(); > build_mem_type_table(); > prepare_page_table(); > map_lowmem(); > Neither x86 nor arm64 get rid of existing mapping in paging_init. Is there a reason this needs to be here for arm? Are there concerns about alias mappings? Thanks, Laura
On Wed, Jan 15, 2014 at 04:32:03PM -0800, Laura Abbott wrote: > Neither x86 nor arm64 get rid of existing mapping in paging_init. Is > there a reason this needs to be here for arm? Are there concerns about > alias mappings? The early mappings we setup in the assembly code are imperfect - they're an approximation. We map just about enough memory to get the kernel going, and we setup a mapping for the debug stuff using a section mapping, which may not be appropriate. The permissions too are a just chosen to get things going, and the subsequent replacement of the page table entries is to fix all that up. We really don't want any old entries left behind.
On Wed, 2014-01-15 at 16:32 -0800, Laura Abbott wrote: > On 1/9/2014 7:50 PM, Mark Salter wrote: > .... > > diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c > > index 987a7f5..038fb75 100644 > > --- a/arch/arm/kernel/setup.c > > +++ b/arch/arm/kernel/setup.c > > @@ -36,6 +36,7 @@ > > #include <asm/cpu.h> > > #include <asm/cputype.h> > > #include <asm/elf.h> > > +#include <asm/io.h> > > #include <asm/procinfo.h> > > #include <asm/psci.h> > > #include <asm/sections.h> > > @@ -887,6 +888,8 @@ void __init setup_arch(char **cmdline_p) > > > > parse_early_param(); > > > > + early_ioremap_init(); > > + > > sort(&meminfo.bank, meminfo.nr_banks, sizeof(meminfo.bank[0]), meminfo_cmp, NULL); > > > > early_paging_init(mdesc, lookup_processor_type(read_cpuid_id())); > > Any chance we could do this even earlier, say right after > setup_processor? It would be nice to be able to do this while FDT > scanning (I have a use case in mind, potential patches are in the works) It looks like that would work...
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index c1f1a7e..78a79a6a 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -1842,6 +1842,17 @@ config UACCESS_WITH_MEMCPY However, if the CPU data cache is using a write-allocate mode, this option is unlikely to provide any performance gain. +config EARLY_IOREMAP + depends on MMU + bool "Provide early_ioremap() support for kernel initialization." + select GENERIC_EARLY_IOREMAP + help + Provide a mechanism for kernel initialisation code to temporarily + map, in a highmem-agnostic way, memory pages in before ioremap() + and friends are available (before paging_init() has run). It uses + the same virtual memory range as kmap so all early mappings must + be unapped before paging_init() is called. + config SECCOMP bool prompt "Enable seccomp to safely compute untrusted bytecode" diff --git a/arch/arm/include/asm/Kbuild b/arch/arm/include/asm/Kbuild index c38b58c..49ec506 100644 --- a/arch/arm/include/asm/Kbuild +++ b/arch/arm/include/asm/Kbuild @@ -4,6 +4,7 @@ generic-y += auxvec.h generic-y += bitsperlong.h generic-y += cputime.h generic-y += current.h +generic-y += early_ioremap.h generic-y += emergency-restart.h generic-y += errno.h generic-y += exec.h diff --git a/arch/arm/include/asm/fixmap.h b/arch/arm/include/asm/fixmap.h index 68ea615..e92b7a4 100644 --- a/arch/arm/include/asm/fixmap.h +++ b/arch/arm/include/asm/fixmap.h @@ -21,8 +21,26 @@ enum fixed_addresses { FIX_KMAP_BEGIN, FIX_KMAP_END = (FIXADDR_TOP - FIXADDR_START) >> PAGE_SHIFT, __end_of_fixed_addresses +/* + * 224 temporary boot-time mappings, used by early_ioremap(), + * before ioremap() is functional. + * + * (P)re-using the FIXADDR region, which is used for highmem + * later on, and statically aligned to 1MB. + */ +#define NR_FIX_BTMAPS 32 +#define FIX_BTMAPS_SLOTS 7 +#define TOTAL_FIX_BTMAPS (NR_FIX_BTMAPS * FIX_BTMAPS_SLOTS) +#define FIX_BTMAP_END FIX_KMAP_BEGIN +#define FIX_BTMAP_BEGIN (FIX_BTMAP_END + TOTAL_FIX_BTMAPS - 1) }; +#define FIXMAP_PAGE_NORMAL (L_PTE_MT_WRITEBACK | L_PTE_YOUNG | L_PTE_PRESENT) +#define FIXMAP_PAGE_IO (L_PTE_MT_DEV_NONSHARED | L_PTE_YOUNG | L_PTE_PRESENT) + +extern void __early_set_fixmap(enum fixed_addresses idx, + phys_addr_t phys, pgprot_t flags); + #include <asm-generic/fixmap.h> #endif diff --git a/arch/arm/include/asm/io.h b/arch/arm/include/asm/io.h index fbeb39c..6b2cc53 100644 --- a/arch/arm/include/asm/io.h +++ b/arch/arm/include/asm/io.h @@ -28,6 +28,7 @@ #include <asm/byteorder.h> #include <asm/memory.h> #include <asm-generic/pci_iomap.h> +#include <asm/early_ioremap.h> #include <xen/xen.h> /* diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c index 987a7f5..038fb75 100644 --- a/arch/arm/kernel/setup.c +++ b/arch/arm/kernel/setup.c @@ -36,6 +36,7 @@ #include <asm/cpu.h> #include <asm/cputype.h> #include <asm/elf.h> +#include <asm/io.h> #include <asm/procinfo.h> #include <asm/psci.h> #include <asm/sections.h> @@ -887,6 +888,8 @@ void __init setup_arch(char **cmdline_p) parse_early_param(); + early_ioremap_init(); + sort(&meminfo.bank, meminfo.nr_banks, sizeof(meminfo.bank[0]), meminfo_cmp, NULL); early_paging_init(mdesc, lookup_processor_type(read_cpuid_id())); diff --git a/arch/arm/mm/Makefile b/arch/arm/mm/Makefile index ecfe6e5..fea855e 100644 --- a/arch/arm/mm/Makefile +++ b/arch/arm/mm/Makefile @@ -15,6 +15,7 @@ endif obj-$(CONFIG_MODULES) += proc-syms.o obj-$(CONFIG_ALIGNMENT_TRAP) += alignment.o +obj-$(CONFIG_EARLY_IOREMAP) += early_ioremap.o obj-$(CONFIG_HIGHMEM) += highmem.o obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o diff --git a/arch/arm/mm/early_ioremap.c b/arch/arm/mm/early_ioremap.c new file mode 100644 index 0000000..c3e2bf2 --- /dev/null +++ b/arch/arm/mm/early_ioremap.c @@ -0,0 +1,93 @@ +/* + * early_ioremap() support for ARM + * + * Based on existing support in arch/x86/mm/ioremap.c + * + * Restrictions: currently only functional before paging_init() + */ + +#include <linux/init.h> +#include <linux/io.h> + +#include <asm/fixmap.h> +#include <asm/pgalloc.h> +#include <asm/pgtable.h> +#include <asm/tlbflush.h> + +#include <asm/mach/map.h> + +static pte_t bm_pte[PTRS_PER_PTE] __aligned(PTE_HWTABLE_SIZE) __initdata; + +static inline pmd_t * __init early_ioremap_pmd(unsigned long addr) +{ + unsigned int index = pgd_index(addr); + pgd_t *pgd = cpu_get_pgd() + index; + pud_t *pud = pud_offset(pgd, addr); + pmd_t *pmd = pmd_offset(pud, addr); + + return pmd; +} + +static inline pte_t * __init early_ioremap_pte(unsigned long addr) +{ + return &bm_pte[pte_index(addr)]; +} + +void __init early_ioremap_init(void) +{ + pmd_t *pmd; + + pmd = early_ioremap_pmd(fix_to_virt(FIX_BTMAP_BEGIN)); + + pmd_populate_kernel(NULL, pmd, bm_pte); + + /* + * Make sure we don't span multiple pmds. + */ + BUILD_BUG_ON((__fix_to_virt(FIX_BTMAP_BEGIN) >> PMD_SHIFT) + != (__fix_to_virt(FIX_BTMAP_END) >> PMD_SHIFT)); + + if (pmd != early_ioremap_pmd(fix_to_virt(FIX_BTMAP_END))) { + WARN_ON(1); + pr_warn("pmd %p != %p\n", + pmd, early_ioremap_pmd(fix_to_virt(FIX_BTMAP_END))); + pr_warn("fix_to_virt(FIX_BTMAP_BEGIN): %08lx\n", + fix_to_virt(FIX_BTMAP_BEGIN)); + pr_warn("fix_to_virt(FIX_BTMAP_END): %08lx\n", + fix_to_virt(FIX_BTMAP_END)); + pr_warn("FIX_BTMAP_END: %d\n", FIX_BTMAP_END); + pr_warn("FIX_BTMAP_BEGIN: %d\n", FIX_BTMAP_BEGIN); + } + + early_ioremap_setup(); +} + +void __init __early_set_fixmap(enum fixed_addresses idx, + phys_addr_t phys, pgprot_t flags) +{ + unsigned long addr = __fix_to_virt(idx); + pte_t *pte; + u64 desc; + + if (idx > FIX_KMAP_END) { + BUG(); + return; + } + pte = early_ioremap_pte(addr); + + if (pgprot_val(flags)) + set_pte_at(NULL, 0xfff00000, pte, + pfn_pte(phys >> PAGE_SHIFT, flags)); + else + pte_clear(NULL, addr, pte); + flush_tlb_kernel_range(addr, addr + PAGE_SIZE); + desc = *pte; +} + +void __init +early_ioremap_shutdown(void) +{ + pmd_t *pmd; + pmd = early_ioremap_pmd(fix_to_virt(FIX_BTMAP_BEGIN)); + pmd_clear(pmd); +} diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c index 580ef2d..bef59b9 100644 --- a/arch/arm/mm/mmu.c +++ b/arch/arm/mm/mmu.c @@ -34,6 +34,7 @@ #include <asm/mach/arch.h> #include <asm/mach/map.h> #include <asm/mach/pci.h> +#include <asm/early_ioremap.h> #include "mm.h" #include "tcm.h" @@ -1405,6 +1406,7 @@ void __init paging_init(const struct machine_desc *mdesc) { void *zero_page; + early_ioremap_reset(); build_mem_type_table(); prepare_page_table(); map_lowmem();