On Tue, May 03, 2016 at 03:41:35PM +1000, Gavin Shan wrote:
>In current implementation, the DMA32 segments required by one specific
>PE isn't calculated with the information hold in the PE independently.
>It conflicts with the PCI hotplug design: PE centralized, meaning the
>PE's DMA32 segments should be calculated from the information hold in
>the PE independently.
>
>This introduces an array (@dma32_segmap) for every PHB to track the
>DMA32 segmeng usage. Besides, this moves the logic calculating PE's
>consumed DMA32 segments to pnv_pci_ioda1_setup_dma_pe() so that PE's
>DMA32 segments are calculated/allocated from the information hold in
>the PE (DMA32 weight). Also the logic is improved: we try to allocate
>as much DMA32 segments as we can. It's acceptable that number of DMA32
>segments less than the expected number are allocated.
>
>Signed-off-by: Gavin Shan <gws...@linux.vnet.ibm.com>
This can cause overlapped DMA32 segments to different PEs in some cases.
I already had the fix and hold for posting after discussion with Michael
on how to handle the series tomorrow.
Thanks,
Gavin
>---
> arch/powerpc/platforms/powernv/pci-ioda.c | 110 ++++++++++++++++--------------
> arch/powerpc/platforms/powernv/pci.h | 7 +-
> 2 files changed, 61 insertions(+), 56 deletions(-)
>
>diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c
>b/arch/powerpc/platforms/powernv/pci-ioda.c
>index f70a4e0..cfd2906 100644
>--- a/arch/powerpc/platforms/powernv/pci-ioda.c
>+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
>@@ -2011,27 +2011,57 @@ static unsigned int pnv_pci_ioda_pe_dma_weight(struct
>pnv_ioda_pe *pe)
> }
>
> static void pnv_pci_ioda1_setup_dma_pe(struct pnv_phb *phb,
>- struct pnv_ioda_pe *pe,
>- unsigned int base,
>- unsigned int segs)
>+ struct pnv_ioda_pe *pe)
> {
>
> struct page *tce_mem = NULL;
> struct iommu_table *tbl;
>- unsigned int tce32_segsz, i;
>+ unsigned int weight, total_weight = 0;
>+ unsigned int tce32_segsz, base, segs, i;
> int64_t rc;
> void *addr;
>
> /* XXX FIXME: Handle 64-bit only DMA devices */
> /* XXX FIXME: Provide 64-bit DMA facilities & non-4K TCE tables etc.. */
> /* XXX FIXME: Allocate multi-level tables on PHB3 */
>+ pci_walk_bus(phb->hose->bus, pnv_pci_ioda_dev_dma_weight,
>+ &total_weight);
>+ weight = pnv_pci_ioda_pe_dma_weight(pe);
>+
>+ segs = (weight * phb->ioda.dma32_count) / total_weight;
>+ if (!segs)
>+ segs = 1;
>+
>+ /*
>+ * Allocate contiguous DMA32 segments. We begin with the expected
>+ * number of segments. With one more attempt, the number of DMA32
>+ * segments to be allocated is decreased by one until one segment
>+ * is allocated successfully.
>+ */
>+ do {
>+ for (base = 0; base <= phb->ioda.dma32_count - segs; base++) {
>+ for (i = base; i < base + segs; i++) {
>+ if (phb->ioda.dma32_segmap[i] !=
>+ IODA_INVALID_PE)
>+ goto found;
>+ }
>+ }
>+ } while (segs--);
>+
>+ if (!segs) {
>+ pe_warn(pe, "No available DMA32 segments\n");
>+ return;
>+ }
>
>+found:
> tbl = pnv_pci_table_alloc(phb->hose->node);
> iommu_register_group(&pe->table_group, phb->hose->global_number,
> pe->pe_number);
> pnv_pci_link_table_and_group(phb->hose->node, 0, tbl, &pe->table_group);
>
> /* Grab a 32-bit TCE table */
>+ pe_info(pe, "DMA weight %d (%d), assigned (%d) %d DMA32 segments\n",
>+ weight, total_weight, base, segs);
> pe_info(pe, " Setting up 32-bit TCE table at %08x..%08x\n",
> base * PNV_IODA1_DMA32_SEGSIZE,
> (base + segs) * PNV_IODA1_DMA32_SEGSIZE - 1);
>@@ -2068,6 +2098,10 @@ static void pnv_pci_ioda1_setup_dma_pe(struct pnv_phb
>*phb,
> }
> }
>
>+ /* Setup DMA32 segment mapping */
>+ for (i = base; i < base + segs; i++)
>+ phb->ioda.dma32_segmap[i] = pe->pe_number;
>+
> /* Setup linux iommu table */
> pnv_pci_setup_iommu_table(tbl, addr, tce32_segsz * segs,
> base * PNV_IODA1_DMA32_SEGSIZE,
>@@ -2542,73 +2576,34 @@ static void pnv_pci_ioda2_setup_dma_pe(struct pnv_phb
>*phb,
> static void pnv_ioda_setup_dma(struct pnv_phb *phb)
> {
> struct pci_controller *hose = phb->hose;
>- unsigned int weight, total_weight, dma_pe_count;
>- unsigned int residual, remaining, segs, base;
