SYSENTER/SYSCALL support

. add cpufeature detection of both
	. use it for both ipc and kernelcall traps, using a register
	  for call number
	. SYSENTER/SYSCALL does not save any context, therefore userland
	  has to save it
	. to accomodate multiple kernel entry/exit types, the entry
	  type is recorded in the process struct. hitherto all types
	  were interrupt (soft int, exception, hard int); now SYSENTER/SYSCALL
	  is new, with the difference that context is not fully restored
	  from proc struct when running the process again. this can't be
	  done as some information is missing.
	. complication: cases in which the kernel has to fully change
	  process context (i.e. sigreturn). in that case the exit type
	  is changed from SYSENTER/SYSEXIT to soft-int (i.e. iret) and
	  context is fully restored from the proc struct. this does mean
	  the PC and SP must change, as the sysenter/sysexit userland code
	  will otherwise try to restore its own context. this is true in the
	  sigreturn case.
	. override all usage by setting libc_ipc=1

include/arch/i386/include/archtypes.h

@@ -33,6 +33,7 @@ typedef struct segframe {
 	reg_t	p_cr3;		/* page table root */
 	u32_t	*p_cr3_v;
 	char	*fpu_state;
+	int	p_kern_trap_style;
 } segframe_t;
 
 struct cpu_info {

include/arch/i386/include/asm.h

@@ -218,6 +218,13 @@
 #ifdef __minix
 #define IMPORT(sym)               \
         .extern _C_LABEL(sym)
+
+#define KERVEC_ORIG 32     /* syscall trap to kernel */
+#define IPCVEC_ORIG 33     /* ipc trap to kernel  */
+
+#define KERVEC_UM 34     /* syscall trap to kernel, user-mapped code */
+#define IPCVEC_UM 35     /* ipc trap to kernel, user-mapped code  */
+
 #endif
 
 #endif /* !_I386_ASM_H_ */

include/arch/i386/include/interrupt.h

@@ -25,8 +25,10 @@
 #define OVERFLOW_VECTOR    4	/* from INTO */
 
 /* Fixed system call vector. */
-#define KERN_CALL_VECTOR  32	/* system calls are made with int SYSVEC */
-#define IPC_VECTOR        33	/* interrupt vector for ipc */
+#define KERN_CALL_VECTOR_ORIG  32 /* system calls are made with int SYSVEC */
+#define IPC_VECTOR_ORIG        33 /* interrupt vector for ipc */
+#define KERN_CALL_VECTOR_UM    34 /* user-mapped equivalent */
+#define IPC_VECTOR_UM          35 /* user-mapped equivalent */
 
 /* Hardware interrupt numbers. */
 #ifndef USE_APIC

include/arch/i386/include/vm.h

@@ -73,6 +73,7 @@ i386/vm.h
 /* CPUID flags */
 #define CPUID1_EDX_FPU		(1L)		/* FPU presence */
 #define CPUID1_EDX_PSE 		(1L <<  3)	/* Page Size Extension */
+#define CPUID1_EDX_SYSENTER	(1L << 11)	/* Intel SYSENTER */
 #define CPUID1_EDX_PGE 		(1L << 13)	/* Page Global (bit) Enable */
 #define CPUID1_EDX_APIC_ON_CHIP (1L << 9)	/* APIC is present on the chip */
 #define CPUID1_EDX_TSC		(1L << 4)	/* Timestamp counter present */
@@ -85,6 +86,8 @@ i386/vm.h
 #define CPUID1_ECX_SSE4_1	(1L << 19)
 #define CPUID1_ECX_SSE4_2	(1L << 20)
 
+#define CPUID_EF_EDX_SYSENTER	(1L << 11)	/* Intel SYSENTER */
+
 #ifndef __ASSEMBLY__
 
 #include <minix/type.h>

include/minix/com.h

@@ -629,6 +629,7 @@
 #define VMCTL_VMINHIBIT_SET	30
 #define VMCTL_VMINHIBIT_CLEAR	31
 #define VMCTL_CLEARMAPCACHE	32
+#define VMCTL_BOOTINHIBIT_CLEAR	33
 
 /* Codes and field names for SYS_SYSCTL. */
 #define SYSCTL_CODE		m1_i1	/* SYSCTL_CODE_* below */

include/minix/const.h

@@ -173,4 +173,8 @@
 /* magic value to put in struct proc entries for sanity checks. */
 #define PMAGIC 0xC0FFEE1
 
