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Subject: Re: [Patch ] Kexec/Kdump support - POWER6
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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Date: Sat, 26 May 2007 08:43:07 +1000
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>  
>  	/* TODO: Use bulk call */
> -	for (i = 0; i < hpte_count; i++)
> -		plpar_pte_remove_raw(0, i, 0, &dummy1, &dummy2);
> +	for (i = 0; i < hpte_count; i++) {
> +		/* dont remove HPTEs with VRMA mappings */
> +		lpar_rc = plpar_pte_remove_raw(H_ANDCOND, i, VRMA_HPTE_B_1TB,
> +						&dummy1, &dummy2);

If you're going to use the B (1T segment) bit instead of the bolted bit,
at least define a proper constant in line with the existing naming of
the hash table constants in mmu-hash64.h. I would suggest doing the same
with the VRMA_MASK/VALUE thing and calling it HPTE_V_VRMA_MASK or
something similar.

> +		if (lpar_rc == H_NOT_FOUND) {
> +			lpar_rc = plpar_pte_read_raw(0, i, &dword0, &dummy1);
> +			if (!lpar_rc && 
> +				(((dword0 >> 24) & VRMA_MASK) != VRMA_MASK))
> +				/* Can be hpte for 1TB Seg. So remove it */
> +				plpar_pte_remove_raw(0, i, 0, &dummy1, &dummy2);
> +		}
> +	}
>  }

In addition, I would recommend following Michael's advice and using
using the bulk remove Hcall whenever possible.

Cheers,
Ben.