Re: [PATCH v7 19/50] powerpc/powernv: Track DMA32 segment consumption

Gavin Shan
2015-11-17T01:56:53Z

On Tue, Nov 17, 2015 at 11:28:20AM +1100, Daniel Axtens wrote:
>Gavin Shan <gwshan@linux.vnet.ibm.com> writes:
>
>> Similar to the mechanism tracking consumed IO/M32/M64 segments,
>> this introduces an array for each PHB to track the consumed DMA32
>> segments, which are going to be released on PCI unplugging time.
>> The index of the array is the DMA32 segment number while the value
>> stored in the element is the assigned PE number.
>>
>
>
>> + /* Setup TCE32 segment mapping */
>Do you mean DMA32 rather than TCE32?

Right, will change it to "DMA32" in next revision.

>> + for (i = base; i < base + segs; i++)
>> + phb->ioda.dma32_segmap[i] = pe->pe_number;
>> +
>I'm pretty sure this is right, but can you just confirm that you
>intended to index into the array starting at base and going to base + segs,
>and not going from 0 to segs? (i.e. not dma32_segmap[i - base]).
>

I think you're saying "I'm not pretty sure this is right". The code doesn't
have problem here: it starts from @base.

>Otherwise looks good.
>
>
>> /* Setup linux iommu table */
>> pnv_pci_setup_iommu_table(tbl, addr, tce32_segsz * segs,
>> base * PNV_IODA1_DMA32_SEGSIZE,
>> @@ -2378,13 +2382,13 @@ static void pnv_pci_ioda1_setup_dma(struct pnv_phb *phb)
>> * then we assign at least one segment per PE, plus more based
>> * on the amount of devices under that PE
>> */
>> - if (dma_pe_count > phb->ioda.tce32_count)
>> + if (dma_pe_count > phb->ioda.dma32_count)
>> residual = 0;
>> else
>> - residual = phb->ioda.tce32_count - dma_pe_count;
>> + residual = phb->ioda.dma32_count - dma_pe_count;
>>
>> pr_info("PCI: Domain %04x has %ld available 32-bit DMA segments\n",
>> - hose->global_number, phb->ioda.tce32_count);
>> + hose->global_number, phb->ioda.dma32_count);
>> pr_info("PCI: %d PE# for a total weight of %d\n",
>> dma_pe_count, total_weight);
>>
>> @@ -2394,7 +2398,7 @@ static void pnv_pci_ioda1_setup_dma(struct pnv_phb *phb)
>> * out one base segment plus any residual segments based on
>> * weight
>> */
>> - remaining = phb->ioda.tce32_count;
>> + remaining = phb->ioda.dma32_count;
>> base = 0;
>> list_for_each_entry(pe, &phb->ioda.pe_list, list) {
>> weight = pnv_pci_ioda_pe_dma_weight(pe);
>> @@ -3094,7 +3098,8 @@ static void __init pnv_pci_init_ioda_phb(struct device_node *np,
>> {
>> struct pci_controller *hose;
>> struct pnv_phb *phb;
>> - unsigned long size, m64map_off, m32map_off, pemap_off, iomap_off = 0;
>> + unsigned long size, m64map_off, m32map_off, pemap_off;
>> + unsigned long iomap_off = 0, dma32map_off = 0;
>> const __be64 *prop64;
>> const __be32 *prop32;
>> int i, len;
>> @@ -3177,6 +3182,10 @@ static void __init pnv_pci_init_ioda_phb(struct device_node *np,
>> phb->ioda.io_segsize = phb->ioda.io_size / phb->ioda.total_pe_num;
>> phb->ioda.io_pci_base = 0; /* XXX calculate this ? */
>>
>> + /* Calculate how many 32-bit TCE segments we have */
>> + phb->ioda.dma32_count = phb->ioda.m32_pci_base /
>> + PNV_IODA1_DMA32_SEGSIZE;
>> +
>> /* Allocate aux data & arrays. We don't have IO ports on PHB3 */
>> size = _ALIGN_UP(phb->ioda.total_pe_num / 8, sizeof(unsigned long));
>> m64map_off = size;
>> @@ -3186,6 +3195,9 @@ static void __init pnv_pci_init_ioda_phb(struct device_node *np,
>> if (phb->type == PNV_PHB_IODA1) {
>> iomap_off = size;
>> size += phb->ioda.total_pe_num * sizeof(phb->ioda.io_segmap[0]);
>> + dma32map_off = size;
>> + size += phb->ioda.dma32_count *
>> + sizeof(phb->ioda.dma32_segmap[0]);
>> }
>> pemap_off = size;
>> size += phb->ioda.total_pe_num * sizeof(struct pnv_ioda_pe);
>> @@ -3201,6 +3213,10 @@ static void __init pnv_pci_init_ioda_phb(struct device_node *np,
>> phb->ioda.io_segmap = aux + iomap_off;
>> for (i = 0; i < phb->ioda.total_pe_num; i++)
>> phb->ioda.io_segmap[i] = IODA_INVALID_PE;
>> +
>> + phb->ioda.dma32_segmap = aux + dma32map_off;
>> + for (i = 0; i < phb->ioda.dma32_count; i++)
>> + phb->ioda.dma32_segmap[i] = IODA_INVALID_PE;
>> }
>> phb->ioda.pe_array = aux + pemap_off;
>> set_bit(phb->ioda.reserved_pe_idx, phb->ioda.pe_alloc);
>> @@ -3208,10 +3224,6 @@ static void __init pnv_pci_init_ioda_phb(struct device_node *np,
>> INIT_LIST_HEAD(&phb->ioda.pe_list);
>> mutex_init(&phb->ioda.pe_list_mutex);
>>
>> - /* Calculate how many 32-bit TCE segments we have */
>> - phb->ioda.tce32_count = phb->ioda.m32_pci_base /
>> - PNV_IODA1_DMA32_SEGSIZE;
>> -
>> #if 0 /* We should really do that ... */
>> rc = opal_pci_set_phb_mem_window(opal->phb_id,
>> window_type,
>> diff --git a/arch/powerpc/platforms/powernv/pci.h b/arch/powerpc/platforms/powernv/pci.h
>> index 2038ef2..0802fcd 100644
>> --- a/arch/powerpc/platforms/powernv/pci.h
>> +++ b/arch/powerpc/platforms/powernv/pci.h
>> @@ -148,6 +148,10 @@ struct pnv_phb {
>> int *m32_segmap;
>> int *io_segmap;
>>
>> + /* DMA32 segment maps - IODA1 only */
>> + unsigned long dma32_count;
>> + int *dma32_segmap;
>> +
>> /* IRQ chip */
>> int irq_chip_init;
>> struct irq_chip irq_chip;
>> @@ -164,9 +168,6 @@ struct pnv_phb {
>> */
>> unsigned char pe_rmap[0x10000];
>>
>> - /* 32-bit TCE tables allocation */
>> - unsigned long tce32_count;
>> -
>> /* TCE cache invalidate registers (physical and
>> * remapped)
>> */

Thanks,
Gavin