patch-2.4.0-test2 linux/arch/ia64/kernel/brl_emu.c

• Lines: 221
• Date: Thu Jun 22 07:09:44 2000
• Orig file: v2.4.0-test1/linux/arch/ia64/kernel/brl_emu.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.4.0-test1/linux/arch/ia64/kernel/brl_emu.c linux/arch/ia64/kernel/brl_emu.c
@@ -0,0 +1,220 @@
+/*
+ *  Emulation of the "brl" instruction for IA64 processors that
+ *  don't support it in hardware. 
+ *  Author: Stephan Zeisset, Intel Corp. <Stephan.Zeisset@intel.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <asm/uaccess.h>
+#include <asm/processor.h>
+
+extern char ia64_set_b1, ia64_set_b2, ia64_set_b3, ia64_set_b4, ia64_set_b5;
+
+struct illegal_op_return {
+	unsigned long fkt, arg1, arg2, arg3;
+};
+
+/*
+ *  The unimplemented bits of a virtual address must be set
+ *  to the value of the most significant implemented bit.
+ *  unimpl_va_mask includes all unimplemented bits and
+ *  the most significant implemented bit, so the result
+ *  of an and operation with the mask must be all 0's
+ *  or all 1's for the address to be valid.
+ */
+#define unimplemented_virtual_address(va) (					\
+	((va) & my_cpu_data.unimpl_va_mask) != 0 &&				\
+	((va) & my_cpu_data.unimpl_va_mask) != my_cpu_data.unimpl_va_mask	\
+)
+
+/*
+ *  The unimplemented bits of a physical address must be 0.
+ *  unimpl_pa_mask includes all unimplemented bits, so the result
+ *  of an and operation with the mask must be all 0's for the
+ *  address to be valid.
+ */
+#define unimplemented_physical_address(pa) (		\
+	((pa) & my_cpu_data.unimpl_pa_mask) != 0	\
+)
+
+/*
+ *  Handle an illegal operation fault that was caused by an 
+ *  unimplemented "brl" instruction.
+ *  If we are not successful (e.g because the illegal operation 
+ *  wasn't caused by a "brl" after all), we return -1.
+ *  If we are successful, we return either 0 or the address
+ *  of a "fixup" function for manipulating preserved register
+ *  state.
+ */
+
+struct illegal_op_return
+ia64_emulate_brl (struct pt_regs *regs, unsigned long ar_ec)
+{
+	unsigned long bundle[2];
+	unsigned long opcode, btype, qp, offset;
+	unsigned long next_ip;
+	struct siginfo siginfo;
+	struct illegal_op_return rv;
+	int tmp_taken, unimplemented_address;
+
+	rv.fkt = (unsigned long) -1;
+
+	/*
+	 *  Decode the instruction bundle.
+	 */
+
+        if (copy_from_user(bundle, (void *) (regs->cr_iip), sizeof(bundle)))
+                return rv; 
+
+	next_ip = (unsigned long) regs->cr_iip + 16;
+
+	/* "brl" must be in slot 2. */
+	if (ia64_psr(regs)->ri != 1) return rv;
+
+	/* Must be "mlx" template */
+	if ((bundle[0] & 0x1e) != 0x4) return rv;
+
+	opcode = (bundle[1] >> 60);
+	btype = ((bundle[1] >> 29) & 0x7);
+	qp = ((bundle[1] >> 23) & 0x3f);
+	offset = ((bundle[1] & 0x0800000000000000L) << 4)
+		| ((bundle[1] & 0x00fffff000000000L) >> 32) 
+		| ((bundle[1] & 0x00000000007fffffL) << 40)
+		| ((bundle[0] & 0xffff000000000000L) >> 24);
+
+	tmp_taken = regs->pr & (1L << qp);
+
+	switch(opcode) {
+		
+		case 0xC:
+			/*
+			 *  Long Branch.
+			 */
+			if (btype != 0) return rv;
+			rv.fkt = 0;
+			if (!(tmp_taken)) {
+				/*
+				 *  Qualifying predicate is 0.
