+
+
+/*
+ * The shared kernel/user "comm page(s)":
+ *
+ * The last eight pages of every address space are reserved for the kernel/user
+ * "comm area". Because they can be addressed via a sign-extended 16-bit field,
+ * it is particularly efficient to access code or data in the comm area with
+ * absolute branches (ba, bla, bca) or absolute load/stores ("lwz r0,-4096(0)").
+ * Because the comm area can be reached from anywhere, dyld is not needed.
+ * Although eight pages are reserved, presently only two are populated and mapped.
+ *
+ * Routines on the comm page(s) can be thought of as the firmware for extended processor
+ * instructions, whose opcodes are special forms of "bla". Ie, they are cpu
+ * capabilities. During system initialization, the kernel populates the comm page with
+ * code customized for the particular processor and platform.
+ *
+ * Because Mach VM cannot map the last page of an address space, the max length of
+ * the comm area is seven pages.
+ */
+
+#define _COMM_PAGE_BASE_ADDRESS (-8*4096) // start at page -8, ie 0xFFFF8000
+#define _COMM_PAGE_AREA_LENGTH ( 7*4096) // reserved length of entire comm area
+#define _COMM_PAGE_AREA_USED ( 2*4096) // we use two pages so far
+
+/* The following set of definitions are used in the kernel, which needs to distinguish between
+ * the 32 and 64-bit commpage addresses and lengths. On PPC they are the same, but on Imtel
+ * they are not.
+ */
+#define _COMM_PAGE32_BASE_ADDRESS ( _COMM_PAGE_BASE_ADDRESS )
+#define _COMM_PAGE64_BASE_ADDRESS ( _COMM_PAGE_BASE_ADDRESS )
+#define _COMM_PAGE32_AREA_LENGTH ( _COMM_PAGE_AREA_LENGTH )
+#define _COMM_PAGE64_AREA_LENGTH ( _COMM_PAGE_AREA_LENGTH )
+#define _COMM_PAGE32_AREA_USED ( _COMM_PAGE_AREA_USED )
+#define _COMM_PAGE64_AREA_USED ( _COMM_PAGE_AREA_USED )
+
+/* The Objective-C runtime fixed address page to optimize message dispatch */
+#define _OBJC_PAGE_BASE_ADDRESS (-20*4096) // start at page -20, ie 0xFFFEC000
+
+/*
+ * Objective-C needs an "absolute" area all the way up to the top of the
+ * address space.
+ * For a ppc32 task, that area gets allocated at runtime from user space.
+ * For a ppc64 task, that area is not within the user-accessible address range,
+ * so we pre-allocate it at exec time (see vm_map_exec()) along with the
+ * comm page.
+ *
+ * NOTE: that means we can't "nest" the 64-bit comm page...
+ */
+#define _COMM_PAGE32_OBJC_SIZE 0ULL
+#define _COMM_PAGE32_OBJC_BASE 0ULL
+#if 0
+#define _COMM_PAGE64_OBJC_SIZE (4 * 4096)
+#define _COMM_PAGE64_OBJC_BASE (_OBJC_PAGE_BASE_ADDRESS)
+#else
+/*
+ * PPC51: ppc64 is limited to 51-bit addresses.
+ * PPC64 has a 51-bit address space limit, so we can't just go and
+ * map the Obj-C area up there. We would have to create a nested pmap
+ * and make a special mapping that redirects the large virtual addresses to
+ * that other address space with lower addresses that fit within the 51-bit
+ * limit.
+ * VM would then have to handle this redirection when we fault one
+ * of these pages in but it doesn't do that at this point, so no
+ * Obj-C area for ppc64 for now :-(
+ */
+#define _COMM_PAGE64_OBJC_SIZE 0ULL
+#define _COMM_PAGE64_OBJC_BASE 0ULL
+#endif
+
+/* data in the comm page */
+