+/* MINIX_KERNFLAGS flags */
+#define MKF_I386_INTEL_SYSENTER	(1L << 0) /* SYSENTER available and supported */
+#define MKF_I386_AMD_SYSCALL	(1L << 1) /* SYSCALL available and supported */
+
 #endif /* _MINIX_CONST_H */

include/minix/cpufeature.h

@@ -21,6 +21,10 @@
 #define _CPUF_I386_HTT		13	/* Supports HTT */
 #define _CPUF_I386_HTT_MAX_NUM	14	/* Maximal num of threads */
 
+#define _CPUF_I386_MTRR		15
+#define _CPUF_I386_SYSENTER	16	/* Intel SYSENTER instrs */
+#define _CPUF_I386_SYSCALL	17	/* AMD SYSCALL instrs */
+
 int _cpufeature(int featureno);
 
 #endif

include/minix/ipc.h

@@ -5,6 +5,7 @@
 #endif
 #include <minix/ipcconst.h>
 #include <minix/type.h>
+#include <minix/const.h>
 
 /*==========================================================================* 
  * Types relating to messages. 						    *
@@ -152,24 +153,37 @@ typedef struct asynmsg
 #define AMF_NOTIFY_ERR	020	/* Send a notification when AMF_DONE is set and
 				 * delivery of the message failed */
 
-/* Hide names to avoid name space pollution. */
-#define echo		_echo
-#define notify		_notify
-#define sendrec		_sendrec
-#define receive		_receive
-#define send		_send
-#define sendnb		_sendnb
-#define senda		_senda
+int _send_orig(endpoint_t dest, message *m_ptr);
+int _receive_orig(endpoint_t src, message *m_ptr, int *status_ptr);
+int _sendrec_orig(endpoint_t src_dest, message *m_ptr);
+int _sendnb_orig(endpoint_t dest, message *m_ptr);
+int _notify_orig(endpoint_t dest);
+int _senda_orig(asynmsg_t *table, size_t count);
+int _do_kernel_call_orig(message *m_ptr);
 
-int echo(message *m_ptr);
-int notify(endpoint_t dest);
-int sendrec(endpoint_t src_dest, message *m_ptr);
-int receive(endpoint_t src, message *m_ptr, int *status_ptr);
-int send(endpoint_t dest, message *m_ptr);
-int sendnb(endpoint_t dest, message *m_ptr);
-int senda(asynmsg_t *table, size_t count);
 int _minix_kernel_info_struct(struct minix_kerninfo **);
 
-int _do_kernel_call(message *m_ptr);
+struct minix_ipcvecs {
+	int (*send_ptr)(endpoint_t dest, message *m_ptr);
+	int (*receive_ptr)(endpoint_t src, message *m_ptr, int *st);
+	int (*sendrec_ptr)(endpoint_t src_dest, message *m_ptr);
+	int (*sendnb_ptr)(endpoint_t dest, message *m_ptr);
+	int (*notify_ptr)(endpoint_t dest);
+	int (*do_kernel_call_ptr)(message *m_ptr);
+	int (*senda_ptr)(asynmsg_t *table, size_t count);
+};
+
+/* kernel-set IPC vectors retrieved by a constructor in libc/sys-minix/init.c */
+extern struct minix_ipcvecs _minix_ipcvecs;
+
+#define CHOOSETRAP(name) (_minix_ipcvecs. name ## _ptr)
+
+#define send		CHOOSETRAP(send)
+#define receive		CHOOSETRAP(receive)
+#define sendrec		CHOOSETRAP(sendrec)
+#define sendnb		CHOOSETRAP(sendnb)
+#define notify		CHOOSETRAP(notify)
+#define do_kernel_call	CHOOSETRAP(do_kernel_call)
+#define senda		CHOOSETRAP(senda)
 
 #endif /* _IPC_H */

include/minix/type.h

@@ -168,8 +168,8 @@ struct minix_kerninfo {
 	 */
 #define KERNINFO_MAGIC 0xfc3b84bf
 	u32_t kerninfo_magic;
-	u32_t minix_feature_flags;
-	u32_t flags_unused1;
+	u32_t minix_feature_flags;	/* features in minix kernel */
+	u32_t ki_flags;			/* what is present in this struct */
 	u32_t flags_unused2;
 	u32_t flags_unused3;
 	u32_t flags_unused4;
@@ -177,7 +177,10 @@ struct minix_kerninfo {
 	struct machine		*machine;
 	struct kmessages	*kmessages;
 	struct loadinfo		*loadinfo;
+	struct minix_ipcvecs	*minix_ipcvecs;
 } __packed;
 
+#define MINIX_KIF_IPCVECS	(1L << 0)
+
 #endif /* _TYPE_H */