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| author | kaf24@scramble.cl.cam.ac.uk <kaf24@scramble.cl.cam.ac.uk> | 2004-03-31 21:42:18 +0000 |
|---|---|---|
| committer | kaf24@scramble.cl.cam.ac.uk <kaf24@scramble.cl.cam.ac.uk> | 2004-03-31 21:42:18 +0000 |
| commit | bc87aae0ec6da1a51e4c1a0c8e238a3f631cff3a (patch) | |
| tree | 339d5ce5d02b38fdfc6dd122d17984faa40893fc /xenolinux-2.4.25-sparse/include/asm-xen/system.h | |
| parent | 3072fef54df8b25abb624a52d0a13bdef9b74b97 (diff) | |
| download | xen-bc87aae0ec6da1a51e4c1a0c8e238a3f631cff3a.tar.gz xen-bc87aae0ec6da1a51e4c1a0c8e238a3f631cff3a.tar.bz2 xen-bc87aae0ec6da1a51e4c1a0c8e238a3f631cff3a.zip | |
bitkeeper revision 1.825.8.1 (406b3b3aiVrvWmI8XjJ_64Sk92hivw)
Many files:
Faster upcall masking from Xen to guest OS.
Diffstat (limited to 'xenolinux-2.4.25-sparse/include/asm-xen/system.h')
| -rw-r--r-- | xenolinux-2.4.25-sparse/include/asm-xen/system.h | 39 |
1 files changed, 26 insertions, 13 deletions
diff --git a/xenolinux-2.4.25-sparse/include/asm-xen/system.h b/xenolinux-2.4.25-sparse/include/asm-xen/system.h index 77b325d61a..86d6c7b150 100644 --- a/xenolinux-2.4.25-sparse/include/asm-xen/system.h +++ b/xenolinux-2.4.25-sparse/include/asm-xen/system.h @@ -302,42 +302,55 @@ static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old, #define safe_halt() ((void)0) -/* - * Note the use of synch_*_bit() operations in the following. These operations - * ensure correct serialisation of checks and updates w.r.t. Xen executing on - * a different CPU. +/* + * The use of 'barrier' in the following reflects their use as local-lock + * operations. Reentrancy must be prevented (e.g., __cli()) /before/ following + * critical operations are executed. All critical operatiosn must complete + * /before/ reentrancy is permitted (e.g., __sti()). Alpha architecture also + * includes these barriers, for example. */ #define __cli() \ do { \ - synch_set_bit(0, &HYPERVISOR_shared_info->evtchn_upcall_mask); \ + HYPERVISOR_shared_info->vcpu_data[0].evtchn_upcall_mask = 1; \ + barrier(); \ } while (0) #define __sti() \ do { \ shared_info_t *_shared = HYPERVISOR_shared_info; \ - synch_clear_bit(0, &_shared->evtchn_upcall_mask); \ - if ( unlikely(synch_test_bit(0, &_shared->evtchn_upcall_pending)) ) \ + barrier(); \ + _shared->vcpu_data[0].evtchn_upcall_mask = 0; \ + if ( unlikely(_shared->vcpu_data[0].evtchn_upcall_pending) ) \ evtchn_do_upcall(NULL); \ } while (0) #define __save_flags(x) \ do { \ - (x) = synch_test_bit(0, &HYPERVISOR_shared_info->evtchn_upcall_mask); \ + (x) = HYPERVISOR_shared_info->vcpu_data[0].evtchn_upcall_mask; \ } while (0) -#define __restore_flags(x) do { if (x) __cli(); else __sti(); } while (0) +#define __restore_flags(x) \ +do { \ + shared_info_t *_shared = HYPERVISOR_shared_info; \ + barrier(); \ + if ( (_shared->vcpu_data[0].evtchn_upcall_mask = x) == 0 ) \ + if ( unlikely(_shared->vcpu_data[0].evtchn_upcall_pending) ) \ + evtchn_do_upcall(NULL); \ +} while (0) #define __save_and_cli(x) \ do { \ - (x) = synch_test_and_set_bit( \ - 0, &HYPERVISOR_shared_info->evtchn_upcall_mask); \ + (x) = HYPERVISOR_shared_info->vcpu_data[0].evtchn_upcall_mask; \ + HYPERVISOR_shared_info->vcpu_data[0].evtchn_upcall_mask = 1; \ + barrier(); \ } while (0) #define __save_and_sti(x) \ do { \ - (x) = synch_test_and_clear_bit( \ - 0, &HYPERVISOR_shared_info->evtchn_upcall_mask); \ + barrier(); \ + (x) = HYPERVISOR_shared_info->vcpu_data[0].evtchn_upcall_mask; \ + HYPERVISOR_shared_info->vcpu_data[0].evtchn_upcall_mask = 0; \ } while (0) #define local_irq_save(x) __save_and_cli(x) |