On 08/11/2013 01:40 PM, Jayachandran C wrote: > Allow usage of scratch register for current pgd even when > MIPS_PGD_C0_CONTEXT is not configured. MIPS_PGD_C0_CONTEXT is set > for 64r2 platforms to indicate availability of Xcontext for saving > cpuid, thus freeing Context to be used for saving PGD. This option > was also tied to using a scratch register for storing PGD. > > This commit will allow usage of scratch register to store the current > pgd if one can be allocated for the platform, even when > MIPS_PGD_C0_CONTEXT is not set. The cpuid will be kept in the CP0 > Context register in this case. > > The code to store the current pgd for the TLB miss handler is now > generated in all cases. When scratch register is available, the PGD > is also stored in the scratch register. > > Signed-off-by: Jayachandran C <jchandra@xxxxxxxxxxxx> This patch breaks booting for me on bcm47xx. I found this commit by bisecting and then reverted it and it made bcm47xx boot again. The boot process stops after: [ 0.000000] Inode-cache hash table entries: 4096 (order: 2, 16384 bytes) The next message would be: [ 0.000000] Writing ErrCtl register=00000000 This issue was seen on bcm4716. This is the boot log: CFE> boot -tftp -elf 192.168.1.195:/brcm47xx/openwrt-brcm47xx-vmlinux-initramfs.elf Loader:elf Filesys:tftp Dev:eth0 File:192.168.1.195:/brcm47xx/openwrt-brcm47xx-vmlinux-initramfs.elf Options:(null) Loading: 0x80001000/4593328 0x804626b0/279760 Entry at 0x80264800 Closing network. Starting program at 0x80264800 [ 0.000000] Linux version 3.12.0-rc1+ (hauke@hauke-desktop) (gcc version 4.6.4 (OpenWrt/Linaro GCC 4.6-2013.05 r37948) ) #151 Tue Sep 24 23:35:35 CEST 2013 [ 0.000000] bootconsole [early0] enabled [ 0.000000] CPU revision is: 00019740 (MIPS 74Kc) [ 0.000000] bcm47xx: using bcma bus [ 0.000000] bcma: bus0: Found chip with id 0x4716, rev 0x01 and package 0x0A [ 0.000000] bcma: bus0: Core 0 found: ChipCommon (manuf 0x4BF, id 0x800, rev 0x1F, class 0x0) [ 0.000000] bcma: bus0: Core 3 found: MIPS 74K (manuf 0x4A7, id 0x82C, rev 0x01, class 0x0) [ 0.000000] bcma: bus0: Found M25P64 serial flash (size: 8192KiB, blocksize: 0x10000, blocks: 128) [ 0.000000] bcma: bus0: Early bus registered [ 0.000000] MIPS: machine is Netgear WNDR3400 V1 [ 0.000000] Determined physical RAM map: [ 0.000000] memory: 04000000 @ 00000000 (usable) [ 0.000000] Initrd not found or empty - disabling initrd [ 0.000000] Zone ranges: [ 0.000000] Normal [mem 0x00000000-0x03ffffff] [ 0.000000] Movable zone start for each node [ 0.000000] Early memory node ranges [ 0.000000] node 0: [mem 0x00000000-0x03ffffff] [ 0.000000] Primary instruction cache 32kB, VIPT, 4-way, linesize 32 bytes. [ 0.000000] Primary data cache 32kB, 4-way, VIPT, cache aliases, linesize 32 bytes [ 0.000000] Built 1 zonelists in Zone order, mobility grouping on. Total pages: 16256 [ 0.000000] Kernel command line: noinitrd console=ttyS0,115200 [ 0.000000] PID hash table entries: 256 (order: -2, 1024 bytes) [ 0.000000] Dentry cache hash table entries: 8192 (order: 3, 32768 bytes) [ 0.000000] Inode-cache hash table entries: 4096 (order: 2, 16384 bytes)
