linux/drivers/xen/platform-pci.c

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// SPDX-License-Identifier: GPL-2.0-only
/******************************************************************************
* platform-pci.c
*
* Xen platform PCI device driver
*
* Authors: ssmith@xensource.com and stefano.stabellini@eu.citrix.com
*
* Copyright (c) 2005, Intel Corporation.
* Copyright (c) 2007, XenSource Inc.
* Copyright (c) 2010, Citrix
*/
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/init.h>
#include <linux/pci.h>
#include <xen/platform_pci.h>
#include <xen/grant_table.h>
#include <xen/xenbus.h>
#include <xen/events.h>
#include <xen/hvm.h>
#include <xen/xen-ops.h>
#define DRV_NAME "xen-platform-pci"
static unsigned long platform_mmio;
static unsigned long platform_mmio_alloc;
static unsigned long platform_mmiolen;
static uint64_t callback_via;
static unsigned long alloc_xen_mmio(unsigned long len)
{
unsigned long addr;
addr = platform_mmio + platform_mmio_alloc;
platform_mmio_alloc += len;
BUG_ON(platform_mmio_alloc > platform_mmiolen);
return addr;
}
static uint64_t get_callback_via(struct pci_dev *pdev)
{
u8 pin;
int irq;
irq = pdev->irq;
if (irq < 16)
return irq; /* ISA IRQ */
pin = pdev->pin;
/* We don't know the GSI. Specify the PCI INTx line instead. */
return ((uint64_t)0x01 << HVM_CALLBACK_VIA_TYPE_SHIFT) | /* PCI INTx identifier */
((uint64_t)pci_domain_nr(pdev->bus) << 32) |
((uint64_t)pdev->bus->number << 16) |
((uint64_t)(pdev->devfn & 0xff) << 8) |
((uint64_t)(pin - 1) & 3);
}
static irqreturn_t do_hvm_evtchn_intr(int irq, void *dev_id)
{
xen_hvm_evtchn_do_upcall();
return IRQ_HANDLED;
}
static int xen_allocate_irq(struct pci_dev *pdev)
{
return request_irq(pdev->irq, do_hvm_evtchn_intr,
IRQF_NOBALANCING | IRQF_TRIGGER_RISING,
"xen-platform-pci", pdev);
}
static int platform_pci_resume(struct device *dev)
{
int err;
xen: Revert commits da72ff5bfcb0 and 72a9b186292d Recent discussion (http://marc.info/?l=xen-devel&m=149192184523741) established that commit 72a9b186292d ("xen: Remove event channel notification through Xen PCI platform device") (and thus commit da72ff5bfcb0 ("partially revert "xen: Remove event channel notification through Xen PCI platform device"")) are unnecessary and, in fact, prevent HVM guests from booting on Xen releases prior to 4.0 Therefore we revert both of those commits. The summary of that discussion is below: Here is the brief summary of the current situation: Before the offending commit (72a9b186292): 1) INTx does not work because of the reset_watches path. 2) The reset_watches path is only taken if you have Xen > 4.0 3) The Linux Kernel by default will use vector inject if the hypervisor support. So even INTx does not work no body running the kernel with Xen > 4.0 would notice. Unless he explicitly disabled this feature either in the kernel or in Xen (and this can only be disabled by modifying the code, not user-supported way to do it). After the offending commit (+ partial revert): 1) INTx is no longer support for HVM (only for PV guests). 2) Any HVM guest The kernel will not boot on Xen < 4.0 which does not have vector injection support. Since the only other mode supported is INTx which. So based on this summary, I think before commit (72a9b186292) we were in much better position from a user point of view. Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2017-04-24 19:04:53 +00:00
if (xen_have_vector_callback)
return 0;
xen: Revert commits da72ff5bfcb0 and 72a9b186292d Recent discussion (http://marc.info/?l=xen-devel&m=149192184523741) established that commit 72a9b186292d ("xen: Remove event channel notification through Xen PCI platform device") (and thus commit da72ff5bfcb0 ("partially revert "xen: Remove event channel notification through Xen PCI platform device"")) are unnecessary and, in fact, prevent HVM guests from booting on Xen releases prior to 4.0 Therefore we revert both of those commits. The summary of that discussion is below: Here is the brief summary of the current situation: Before the offending commit (72a9b186292): 1) INTx does not work because of the reset_watches path. 2) The reset_watches path is only taken if you have Xen > 4.0 3) The Linux Kernel by default will use vector inject if the hypervisor support. So even INTx does not work no body running the kernel with Xen > 4.0 would notice. Unless he explicitly disabled this feature either in the kernel or in Xen (and this can only be disabled by modifying the code, not user-supported way to do it). After the offending commit (+ partial revert): 1) INTx is no longer support for HVM (only for PV guests). 2) Any HVM guest The kernel will not boot on Xen < 4.0 which does not have vector injection support. Since the only other mode supported is INTx which. So based on this summary, I think before commit (72a9b186292) we were in much better position from a user point of view. Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2017-04-24 19:04:53 +00:00
