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
next prev parent 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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