Thread (43 messages) 43 messages, 6 authors, 2011-05-20

Re: [PATCH 3/7] [RFC] add support for BlueGene/P FPU

From: Michael Neuling <hidden>
Date: 2011-05-19 05:58:41
Also in: lkml

Eric,
This patch adds save/restore register support for the BlueGene/P
double hummer FPU.
What does this mean?  Needs more details here.
Signed-off-by: Eric Van Hensbergen <redacted>
---
 arch/powerpc/include/asm/ppc_asm.h |   39 ++++++++++++++++++++++++----------
-
quoted hunk ↗ jump to hunk
 arch/powerpc/kernel/fpu.S          |    8 +++---
 arch/powerpc/platforms/44x/Kconfig |    9 ++++++++
 3 files changed, 40 insertions(+), 16 deletions(-)
diff --git a/arch/powerpc/include/asm/ppc_asm.h b/arch/powerpc/include/asm/pp
c_asm.h
quoted hunk ↗ jump to hunk
index 9821006..daa22bb 100644
--- a/arch/powerpc/include/asm/ppc_asm.h
+++ b/arch/powerpc/include/asm/ppc_asm.h
@@ -88,6 +88,13 @@ END_FW_FTR_SECTION_IFSET(FW_FEATURE_SPLPAR)
 				REST_10GPRS(22, base)
 #endif
 
+#ifdef CONFIG_BGP
+#define LFPDX(frt, ra, rb)	.long (31<<26)|((frt)<<21)|((ra)<<16)| \
+							((rb)<<11)|(462<<1)
+#define STFPDX(frt, ra, rb)	.long (31<<26)|((frt)<<21)|((ra)<<16)| \
+							((rb)<<11)|(974<<1)
+#endif /* CONFIG_BGP */
Put these in arch/powerpc/include/asm/ppc-opcode.h and reformat to fit
whats there already.  

Also, don't need to put these defines inside a #ifdef.
quoted hunk ↗ jump to hunk
+
 #define SAVE_2GPRS(n, base)	SAVE_GPR(n, base); SAVE_GPR(n+1, base)
 #define SAVE_4GPRS(n, base)	SAVE_2GPRS(n, base); SAVE_2GPRS(n+2, base)
 #define SAVE_8GPRS(n, base)	SAVE_4GPRS(n, base); SAVE_4GPRS(n+4, base)
@@ -97,18 +104,26 @@ END_FW_FTR_SECTION_IFSET(FW_FEATURE_SPLPAR)
 #define REST_8GPRS(n, base)	REST_4GPRS(n, base); REST_4GPRS(n+4, base)
 #define REST_10GPRS(n, base)	REST_8GPRS(n, base); REST_2GPRS(n+8, base)
 
-#define SAVE_FPR(n, base)	stfd	n,THREAD_FPR0+8*TS_FPRWIDTH*(n)(base)
-#define SAVE_2FPRS(n, base)	SAVE_FPR(n, base); SAVE_FPR(n+1, base)
-#define SAVE_4FPRS(n, base)	SAVE_2FPRS(n, base); SAVE_2FPRS(n+2, base)
-#define SAVE_8FPRS(n, base)	SAVE_4FPRS(n, base); SAVE_4FPRS(n+4, base)
-#define SAVE_16FPRS(n, base)	SAVE_8FPRS(n, base); SAVE_8FPRS(n+8, base)
-#define SAVE_32FPRS(n, base)	SAVE_16FPRS(n, base); SAVE_16FPRS(n+16, base)
-#define REST_FPR(n, base)	lfd	n,THREAD_FPR0+8*TS_FPRWIDTH*(n)(base)
-#define REST_2FPRS(n, base)	REST_FPR(n, base); REST_FPR(n+1, base)
-#define REST_4FPRS(n, base)	REST_2FPRS(n, base); REST_2FPRS(n+2, base)
-#define REST_8FPRS(n, base)	REST_4FPRS(n, base); REST_4FPRS(n+4, base)
-#define REST_16FPRS(n, base)	REST_8FPRS(n, base); REST_8FPRS(n+8, base)
-#define REST_32FPRS(n, base)	REST_16FPRS(n, base); REST_16FPRS(n+16, base)
+#ifdef CONFIG_BGP
+#define SAVE_FPR(n, b, base)	li b, THREAD_FPR0+(16*(n)); STFPDX(n, base, b)
+#define REST_FPR(n, b, base)	li b, THREAD_FPR0+(16*(n)); LFPDX(n, base, b)
16*?  Are these FP regs 64 or 128 bits wide?  If 128 you are doing to
have to play with TS_WIDTH to get the size of the FPs correct in the
thread_struct.

