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Date:      Thu, 13 Dec 2018 04:48:28 +0000 (UTC)
From:      Justin Hibbits <jhibbits@FreeBSD.org>
To:        src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org
Subject:   svn commit: r342025 - head/sys/powerpc/booke
Message-ID:  <201812130448.wBD4mSNL018582@repo.freebsd.org>

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Author: jhibbits
Date: Thu Dec 13 04:48:28 2018
New Revision: 342025
URL: https://svnweb.freebsd.org/changeset/base/342025

Log:
  powerpcspe: Fix GPR handling in SPE exception handler
  
  Optimize the exception handler to only save and load the upper word of the
  GPRs used in the emulating instruction.  This reduces the save/load
  overhead, and as a side effect does not overwrite the upper word of any
  temporary register.
  
  With this commit I am now able to run editors/abiword and math/gnumeric on a
  e500-based system.
  
  MFC after:	1 week
  MFC With:	r341752,r341751

Modified:
  head/sys/powerpc/booke/spe.c

Modified: head/sys/powerpc/booke/spe.c
==============================================================================
--- head/sys/powerpc/booke/spe.c	Thu Dec 13 04:40:53 2018	(r342024)
+++ head/sys/powerpc/booke/spe.c	Thu Dec 13 04:48:28 2018	(r342025)
@@ -66,7 +66,6 @@ save_vec_int(struct thread *td)
 	 */
 	msr = mfmsr();
 	mtmsr(msr | PSL_VEC);
-	isync();
 
 	/*
 	 * Save the vector registers and SPEFSCR to the PCB
@@ -419,6 +418,52 @@ spe_explode(struct fpemu *fe, struct fpn *fp, uint32_t
 	return (0);
 }
 
+/*
+ * Save the high word of a 64-bit GPR for manipulation in the exception handler.
+ */
+static uint32_t
+spe_save_reg_high(int reg)
+{
+	uint32_t vec[2];
+#define EVSTDW(n)   case n: __asm ("evstdw %1,0(%0)" \
+		:: "b"(vec), "n"(n)); break;
+	switch (reg) {
+	EVSTDW(0);	EVSTDW(1);	EVSTDW(2);	EVSTDW(3);
+	EVSTDW(4);	EVSTDW(5);	EVSTDW(6);	EVSTDW(7);
+	EVSTDW(8);	EVSTDW(9);	EVSTDW(10);	EVSTDW(11);
+	EVSTDW(12);	EVSTDW(13);	EVSTDW(14);	EVSTDW(15);
+	EVSTDW(16);	EVSTDW(17);	EVSTDW(18);	EVSTDW(19);
+	EVSTDW(20);	EVSTDW(21);	EVSTDW(22);	EVSTDW(23);
+	EVSTDW(24);	EVSTDW(25);	EVSTDW(26);	EVSTDW(27);
+	EVSTDW(28);	EVSTDW(29);	EVSTDW(30);	EVSTDW(31);
+	}
+#undef EVSTDW
+
+	return (vec[0]);
+}
+
+/*
+ * Load the given value into the high word of the requested register.
+ */
+static void
+spe_load_reg_high(int reg, uint32_t val)
+{
+#define	EVLDW(n)   case n: __asm __volatile("evmergelo "#n",%0,0," \
+	    :: "r"(val)); break;
+	switch (reg) {
+	EVLDW(1);	EVLDW(2);	EVLDW(3);	EVLDW(4);
+	EVLDW(5);	EVLDW(6);	EVLDW(7);	EVLDW(8);
+	EVLDW(9);	EVLDW(10);	EVLDW(11);	EVLDW(12);
+	EVLDW(13);	EVLDW(14);	EVLDW(15);	EVLDW(16);
+	EVLDW(17);	EVLDW(18);	EVLDW(19);	EVLDW(20);
+	EVLDW(21);	EVLDW(22);	EVLDW(23);	EVLDW(24);
+	EVLDW(25);	EVLDW(26);	EVLDW(27);	EVLDW(28);
+	EVLDW(29);	EVLDW(30);	EVLDW(31);	EVLDW(0);
+	}
+#undef EVLDW
+
+}
+
 void
 spe_handle_fpdata(struct trapframe *frame)
 {
@@ -426,11 +471,12 @@ spe_handle_fpdata(struct trapframe *frame)
 	struct fpn *result;
 	uint32_t instr, instr_sec_op;
 	uint32_t cr_shift, ra, rb, rd, src;
-	uint32_t high, low, res; /* For vector operations. */
+	uint32_t high, low, res, tmp; /* For vector operations. */
 	uint32_t spefscr = 0;
 	uint32_t ftod_res[2];
 	int width; /* Single, Double, Vector, Integer */
 	int err;
+	uint32_t msr;
 