+				 *  Skip instruction.
+				 */
+				regs->cr_iip = next_ip;
+				ia64_psr(regs)->ri = 0;
+				return rv;
+			}
+			break;
+
+		case 0xD:
+			/*
+			 *  Long Call.
+			 */
+			rv.fkt = 0;
+			if (!(tmp_taken)) {
+				/*
+				 *  Qualifying predicate is 0.
+				 *  Skip instruction.
+				 */
+				regs->cr_iip = next_ip;
+				ia64_psr(regs)->ri = 0;
+				return rv;
+			}
+
+			/*
+			 *  BR[btype] = IP+16
+			 */
+			switch(btype) {
+				case 0:
+					regs->b0 = next_ip;
+					break;
+				case 1:
+					rv.fkt = (unsigned long) &ia64_set_b1;
+					break;
+				case 2:
+					rv.fkt = (unsigned long) &ia64_set_b2;
+					break;
+				case 3:
+					rv.fkt = (unsigned long) &ia64_set_b3;
+					break;
+				case 4:
+					rv.fkt = (unsigned long) &ia64_set_b4;
+					break;
+				case 5:
+					rv.fkt = (unsigned long) &ia64_set_b5;
+					break;
+				case 6:
+					regs->b6 = next_ip;
+					break;
+				case 7:
+					regs->b7 = next_ip;
+					break;
+			}
+			rv.arg1 = next_ip;
+
+			/*
+			 *  AR[PFS].pfm = CFM
+			 *  AR[PFS].pec = AR[EC]
+			 *  AR[PFS].ppl = PSR.cpl
+			 */
+			regs->ar_pfs = ((regs->cr_ifs & 0x3fffffffff)
+					| (ar_ec << 52)
+					| ((unsigned long) ia64_psr(regs)->cpl << 62));
+
+			/*
+			 *  CFM.sof -= CFM.sol
+			 *  CFM.sol = 0
+			 *  CFM.sor = 0
+			 *  CFM.rrb.gr = 0
+			 *  CFM.rrb.fr = 0
+			 *  CFM.rrb.pr = 0
+			 */
+			regs->cr_ifs = ((regs->cr_ifs & 0xffffffc00000007f)
+					- ((regs->cr_ifs >> 7) & 0x7f));
+				
+			break;
+
+		default:
+			/*
+			 *  Unknown opcode.
+			 */
+			return rv;
+
+	}
+
+	regs->cr_iip += offset; 
+	ia64_psr(regs)->ri = 0;
+
+	if (ia64_psr(regs)->it == 0)
+		unimplemented_address = unimplemented_physical_address(regs->cr_iip);
+	else
+		unimplemented_address = unimplemented_virtual_address(regs->cr_iip);
+
+	if (unimplemented_address) { 
+		/*
+		 *  The target address contains unimplemented bits.
+		 */
+		printk("Woah! Unimplemented Instruction Address Trap!\n");
+		siginfo.si_signo = SIGILL;
+		siginfo.si_errno = 0;
+		siginfo.si_code = ILL_BADIADDR;
+		force_sig_info(SIGILL, &siginfo, current);
+	} else if (ia64_psr(regs)->tb) {
+		/*
+		 *  Branch Tracing is enabled.
+		 *  Force a taken branch signal.
+		 */
+		siginfo.si_signo = SIGTRAP;
+		siginfo.si_errno = 0;
+		siginfo.si_code = TRAP_BRANCH;
+		force_sig_info(SIGTRAP, &siginfo, current);
+	} else if (ia64_psr(regs)->ss) {
+		/*
+		 *  Single Step is enabled.
+		 *  Force a trace signal.
+		 */
+		siginfo.si_signo = SIGTRAP;
+		siginfo.si_errno = 0;
+		siginfo.si_code = TRAP_TRACE;
+		force_sig_info(SIGTRAP, &siginfo, current);
+	}
+	return rv;
+}