On 05/03/2016 11:22 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#.
Can you possibly have more than 256 PEs? Or exactly 256? What patch in this
series makes use of it?
I probably asked but do not remember the answer :)
Looks like waste of memory - you only used a small fraction of
pe_rmap[0x10000] and now the waste is quadrupled.
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.
Looks like using IODA_INVALID_PE is the only reason for this patch.
Signed-off-by: Gavin Shan <gwshan@xxxxxxxxxxxxxxxxxx>
Reviewed-by: Daniel Axtens <dja@xxxxxxxxxx>
---
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 cbd4c0b..cf96cb5 100644
--- a/arch/powerpc/platforms/powernv/pci-ioda.c
+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
@@ -768,7 +768,7 @@ 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) {
@@ -3406,6 +3406,10 @@ 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 (segno = 0; segno < ARRAY_SIZE(phb->ioda.pe_rmap); segno++)
+ phb->ioda.pe_rmap[segno] = 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 904f60b..80f5326 100644
--- a/arch/powerpc/platforms/powernv/pci.h
+++ b/arch/powerpc/platforms/powernv/pci.h
@@ -156,11 +156,8 @@ 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} */
+ unsigned int pe_rmap[0x10000];
/* TCE cache invalidate registers (physical and
* remapped)
--
Alexey
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