Re: [PATCH 1/4] MIPS: Replace _PAGE_READ with _PAGE_NO_READ

From: Kevin Cernekee
Date: Fri May 13 2011 - 18:06:40 EST

On Fri, May 13, 2011 at 11:45 AM, Jayachandran C.
<jayachandranc@xxxxxxxxxxxxxxxxx> wrote:
> The current linux-mips queue works for me, and I don't have the old source
> or binaries with me anymore. You surely should be able build with
> nlm_xlr_defconfig and see if the rixi is enabled in the build, if you want
> any config register dump on the CPU, please let me know.

I was able to locate an old MIPS R5000 based system and get linux-mips
queue running on it. Here are the settings:

CONFIG_ARCH_DMA_ADDR_T_64BIT=y
CONFIG_64BIT_PHYS_ADDR=y
CONFIG_ARCH_PHYS_ADDR_T_64BIT=y
CONFIG_PHYS_ADDR_T_64BIT=y
CONFIG_SYS_SUPPORTS_32BIT_KERNEL=y
CONFIG_CPU_SUPPORTS_32BIT_KERNEL=y
CONFIG_SYS_SUPPORTS_64BIT_KERNEL=y
CONFIG_CPU_SUPPORTS_64BIT_KERNEL=y
CONFIG_32BIT=y
# CONFIG_64BIT is not set
CONFIG_SMP=y

This was intended to mimic the XLR configuration: 32-bit kernel on a
64-bit CPU with 64-bit physical addressing, SMP (albeit with 1 CPU),
no RI/XI.

After applying all 4 of my page cleanup patches, the system still
booted and ran normally.

Userspace is glibc with a bash shell (also tried uClibc w/bash, same
result). Since the reported assertion appeared to be in bash.

Jayachandran - how do you think we should debug this? It seems like
the problem only shows up on XLR. Since this is a relatively new
platform, is it possible that something else might be broken still?

FWIW, here are the TLB handlers:

Refill:

80000000: 401b2000 mfc0 k1,c0_context
80000004: 3c1a80a5 lui k0,0x80a5
80000008: 001bddc2 srl k1,k1,0x17
8000000c: 035bd821 addu k1,k0,k1
80000010: 401a4000 mfc0 k0,c0_badvaddr
80000014: 8f7b4000 lw k1,16384(k1)
80000018: 001ad542 srl k0,k0,0x15
8000001c: 001ad080 sll k0,k0,0x2
80000020: 037ad821 addu k1,k1,k0
80000024: 401a2000 mfc0 k0,c0_context
80000028: 8f7b0000 lw k1,0(k1)
8000002c: 335a0ff0 andi k0,k0,0xff0
80000030: 037ad821 addu k1,k1,k0
80000034: df7a0000 ld k0,0(k1)
80000038: df7b0008 ld k1,8(k1)
8000003c: 001ad1ba dsrl k0,k0,0x6
80000040: 409a1000 mtc0 k0,c0_entrylo0
80000044: 001bd9ba dsrl k1,k1,0x6
80000048: 409b1800 mtc0 k1,c0_entrylo1
8000004c: 00000000 nop
80000050: 42000006 tlbwr
80000054: 42000018 eret

Load:

801fe000: 401b2000 mfc0 k1,c0_context
801fe004: 3c1a80a5 lui k0,0x80a5
801fe008: 001bddc2 srl k1,k1,0x17
801fe00c: 035bd821 addu k1,k0,k1
801fe010: 401a4000 mfc0 k0,c0_badvaddr
801fe014: 8f7b4000 lw k1,16384(k1)
801fe018: 001ad542 srl k0,k0,0x15
801fe01c: 001ad080 sll k0,k0,0x2
801fe020: 037ad821 addu k1,k1,k0
801fe024: 401a4000 mfc0 k0,c0_badvaddr
801fe028: 8f7b0000 lw k1,0(k1)
801fe02c: 001ad242 srl k0,k0,0x9
801fe030: 335a0ff8 andi k0,k0,0xff8
801fe034: 037ad821 addu k1,k1,k0
801fe038: d37a0000 lld k0,0(k1)
801fe03c: 42000008 tlbp
801fe040: 335a0001 andi k0,k0,0x1
801fe044: 13400010 beqz k0,0x801fe088
801fe048: d37a0000 lld k0,0(k1)
801fe04c: 375a0084 ori k0,k0,0x84
801fe050: f37a0000 scd k0,0(k1)
801fe054: 1340fff8 beqz k0,0x801fe038
801fe058: 00000000 nop
801fe05c: 377b0008 ori k1,k1,0x8
801fe060: 3b7b0008 xori k1,k1,0x8
801fe064: df7a0000 ld k0,0(k1)
801fe068: df7b0008 ld k1,8(k1)
801fe06c: 001ad1ba dsrl k0,k0,0x6
801fe070: 409a1000 mtc0 k0,c0_entrylo0
801fe074: 001bd9ba dsrl k1,k1,0x6
801fe078: 409b1800 mtc0 k1,c0_entrylo1
801fe07c: 00000000 nop
801fe080: 42000002 tlbwi
801fe084: 42000018 eret
801fe088: 080036d8 j 0x8000db60
801fe08c: 00000000 nop