I think there's a bug here.
+#else /* CONFIG_BGP */
+#define SAVE_FPR(n, b, base)	(stfd	n, THREAD_FPR0+8*TS_FPRWIDTH*(n)(base))
+#define REST_FPR(n, b, base)	(lfd	n, THREAD_FPR0+8*TS_FPRWIDTH*(n)(base))
+#endif /* CONFIG_BGP */
+
+#define SAVE_2FPRS(n, b, base)	SAVE_FPR(n, b, base); SAVE_FPR(n+1, b, 
base)
+#define SAVE_4FPRS(n, b, base)	SAVE_2FPRS(n, b, base); SAVE_2FPRS(n+2,
 b, base)
+#define SAVE_8FPRS(n, b, base)	SAVE_4FPRS(n, b, base); SAVE_4FPRS(n+4,
 b, base)
+#define SAVE_16FPRS(n, b, base)	SAVE_8FPRS(n, b, base); SAVE_8FPRS(n+8,
 b, base)
+#define SAVE_32FPRS(n, b, base)	SAVE_16FPRS(n, b, base); \
+				SAVE_16FPRS(n+16, b, base)
+#define REST_2FPRS(n, b, base)	REST_FPR(n, b, base); REST_FPR(n+1, b, 
base)
+#define REST_4FPRS(n, b, base)	REST_2FPRS(n, b, base); REST_2FPRS(n+2,
 b, base)
+#define REST_8FPRS(n, b, base)	REST_4FPRS(n, b, base); REST_4FPRS(n+4,
 b, base)
+#define REST_16FPRS(n, b, base)	REST_8FPRS(n, b, base); REST_8FPRS(n+8,
 b, base)
quoted hunk ↗ jump to hunk
+#define REST_32FPRS(n, b, base)	REST_16FPRS(n, b, base); \
+				REST_16FPRS(n+16, b, base)
 
 #define SAVE_VR(n,b,base)	li b,THREAD_VR0+(16*(n));  stvx n,base,b
 #define SAVE_2VRS(n,b,base)	SAVE_VR(n,b,base); SAVE_VR(n+1,b,base)
diff --git a/arch/powerpc/kernel/fpu.S b/arch/powerpc/kernel/fpu.S
index de36955..9f11c66 100644
--- a/arch/powerpc/kernel/fpu.S
+++ b/arch/powerpc/kernel/fpu.S
@@ -30,7 +30,7 @@
 BEGIN_FTR_SECTION							\
 	b	2f;							\
 END_FTR_SECTION_IFSET(CPU_FTR_VSX);					\
-	REST_32FPRS(n,base);						\
+	REST_32FPRS(n,c,base);						\
 	b	3f;							\
 2:	REST_32VSRS(n,c,base);						\
 3:
@@ -39,13 +39,13 @@ END_FTR_SECTION_IFSET(CPU_FTR_VSX);		
			\
quoted hunk ↗ jump to hunk
 BEGIN_FTR_SECTION							\
 	b	2f;							\
 END_FTR_SECTION_IFSET(CPU_FTR_VSX);					\
-	SAVE_32FPRS(n,base);						\
+	SAVE_32FPRS(n,c,base);						\
 	b	3f;							\
 2:	SAVE_32VSRS(n,c,base);						\
 3:
 #else
-#define REST_32FPVSRS(n,b,base)	REST_32FPRS(n, base)
-#define SAVE_32FPVSRS(n,b,base)	SAVE_32FPRS(n, base)
+#define REST_32FPVSRS(n,b,base)	REST_32FPRS(n,b,base)
+#define SAVE_32FPVSRS(n,b,base)	SAVE_32FPRS(n,b,base)
 #endif
 
 /*
diff --git a/arch/powerpc/platforms/44x/Kconfig b/arch/powerpc/platforms/44x/
Kconfig
quoted hunk ↗ jump to hunk
index f485fc5f..24a515e 100644
--- a/arch/powerpc/platforms/44x/Kconfig
+++ b/arch/powerpc/platforms/44x/Kconfig
@@ -169,6 +169,15 @@ config YOSEMITE
 	help
 	  This option enables support for the AMCC PPC440EP evaluation board.
 
+config	BGP
Does this FPU feature have a specific name like double hammer?  I'd
rather have the BGP defconfig depend on PPC_FPU_DOUBLE_HUMMER, or
something like that...
+	bool "Blue Gene/P"
+	depends on 44x
+	default n
+	select PPC_FPU
+	select PPC_DOUBLE_FPU
... in fact, it seem you are doing something like these here but you
don't use PPC_DOUBLE_FPU anywhere?

Mikey
+	help
+	  This option enables support for the IBM BlueGene/P supercomputer.
+
 config ISS4xx
 	bool "ISS 4xx Simulator"
 	depends on (44x || 40x)
-- 
1.7.4.1

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