[Qemu-devel] [RFC PATCH v3 04/18] spapr_pci: Introduce a liobn number generating macros

[Alexey Kardashevskiy <aik@ozlabs.ru>]

We are going to have multiple DMA windows per PHB and we want them to
migrate so we need a predictable way of assigning LIOBNs.

This introduces a macro which makes up a LIOBN from fixed prefix,
PHB index (unique PHB id) and window number.

This introduces a SPAPR_PCI_DMA_WINDOW_NUM() to know the window number
from LIOBN. It is used to distinguish the default 32bit windows from
dynamic windows and avoid picking default DMA window properties from
a wrong TCE table.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
---
 hw/ppc/spapr_pci.c     | 4 ++--
 include/hw/ppc/spapr.h | 3 ++-
 2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c
index ad0da7f..c6cf5c1 100644
--- a/hw/ppc/spapr_pci.c
+++ b/hw/ppc/spapr_pci.c
@@ -502,7 +502,7 @@ static void spapr_phb_realize(DeviceState *dev, Error **errp)
         }
 
         sphb->buid = SPAPR_PCI_BASE_BUID + sphb->index;
-        sphb->dma_liobn = SPAPR_PCI_BASE_LIOBN + sphb->index;
+        sphb->dma_liobn = SPAPR_PCI_LIOBN(sphb->index, 0);
 
         windows_base = SPAPR_PCI_WINDOW_BASE
             + sphb->index * SPAPR_PCI_WINDOW_SPACING;
@@ -837,7 +837,7 @@ static int spapr_phb_children_dt(Object *child, void *opaque)
     sPAPRTCETable *tcet;
 
     tcet = (sPAPRTCETable *) object_dynamic_cast(child, TYPE_SPAPR_TCE_TABLE);
-    if (!tcet) {
+    if (!tcet || SPAPR_PCI_DMA_WINDOW_NUM(tcet->liobn)) {
         return 0;
     }
 
diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
index 749daf4..c24fa96 100644
--- a/include/hw/ppc/spapr.h
+++ b/include/hw/ppc/spapr.h
@@ -441,7 +441,8 @@ int spapr_rtas_device_tree_setup(void *fdt, hwaddr rtas_addr,
 #define SPAPR_TCE_PAGE_MASK    (SPAPR_TCE_PAGE_SIZE - 1)
 
 #define SPAPR_VIO_BASE_LIOBN    0x00000000
-#define SPAPR_PCI_BASE_LIOBN    0x80000000
+#define SPAPR_PCI_LIOBN(i, n)   (0x80000000 | ((i) << 8) | (n))
+#define SPAPR_PCI_DMA_WINDOW_NUM(liobn) ((liobn) & 0xff)
 
 #define RTAS_ERROR_LOG_MAX      2048
 
-- 
2.0.0