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* sparc: Don't leak context bits into thread->fault_addressDavid S. Miller2016-07-281-0/+12
| | | | | | | | | | | | | | | | On pre-Niagara systems, we fetch the fault address on data TLB exceptions from the TLB_TAG_ACCESS register. But this register also contains the context ID assosciated with the fault in the low 13 bits of the register value. This propagates into current_thread_info()->fault_address and can cause trouble later on. So clear the low 13-bits out of the TLB_TAG_ACCESS value in the cases where it matters. Reported-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* sparc64: Adjust vmalloc region size based upon available virtual address bits.David S. Miller2014-10-061-4/+4
| | | | | | | | | | | | | | In order to accomodate embedded per-cpu allocation with large numbers of cpus and numa nodes, we have to use as much virtual address space as possible for the vmalloc region. Otherwise we can get things like: PERCPU: max_distance=0x380001c10000 too large for vmalloc space 0xff00000000 So, once we select a value for PAGE_OFFSET, derive the size of the vmalloc region based upon that. Signed-off-by: David S. Miller <davem@davemloft.net> Acked-by: Bob Picco <bob.picco@oracle.com>
* sparc64: Use kernel page tables for vmemmap.David S. Miller2014-10-061-7/+2
| | | | | | | | | | | | | | For sparse memory configurations, the vmemmap array behaves terribly and it takes up an inordinate amount of space in the BSS section of the kernel image unconditionally. Just build huge PMDs and look them up just like we do for TLB misses in the vmalloc area. Kernel BSS shrinks by about 2MB. Signed-off-by: David S. Miller <davem@davemloft.net> Acked-by: Bob Picco <bob.picco@oracle.com>
* sparc64: Fix physical memory management regressions with large max_phys_bits.David S. Miller2014-10-061-99/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If max_phys_bits needs to be > 43 (f.e. for T4 chips), things like DEBUG_PAGEALLOC stop working because the 3-level page tables only can cover up to 43 bits. Another problem is that when we increased MAX_PHYS_ADDRESS_BITS up to 47, several statically allocated tables became enormous. Compounding this is that we will need to support up to 49 bits of physical addressing for M7 chips. The two tables in question are sparc64_valid_addr_bitmap and kpte_linear_bitmap. The first holds a bitmap, with 1 bit for each 4MB chunk of physical memory, indicating whether that chunk actually exists in the machine and is valid. The second table is a set of 2-bit values which tell how large of a mapping (4MB, 256MB, 2GB, 16GB, respectively) we can use at each 256MB chunk of ram in the system. These tables are huge and take up an enormous amount of the BSS section of the sparc64 kernel image. Specifically, the sparc64_valid_addr_bitmap is 4MB, and the kpte_linear_bitmap is 128K. So let's solve the space wastage and the DEBUG_PAGEALLOC problem at the same time, by using the kernel page tables (as designed) to manage this information. We have to keep using large mappings when DEBUG_PAGEALLOC is disabled, and we do this by encoding huge PMDs and PUDs. On a T4-2 with 256GB of ram the kernel page table takes up 16K with DEBUG_PAGEALLOC disabled and 256MB with it enabled. Furthermore, this memory is dynamically allocated at run time rather than coded statically into the kernel image. Signed-off-by: David S. Miller <davem@davemloft.net> Acked-by: Bob Picco <bob.picco@oracle.com>
* sparc64: Use 'ILOG2_4MB' instead of constant '22'.David S. Miller2014-05-041-1/+1
| | | | Signed-off-by: David S. Miller <davem@davemloft.net>
* sparc64: Make PAGE_OFFSET variable.David S. Miller2013-11-131-5/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | | Choose PAGE_OFFSET dynamically based upon cpu type. Original UltraSPARC-I (spitfire) chips only supported a 44-bit virtual address space. Newer chips (T4 and later) support 52-bit virtual addresses and up to 47-bits of physical memory space. Therefore we have to adjust PAGE_SIZE dynamically based upon the capabilities of the chip. Note that this change alone does not allow us to support > 43-bit physical memory, to do that we need to re-arrange our page table support. The current encodings of the pmd_t and pgd_t pointers restricts us to "32 + 11" == 43 bits. This change can waste quite a bit of memory for the various tables. In particular, a future change should work to size and allocate kern_linear_bitmap[] and sparc64_valid_addr_bitmap[] dynamically. This isn't easy as we really cannot take a TLB miss when accessing kern_linear_bitmap[]. We'd have to lock it into the TLB or similar. Signed-off-by: David S. Miller <davem@davemloft.net> Acked-by: Bob Picco <bob.picco@oracle.com>
