HIGHMEM Query

[<Rishabh@soc-soft.com>]

hi,

 

I have been working on HIGHMEM fixation for 2.4.20 linux MVL kernel for MIPS architecture.

I am getting DATA BUS ERROR(ADDR: 0xffffd000) exception when loading (copying the data received from ethernet to the kernel space in FIXADDR SPACE) “/sbin/init” from TARGET ROOT DIR (through NFS). I figured out that this is because there is no corresponding page table entry for the same.

 

I checked that the virtual address is generated by making a call to kmap_atomic(). Which internally calls set_pte() and then local_flush_tlb_all(). Virtual Address is generated by making a call to        

 

vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);

1> Where is the page table entries updated?

2> When are they updated with the processor?

 

 

Regards,

 

Rishabh

 

                                   

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