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* tile: ensure interrupts disabled for preempt_schedule_irq()Chris Metcalf2013-09-271-0/+3
| | | | | | | | When coming from a page fault (for example), interrupts might be enabled as we enter the code to return from interrupt. Cc: stable@vger.kernel.org Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
* tile: remove support for TILE64Chris Metcalf2013-09-031-2/+0
| | | | | | | | | | | This chip is no longer being actively developed for (it was superceded by the TILEPro64 in 2008), and in any case the existing compiler and toolchain in the community do not support it. It's unlikely that the kernel works with TILE64 at this point as the configuration has not been tested in years. The support is also awkward as it requires maintaining a significant number of ifdefs. So, just remove it altogether. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
* tile: parameterize VA and PA space more cleanlyChris Metcalf2013-09-031-3/+5
| | | | | | | | | | | | | | | | | | | | | | The existing code relied on the hardware definition (<arch/chip.h>) to specify how much VA and PA space was available. It's convenient to allow customizing this for some configurations, so provide symbols MAX_PA_WIDTH and MAX_VA_WIDTH in <asm/page.h> that can be modified if desired. Additionally, move away from the MEM_XX_INTRPT nomenclature to define the start of various regions within the VA space. In fact the cleaner symbol is, for example, MEM_SV_START, to indicate the start of the area used for supervisor code; the actual address of the interrupt vectors is not as important, and can be changed if desired. As part of this change, convert from "intrpt1" nomenclature (which built in the old privilege-level 1 model) to a simple "intrpt". Also strip out some tilepro-specific code supporting modifying the PL the kernel could run at, since we don't actually support using different PLs in tilepro, only tilegx. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
* tile: don't assume user privilege is zeroChris Metcalf2013-09-031-6/+17
| | | | | | | | | | Technically, user privilege is anything less than kernel privilege. We modify the existing user_mode() macro to have this semantic (and use it in a couple of places it wasn't being used before), and add an IS_KERNEL_EX1() macro to the assembly code as well. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
* tilegx: change how we find the kernel stackChris Metcalf2013-08-301-11/+10
| | | | | | | | | | | | | | | | | | | | | | | | Previously, we used a special-purpose register (SPR_SYSTEM_SAVE_K_0) to hold the CPU number and the top of the current kernel stack by using the low bits to hold the CPU number, and using the high bits to hold the address of the page just above where we'd want the kernel stack to be. That way we could initialize a new SP when first entering the kernel by just masking the SPR value and subtracting a couple of words. However, it's actually more useful to be able to place an arbitrary kernel-top value in the SPR. This allows us to create a new stack context (e.g. for virtualization) with an arbitrary top-of-stack VA. To make this work, we now store the CPU number in the high bits, above the highest legal VA bit (42 bits in the current tilegx microarchitecture). The full 42 bits are thus available to store the top of stack value. Getting the current cpu (a relatively common operation) is still fast; it's now a shift rather than a mask. We make this change only for tilegx, since tilepro has too few SPR bits to do this, and we don't need this support on tilepro anyway. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
* tile: provide traceability for hypervisor callsChris Metcalf2013-08-131-1/+1
| | | | | | | | | | | | | | | | | | This change adds infrastructure (CONFIG_TILE_HVGLUE_TRACE) that provides C code wrappers for the calls the kernel makes to the Tilera hypervisor. This allows standard kernel infrastructure like FTRACE to be able to instrument hypervisor calls. To allow direct calls to the true API, we export their names with a leading underscore as well. This is important for the few contexts where we need to make hypervisor calls without touching the stack. As part of this change, we also switch from creating the symbols with linker magic to creating them with assembler magic. This lets us provide a symbol type and generally make them appear more as symbols and less as just random values in the Elf namespace. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
* tile: improve illegal translation interrupt handlingChris Metcalf2013-08-131-1/+1
| | | | | | | | | | | | | | First, don't re-enable interrupts blindly in the Linux trap handler. We already handle page faults this way; synchronous interrupts like ILL_TRANS will fire even when interrupts are disabled, and we don't want to re-enable interrupts in that case. For ILL_TRANS, we now pass the ILL_VA_PC reason into the trap handler so we can report it properly; this is the address that caused the illegal translation trap. We print the address as part of the pr_alert() message now if it's coming from the kernel. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
