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2008-04-28sparc64: Split entry.S up into seperate files.David S. Miller
entry.S was a hodge-podge of several totally unrelated sets of assembler routines, ranging from FPU trap handlers to hypervisor call functions. Split it up into topic-sized pieces. Signed-off-by: David S. Miller <davem@davemloft.net>
2008-03-21[SPARC64]: Remove most limitations to kernel image size.David S. Miller
Currently kernel images are limited to 8MB in size, and this causes problems especially when enabling features that take up a lot of kernel image space such as lockdep. The code now will align the kernel image size up to 4MB and map that many locked TLB entries. So, the only practical limitation is the number of available locked TLB entries which is 16 on Cheetah and 64 on pre-Cheetah sparc64 cpus. Niagara cpus don't actually have hw locked TLB entry support. Rather, the hypervisor transparently provides support for "locked" TLB entries since it runs with physical addressing and does the initial TLB miss processing. Fully utilizing this change requires some help from SILO, a patch for which will be submitted to the maintainer. Essentially, SILO will only currently map up to 8MB for the kernel image and that needs to be increased. Note that neither this patch nor the SILO bits will help with network booting. The openfirmware code will only map up to a certain amount of kernel image during a network boot and there isn't much we can to about that other than to implemented a layered network booting facility. Solaris has this, and calls it "wanboot" and we may implement something similar at some point. Signed-off-by: David S. Miller <davem@davemloft.net>
2008-02-07[SPARC64]: Fix booting on non-zero cpu.David S. Miller
The early per-cpu handling needs a slight tweak to work when booting on a non-zero cpu. We got away with this for a long time, but can't any longer as now even printk() calls functions (cpu_clock() for example) that thus make early references to per-cpu variables. Signed-off-by: David S. Miller <davem@davemloft.net>
2007-09-16[SPARC64]: Fix lockdep, particularly on SMP.David S. Miller
As noted by Al Viro, when we try to call prom_set_trap_table() in the SMP trampoline code we try to take the PROM call spinlock which doesn't work because the current thread pointer isn't valid yet and lockdep depends upon that being correct. Furthermore, we cannot set the current thread pointer register because it can't be properly dereferenced until we return from prom_set_trap_table(). Kernel TLB misses only work after that call. So do the PROM call to set the trap table directly instead of going through the OBP library C code, and thus avoid the lock altogether. These calls are guarenteed to be serialized fully. Since there are now no calls to the prom_set_trap_table{_sun4v}() library functions, they can be deleted. Signed-off-by: David S. Miller <davem@davemloft.net>
2007-08-16[SPARC64]: Do not touch %tick_cmpr on sun4v cpus.David S. Miller
This register is not a part of the sun4v architecture. Niagara 1 and 2 happened to leave it around. Signed-off-by: David S. Miller <davem@davemloft.net>
2007-08-16[SPARC64]: Niagara-2 optimized copies.David S. Miller
The bzero/memset implementation stays the same as Niagara-1. Signed-off-by: David S. Miller <davem@davemloft.net>
2007-08-08[SPARC64]: Do not assume sun4v chips have load-twin/store-init support.David S. Miller
Check the cpu type in the OBP device tree before committing to using the optimized Niagara memcpy and memset implementation. If we don't recognize the cpu type, use a completely generic version. Signed-off-by: David S. Miller <davem@davemloft.net>
2007-07-24[SPARC64]: Mark most of initial bootup asm as .text.init.ref_okDavid S. Miller
We can't mark the whole thing init because there are dependencies in bootloaders that assume that _start, or whatever the image entry value, is 2 instructions before the "HdrS" signature. In fact, TILO assumes this entry is always at 0x4000, yikes! Also, right after the bootloader info area there are OBP strings and values that get used later in the boot process, and those are not all provably .init yet. Signed-off-by: David S. Miller <davem@davemloft.net>
2007-07-19[SPARC64]: Fix two year old bug in early bootup asm.David S. Miller
We try to fetch the CIF entry pointer from %o4, but that can get clobbered by the early OBP calls. It is saved in %l7 already, so actually this "mov %o4, %l7" can just be completely removed with no other changes. Signed-off-by: David S. Miller <davem@davemloft.net>
2007-05-29[SPARC64]: Fix two bugs wrt. kernel 4MB TSB.David S. Miller
1) The TSB lookup was not using the correct hash mask. 2) It was not aligned on a boundary equal to it's size, which is required by the sun4v Hypervisor. wasn't having it's return value checked, and that bug will be fixed up as well in a subsequent changeset. Signed-off-by: David S. Miller <davem@davemloft.net>
2007-05-29[SPARC64]: Eliminate NR_CPUS limitations.David S. Miller
Cheetah systems can have cpuids as large as 1023, although physical systems don't have that many cpus. Only three limitations existed in the kernel preventing arbitrary NR_CPUS values: 1) dcache dirty cpu state stored in page->flags on D-cache aliasing platforms. With some build time calculations and some build-time BUG checks on page->flags layout, this one was easily solved. 2) The cheetah XCALL delivery code could only handle a cpumask with up to 32 cpus set. Some simple looping logic clears that up too. 3) thread_info->cpu was a u8, easily changed to a u16. There are a few spots in the kernel that still put NR_CPUS sized arrays on the kernel stack, but that's not a sparc64 specific problem. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-12-17[SPARC64]: Kill no-remapping-needed code in head.SDavid S. Miller