Store:

801fe200: 401b2000 mfc0 k1,c0_context
801fe204: 3c1a80a5 lui k0,0x80a5
801fe208: 001bddc2 srl k1,k1,0x17
801fe20c: 035bd821 addu k1,k0,k1
801fe210: 401a4000 mfc0 k0,c0_badvaddr
801fe214: 8f7b4000 lw k1,16384(k1)
801fe218: 001ad542 srl k0,k0,0x15
801fe21c: 001ad080 sll k0,k0,0x2
801fe220: 037ad821 addu k1,k1,k0
801fe224: 401a4000 mfc0 k0,c0_badvaddr
801fe228: 8f7b0000 lw k1,0(k1)
801fe22c: 001ad242 srl k0,k0,0x9
801fe230: 335a0ff8 andi k0,k0,0xff8
801fe234: 037ad821 addu k1,k1,k0
801fe238: d37a0000 lld k0,0(k1)
801fe23c: 42000008 tlbp
801fe240: 335a0003 andi k0,k0,0x3
801fe244: 3b5a0003 xori k0,k0,0x3
801fe248: 17400010 bnez k0,0x801fe28c
801fe24c: d37a0000 lld k0,0(k1)
801fe250: 375a018c ori k0,k0,0x18c
801fe254: f37a0000 scd k0,0(k1)
801fe258: 1340fff7 beqz k0,0x801fe238
801fe25c: 00000000 nop
801fe260: 377b0008 ori k1,k1,0x8
801fe264: 3b7b0008 xori k1,k1,0x8
801fe268: df7a0000 ld k0,0(k1)
801fe26c: df7b0008 ld k1,8(k1)
801fe270: 001ad1ba dsrl k0,k0,0x6
801fe274: 409a1000 mtc0 k0,c0_entrylo0
801fe278: 001bd9ba dsrl k1,k1,0x6
801fe27c: 409b1800 mtc0 k1,c0_entrylo1
801fe280: 00000000 nop
801fe284: 42000002 tlbwi
801fe288: 42000018 eret
801fe28c: 0800371d j 0x8000dc74
801fe290: 00000000 nop

Modify:

801fe400: 401b2000 mfc0 k1,c0_context
801fe404: 3c1a80a5 lui k0,0x80a5
801fe408: 001bddc2 srl k1,k1,0x17
801fe40c: 035bd821 addu k1,k0,k1
801fe410: 401a4000 mfc0 k0,c0_badvaddr
801fe414: 8f7b4000 lw k1,16384(k1)
801fe418: 001ad542 srl k0,k0,0x15
801fe41c: 001ad080 sll k0,k0,0x2
801fe420: 037ad821 addu k1,k1,k0
801fe424: 401a4000 mfc0 k0,c0_badvaddr
801fe428: 8f7b0000 lw k1,0(k1)
801fe42c: 001ad242 srl k0,k0,0x9
801fe430: 335a0ff8 andi k0,k0,0xff8
801fe434: 037ad821 addu k1,k1,k0
801fe438: d37a0000 lld k0,0(k1)
801fe43c: 42000008 tlbp
801fe440: 335a0002 andi k0,k0,0x2
801fe444: 13400010 beqz k0,0x801fe488
801fe448: d37a0000 lld k0,0(k1)
801fe44c: 375a018c ori k0,k0,0x18c
801fe450: f37a0000 scd k0,0(k1)
801fe454: 1340fff8 beqz k0,0x801fe438
801fe458: 00000000 nop
801fe45c: 377b0008 ori k1,k1,0x8
801fe460: 3b7b0008 xori k1,k1,0x8
801fe464: df7a0000 ld k0,0(k1)
801fe468: df7b0008 ld k1,8(k1)
801fe46c: 001ad1ba dsrl k0,k0,0x6
801fe470: 409a1000 mtc0 k0,c0_entrylo0
801fe474: 001bd9ba dsrl k1,k1,0x6
801fe478: 409b1800 mtc0 k1,c0_entrylo1
801fe47c: 00000000 nop
801fe480: 42000002 tlbwi
801fe484: 42000018 eret
801fe488: 0800371d j 0x8000dc74
801fe48c: 00000000 nop
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/