Changeset eacb957 in mainline
- Timestamp:
- 2009-12-25T19:38:36Z (15 years ago)
- Branches:
- lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export
- Children:
- bb2dbf8
- Parents:
- c26eb39 (diff), 245e8399 (diff)
Note: this is a merge changeset, the changes displayed below correspond to the merge itself.
Use the(diff)
links above to see all the changes relative to each parent. - Files:
-
- 3 edited
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kernel/arch/sparc64/src/context.S
rc26eb39 reacb957 28 28 29 29 #include <arch/context_offset.h> 30 31 /** 32 * Both context_save_arch() and context_restore_arch() are 33 * leaf-optimized procedures. This kind of optimization 34 * is very important and prevents any implicit window 35 * spill/fill/clean traps in these very core kernel 36 * functions. 37 */ 38 39 #include <arch/context_offset.h> 30 #include <arch/arch.h> 31 #include <arch/regdef.h> 40 32 41 33 .text … … 44 36 .global context_restore_arch 45 37 38 /* 39 * context_save_arch() is required not to create its own stack frame. See the 40 * generic context.h for explanation. 41 */ 46 42 context_save_arch: 43 # 44 # Force all our active register windows to memory so that we can find 45 # them there even if e.g. the thread is migrated to another processor. 46 # 47 flushw 48 47 49 CONTEXT_SAVE_ARCH_CORE %o0 48 50 retl … … 51 53 context_restore_arch: 52 54 # 53 # Flush all active windows. 54 # This is essential, because CONTEXT_LOAD overwrites 55 # %sp of CWP - 1 with the value written to %fp of CWP. 56 # Flushing all active windows mitigates this problem 57 # as CWP - 1 becomes the overlap window. 55 # Forget all previous windows, they are not going to be needed again. 56 # Enforce a window fill on the next RESTORE instruction by setting 57 # CANRESTORE to zero and other window configuration registers 58 # accordingly. Note that the same can be achieved by executing the 59 # FLUSHW instruction, but since we don't need to remember the previous 60 # windows, we do the former and save thus some unnecessary window 61 # spills. 58 62 # 59 flushw 60 63 rdpr %pstate, %l0 64 andn %l0, PSTATE_IE_BIT, %l1 65 wrpr %l1, %pstate 66 wrpr %g0, 0, %canrestore 67 wrpr %g0, 0, %otherwin 68 wrpr %g0, NWINDOWS - 2, %cansave 69 wrpr %l0, %pstate 70 61 71 CONTEXT_RESTORE_ARCH_CORE %o0 62 72 retl -
kernel/arch/sparc64/src/trap/trap_table.S
rc26eb39 reacb957 652 652 * spilled to kernel memory (i.e. register window buffer). Moreover, 653 653 * if the scheduler was called in the meantime, all valid windows 654 * belonging to other threads were spilled by context_ restore().654 * belonging to other threads were spilled by context_save(). 655 655 * If OTHERWIN is non-zero, then some userspace windows are still 656 656 * valid. Others might have been spilled. However, the CWP pointer -
uspace/lib/libc/arch/sparc64/src/fibril.S
rc26eb39 reacb957 35 35 36 36 context_save: 37 # 38 # We rely on the kernel to flush our active register windows to memory 39 # should a thread switch occur. 40 # 37 41 CONTEXT_SAVE_ARCH_CORE %o0 38 42 retl … … 42 46 # 43 47 # Flush all active windows. 44 # This is essential, because CONTEXT_LOAD overwrites 45 # %sp of CWP - 1 with the value written to %fp of CWP. 46 # Flushing all active windows mitigates this problem 47 # as CWP - 1 becomes the overlap window. 48 # 48 # This is essential, because CONTEXT_RESTORE_ARCH_CORE overwrites %sp of 49 # CWP - 1 with the value written to %fp of CWP. Flushing all active 50 # windows mitigates this problem as CWP - 1 becomes the overlap window. 51 # 49 52 flushw 50 53
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