It branches around some necessary prom calls, which we would need to do even if we are mapped at the correct location already. So it doesn't work. The idea was that this sort of thing could be used for the eventual kexec implementation, but it is clear that this will need to be done differently. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-12-10[SPARC64]: Add irqtrace/stacktrace/lockdep support.David S. Miller
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-07-14[SPARC64]: Make sure IRQs are disabled properly during early boot.David S. Miller
Else we trigger the new irqs_disable() assertion in start_kernel(). Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-30Remove obsolete #include <linux/config.h>Jörn Engel
Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-05-31[SPARC64]: Make smp_processor_id() functional before start_kernel()David S. Miller
Uses of smp_processor_id() get pushed earlier and earlier in the start_kernel() sequence. So just get it working before we call start_kernel() to avoid all possible problems. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20[SPARC64]: Put syscall tables after trap table.David S. Miller
Otherwise with too much stuff enabled in the kernel config we can end up with an unaligned trap table. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20[SPARC64]: Niagara optimized memset/bzero/clear_user.David S. Miller
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20[SPARC64]: Fix sun4v early bootup.David S. Miller
prom_sun4v_name should be "sun4v" not "SUNW,sun4v" Also, this is too early to make use of the .sun4v_Xinsn_patch code patching, so just check things manually. This gets us at least to prom_init() on Niagara. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20[SPARC64]: Use ASI_SCRATCHPAD address 0x0 properly.David S. Miller
This is where the virtual address of the fault status area belongs. To set it up we don't make a hypervisor call, instead we call OBP's SUNW,set-trap-table with the real address of the fault status area as the second argument. And right before that call we write the virtual address into ASI_SCRATCHPAD vaddr 0x0. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20[SPARC64]: Detect sun4v early in boot process.David S. Miller
We look for "SUNW,sun4v" in the 'compatible' property of the root OBP device tree node. Protect every %ver register access, to make sure it is not touched on sun4v, as %ver is hyperprivileged there. Lock kernel TLB entries using hypervisor calls instead of calls into OBP. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20[SPARC64]: Sun4v interrupt handling.David S. Miller
Sun4v has 4 interrupt queues: cpu, device, resumable errors, and non-resumable errors. A set of head/tail offset pointers help maintain a work queue in physical memory. The entries are 64-bytes in size. Each queue is allocated then registered with the hypervisor as we bring cpus up. The two error queues each get a kernel side buffer that we use to quickly empty the main interrupt queue before we call up to C code to log the event and possibly take evasive action. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20[SPARC64]: Patch up mmu context register writes for sun4v.David S. Miller
sun4v uses ASI_MMU instead of ASI_DMMU Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20[SPARC64]: Niagara copy/clear page.David S. Miller
Happily we have no D-cache aliasing issues on these chips, so the implementation is very straightforward. Add a stub in bootup which will be where the patching calls will be made for niagara/sun4v/hypervisor. 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]: Increase swapper_tsb size to 32K.David S. Miller
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20[SPARC64]: Kill sole argument passed to setup_tba().David S. Miller
No longer used, and move extern declaration to a header file. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20[SPARC64]: Elminate all usage of hard-coded trap globals.David S. Miller
UltraSPARC has special sets of global registers which are switched to for certain trap types. There is one set for MMU related traps, one set of Interrupt Vector processing, and another set (called the Alternate globals) for all other trap types. For what seems like forever we've hard coded the values in some of these trap registers. Some examples include: 1) Interrupt Vector global %g6 holds current processors interrupt work struct where received interrupts are managed for IRQ handler dispatch. 2) MMU global %g7 holds the base of the page tables of the currently active address space. 