__ioremap() took a set of page table flags (specifically the cacheable
and bufferable bits) to control the mapping type. However, with
the advent of ARMv6, this is far too limited.
Replace the page table flags with a memory type index, so that the
desired attributes can be selected from the mem_type table.
Finally, to prevent silent miscompilation due to the differing
arguments, rename the __ioremap() and __ioremap_pfn() functions.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Add prot_pte_ext to the mem_types table to allow the extended pte
attributes to be passed to set_pte_ext(), thereby permitting us to
specify memory type information for the hardware PTE entries.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
We really want to be using the memory type table in ioremap, so we
only have to do the CPU type fixups in one place.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Catalin Marinas at ARM Ltd says:
> The CPU architects in ARM intended supersections only as a way to map
> addresses >= 4GB. Supersections are not mandated by the architecture
> and there is no easy way to detect their hardware support at run-time
> (other than checking for a specific core). From the analysis done in
> ARM, there wasn't a clear performance gain by using supersections
> rather than sections (no significant improvement in the TLB misses).
Therefore, we should avoid using supersections unless there's a real
need (iow, we're mapping addresses >= 4GB).
This means that we can simplify create_mapping() a bit since we will
only use supersection mappings for addresses >= 4GB, which means that
the physical, virtual and length must be multiples of the supersection
mapping size.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Supersections do not have a field for the domain and it is always
0. This patch prevents the creation of supersections during ioremap
when DOMAIN_IO is not zero (i.e. !defined(CONFIG_IO_36)).
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
We need to ensure that the area size is page aligned so that
remap_area_pte() doesn't increment the address past the end of
the desired area.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Since we're keeping the ioremap code, we might as well keep it as
close to the standard kernel as possible.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
L_PTE_ASID is not really required to be stored in every PTE, since we
can identify it via the address passed to set_pte_at(). So, create
set_pte_ext() which takes the address of the PTE to set, the Linux
PTE value, and the additional CPU PTE bits which aren't encoded in
the Linux PTE value.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
One of the changes necessary for shared page tables is to standardize the
pxx_page macros. pte_page and pmd_page have always returned the struct
page associated with their entry, while pte_page_kernel and pmd_page_kernel
have returned the kernel virtual address. pud_page and pgd_page, on the
other hand, return the kernel virtual address.
Shared page tables needs pud_page and pgd_page to return the actual page
structures. There are very few actual users of these functions, so it is
simple to standardize their usage.
Since this is basic cleanup, I am submitting these changes as a standalone
patch. Per Hugh Dickins' comments about it, I am also changing the
pxx_page_kernel macros to pxx_page_vaddr to clarify their meaning.
Signed-off-by: Dave McCracken <dmccr@us.ibm.com>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Patch from Catalin Marinas
This patch adds #ifdef around some variables in the arch/arm/mm/ioremap.c
file.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
No need for 'cr' to be a local variable, which is unused in the
SMP case, and only used once in the UP case. Just call get_cr()
directly.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Lennert Buytenhek
Commit ff0daca525 broke the SMP build,
this patch fixes it up again.
Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Lennert Buytenhek
Analogous to the previous patch that allows ioremap() to use section
mappings, this patch allows ioremap() to use supersection mappings.
Original patch by Deepak Saxena.
Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Allow section mappings to be setup using ioremap() and torn down
with iounmap(). This requires additional support in the MM
context switch to ensure that mappings are properly synchronised
when mapped in.
Based an original implementation by Deepak Saxena, reworked and
ARMv6 support added by rmk.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
nommu doesn't have any form of remapping support, so ioremap, etc
become stubs which just return the casted address, doing nothing
else.
Move ioport_map(), ioport_unmap(), pci_iomap(), pci_iounmap()
into a separate file which is always built.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Catalin Marinas
This patch modifies the __ioremap_pfn and __iounmap functions in
arch/arm/mm/ioremap.c to use vunmap instead of vfree.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
asm/hardware.h is not required for the majority of processor support
files, ioremap support, mm initialisation, acorn IO support, nor
the debug code (which picks up its machine specific includes via
debug-macros.S)
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
arch/arm/mm/ioremap.c:145: warning: passing argument 1 of 'vfree' makes pointer from integer without a cast
resulted from commit id 9d4ae7276a
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Deepak Saxena
In working on adding 36-bit addressed supersection support to ioremap(),
I came to the conclusion that it would be far simpler to do so by just
splitting __ioremap() into a main external interface and adding an
__ioremap_pfn() function that takes a pfn + offset into the page that
__ioremap() can call. This way existing callers of __ioremap() won't have
to change their code and 36-bit systems will just call __ioremap_pfn()
and we will not have to deal with unsigned long long variables.
Note that __ioremap_pfn() should _NOT_ be called directly by drivers
but is reserved for use by arch_ioremap() implementations that map
32-bit resource regions into the real 36-bit address and then call
this new function.
Signed-off-by: Deepak Saxena <dsaxena@plexity.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The "align" argument in ARMs __ioremap is unused and provides a
misleading expectation that it might do something. It doesn't.
Remove it.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
First step in pushing down the page_table_lock. init_mm.page_table_lock has
been used throughout the architectures (usually for ioremap): not to serialize
kernel address space allocation (that's usually vmlist_lock), but because
pud_alloc,pmd_alloc,pte_alloc_kernel expect caller holds it.
Reverse that: don't lock or unlock init_mm.page_table_lock in any of the
architectures; instead rely on pud_alloc,pmd_alloc,pte_alloc_kernel to take
and drop it when allocating a new one, to check lest a racing task already
did. Similarly no page_table_lock in vmalloc's map_vm_area.
Some temporary ugliness in __pud_alloc and __pmd_alloc: since they also handle
user mms, which are converted only by a later patch, for now they have to lock
differently according to whether or not it's init_mm.
If sources get muddled, there's a danger that an arch source taking
init_mm.page_table_lock will be mixed with common source also taking it (or
neither take it). So break the rules and make another change, which should
break the build for such a mismatch: remove the redundant mm arg from
pte_alloc_kernel (ppc64 scrapped its distinct ioremap_mm in 2.6.13).
Exceptions: arm26 used pte_alloc_kernel on user mm, now pte_alloc_map; ia64
used pte_alloc_map on init_mm, now pte_alloc_kernel; parisc had bad args to
pmd_alloc and pte_alloc_kernel in unused USE_HPPA_IOREMAP code; ppc64
map_io_page forgot to unlock on failure; ppc mmu_mapin_ram and ppc64 im_free
took page_table_lock for no good reason.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Russell King