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path: root/arch/sparc64/kernel/trampoline.S
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2006-03-20[SPARC64]: Get SUN4V SMP working.David S. Miller
The sibling cpu bringup is extremely fragile. We can only perform the most basic calls until we take over the trap table from the firmware/hypervisor on the new cpu. This means no accesses to %g4, %g5, %g6 since those can't be TLB translated without our trap handlers. In order to achieve this: 1) Change sun4v_init_mondo_queues() so that it can operate in several modes. It can allocate the queues, or install them in the current processor, or both. The boot cpu does both in it's call early on. Later, the boot cpu allocates the sibling cpu queue, starts the sibling cpu, then the sibling cpu loads them in. 2) init_cur_cpu_trap() is changed to take the current_thread_info() as an argument instead of reading %g6 directly on the current cpu. 3) Create a trampoline stack for the sibling cpus. We do our basic kernel calls using this stack, which is locked into the kernel image, then go to our proper thread stack after taking over the trap table. 4) While we are in this delicate startup state, we put 0xdeadbeef into %g4/%g5/%g6 in order to catch accidental accesses. 5) On the final prom_set_trap_table*() call, we put &init_thread_union into %g6. This is a hack to make prom_world(0) work. All that wants to do is restore the %asi register using get_thread_current_ds(). Longer term we should just do the OBP calls to set the trap table by hand just like we do for everything else. This would avoid that silly prom_world(0) issue, then we can remove the init_thread_union hack. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20[SPARC64]: arch/sparc64/kernel/trampoline.S needs asm/cpudata.hDavid S. Miller
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20[SPARC64]: Fix mondo queue allocations.David S. Miller
We have to use bootmem during init_IRQ and page alloc for sibling cpu calls. Also, fix incorrect hypervisor call return value checks in the hypervisor SMP cpu mondo send code. 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]: Fix hypervisor call arg passing.David S. Miller
Function goes in %o5, args go in %o0 --> %o5. 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]: Allocate and register the 4 sun4v mondo queues at bootup.David S. Miller
Needs to occur before we enable PSTATE_IE in %pstate. 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]: 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>
2005-10-04[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>
2005-09-22[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>
2005-06-27[SPARC64]: Avoid membar instructions in delay slots.David S. Miller
In particular, avoid membar instructions in the delay slot of a jmpl instruction. UltraSPARC-I, II, IIi, and IIe have a bug, documented in the UltraSPARC-IIi User's Manual, Appendix K, Erratum 51 The long and short of it is that if the IMU unit misses on a branch or jmpl, and there is a store buffer synchronizing membar in the delay slot, the chip can stop fetching instructions. If interrupts are enabled or some other trap is enabled, the chip will unwedge itself, but performance will suffer. We already had a workaround for this bug in a few spots, but it's better to have the entire tree sanitized for this rule. Signed-off-by: David S. Miller <davem@davemloft.net>
2005-04-16Linux-2.6.12-rc2v2.6.12-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!