err = xen_set_callback_via(callback_via);
if (err) {
dev_err(dev, "platform_pci_resume failure!\n");
return err;
}
return 0;
}
static int platform_pci_probe(struct pci_dev *pdev,
const struct pci_device_id *ent)
{
int i, ret;
long ioaddr;
long mmio_addr, mmio_len;
unsigned int max_nr_gframes;
unsigned long grant_frames;
if (!xen_domain())
return -ENODEV;
i = pci_enable_device(pdev);
if (i)
return i;
ioaddr = pci_resource_start(pdev, 0);
mmio_addr = pci_resource_start(pdev, 1);
mmio_len = pci_resource_len(pdev, 1);
if (mmio_addr == 0 || ioaddr == 0) {
dev_err(&pdev->dev, "no resources found\n");
ret = -ENOENT;
goto pci_out;
}
ret = pci_request_region(pdev, 1, DRV_NAME);
if (ret < 0)
goto pci_out;
ret = pci_request_region(pdev, 0, DRV_NAME);
if (ret < 0)
goto mem_out;
platform_mmio = mmio_addr;
platform_mmiolen = mmio_len;
xen: Revert commits da72ff5bfcb0 and 72a9b186292d Recent discussion (http://marc.info/?l=xen-devel&m=149192184523741) established that commit 72a9b186292d ("xen: Remove event channel notification through Xen PCI platform device") (and thus commit da72ff5bfcb0 ("partially revert "xen: Remove event channel notification through Xen PCI platform device"")) are unnecessary and, in fact, prevent HVM guests from booting on Xen releases prior to 4.0 Therefore we revert both of those commits. The summary of that discussion is below: Here is the brief summary of the current situation: Before the offending commit (72a9b186292): 1) INTx does not work because of the reset_watches path. 2) The reset_watches path is only taken if you have Xen > 4.0 3) The Linux Kernel by default will use vector inject if the hypervisor support. So even INTx does not work no body running the kernel with Xen > 4.0 would notice. Unless he explicitly disabled this feature either in the kernel or in Xen (and this can only be disabled by modifying the code, not user-supported way to do it). After the offending commit (+ partial revert): 1) INTx is no longer support for HVM (only for PV guests). 2) Any HVM guest The kernel will not boot on Xen < 4.0 which does not have vector injection support. Since the only other mode supported is INTx which. So based on this summary, I think before commit (72a9b186292) we were in much better position from a user point of view. Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2017-04-24 19:04:53 +00:00
if (!xen_have_vector_callback) {
ret = xen_allocate_irq(pdev);
if (ret) {
dev_warn(&pdev->dev, "request_irq failed err=%d\n", ret);
goto out;
}
/*
* It doesn't strictly *have* to run on CPU0 but it sure
* as hell better process the event channel ports delivered
* to CPU0.
*/
irq_set_affinity(pdev->irq, cpumask_of(0));
callback_via = get_callback_via(pdev);
ret = xen_set_callback_via(callback_via);
if (ret) {
dev_warn(&pdev->dev, "Unable to set the evtchn callback "
"err=%d\n", ret);
goto out;
}
}
max_nr_gframes = gnttab_max_grant_frames();
grant_frames = alloc_xen_mmio(PAGE_SIZE * max_nr_gframes);
ret = gnttab_setup_auto_xlat_frames(grant_frames);
if (ret)
goto out;
ret = gnttab_init();
if (ret)
goto grant_out;
return 0;
grant_out:
gnttab_free_auto_xlat_frames();
out:
pci_release_region(pdev, 0);
mem_out:
pci_release_region(pdev, 1);
pci_out:
pci_disable_device(pdev);
return ret;
}
static const struct pci_device_id platform_pci_tbl[] = {
{PCI_VENDOR_ID_XEN, PCI_DEVICE_ID_XEN_PLATFORM,
PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0},
{0,}
};
static const struct dev_pm_ops platform_pm_ops = {
.resume_noirq = platform_pci_resume,
};
static struct pci_driver platform_driver = {
.name = DRV_NAME,
.probe = platform_pci_probe,
.id_table = platform_pci_tbl,
.driver = {
.pm = &platform_pm_ops,
},
};
builtin_pci_driver(platform_driver);