 	err = fueword32((void *)frame->srr0, &instr);
 	
@@ -441,6 +487,7 @@ spe_handle_fpdata(struct trapframe *frame)
 	if ((instr >> OPC_SHIFT) != SPE_OPC)
 		return;
 
+	msr = mfmsr();
 	/*
 	 * 'cr' field is the upper 3 bits of rd.  Magically, since a) rd is 5
 	 * bits, b) each 'cr' field is 4 bits, and c) Only the 'GT' bit is
@@ -460,32 +507,35 @@ spe_handle_fpdata(struct trapframe *frame)
 	width = NONE;
 	switch (src) {
 	case SPE:
-		save_vec_nodrop(curthread);
+		mtmsr(msr | PSL_VEC);
 		switch (instr_sec_op) {
 		case EVFSABS:
-			curthread->td_pcb->pcb_vec.vr[rd][0] = 
-			    curthread->td_pcb->pcb_vec.vr[ra][0] & ~(1U << 31);
+			high = spe_save_reg_high(ra) & ~(1U << 31);
 			frame->fixreg[rd] = frame->fixreg[ra] & ~(1U << 31);
+			spe_load_reg_high(rd, high);
 			break;
 		case EVFSNABS:
-			curthread->td_pcb->pcb_vec.vr[rd][0] = 
-			    curthread->td_pcb->pcb_vec.vr[ra][0] | (1U << 31);
+			high = spe_save_reg_high(ra) | (1U << 31);
 			frame->fixreg[rd] = frame->fixreg[ra] | (1U << 31);
+			spe_load_reg_high(rd, high);
 			break;
 		case EVFSNEG:
-			curthread->td_pcb->pcb_vec.vr[rd][0] = 
-			    curthread->td_pcb->pcb_vec.vr[ra][0] ^ (1U << 31);
+			high = spe_save_reg_high(ra) ^ (1U << 31);
 			frame->fixreg[rd] = frame->fixreg[ra] ^ (1U << 31);
+			spe_load_reg_high(rd, high);
 			break;
 		default:
 			/* High word */
 			spe_explode(&fpemu, &fpemu.fe_f1, SINGLE,
-			    curthread->td_pcb->pcb_vec.vr[ra][0], 0);
+			    spe_save_reg_high(ra), 0);
 			spe_explode(&fpemu, &fpemu.fe_f2, SINGLE,
-			    curthread->td_pcb->pcb_vec.vr[rb][0], 0);
+			    spe_save_reg_high(rb), 0);
 			high = spe_emu_instr(instr_sec_op, &fpemu, &result,
-			    &curthread->td_pcb->pcb_vec.vr[rd][0]);
+			    &tmp);
 
