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From: Anton Blanchard <anton@samba.org>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
	Paul Mackerras <paulus@samba.org>
Cc: linuxppc-dev@lists.ozlabs.org
Subject: [PATCH 16/39] powerpc: Handle VSX alignment faults in little endian mode
Date: Mon, 23 Sep 2013 12:04:50 +1000	[thread overview]
Message-ID: <1379901913-5945-17-git-send-email-anton@samba.org> (raw)
In-Reply-To: <1379901913-5945-1-git-send-email-anton@samba.org>

Things are complicated by the fact that VSX elements are big
endian ordered even in little endian mode. 8 byte loads and
stores also write to the top 8 bytes of the register.

Signed-off-by: Anton Blanchard <anton@samba.org>
---
 arch/powerpc/kernel/align.c | 41 +++++++++++++++++++++++++++++++++--------
 1 file changed, 33 insertions(+), 8 deletions(-)

diff --git a/arch/powerpc/kernel/align.c b/arch/powerpc/kernel/align.c
index cce82b1..59f70ad 100644
--- a/arch/powerpc/kernel/align.c
+++ b/arch/powerpc/kernel/align.c
@@ -630,7 +630,7 @@ static int emulate_spe(struct pt_regs *regs, unsigned int reg,
 }
 #endif /* CONFIG_SPE */
 
-#if defined(CONFIG_VSX) && defined(__BIG_ENDIAN__)
+#ifdef CONFIG_VSX
 /*
  * Emulate VSX instructions...
  */
@@ -658,8 +658,25 @@ static int emulate_vsx(unsigned char __user *addr, unsigned int reg,
 
 	lptr = (unsigned long *) ptr;
 
+#ifdef __LITTLE_ENDIAN__
+	if (flags & SW) {
+		elsize = length;
+		sw = length-1;
+	} else {
+		/*
+		 * The elements are BE ordered, even in LE mode, so process
+		 * them in reverse order.
+		 */
+		addr += length - elsize;
+
+		/* 8 byte memory accesses go in the top 8 bytes of the VR */
+		if (length == 8)
+			ptr += 8;
+	}
+#else
 	if (flags & SW)
 		sw = elsize-1;
+#endif
 
 	for (j = 0; j < length; j += elsize) {
 		for (i = 0; i < elsize; ++i) {
@@ -669,19 +686,31 @@ static int emulate_vsx(unsigned char __user *addr, unsigned int reg,
 				ret |= __get_user(ptr[i^sw], addr + i);
 		}
 		ptr  += elsize;
+#ifdef __LITTLE_ENDIAN__
+		addr -= elsize;
+#else
 		addr += elsize;
+#endif
 	}
 
+#ifdef __BIG_ENDIAN__
+#define VSX_HI 0
+#define VSX_LO 1
+#else
+#define VSX_HI 1
+#define VSX_LO 0
+#endif
+
 	if (!ret) {
 		if (flags & U)
 			regs->gpr[areg] = regs->dar;
 
 		/* Splat load copies the same data to top and bottom 8 bytes */
 		if (flags & SPLT)
-			lptr[1] = lptr[0];
-		/* For 8 byte loads, zero the top 8 bytes */
+			lptr[VSX_LO] = lptr[VSX_HI];
+		/* For 8 byte loads, zero the low 8 bytes */
 		else if (!(flags & ST) && (8 == length))
-			lptr[1] = 0;
+			lptr[VSX_LO] = 0;
 	} else
 		return -EFAULT;
 
@@ -805,7 +834,6 @@ int fix_alignment(struct pt_regs *regs)
 	/* DAR has the operand effective address */
 	addr = (unsigned char __user *)regs->dar;
 
-#ifdef __BIG_ENDIAN__
 #ifdef CONFIG_VSX
 	if ((instruction & 0xfc00003e) == 0x7c000018) {
 		unsigned int elsize;
@@ -840,9 +868,6 @@ int fix_alignment(struct pt_regs *regs)
 		return emulate_vsx(addr, reg, areg, regs, flags, nb, elsize);
 	}
 #endif
-#else
-	return -EFAULT;
-#endif
 	/* A size of 0 indicates an instruction we don't support, with
 	 * the exception of DCBZ which is handled as a special case here
 	 */
-- 
1.8.1.2

  parent reply	other threads:[~2013-09-23  2:04 UTC|newest]