> struct pnv_ioda_pe *pe;
>-
>- total_weight = 0;
>- pci_walk_bus(phb->hose->bus, pnv_pci_ioda_dev_dma_weight,
>- &total_weight);
>-
>- dma_pe_count = 0;
>- list_for_each_entry(pe, &phb->ioda.pe_list, list) {
>- weight = pnv_pci_ioda_pe_dma_weight(pe);
>- if (weight > 0)
>- dma_pe_count++;
>- }
>+ unsigned int weight;
>
> /* If we have more PE# than segments available, hand out one
> * per PE until we run out and let the rest fail. If not,
> * 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)
>- residual = 0;
>- else
>- residual = phb->ioda.tce32_count - dma_pe_count;
>-
>- pr_info("PCI: Domain %04x has %ld available 32-bit DMA segments\n",
>- hose->global_number, phb->ioda.tce32_count);
>- pr_info("PCI: %d PE# for a total weight of %d\n",
>- dma_pe_count, total_weight);
>+ pr_info("PCI: Domain %04x has %d available 32-bit DMA segments\n",
>+ hose->global_number, phb->ioda.dma32_count);
>
> pnv_pci_ioda_setup_opal_tce_kill(phb);
>
>- /* Walk our PE list and configure their DMA segments, hand them
>- * out one base segment plus any residual segments based on
>- * weight
>- */
>- remaining = phb->ioda.tce32_count;
>- base = 0;
>+ /* Walk our PE list and configure their DMA segments */
> list_for_each_entry(pe, &phb->ioda.pe_list, list) {
> weight = pnv_pci_ioda_pe_dma_weight(pe);
> if (!weight)
> continue;
>
>- if (!remaining) {
>- pe_warn(pe, "No DMA32 resources available\n");
>- continue;
>- }
>- segs = 1;
>- if (residual) {
>- segs += ((weight * residual) + (total_weight / 2)) /
>- total_weight;
>- if (segs > remaining)
>- segs = remaining;
>- }
>-
> /*
> * For IODA2 compliant PHB3, we needn't care about the weight.
> * The all available 32-bits DMA space will be assigned to
> * the specific PE.
> */
> if (phb->type == PNV_PHB_IODA1) {
>- pe_info(pe, "DMA weight %d, assigned %d DMA32
>segments\n",
>- weight, segs);
>- pnv_pci_ioda1_setup_dma_pe(phb, pe, base, segs);
>+ pnv_pci_ioda1_setup_dma_pe(phb, pe);
> } else if (phb->type == PNV_PHB_IODA2) {
> pe_info(pe, "Assign DMA32 space\n");
>- segs = 0;
> pnv_pci_ioda2_setup_dma_pe(phb, pe);
> } else if (phb->type == PNV_PHB_NPU) {
> /*
>@@ -2618,9 +2613,6 @@ static void pnv_ioda_setup_dma(struct pnv_phb *phb)
> * as the PHB3 TVT.
> */
> }
>-
>- remaining -= segs;
>- base += segs;
> }
> }
>
>@@ -3327,7 +3319,8 @@ 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 len;
>@@ -3413,6 +3406,10 @@ 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;
>@@ -3422,6 +3419,9 @@ 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);
>@@ -3437,6 +3437,10 @@ static void __init pnv_pci_init_ioda_phb(struct
>device_node *np,
> phb->ioda.io_segmap = aux + iomap_off;
> for (segno = 0; segno < phb->ioda.total_pe_num; segno++)
> phb->ioda.io_segmap[segno] = IODA_INVALID_PE;
>+
>+ phb->ioda.dma32_segmap = aux + dma32map_off;
>+ for (segno = 0; segno < phb->ioda.dma32_count; segno++)
>+ phb->ioda.dma32_segmap[segno] = IODA_INVALID_PE;
> }
> phb->ioda.pe_array = aux + pemap_off;
> set_bit(phb->ioda.reserved_pe_idx, phb->ioda.pe_alloc);
>@@ -3445,7 +3449,7 @@ static void __init pnv_pci_init_ioda_phb(struct
>device_node *np,
> 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 /
>+ phb->ioda.dma32_count = phb->ioda.m32_pci_base /
> PNV_IODA1_DMA32_SEGSIZE;
>
> #if 0 /* We should really do that ... */
>diff --git a/arch/powerpc/platforms/powernv/pci.h
>b/arch/powerpc/platforms/powernv/pci.h
>index 117cfcd..14d9391 100644
>--- a/arch/powerpc/platforms/powernv/pci.h
>+++ b/arch/powerpc/platforms/powernv/pci.h
>@@ -142,6 +142,10 @@ struct pnv_phb {
> unsigned int *m32_segmap;
> unsigned int *io_segmap;
>
>+ /* DMA32 segment maps - IODA1 only */
>+ unsigned int dma32_count;
>+ unsigned int *dma32_segmap;
>+
> /* IRQ chip */
> int irq_chip_init;
> struct irq_chip irq_chip;
>@@ -158,9 +162,6 @@ struct pnv_phb {
> */
> unsigned char pe_rmap[0x10000];
>
>- /* 32-bit TCE tables allocation */
>- unsigned long tce32_count;
>-
> /* TCE cache invalidate registers (physical and
> * remapped)
> */
>--
>2.1.0
>
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