+			if (high < 0)
+				spe_load_reg_high(rd, tmp);
+
 			spefscr = fpscr_to_spefscr(fpemu.fe_cx) << 16;
 			/* Clear the fpemu to start over on the lower bits. */
 			memset(&fpemu, 0, sizeof(fpemu));
@@ -508,7 +558,6 @@ spe_handle_fpdata(struct trapframe *frame)
 				width = VECTOR;
 			break;
 		}
-		enable_vec(curthread);
 		goto end;
 
 	case SPFP:
@@ -524,8 +573,7 @@ spe_handle_fpdata(struct trapframe *frame)
 			break;
 		case EFSCFD:
 			spe_explode(&fpemu, &fpemu.fe_f3, DOUBLE,
-			    curthread->td_pcb->pcb_vec.vr[rb][0],
-			    frame->fixreg[rb]);
+			    spe_save_reg_high(rb), frame->fixreg[rb]);
 			result = &fpemu.fe_f3;
 			width = SINGLE;
 			break;
@@ -538,25 +586,22 @@ spe_handle_fpdata(struct trapframe *frame)
 		}
 		break;
 	case DPFP:
-		save_vec_nodrop(curthread);
+		mtmsr(msr | PSL_VEC);
 		switch (instr_sec_op) {
 		case EFDABS:
-			curthread->td_pcb->pcb_vec.vr[rd][0] = 
-			    curthread->td_pcb->pcb_vec.vr[ra][0] & ~(1U << 31);
+			high = spe_save_reg_high(ra) & ~(1U << 31);
 			frame->fixreg[rd] = frame->fixreg[ra];
-			enable_vec(curthread);
+			spe_load_reg_high(rd, high);
 			break;
 		case EFDNABS:
-			curthread->td_pcb->pcb_vec.vr[rd][0] = 
-			    curthread->td_pcb->pcb_vec.vr[ra][0] | (1U << 31);
+			high = spe_save_reg_high(ra) | (1U << 31);
 			frame->fixreg[rd] = frame->fixreg[ra];
-			enable_vec(curthread);
+			spe_load_reg_high(rd, high);
 			break;
 		case EFDNEG:
-			curthread->td_pcb->pcb_vec.vr[rd][0] = 
-			    curthread->td_pcb->pcb_vec.vr[ra][0] ^ (1U << 31);
+			high = spe_save_reg_high(ra) ^ (1U << 31);
 			frame->fixreg[rd] = frame->fixreg[ra];
-			enable_vec(curthread);
+			spe_load_reg_high(rd, high);
 			break;
 		case EFDCFS:
 			spe_explode(&fpemu, &fpemu.fe_f3, SINGLE,
@@ -566,11 +611,9 @@ spe_handle_fpdata(struct trapframe *frame)
 			break;
 		default:
 			spe_explode(&fpemu, &fpemu.fe_f1, DOUBLE,
-			    curthread->td_pcb->pcb_vec.vr[ra][0],
-			    frame->fixreg[ra]);
+			    spe_save_reg_high(ra), frame->fixreg[ra]);
 			spe_explode(&fpemu, &fpemu.fe_f2, DOUBLE,
-			    curthread->td_pcb->pcb_vec.vr[rb][0],
-			    frame->fixreg[rb]);
+			    spe_save_reg_high(rb), frame->fixreg[rb]);
 			width = DOUBLE;
 		}
 		break;
@@ -609,10 +652,8 @@ spe_handle_fpdata(struct trapframe *frame)
 			frame->fixreg[rd] = fpu_ftos(&fpemu, result);
 			break;
 		case DOUBLE:
-			curthread->td_pcb->pcb_vec.vr[rd][0] =
-			    fpu_ftod(&fpemu, result, ftod_res);
+			spe_load_reg_high(rd, fpu_ftod(&fpemu, result, ftod_res));
 			frame->fixreg[rd] = ftod_res[1];
-			enable_vec(curthread);
 			break;
 		default:
 			panic("Unknown storage width %d", width);
@@ -624,6 +665,7 @@ end:
 	spefscr |= (mfspr(SPR_SPEFSCR) & ~SPEFSCR_FINVS);
 	mtspr(SPR_SPEFSCR, spefscr);
 	frame->srr0 += 4;
+	mtmsr(msr);
 
 	return;
 }



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