3) Alternate global %g6 held the current_thread_info() value. Such hardcoding has resulted in some serious issues in many areas. There are some code sequences where having another register available would help clean up the implementation. Taking traps such as cross-calls from the OBP firmware requires some trick code sequences wherein we have to save away and restore all of the special sets of global registers when we enter/exit OBP. We were also using the IMMU TSB register on SMP to hold the per-cpu area base address, which doesn't work any longer now that we actually use the TSB facility of the cpu. The implementation is pretty straight forward. One tricky bit is getting the current processor ID as that is different on different cpu variants. We use a stub with a fancy calling convention which we patch at boot time. The calling convention is that the stub is branched to and the (PC - 4) to return to is in register %g1. The cpu number is left in %g6. This stub can be invoked by using the __GET_CPUID macro. We use an array of per-cpu trap state to store the current thread and physical address of the current address space's page tables. The TRAP_LOAD_THREAD_REG loads %g6 with the current thread from this table, it uses __GET_CPUID and also clobbers %g1. TRAP_LOAD_IRQ_WORK is used by the interrupt vector processing to load the current processor's IRQ software state into %g6. It also uses __GET_CPUID and clobbers %g1. Finally, TRAP_LOAD_PGD_PHYS loads the physical address base of the current address space's page tables into %g7, it clobbers %g1 and uses __GET_CPUID. Many refinements are possible, as well as some tuning, with this stuff in place. 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>
2005-10-11[SPARC64]: Fix net booting on Ultra5David S. Miller
We were not doing alignment properly when remapping the kernel image. What we want is a 4MB aligned physical address to map at KERNBASE. Mistakedly we were 4MB aligning the virtual address where the kernel initially sits, that's wrong. Instead, we should PAGE align the virtual address, then 4MB align the physical address result the prom gives to us. Signed-off-by: David S. Miller <davem@davemloft.net>
2005-10-10[SPARC64]: Fix Ultra5, Ultra60, et al. boot failures.David S. Miller
On the boot processor, we need to do the move onto the Linux trap table a little bit differently else we'll take unhandlable faults in the firmware address space. Previously we would do the following: 1) Disable PSTATE_IE in %pstate. 2) Set %tba by hand to sparc64_ttable_tl0 3) Initialize alternate, mmu, and interrupt global trap registers. 4) Call prom_set_traptable() That doesn't work very well actually with the way we boot the kernel VM these days. It worked by luck on many systems because the firmware accesses for the prom_set_traptable() call happened to be loaded into the TLB already, something we cannot assume. So the new scheme is this: 1) Clear PSTATE_IE in %pstate and set %pil to 15 2) Call prom_set_traptable() 3) Initialize alternate, mmu, and interrupt global trap registers. and this works quite well. This sequence has been moved into a callable function in assembler named setup-trap_table(). The idea is that eventually trampoline.S can use this code as well. That isn't possible currently due to some complications, but eventually we should be able to do it. Thanks to Meelis Roos for the Ultra5 boot failure report. Signed-off-by: David S. Miller <davem@davemloft.net>
2005-10-04[SPARC64]: Replace cheetah+ code patching with variables.David S. Miller
Instead of code patching to handle the page size fields in the context registers, just use variables from which we get the proper values. Signed-off-by: David S. Miller <davem@davemloft.net>
2005-09-28[SPARC64]: Fix fault handling in unaligned trap handler.David S. Miller
We were not calling kernel_mna_trap_fault() correctly. Instead of being fancy, just return 0 vs. -EFAULT from the assembler stubs, and handle that return value as appropriate. Create an "__retl_efault" stub for assembler exception table entries and use it where possible. 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>
2005-09-22[SPARC64]: Fix comment typo in head.SDavid S. Miller
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-09-22[SPARC64]: Rewrite bootup sequence.David S. Miller
Instead of all of this cpu-specific code to remap the kernel to the correct location, use portable firmware calls to do this instead. What we do now is the following in position independant assembler: chosen_node = prom_finddevice("/chosen"); prom_mmu_ihandle_cache = prom_getint(chosen_node, "mmu"); vaddr = 4MB_ALIGN(current_text_addr()); prom_translate(vaddr, &paddr_high, &paddr_low, &mode); prom_boot_mapping_mode = mode; prom_boot_mapping_phys_high = paddr_high; prom_boot_mapping_phys_low = paddr_low; prom_map(-1, 8 * 1024 * 1024, KERNBASE, paddr_low); and that replaces the massive amount of by-hand TLB probing and programming we used to do here. The new code should also handle properly the case where the kernel is mapped at the correct address already (think: future kexec support). Consequently, the bulk of remap_kernel() dies as does the entirety of arch/sparc64/prom/map.S We try to share some strings in the PROM library with the ones used at bootup, and while we're here mark input strings to oplib.h routines with "const" when appropriate. There are many more simplifications now possible. For one thing, we can consolidate the two copies we now have of a lot of cpu setup code sitting in head.S and trampoline.S. This is a significant step towards CONFIG_DEBUG_PAGEALLOC support. 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>
2005-08-30[SPARC64]: Kill BRANCH_IF_ANY_CHEETAH() from copy page.David S. Miller
Just patch the branch at boot time instead. Signed-off-by: David S. Miller <davem@davemloft.net>
2005-04-16Linux-2.6.12-rc2Linus Torvalds
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!