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path: root/arch/sparc64/kernel/ktlb.S
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2006-03-20[SPARC64]: Fix indexing into kpte_linear_bitmap.David S. Miller
Need to shift back up by 3 bits to get 8-byte entry index. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20[SPARC64]: Create a seperate kernel TSB for 4MB/256MB mappings.David S. Miller
It can map all of the linear kernel mappings with zero TSB hash conflicts for systems with 16GB or less ram. In such cases, on SUN4V, once we load up this TSB the first time with all the mappings, we never take a linear kernel mapping TLB miss ever again, the hypervisor handles them all. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20[SPARC64]: Make use of Niagara 256MB PTEs for kernel mappings.David S. Miller
We use a bitmap, one bit for every 256MB of memory. If the bit is set we can use a 256MB PTE for linear mappings, else we have to use a 4MB PTE. SUN4V support is there, and we can very easily add support for Panther cpu 256MB PTEs in the future. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20[SPARC64]: Set %gl to 1 in kvmap_itlb_longpath on SUN4V.David S. Miller
Just like kvmap_dtlb_longpath we have to force the global register level to one in order to mimick the PSTATE_MG --> PSTATE_AG trasition done on SUN4U. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20[SPARC64]: More TLB/TSB handling fixes.David S. Miller
The SUN4V convention with non-shared TSBs is that the context bit of the TAG is clear. So we have to choose an "invalid" bit and initialize new TSBs appropriately. Otherwise a zero TAG looks "valid". Make sure, for the window fixup cases, that we use the right global registers and that we don't potentially trample on the live global registers in etrap/rtrap handling (%g2 and %g6) and that we put the missing virtual address properly in %g5. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20[SPARC64]: Deal with PTE layout differences in SUN4V.David S. Miller
Yes, you heard it right, they changed the PTE layout for SUN4V. Ho hum... This is the simple and inefficient way to support this. It'll get optimized, don't worry. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20[SPARC64]: Fix some SUN4V TLB miss bugs.David S. Miller
Code patching did not sign extend negative branch offsets correctly. Kernel TLB miss path needs patching and %g4 register preservation in order to handle SUN4V correctly. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20[SPARC64]: Rename gl_{1,2}insn_patch --> sun4v_{1,2}insn_patchDavid S. Miller
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20[SPARC64]: Initial sun4v TLB miss handling infrastructure.David S. Miller
Things are a little tricky because, unlike sun4u, we have to: 1) do a hypervisor trap to do the TLB load. 2) do the TSB lookup calculations by hand Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20[SPARC64]: Sanitize %pstate writes for sun4v.David S. Miller
If we're just switching between different alternate global sets, nop it out on sun4v. Also, get rid of all of the alternate global save/restore in the OBP CIF trampoline code. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20[SPARC64]: Access TSB with physical addresses when possible.David S. Miller
This way we don't need to lock the TSB into the TLB. The trick is that every TSB load/store is registered into a special instruction patch section. The default uses virtual addresses, and the patch instructions use physical address load/stores. We can't do this on all chips because only cheetah+ and later have the physical variant of the atomic quad load. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20[SPARC64]: Move away from virtual page tables, part 1.David S. Miller
We now use the TSB hardware assist features of the UltraSPARC MMUs. SMP is currently knowingly broken, we need to find another place to store the per-cpu base pointers. We hid them away in the TSB base register, and that obviously will not work any more :-) Another known broken case is non-8KB base page size. Also noticed that flush_tlb_all() is not referenced anywhere, only the internal __flush_tlb_all() (local cpu only) is used by the sparc64 port, so we can get rid of flush_tlb_all(). The kernel gets it's own 8KB TSB (swapper_tsb) and each address space gets it's own private 8K TSB. Later we can add code to dynamically increase the size of per-process TSB as the RSS grows. An 8KB TSB is good enough for up to about a 4MB RSS, after which the TSB starts to incur many capacity and conflict misses. We even accumulate OBP translations into the kernel TSB. Another area for refinement is large page size support. We could use a secondary address space TSB to handle those. Signed-off-by: David S. Miller <davem@davemloft.net>
2005-10-12[SPARC64]: Fix boot failures on SunBlade-150David S. Miller
The sequence to move over to the Linux trap tables from the firmware ones needs to be more air tight. It turns out that to be %100 safe we do need to be able to translate OBP mappings in our TLB miss handlers early. In order not to eat up a lot of kernel image memory with static page tables, just use the translations array in the OBP TLB miss handlers. That solves the bulk of the problem. Furthermore, to make sure the OBP TLB miss path will work even before the fixed MMU globals are loaded, explicitly load %g1 to TLB_SFSR at the beginning of the i-TLB and d-TLB miss handlers. To ease the OBP TLB miss walking of the prom_trans[] array, we sort it then delete all of the non-OBP entries in there (for example, there are entries for the kernel image itself which we're not interested in at all). We also save about 32K of kernel image size with this change. Not a bad side effect :-) There are still some reasons why trampoline.S can't use the setup_trap_table() yet. The most noteworthy are: 1) OBP boots secondary processors with non-bias'd stack for some reason. This is easily fixed by using a small bootup stack in the kernel image explicitly for this purpose. 2) Doing a firmware call via the normal C call prom_set_trap_table() goes through the whole OBP enter/exit sequence that saves and restores OBP and Linux kernel state in the MMUs. This path unfortunately does a "flush %g6" while loading up the OBP locked TLB entries for the firmware call. If we setup the %g6 in the trampoline.S code properly, that is in the PAGE_OFFSET linear mapping, but we're not on the kernel trap table yet so those addresses won't translate properly. One idea is to do a by-hand firmware call like we do in the early bootup code and elsewhere here in trampoline.S But this fails as well, as aparently the secondary processors are not booted with OBP's special locked TLB entries loaded. These are necessary for the firwmare to processes TLB misses correctly up until the point where we take over the trap table. This does need to be resolved at some point. Signed-off-by: David S. Miller <davem@davemloft.net>
2005-09-25[SPARC64]: Add CONFIG_DEBUG_PAGEALLOC support.David S. Miller
The trick is that we do the kernel linear mapping TLB miss starting with an instruction sequence like this: ba,pt %xcc, kvmap_load xor %g2, %g4, %g5 succeeded by an instruction sequence which performs a full page table walk starting at swapper_pg_dir. We first take over the trap table from the firmware. Then, using this constant PTE generation for the linear mapping area above, we build the kernel page tables for the linear mapping. After this is setup, we patch that branch above into a "nop", which will cause TLB misses to fall through to the full page table walk. With this, the page unmapping for CONFIG_DEBUG_PAGEALLOC is trivial. Signed-off-by: David S. Miller <davem@davemloft.net>
2005-09-21[SPARC64]: Remove ktlb.S instruction patching.David S. Miller
This was kind of ugly, and actually buggy. The bug was that we didn't handle a machine with memory starting > 4GB. If the 'prompmd' was allocated in physical memory > 4GB we'd croak because the obp_iaddr_patch and obp_daddr_patch things only supported a 32-bit physical address. So fix this by just loading the appropriate values from two variables in the kernel image, which is locked into the TLB and thus accesses to them can't cause a recursive TLB miss. Signed-off-by: David S. Miller <davem@davemloft.net>
2005-09-21[SPARC64]: Move kernel TLB miss handling into a seperate file.David S. Miller
Signed-off-by: David S. Miller <davem@davemloft.net>