Thread overview: 49+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-09-23  2:04 [PATCH 00/39] Second round of 64bit PowerPC little endian patches Anton Blanchard
2013-09-23  2:04 ` [PATCH 01/39] powerpc: Fix endian issues in VMX copy loops Anton Blanchard
2013-09-23  2:04 ` [PATCH 02/39] powerpc: Book 3S MMU little endian support Anton Blanchard
2013-09-23  2:04 ` [PATCH 03/39] powerpc: Fix offset of FPRs in VSX registers in little endian builds Anton Blanchard
2013-09-23  2:04 ` [PATCH 04/39] powerpc: PTRACE_PEEKUSR/PTRACE_POKEUSER of FPR " Anton Blanchard
2013-09-23  2:04 ` [PATCH 05/39] powerpc: Little endian builds double word swap VSX state during context save/restore Anton Blanchard
2013-09-23  2:04 ` [PATCH 06/39] powerpc: Support endian agnostic MMIO Anton Blanchard
2013-09-23  2:04 ` [PATCH 07/39] powerpc: Add little endian support for word-at-a-time functions Anton Blanchard
2013-09-23  2:04 ` [PATCH 08/39] powerpc: Set MSR_LE bit on little endian builds Anton Blanchard
2013-09-23  2:04 ` [PATCH 09/39] powerpc: Reset MSR_LE on signal entry Anton Blanchard
2013-09-23  2:04 ` [PATCH 10/39] powerpc: Include the appropriate endianness header Anton Blanchard
2013-09-23  2:04 ` [PATCH 11/39] powerpc: endian safe trampoline Anton Blanchard
2013-12-28  7:24   ` Olof Johansson
2013-12-28  7:58     ` Benjamin Herrenschmidt
2013-09-23  2:04 ` [PATCH 12/39] powerpc: Remove open coded byte swap macro in alignment handler Anton Blanchard
2013-09-23  2:04 ` [PATCH 13/39] powerpc: Remove hard coded FP offsets " Anton Blanchard
2013-09-23  2:04 ` [PATCH 14/39] powerpc: Alignment handler shouldn't access VSX registers with TS_FPR Anton Blanchard
2013-09-23  2:04 ` [PATCH 15/39] powerpc: Add little endian support to alignment handler Anton Blanchard
2013-09-23  2:04 ` Anton Blanchard [this message]
2013-09-23  2:04 ` [PATCH 17/39] powerpc: Use generic checksum code in little endian Anton Blanchard
2013-09-23  2:04 ` [PATCH 18/39] powerpc: Use generic memcpy " Anton Blanchard
2013-09-23  2:04 ` [PATCH 19/39] powerpc: uname should return ppc64le/ppcle on little endian builds Anton Blanchard
2013-09-23  2:04 ` [PATCH 20/39] powerpc: Little endian fixes for platforms/powernv/opal.c Anton Blanchard
2013-09-23  2:04 ` [PATCH 21/39] powerpc: Little endian fix for arch/powerpc/platforms/powernv/pci.c Anton Blanchard
2013-09-23  2:04 ` [PATCH 22/39] powerpc: Little endian fix for arch/powerpc/platforms/powernv/pci-p5ioc2.c Anton Blanchard
2013-09-23  2:04 ` [PATCH 23/39] powerpc: Little endian sparse clean up for arch/powerpc/platforms/powernv/pci-ioda.c Anton Blanchard
2013-09-23  2:04 ` [PATCH 24/39] powerpc/powernv: Fix endian issues in OPAL RTC driver Anton Blanchard
2013-09-23  2:04 ` [PATCH 25/39] powerpc/powernv: Fix endian issues in OPAL ICS backend Anton Blanchard
2013-09-23  2:05 ` [PATCH 26/39] powerpc/powernv: Make OPAL NVRAM device tree accesses endian safe Anton Blanchard
2013-09-23  2:05 ` [PATCH 27/39] powerpc/powernv: Fix endian issues in powernv PCI code Anton Blanchard
2013-09-23  2:05 ` [PATCH 28/39] powerpc/powernv: Fix endian issues in OPAL console and udbg backend Anton Blanchard
2013-09-23  2:05 ` [PATCH 29/39] powerpc/powernv: Fix OPAL entry and exit in little endian mode Anton Blanchard
2013-09-23  2:05 ` [PATCH 30/39] powerpc/powernv: Don't register exception handlers " Anton Blanchard
2013-09-23  2:05 ` [PATCH 31/39] powerpc/powernv: More little endian issues in OPAL RTC driver Anton Blanchard
2013-09-23  2:05 ` [PATCH 32/39] powerpc/powernv: Fix some PCI sparse errors and one LE bug Anton Blanchard
2013-09-23  2:05 ` [PATCH 33/39] powerpc/hvsi: Fix endian issues in HVSI driver Anton Blanchard
2013-09-23  2:05 ` [PATCH 34/39] tty/hvc_opal: powerpc: Make OPAL HVC device tree accesses endian safe Anton Blanchard
2013-09-23  2:05 ` [PATCH 35/39] KVM: PPC: Disable KVM on little endian builds Anton Blanchard
2013-09-23  2:05 ` [PATCH 36/39] powerpc/kvm/book3s_hv: Add little endian guest support Anton Blanchard
2013-09-25 12:10   ` [PATCH] powerpc/kvmbook3s_hv: propagate H_SET_MODE to the host Laurent Dufour
2013-09-25 12:27     ` Greg Kurz
2013-09-25 22:31     ` Paul Mackerras
2013-09-27  8:14       ` Laurent Dufour
2013-09-27 13:59       ` [PATCH V2] powerpc/kvm/book3s_hv: propagate H_SET_MODE_RESOURCE_LE " Laurent Dufour
2013-09-27 14:45         ` Greg Kurz
2013-09-30 18:40   ` [PATCH 36/39] powerpc/kvm/book3s_hv: Add little endian guest support Alexander Graf
2013-09-23  2:05 ` [PATCH 37/39] powerpc: Add ability to build little endian kernels Anton Blanchard
2013-09-23  2:05 ` [PATCH 38/39] powerpc: Don't set HAVE_EFFICIENT_UNALIGNED_ACCESS on little endian builds Anton Blanchard
2013-09-23  2:05 ` [PATCH 39/39] powerpc: Work around little endian gcc bug Anton Blanchard

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