[PATCH 07/10] xen/pcifront: Use Xen-SWIOTLB when initting if required.
From: Konrad Rzeszutek Wilk
Date: Mon Sep 10 2012 - 15:58:33 EST
We piggyback on "xen/swiotlb: Use the swiotlb_late_init_with_tbl to init
Xen-SWIOTLB late when PV PCI is used." functionality to start up
the Xen-SWIOTLB if we are hot-plugged. This allows us to bypass
the need to supply 'iommu=soft' on the Linux command line (mostly).
With this patch, if a user forgot 'iommu=soft' on the command line,
and hotplug a PCI device they will get:
pcifront pci-0: Installing PCI frontend
Warning: only able to allocate 4 MB for software IO TLB
software IO TLB [mem 0x2a000000-0x2a3fffff] (4MB) mapped at [ffff88002a000000-ffff88002a3fffff]
pcifront pci-0: Creating PCI Frontend Bus 0000:00
pcifront pci-0: PCI host bridge to bus 0000:00
pci_bus 0000:00: root bus resource [io 0x0000-0xffff]
pci_bus 0000:00: root bus resource [mem 0x00000000-0xfffffffff]
pci 0000:00:00.0: [8086:10d3] type 00 class 0x020000
pci 0000:00:00.0: reg 10: [mem 0xfe5c0000-0xfe5dffff]
pci 0000:00:00.0: reg 14: [mem 0xfe500000-0xfe57ffff]
pci 0000:00:00.0: reg 18: [io 0xe000-0xe01f]
pci 0000:00:00.0: reg 1c: [mem 0xfe5e0000-0xfe5e3fff]
pcifront pci-0: claiming resource 0000:00:00.0/0
pcifront pci-0: claiming resource 0000:00:00.0/1
pcifront pci-0: claiming resource 0000:00:00.0/2
pcifront pci-0: claiming resource 0000:00:00.0/3
e1000e: Intel(R) PRO/1000 Network Driver - 2.0.0-k
e1000e: Copyright(c) 1999 - 2012 Intel Corporation.
e1000e 0000:00:00.0: Disabling ASPM L0s L1
e1000e 0000:00:00.0: enabling device (0000 -> 0002)
e1000e 0000:00:00.0: Xen PCI mapped GSI16 to IRQ34
e1000e 0000:00:00.0: (unregistered net_device): Interrupt Throttling Rate (ints/sec) set to dynamic conservative mode
e1000e 0000:00:00.0: eth0: (PCI Express:2.5GT/s:Width x1) 00:1b:21:ab:c6:13
e1000e 0000:00:00.0: eth0: Intel(R) PRO/1000 Network Connection
e1000e 0000:00:00.0: eth0: MAC: 3, PHY: 8, PBA No: E46981-005
The "Warning only" will go away if one supplies 'iommu=soft' instead
as we have a higher chance of being able to allocate large swaths of
memory.
Acked-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
---
drivers/pci/xen-pcifront.c | 13 +++++++++----
1 files changed, 9 insertions(+), 4 deletions(-)
diff --git a/drivers/pci/xen-pcifront.c b/drivers/pci/xen-pcifront.c
index d6cc62c..0ad8ca3 100644
--- a/drivers/pci/xen-pcifront.c
+++ b/drivers/pci/xen-pcifront.c
@@ -21,6 +21,7 @@
#include <linux/bitops.h>
#include <linux/time.h>
+#include <asm/xen/swiotlb-xen.h>
#define INVALID_GRANT_REF (0)
#define INVALID_EVTCHN (-1)
@@ -668,7 +669,7 @@ static irqreturn_t pcifront_handler_aer(int irq, void *dev)
schedule_pcifront_aer_op(pdev);
return IRQ_HANDLED;
}
-static int pcifront_connect(struct pcifront_device *pdev)
+static int pcifront_connect_and_init_dma(struct pcifront_device *pdev)
{
int err = 0;
@@ -681,9 +682,13 @@ static int pcifront_connect(struct pcifront_device *pdev)
dev_err(&pdev->xdev->dev, "PCI frontend already installed!\n");
err = -EEXIST;
}
-
spin_unlock(&pcifront_dev_lock);
+ if (!err && !swiotlb_nr_tbl()) {
+ err = pci_xen_swiotlb_init_late();
+ if (err)
+ dev_err(&pdev->xdev->dev, "Could not setup SWIOTLB!\n");
+ }
return err;
}
@@ -842,10 +847,10 @@ static int __devinit pcifront_try_connect(struct pcifront_device *pdev)
XenbusStateInitialised)
goto out;
- err = pcifront_connect(pdev);
+ err = pcifront_connect_and_init_dma(pdev);
if (err) {
xenbus_dev_fatal(pdev->xdev, err,
- "Error connecting PCI Frontend");
+ "Error setting up PCI Frontend");
goto out;
}
--
1.7.7.6
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