* tile: support CONFIG_PREEMPTChris Metcalf2013-08-131-6/+24
| | | | | | | | | | This change adds support for CONFIG_PREEMPT (full kernel preemption). In addition to the core support, this change includes a number of places where we fix up uses of smp_processor_id() and per-cpu variables. I also eliminate the PAGE_HOME_HERE and PAGE_HOME_UNKNOWN values for page homing, as it turns out they weren't being used. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
* tile: fast-path unaligned memory access for tilegxChris Metcalf2013-08-131-7/+224
| | | | | | | | | | | | | | | | | | | | | | | | | This change enables unaligned userspace memory access via a kernel fast path on tilegx. The kernel tracks user PC/instruction pairs per-thread using a direct-mapped cache in userspace. The cache maps those PC/instruction pairs to JIT'ed instruction sequences that load or store using byte-wide load store intructions and then synthesize 2-, 4- or 8-byte load or store results. Once an instruction has been seen to generate an unaligned access once, subsequent hits on that instruction typically require overhead of only around 50 cycles if cache and TLB is hot. We support the prctl() PR_GET_UNALIGN / PR_SET_UNALIGN sys call to enable or disable unaligned fixups on a per-process basis. To do this we pull some of the tilepro unaligned support out of the single_step.c file; tilepro uses instruction disassembly for both single-step and unaligned access support. Since tilegx actually has hardware singlestep support, though, it's cleaner to keep the tilegx unaligned access code in a separate file. While we're at it, properly rename the tilepro-specific types, etc., to have tilepro suffixes instead of generic tile suffixes. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
* tile: support TIF_SYSCALL_TRACEPOINT; select HAVE_SYSCALL_TRACEPOINTSSimon Marchi2013-03-221-4/+10
| | | | | | | | | This patch adds support for the TIF_SYSCALL_TRACEPOINT on the tile architecture. Basically, it calls the appropriate tracepoints on syscall entry and exit. Signed-off-by: Simon Marchi <simon.marchi@polymtl.ca> Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
* arch/tile: Call tracehook_report_syscall_{entry,exit} in syscall traceSimon Marchi2013-03-211-2/+8
| | | | | | | | | | Call tracehook functions for syscall tracing. The check for TIF_SYSCALL_TRACE was removed, because the same check is done right before in the assembly file. Signed-off-by: Simon Marchi <simon.marchi@polymtl.ca> Signed-off-by: Chris Metcalf <cmetcalf@tilera.com> [with ptrace.h fixup]
* tile: tag some code with #ifdef CONFIG_COMPATChris Metcalf2013-02-081-0/+4
| | | | | | This allows us to disable COMPAT mode without a link error. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
* arch/tile: eliminate pt_regs trampolines for syscallsChris Metcalf2012-10-231-12/+1
| | | | | | | | | | Using the new current_pt_regs() model, we can remove some trampolines from assembly code and call directly to the C syscall implementations. rt_sigreturn() and clone() still need some assembly wrapping, but no longer are passed a pt_regs pointer. sigaltstack() and the tilepro-specific cmpxchg_badaddr() syscalls are now just straight C. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
* tile: switch to generic sys_execve()Al Viro2012-10-231-1/+0
| | | | | Acked-by: Chris Metcalf <cmetcalf@tilera.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* tile: support GENERIC_KERNEL_THREAD and GENERIC_KERNEL_EXECVEChris Metcalf2012-10-201-0/+15
| | | | | | | Also provide an optimized current_pt_regs() while we're at it. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Drop struct pt_regs * argument in compat_sys_execve()Al Viro2012-10-201-1/+0
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* arch/tile: fix hardwall for tilegx and generalize for idn and ipiChris Metcalf2012-05-251-1/+1
| | | | | | | | | | | | | | | | | | | The hardwall drain code was not properly implemented for tilegx, just tilepro, so you couldn't reliably restart an application that made use of the udn. In addition, the code was only applicable to the udn (user dynamic network). On tilegx there is a second user network that is available (the "idn"), and there is support for having I/O shims deliver user-level interrupts to applications ("ipi") which functions in a very similar way to the inter-core permissions used for udn/idn. So this change also generalizes the code from supporting just the udn to supports udn/idn/ipi on tilegx. By default we now use /dev/hardwall/{udn,idn,ipi} with separate minor numbers for the three devices. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
* arch/tile: use interrupt critical sections lessChris Metcalf2012-05-251-35/+43