* sparc64: Document the shift counts used to validate linear kernel addresses.David S. Miller2013-11-131-5/+5
| | | | | | | | This way we can see exactly what they are derived from, and in particular how they would change if we were to use a different PAGE_OFFSET value. Signed-off-by: David S. Miller <davem@davemloft.net> Acked-by: Bob Picco <bob.picco@oracle.com>
* sparc64: Fix ITLB handler of null pageKirill Tkhai2013-08-031-2/+1
| | | | | | | | | | | | | | | 1)Use kvmap_itlb_longpath instead of kvmap_dtlb_longpath. 2)Handle page #0 only, don't handle page #1: bleu -> blu (KERNBASE is 0x400000, so #1 does not exist too. But everything is possible in the future. Fix to not to have problems later.) 3)Remove unused kvmap_itlb_nonlinear. Signed-off-by: Kirill Tkhai <tkhai@yandex.ru> CC: David Miller <davem@davemloft.net> Signed-off-by: David S. Miller <davem@davemloft.net>
* sparc64: Support 2GB and 16GB page sizes for kernel linear mappings.David S. Miller2012-09-071-15/+10
| | | | | | | | | | | | | | | | | SPARC-T4 supports 2GB pages. So convert kpte_linear_bitmap into an array of 2-bit values which index into kern_linear_pte_xor. Now kern_linear_pte_xor is used for 4 page size aligned regions, 4MB, 256MB, 2GB, and 16GB respectively. Enabling 2GB pages is currently hardcoded using a check against sun4v_chip_type. In the future this will be done more cleanly by interrogating the machine description which is the correct way to determine this kind of thing. Signed-off-by: David S. Miller <davem@davemloft.net>
* sparc: Access kernel TSB using physical addressing when possible.David S. Miller2011-08-051-12/+12
| | | | | | | | On sun4v this is basically required since we point the hypervisor and the TSB walking hardware at these tables using physical addressing too. Signed-off-by: David S. Miller <davem@davemloft.net>
* sparc64: Increase vmalloc size to fix percpu regressions.David S. Miller2009-09-281-4/+4
| | | | | | | | | | Since we now use the embedding percpu allocator we have to make the vmalloc area at least as large as the stretch can be between nodes. Besides some minor asm adjustments, this turned out to be pretty trivial. Signed-off-by: David S. Miller <davem@davemloft.net>
* sparc64: Validate linear D-TLB misses.David S. Miller2009-08-261-4/+38
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When page alloc debugging is not enabled, we essentially accept any virtual address for linear kernel TLB misses. But with kgdb, kernel address probing, and other facilities we can try to access arbitrary crap. So, make sure the address we miss on will translate to physical memory that actually exists. In order to make this work we have to embed the valid address bitmap into the kernel image. And in order to make that less expensive we make an adjustment, in that the max physical memory address is decreased to "1 << 41", even on the chips that support a 42-bit physical address space. We can do this because bit 41 indicates "I/O space" and thus covers non-memory ranges. The result of this is that: 1) kpte_linear_bitmap shrinks from 2K to 1K in size 2) we need 64K more for the valid address bitmap We can't let the valid address bitmap be dynamically allocated once we start using it to validate TLB misses, otherwise we have crazy issues to deal with wrt. recursive TLB misses and such. If we're in a TLB miss it could be the deepest trap level that's legal inside of the cpu. So if we TLB miss referencing the bitmap, the cpu will be out of trap levels and enter RED state. To guard against out-of-range accesses to the bitmap, we have to check to make sure no bits in the physical address above bit 40 are set. We could export and use last_valid_pfn for this check, but that's just an unnecessary extra memory reference. On the plus side of all this, since we load all of these translations into the special 4MB mapping TSB, and we check the TSB first for TLB misses, there should be absolutely no real cost for these new checks in the TLB miss path. Reported-by: heyongli@gmail.com Signed-off-by: David S. Miller <davem@davemloft.net>
* sparc,sparc64: unify kernel/Sam Ravnborg2008-12-041-0/+304
o Move all files from sparc64/kernel/ to sparc/kernel - rename as appropriate o Update sparc/Makefile to the changes o Update sparc/kernel/Makefile to include the sparc64 files NOTE: This commit changes link order on sparc64! Link order had to change for either of sparc32 and sparc64. And assuming sparc64 see more testing than sparc32 change link order on sparc64 where issues will be caught faster. Signed-off-by: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: David S. Miller <davem@davemloft.net>