- 21 2月, 2010 1 次提交
-
-
由 Russell King 提交于
On VIVT ARM, when we have multiple shared mappings of the same file in the same MM, we need to ensure that we have coherency across all copies. We do this via make_coherent() by making the pages uncacheable. This used to work fine, until we allowed highmem with highpte - we now have a page table which is mapped as required, and is not available for modification via update_mmu_cache(). Ralf Beache suggested getting rid of the PTE value passed to update_mmu_cache(): On MIPS update_mmu_cache() calls __update_tlb() which walks pagetables to construct a pointer to the pte again. Passing a pte_t * is much more elegant. Maybe we might even replace the pte argument with the pte_t? Ben Herrenschmidt would also like the pte pointer for PowerPC: Passing the ptep in there is exactly what I want. I want that -instead- of the PTE value, because I have issue on some ppc cases, for I$/D$ coherency, where set_pte_at() may decide to mask out the _PAGE_EXEC. So, pass in the mapped page table pointer into update_mmu_cache(), and remove the PTE value, updating all implementations and call sites to suit. Includes a fix from Stephen Rothwell: sparc: fix fallout from update_mmu_cache API change Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au> Acked-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
-
- 10 4月, 2009 1 次提交
-
-
由 David Howells 提交于
Signed-off-by: NDavid Howells <dhowells@redhat.com>
-
- 28 4月, 2008 1 次提交
-
-
由 Nick Piggin 提交于
s390 for one, cannot implement VM_MIXEDMAP with pfn_valid, due to their memory model (which is more dynamic than most). Instead, they had proposed to implement it with an additional path through vm_normal_page(), using a bit in the pte to determine whether or not the page should be refcounted: vm_normal_page() { ... if (unlikely(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP))) { if (vma->vm_flags & VM_MIXEDMAP) { #ifdef s390 if (!mixedmap_refcount_pte(pte)) return NULL; #else if (!pfn_valid(pfn)) return NULL; #endif goto out; } ... } This is fine, however if we are allowed to use a bit in the pte to determine refcountedness, we can use that to _completely_ replace all the vma based schemes. So instead of adding more cases to the already complex vma-based scheme, we can have a clearly seperate and simple pte-based scheme (and get slightly better code generation in the process): vm_normal_page() { #ifdef s390 if (!mixedmap_refcount_pte(pte)) return NULL; return pte_page(pte); #else ... #endif } And finally, we may rather make this concept usable by any architecture rather than making it s390 only, so implement a new type of pte state for this. Unfortunately the old vma based code must stay, because some architectures may not be able to spare pte bits. This makes vm_normal_page a little bit more ugly than we would like, but the 2 cases are clearly seperate. So introduce a pte_special pte state, and use it in mm/memory.c. It is currently a noop for all architectures, so this doesn't actually result in any compiled code changes to mm/memory.o. BTW: I haven't put vm_normal_page() into arch code as-per an earlier suggestion. The reason is that, regardless of where vm_normal_page is actually implemented, the *abstraction* is still exactly the same. Also, while it depends on whether the architecture has pte_special or not, that is the only two possible cases, and it really isn't an arch specific function -- the role of the arch code should be to provide primitive functions and accessors with which to build the core code; pte_special does that. We do not want architectures to know or care about vm_normal_page itself, and we definitely don't want them being able to invent something new there out of sight of mm/ code. If we made vm_normal_page an arch function, then we have to make vm_insert_mixed (next patch) an arch function too. So I don't think moving it to arch code fundamentally improves any abstractions, while it does practically make the code more difficult to follow, for both mm and arch developers, and easier to misuse. [akpm@linux-foundation.org: build fix] Signed-off-by: NNick Piggin <npiggin@suse.de> Acked-by: NCarsten Otte <cotte@de.ibm.com> Cc: Jared Hulbert <jaredeh@gmail.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
- 09 2月, 2008 1 次提交
-
-
由 David Howells 提交于
Add architecture support for the MN10300/AM33 CPUs produced by MEI to the kernel. This patch also adds board support for the ASB2303 with the ASB2308 daughter board, and the ASB2305. The only processor supported is the MN103E010, which is an AM33v2 core plus on-chip devices. [akpm@linux-foundation.org: nuke cvs control strings] Signed-off-by: NMasakazu Urade <urade.masakazu@jp.panasonic.com> Signed-off-by: NKoichi Yasutake <yasutake.koichi@jp.panasonic.com> Signed-off-by: NDavid Howells <dhowells@redhat.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-