+#define _COMM_PAGE_SIGNATURE (_COMM_PAGE_BASE_ADDRESS+0x000) // first few bytes are a signature
+#define _COMM_PAGE_VERSION (_COMM_PAGE_BASE_ADDRESS+0x01E) // 16-bit version#
+#define _COMM_PAGE_THIS_VERSION 2 // this is version 2 of the commarea format
+
+#define _COMM_PAGE_CPU_CAPABILITIES (_COMM_PAGE_BASE_ADDRESS+0x020) // mirror of extern int _cpu_capabilities
+#define _COMM_PAGE_NCPUS (_COMM_PAGE_BASE_ADDRESS+0x021) // number of configured CPUs
+#define _COMM_PAGE_ALTIVEC (_COMM_PAGE_BASE_ADDRESS+0x024) // nonzero if Altivec available
+#define _COMM_PAGE_64_BIT (_COMM_PAGE_BASE_ADDRESS+0x025) // nonzero if 64-bit processor
+#define _COMM_PAGE_CACHE_LINESIZE (_COMM_PAGE_BASE_ADDRESS+0x026) // cache line size (16-bit field)
+
+#define _COMM_PAGE_UNUSED1 (_COMM_PAGE_BASE_ADDRESS+0x028) // 24 unused bytes
+
+#define _COMM_PAGE_2_TO_52 (_COMM_PAGE_BASE_ADDRESS+0x040) // double float constant 2**52
+#define _COMM_PAGE_10_TO_6 (_COMM_PAGE_BASE_ADDRESS+0x048) // double float constant 10**6
+#define _COMM_PAGE_MAGIC_FE (_COMM_PAGE_BASE_ADDRESS+0x050) // magic constant 0xFEFEFEFEFEFEFEFF (to find 0s)
+#define _COMM_PAGE_MAGIC_80 (_COMM_PAGE_BASE_ADDRESS+0x058) // magic constant 0x8080808080808080 (to find 0s)
+
+#define _COMM_PAGE_TIMEBASE (_COMM_PAGE_BASE_ADDRESS+0x060) // used by gettimeofday()
+#define _COMM_PAGE_TIMESTAMP (_COMM_PAGE_BASE_ADDRESS+0x068) // used by gettimeofday()
+#define _COMM_PAGE_SEC_PER_TICK (_COMM_PAGE_BASE_ADDRESS+0x070) // used by gettimeofday()
+
+ /* jump table (bla to this address, which may be a branch to the actual code somewhere else) */
+ /* When new jump table entries are added, corresponding symbols should be added below */
+
+#define _COMM_PAGE_COMPARE_AND_SWAP32 (_COMM_PAGE_BASE_ADDRESS+0x080) // compare-and-swap word, no barrier
+#define _COMM_PAGE_COMPARE_AND_SWAP64 (_COMM_PAGE_BASE_ADDRESS+0x0c0) // compare-and-swap doubleword, no barrier
+#define _COMM_PAGE_ENQUEUE (_COMM_PAGE_BASE_ADDRESS+0x100) // enqueue
+#define _COMM_PAGE_DEQUEUE (_COMM_PAGE_BASE_ADDRESS+0x140) // dequeue
+#define _COMM_PAGE_MEMORY_BARRIER (_COMM_PAGE_BASE_ADDRESS+0x180) // memory barrier
+#define _COMM_PAGE_ATOMIC_ADD32 (_COMM_PAGE_BASE_ADDRESS+0x1a0) // add atomic word
+#define _COMM_PAGE_ATOMIC_ADD64 (_COMM_PAGE_BASE_ADDRESS+0x1c0) // add atomic doubleword
+
+#define _COMM_PAGE_UNUSED3 (_COMM_PAGE_BASE_ADDRESS+0x1e0) // 32 unused bytes
+
+#define _COMM_PAGE_ABSOLUTE_TIME (_COMM_PAGE_BASE_ADDRESS+0x200) // mach_absolute_time()
+#define _COMM_PAGE_SPINLOCK_TRY (_COMM_PAGE_BASE_ADDRESS+0x220) // spinlock_try()
+#define _COMM_PAGE_SPINLOCK_LOCK (_COMM_PAGE_BASE_ADDRESS+0x260) // spinlock_lock()
+#define _COMM_PAGE_SPINLOCK_UNLOCK (_COMM_PAGE_BASE_ADDRESS+0x2a0) // spinlock_unlock()
+#define _COMM_PAGE_PTHREAD_GETSPECIFIC (_COMM_PAGE_BASE_ADDRESS+0x2c0) // pthread_getspecific()
+#define _COMM_PAGE_GETTIMEOFDAY (_COMM_PAGE_BASE_ADDRESS+0x2e0) // used by gettimeofday()
+#define _COMM_PAGE_FLUSH_DCACHE (_COMM_PAGE_BASE_ADDRESS+0x4e0) // sys_dcache_flush()
+#define _COMM_PAGE_FLUSH_ICACHE (_COMM_PAGE_BASE_ADDRESS+0x520) // sys_icache_invalidate()
+#define _COMM_PAGE_PTHREAD_SELF (_COMM_PAGE_BASE_ADDRESS+0x580) // pthread_self()
+
+#define _COMM_PAGE_UNUSED4 (_COMM_PAGE_BASE_ADDRESS+0x5a0) // 32 unused bytes
