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From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
To: Phileas Fogg <phileas-fogg@mail.ru>,
	Geoff Levand <geoff@infradead.org>,
	linuxppc-dev@lists.ozlabs.org
Subject: Re: Re[3]: PS3 platform is broken on Linux 3.7.0
Date: Mon, 11 Feb 2013 15:56:18 +0530	[thread overview]
Message-ID: <87zjzb4051.fsf@linux.vnet.ibm.com> (raw)
In-Reply-To: <87k3qg4092.fsf@linux.vnet.ibm.com>

"Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> writes:

> Phileas Fogg <phileas-fogg@mail.ru> writes:
>
>>  And another note.
>> I took a look at the MMU chapter in the Cell Architecture handbook and i=
ndeed the first 15 bits in VA are treated as 0 by the hardware.
>>
>> Quote:
>>
>> 1. High-order bits above 65 bits in the 80-bit virtual address (VA[0:14]=
) are not implemented. The hardware always
>> =C2=A0=C2=A0 treats these bits as `0'. Software must not set these bits =
to any other value than `0' or the results are undefined in
>> =C2=A0=C2=A0 the PPE.
>>
>>
>
> True, we missed the below part of ISA doc:
>
> ISA doc says
>
> "On implementations that support a virtual address size
> of only n bits, n < 78, bits 0:77-n of the AVA field must be
> zeros. "
>
> The Cell document I found at=20
>
> https://www-01.ibm.com/chips/techlib/techlib.nsf/techdocs/7A77CCDF14FE70D=
5852575CA0074E8ED/$file/CellBE_Handbook_v1.12_3Apr09_pub.pdf
>
> gives=20
>
> Virtual Address (VA) Size -> 65 bits
>
> So as per ISA, bits 0:12 should be zero, which should make 0:14 of PTE
> fields zero for Cell.
>
> I will try to do a patch.=20
>

Can you try this patch ?

diff --git a/arch/powerpc/include/asm/mmu-hash64.h b/arch/powerpc/include/a=
sm/mmu-hash64.h
index 2fdb47a..f01fd9a 100644
--- a/arch/powerpc/include/asm/mmu-hash64.h
+++ b/arch/powerpc/include/asm/mmu-hash64.h
@@ -381,21 +381,37 @@ extern void slb_set_size(u16 size);
  * hash collisions.
  */
=20
+/* This should go in Kconfig */
+/*
+ * Be careful with this value. This determines the VSID_MODULUS_*  and that
+ * need to be co-prime with VSID_MULTIPLIER*
+ */
+#if 1
+#define MAX_VIRTUAL_ADDR_BITS	65
+#else
+#define MAX_VIRTUAL_ADDR_BITS	66
+#endif
+/*
+ * One bit is taken by the kernel, only the rest of space is available for=
 the
+ * user space.
+ */
+#define CONTEXT_BITS		(MAX_VIRTUAL_ADDR_BITS - \
+				 (USER_ESID_BITS + SID_SHIFT + 1))
+#define USER_ESID_BITS		18
+#define USER_ESID_BITS_1T	6
+
 /*
  * This should be computed such that protovosid * vsid_mulitplier
  * doesn't overflow 64 bits. It should also be co-prime to vsid_modulus
  */
 #define VSID_MULTIPLIER_256M	ASM_CONST(12538073)	/* 24-bit prime */
-#define VSID_BITS_256M		38
+#define VSID_BITS_256M		(CONTEXT_BITS + USER_ESID_BITS + 1)
 #define VSID_MODULUS_256M	((1UL<<VSID_BITS_256M)-1)
=20
 #define VSID_MULTIPLIER_1T	ASM_CONST(12538073)	/* 24-bit prime */
-#define VSID_BITS_1T		26
+#define VSID_BITS_1T		(CONTEXT_BITS + USER_ESID_BITS_1T + 1)
 #define VSID_MODULUS_1T		((1UL<<VSID_BITS_1T)-1)
=20
-#define CONTEXT_BITS		19
-#define USER_ESID_BITS		18
-#define USER_ESID_BITS_1T	6
=20
 #define USER_VSID_RANGE	(1UL << (USER_ESID_BITS + SID_SHIFT))
=20

  reply	other threads:[~2013-02-11 10:26 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-12-14 12:35 PS3 platform is broken on Linux 3.7.0 Phileas Fogg
2012-12-19 21:53 ` Benjamin Herrenschmidt
2013-01-12  2:12   ` Geoff Levand
2013-01-14 23:37     ` Geoff Levand
2013-02-10  8:59       ` Re[2]: " Phileas Fogg
2013-02-10  9:16         ` Re[3]: " Phileas Fogg
2013-02-10 16:11           ` Aneesh Kumar K.V
2013-02-11 10:26             ` Aneesh Kumar K.V [this message]
2013-02-11 16:57               ` Re[5]: " Phileas Fogg
2013-02-12  1:11               ` Re[3]: " Geoff Levand
2013-02-11 20:56         ` Re[2]: " Geoff Levand
2013-02-10 11:45   ` Phileas Fogg
2013-02-10 12:17     ` Re[3]: " Phileas Fogg
2013-02-10 15:46       ` Aneesh Kumar K.V
2013-02-10 17:51         ` Re[5]: " Phileas Fogg
2013-02-11  3:39           ` Michael Ellerman
2013-02-13  7:32 ` Geoff Levand
2013-02-13 22:37   ` Michael Ellerman

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