| | | | | | | | | | | | | | | | | | | | | | In general we want to avoid ever touching memory while within an interrupt critical section, since the page fault path goes through a different path from the hypervisor when in an interrupt critical section, and we carefully decided with tilegx that we didn't need to support this path in the kernel. (On tilepro we did implement that path as part of supporting atomic instructions in software.) In practice we always need to touch the kernel stack, since that's where we store the interrupt state before releasing the critical section, but this change cleans up a few things. The IRQ_ENABLE macro is split up so that when we want to enable interrupts in a deferred way (e.g. for cpu_idle or for interrupt return) we can read the per-cpu enable mask before entering the critical section. The cache-migration code is changed to use interrupt masking instead of interrupt critical sections. And, the interrupt-entry code is changed so that we defer loading "tp" from per-cpu data until after we have released the interrupt critical section. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
* arch/tile: fix up some issues in calling do_work_pending()Chris Metcalf2012-05-161-10/+28
| | | | | | | | | | | | | | | | | | | | | | First, we were at risk of handling thread-info flags, in particular do_signal(), when returning from kernel space. This could happen after a failed kernel_execve(), or when forking a kernel thread. The fix is to test in do_work_pending() for user_mode() and return immediately if so; we already had this test for one of the flags, so I just hoisted it to the top of the function. Second, if a ptraced process updated the callee-saved registers in the ptregs struct and then processed another thread-info flag, we would overwrite the modifications with the original callee-saved registers. To fix this, we add a register to note if we've already saved the registers once, and skip doing it on additional passes through the loop. To avoid a performance hit from the couple of extra instructions involved, I modified the GET_THREAD_INFO() macro to be guaranteed to be one instruction, then bundled it with adjacent instructions, yielding an overall net savings. Reported-By: Al Viro <viro@ZenIV.linux.org.uk> Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
* arch/tile: avoid accidentally unmasking NMI-type interrupt accidentallyChris Metcalf2012-04-021-3/+16
| | | | | | | | | | The return path as we reload registers and core state requires that r30 hold a boolean indicating whether we are returning from an NMI, but in a couple of cases we weren't setting this properly, with the result that we could accidentally unmask the NMI interrupt(s), which could cause confusion. Now we set r30 in every place where we jump into the interrupt return path. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
* arch/tile: fix single-stepping over swint1 instructions on tilegxChris Metcalf2012-04-021-3/+18
| | | | | | | | | If we are single-stepping and make a syscall, we call ptrace_notify() explicitly on the return path back to user space, since we are returning to a pc value set artificially to the next instruction, and otherwise we won't register that we stepped over the syscall instruction (swint1). Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
* arch/tile: fix up some minor trap handling issuesChris Metcalf2012-04-021-1/+1
| | | | | | | | | | We now respond to MEM_ERROR traps (e.g. an atomic instruction to non-cacheable memory) with a SIGBUS. We also no longer generate a console crash message if a user process die due to a SIGTRAP. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
* arch/tile: work around a hardware issue with the return-address stackChris Metcalf2012-04-021-0/+12
| | | | | | | In certain circumstances we need to do a bunch of jump-and-link instructions to fill the hardware return-address stack with nonzero values. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
* arch/tile: finish enabling support for TILE-Gx 64-bit chipChris Metcalf2011-05-121-0/+1231
This support was partially present in the existing code (look for "__tilegx__" ifdefs) but with this change you can build a working kernel using the TILE-Gx toolchain and ARCH=tilegx. Most of these files are new, generally adding a foo_64.c file where previously there was just a foo_32.c file. The ARCH=tilegx directive redirects to arch/tile, not arch/tilegx, using the existing SRCARCH mechanism in the top-level Makefile. Changes to existing files: - <asm/bitops.h> and <asm/bitops_32.h> changed to factor the include of <asm-generic/bitops/non-atomic.h> in the common header. - <asm/compat.h> and arch/tile/kernel/compat.c changed to remove the "const" markers I had put on compat_sys_execve() when trying to match some recent similar changes to the non-compat execve. It turns out the compat version wasn't "upgraded" to use const. - <asm/opcode-tile_64.h> and <asm/opcode_constants_64.h> were previously included accidentally, with the 32-bit contents. Now they have the proper 64-bit contents. Finally, I had to hack the existing hacky drivers/input/input-compat.h to add yet another "#ifdef" for INPUT_COMPAT_TEST (same as x86_64). Signed-off-by: Chris Metcalf <cmetcalf@tilera.com> Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> [drivers/input]