Subject: Re: [PATCH v8 18/45] powerpc/powernv: Increase PE# capacity

From: Alexey Kardashevskiy <[email-masked]>
Date: Tue, 19 Apr 2016 12:02:23 +1000

On 02/17/2016 02:44 PM, Gavin Shan wrote:
> Each PHB maintains an array helping to translate 2-bytes Request
> ID (RID) to PE# with the assumption that PE# takes one byte, meaning
> that we can't have more than 256 PEs. However, pci_dn->pe_number
> already had 4-bytes for the PE#.
>
> This extends the PE# capacity for every PHB. After that, the PE number
> is represented by 4-bytes value. Then we can reuse IODA_INVALID_PE to
> check the PE# in phb->pe_rmap[] is valid or not.

This should be merged into "[PATCH v8 21/45] powerpc/powernv: Create PEs at 
PCI hot plugging time" as it does not make sense alone (this patch does the 
initialization but only 3 patches apart this default value is analyzed -> 
hard to review).

> Signed-off-by: Gavin Shan <[email-masked]>
> Reviewed-by: Daniel Axtens <[email-masked]>
> ---
>   arch/powerpc/platforms/powernv/pci-ioda.c | 6 +++++-
>   arch/powerpc/platforms/powernv/pci.h      | 7 ++-----
>   2 files changed, 7 insertions(+), 6 deletions(-)
>
> diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
> index 59782fba..7800897 100644
> --- a/arch/powerpc/platforms/powernv/pci-ioda.c
> +++ b/arch/powerpc/platforms/powernv/pci-ioda.c
> @@ -757,7 +757,7 @@ static int pnv_ioda_deconfigure_pe(struct pnv_phb *phb, struct pnv_ioda_pe *pe)
>
>   	/* Clear the reverse map */
>   	for (rid = pe->rid; rid < rid_end; rid++)
> -		phb->ioda.pe_rmap[rid] = 0;
> +		phb->ioda.pe_rmap[rid] = IODA_INVALID_PE;
>
>   	/* Release from all parents PELT-V */
>   	while (parent) {
> @@ -3387,6 +3387,10 @@ static void __init pnv_pci_init_ioda_phb(struct device_node *np,
>   	if (prop32)
>   		phb->ioda.reserved_pe_idx = be32_to_cpup(prop32);
>
> +	/* Invalidate RID to PE# mapping */
> +	for (i = 0; i < ARRAY_SIZE(phb->ioda.pe_rmap); ++i)
> +		phb->ioda.pe_rmap[i] = IODA_INVALID_PE;
> +
>   	/* Parse 64-bit MMIO range */
>   	pnv_ioda_parse_m64_window(phb);
>
> diff --git a/arch/powerpc/platforms/powernv/pci.h b/arch/powerpc/platforms/powernv/pci.h
> index 350e630..928cf81 100644
> --- a/arch/powerpc/platforms/powernv/pci.h
> +++ b/arch/powerpc/platforms/powernv/pci.h
> @@ -160,11 +160,8 @@ struct pnv_phb {
>   		struct list_head	pe_list;
>   		struct mutex            pe_list_mutex;
>
> -		/* Reverse map of PEs, will have to extend if
> -		 * we are to support more than 256 PEs, indexed
> -		 * bus { bus, devfn }
> -		 */
> -		unsigned char		pe_rmap[0x10000];
> +		/* Reverse map of PEs, indexed by {bus, devfn} */
> +		int			pe_rmap[0x10000];
>
>   		/* TCE cache invalidate registers (physical and
>   		 * remapped)
>

-- 
Alexey