+
+#define _COMM_PAGE_RELINQUISH (_COMM_PAGE_BASE_ADDRESS+0x5c0) // used by spinlocks
+
+#define _COMM_PAGE_UNUSED5 (_COMM_PAGE_BASE_ADDRESS+0x5e0) // 32 unused bytes
+
+#define _COMM_PAGE_BZERO (_COMM_PAGE_BASE_ADDRESS+0x600) // bzero()
+#define _COMM_PAGE_BCOPY (_COMM_PAGE_BASE_ADDRESS+0x780) // bcopy()
+#define _COMM_PAGE_MEMCPY (_COMM_PAGE_BASE_ADDRESS+0x7a0) // memcpy()
+#define _COMM_PAGE_MEMMOVE (_COMM_PAGE_BASE_ADDRESS+0x7a0) // memmove()
+
+#define _COMM_PAGE_COMPARE_AND_SWAP32B (_COMM_PAGE_BASE_ADDRESS+0xf80) // compare-and-swap word w barrier
+#define _COMM_PAGE_COMPARE_AND_SWAP64B (_COMM_PAGE_BASE_ADDRESS+0xfc0) // compare-and-swap doubleword w barrier
+
+#define _COMM_PAGE_MEMSET_PATTERN (_COMM_PAGE_BASE_ADDRESS+0x1000)// used by nonzero memset()
+#define _COMM_PAGE_BIGCOPY (_COMM_PAGE_BASE_ADDRESS+0x1140)// very-long-operand copies
+
+#define _COMM_PAGE_END (_COMM_PAGE_BASE_ADDRESS+0x1700)// end of commpage area
+
+#ifdef __ASSEMBLER__
+#ifdef __COMM_PAGE_SYMBOLS
+
+#define CREATE_COMM_PAGE_SYMBOL(symbol_name, symbol_address) \
+ .org (symbol_address - _COMM_PAGE_BASE_ADDRESS) @\
+symbol_name: nop
+
+ .text // Required to make a well behaved symbol file
+
+ CREATE_COMM_PAGE_SYMBOL(___compare_and_swap32, _COMM_PAGE_COMPARE_AND_SWAP32)
+ CREATE_COMM_PAGE_SYMBOL(___compare_and_swap64, _COMM_PAGE_COMPARE_AND_SWAP64)
+ CREATE_COMM_PAGE_SYMBOL(___atomic_enqueue, _COMM_PAGE_ENQUEUE)
+ CREATE_COMM_PAGE_SYMBOL(___atomic_dequeue, _COMM_PAGE_DEQUEUE)
+ CREATE_COMM_PAGE_SYMBOL(___memory_barrier, _COMM_PAGE_MEMORY_BARRIER)
+ CREATE_COMM_PAGE_SYMBOL(___atomic_add32, _COMM_PAGE_ATOMIC_ADD32)
+ CREATE_COMM_PAGE_SYMBOL(___atomic_add64, _COMM_PAGE_ATOMIC_ADD64)
+ CREATE_COMM_PAGE_SYMBOL(___mach_absolute_time, _COMM_PAGE_ABSOLUTE_TIME)
+ CREATE_COMM_PAGE_SYMBOL(___spin_lock_try, _COMM_PAGE_SPINLOCK_TRY)
+ CREATE_COMM_PAGE_SYMBOL(___spin_lock, _COMM_PAGE_SPINLOCK_LOCK)
+ CREATE_COMM_PAGE_SYMBOL(___spin_unlock, _COMM_PAGE_SPINLOCK_UNLOCK)
+ CREATE_COMM_PAGE_SYMBOL(___pthread_getspecific, _COMM_PAGE_PTHREAD_GETSPECIFIC)
+ CREATE_COMM_PAGE_SYMBOL(___gettimeofday, _COMM_PAGE_GETTIMEOFDAY)
+ CREATE_COMM_PAGE_SYMBOL(___sys_dcache_flush, _COMM_PAGE_FLUSH_DCACHE)
+ CREATE_COMM_PAGE_SYMBOL(___sys_icache_invalidate, _COMM_PAGE_FLUSH_ICACHE)
+ CREATE_COMM_PAGE_SYMBOL(___pthread_self, _COMM_PAGE_PTHREAD_SELF)
+ CREATE_COMM_PAGE_SYMBOL(___spin_lock_relinquish, _COMM_PAGE_RELINQUISH)
+ CREATE_COMM_PAGE_SYMBOL(___bzero, _COMM_PAGE_BZERO)
+ CREATE_COMM_PAGE_SYMBOL(___bcopy, _COMM_PAGE_BCOPY)
+ CREATE_COMM_PAGE_SYMBOL(___memcpy, _COMM_PAGE_MEMCPY)
+// CREATE_COMM_PAGE_SYMBOL(___memmove, _COMM_PAGE_MEMMOVE)
+ CREATE_COMM_PAGE_SYMBOL(___compare_and_swap32b, _COMM_PAGE_COMPARE_AND_SWAP32B)
+ CREATE_COMM_PAGE_SYMBOL(___compare_and_swap64b, _COMM_PAGE_COMPARE_AND_SWAP64B)
+ CREATE_COMM_PAGE_SYMBOL(___memset_pattern, _COMM_PAGE_MEMSET_PATTERN)
+ CREATE_COMM_PAGE_SYMBOL(___bigcopy, _COMM_PAGE_BIGCOPY)
+
+ CREATE_COMM_PAGE_SYMBOL(___end_comm_page, _COMM_PAGE_END)
+
+ .data // Required to make a well behaved symbol file
+ .long 0 // Required to make a well behaved symbol file
+
+#endif /* __COMM_PAGE_SYMBOLS */
+#endif /* __ASSEMBLER__ */
+
projects / apple / xnu.git / blobdiff