[RFC PATCH 4/6] sparc64: Bind PCIe devices to use IOMMU v2 service

From: Tushar Dave
Date: Thu Oct 06 2016 - 19:34:46 EST


In order to use Hypervisor (HV) IOMMU v2 API for map/demap, each PCIe
device has to be bound to IOTSB using HV API pci_iotsb_bind().

Signed-off-by: Tushar Dave <tushar.n.dave@xxxxxxxxxx>
Reviewed-by: chris hyser <chris.hyser@xxxxxxxxxx>
Acked-by: Sowmini Varadhan <sowmini.varadhan@xxxxxxxxxx>
---
arch/sparc/kernel/pci_sun4v.c | 43 +++++++++++++++++++++++++++++++++++++++
arch/sparc/kernel/pci_sun4v.h | 3 +++
arch/sparc/kernel/pci_sun4v_asm.S | 14 +++++++++++++
3 files changed, 60 insertions(+)

diff --git a/arch/sparc/kernel/pci_sun4v.c b/arch/sparc/kernel/pci_sun4v.c
index 5404b33..c7f3a0b3 100644
--- a/arch/sparc/kernel/pci_sun4v.c
+++ b/arch/sparc/kernel/pci_sun4v.c
@@ -216,6 +216,43 @@ range_alloc_fail:
return NULL;
}

+unsigned long dma_4v_iotsb_bind(unsigned long devhandle,
+ unsigned long iotsb_num,
+ struct pci_bus *bus_dev)
+{
+ struct pci_dev *pdev;
+ unsigned long err;
+ unsigned int bus;
+ unsigned int device;
+ unsigned int fun;
+
+ list_for_each_entry(pdev, &bus_dev->devices, bus_list) {
+ if (pdev->subordinate) {
+ /* No need to bind pci bridge */
+ dma_4v_iotsb_bind(devhandle, iotsb_num,
+ pdev->subordinate);
+ } else {
+ bus = bus_dev->number;
+ device = PCI_SLOT(pdev->devfn);
+ fun = PCI_FUNC(pdev->devfn);
+ err = pci_sun4v_iotsb_bind(devhandle, iotsb_num,
+ HV_PCI_DEVICE_BUILD(bus,
+ device,
+ fun));
+
+ /* If bind fails for one device it is going to fail
+ * for rest of the devices because we are sharing
+ * IOTSB. So in case of failure simply return with
+ * error.
+ */
+ if (err)
+ return err;
+ }
+ }
+
+ return 0;
+}
+
static void dma_4v_iommu_demap(void *demap_arg, unsigned long entry,
unsigned long npages)
{
@@ -628,6 +665,12 @@ static int pci_sun4v_atu_alloc_iotsb(struct pci_pbm_info *pbm)
}
iotsb->iotsb_num = iotsb_num;

+ err = dma_4v_iotsb_bind(pbm->devhandle, iotsb_num, pbm->pci_bus);
+ if (err) {
+ pr_err(PFX "pci_iotsb_bind failed error: %ld\n", err);
+ goto iotsb_conf_failed;
+ }
+
return 0;

iotsb_conf_failed:
diff --git a/arch/sparc/kernel/pci_sun4v.h b/arch/sparc/kernel/pci_sun4v.h
index 0ef6d1c..1019e0f 100644
--- a/arch/sparc/kernel/pci_sun4v.h
+++ b/arch/sparc/kernel/pci_sun4v.h
@@ -96,4 +96,7 @@ unsigned long pci_sun4v_iotsb_conf(unsigned long devhandle,
unsigned long page_size,
unsigned long dvma_base,
u64 *iotsb_num);
+unsigned long pci_sun4v_iotsb_bind(unsigned long devhandle,
+ unsigned long iotsb_num,
+ unsigned int pci_device);
#endif /* !(_PCI_SUN4V_H) */
diff --git a/arch/sparc/kernel/pci_sun4v_asm.S b/arch/sparc/kernel/pci_sun4v_asm.S
index fd94d0e..22024a9 100644
--- a/arch/sparc/kernel/pci_sun4v_asm.S
+++ b/arch/sparc/kernel/pci_sun4v_asm.S
@@ -378,3 +378,17 @@ ENTRY(pci_sun4v_iotsb_conf)
retl
stx %o1, [%g1]
ENDPROC(pci_sun4v_iotsb_conf)
+
+ /*
+ * %o0: devhandle
+ * %o1: iotsb_num/iotsb_handle
+ * %o2: pci_device
+ *
+ * returns %o0: status
+ */
+ENTRY(pci_sun4v_iotsb_bind)
+ mov HV_FAST_PCI_IOTSB_BIND, %o5
+ ta HV_FAST_TRAP
+ retl
+ nop
+ENDPROC(pci_sun4v_iotsb_bind)
--
1.9.1