[mirror_ubuntu-jammy-kernel.git] / drivers / xen / xen-pciback / pciback_ops.c

// SPDX-License-Identifier: GPL-2.0
/*
 * PCI Backend Operations - respond to PCI requests from Frontend
 *
 *   Author: Ryan Wilson <hap9@epoch.ncsc.mil>
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#define dev_fmt pr_fmt

#include <linux/moduleparam.h>
#include <linux/wait.h>
#include <linux/bitops.h>
#include <xen/events.h>
#include <linux/sched.h>
#include "pciback.h"

static irqreturn_t xen_pcibk_guest_interrupt(int irq, void *dev_id);

/* Ensure a device is has the fake IRQ handler "turned on/off" and is
 * ready to be exported. This MUST be run after xen_pcibk_reset_device
 * which does the actual PCI device enable/disable.
 */
static void xen_pcibk_control_isr(struct pci_dev *dev, int reset)
{
	struct xen_pcibk_dev_data *dev_data;
	int rc;
	int enable = 0;

	dev_data = pci_get_drvdata(dev);
	if (!dev_data)
		return;

	/* We don't deal with bridges */
	if (dev->hdr_type != PCI_HEADER_TYPE_NORMAL)
		return;

	if (reset) {
		dev_data->enable_intx = 0;
		dev_data->ack_intr = 0;
	}
	enable =  dev_data->enable_intx;

	/* Asked to disable, but ISR isn't runnig */
	if (!enable && !dev_data->isr_on)
		return;

	/* Squirrel away the IRQs in the dev_data. We need this
	 * b/c when device transitions to MSI, the dev->irq is
	 * overwritten with the MSI vector.
	 */
	if (enable)
		dev_data->irq = dev->irq;

	/*
	 * SR-IOV devices in all use MSI-X and have no legacy
	 * interrupts, so inhibit creating a fake IRQ handler for them.
	 */
	if (dev_data->irq == 0)
		goto out;

	dev_dbg(&dev->dev, "%s: #%d %s %s%s %s-> %s\n",
		dev_data->irq_name,
		dev_data->irq,
		pci_is_enabled(dev) ? "on" : "off",
		dev->msi_enabled ? "MSI" : "",
		dev->msix_enabled ? "MSI/X" : "",
		dev_data->isr_on ? "enable" : "disable",
		enable ? "enable" : "disable");

	if (enable) {
		/*
		 * The MSI or MSI-X should not have an IRQ handler. Otherwise
		 * if the guest terminates we BUG_ON in free_msi_irqs.
		 */
		if (dev->msi_enabled || dev->msix_enabled)
			goto out;

		rc = request_irq(dev_data->irq,
				xen_pcibk_guest_interrupt, IRQF_SHARED,
				dev_data->irq_name, dev);
		if (rc) {
			dev_err(&dev->dev, "%s: failed to install fake IRQ " \
				"handler for IRQ %d! (rc:%d)\n",
				dev_data->irq_name, dev_data->irq, rc);
			goto out;
		}
	} else {
		free_irq(dev_data->irq, dev);
		dev_data->irq = 0;
	}
	dev_data->isr_on = enable;
	dev_data->ack_intr = enable;
out:
	dev_dbg(&dev->dev, "%s: #%d %s %s%s %s\n",
		dev_data->irq_name,
		dev_data->irq,
		pci_is_enabled(dev) ? "on" : "off",
		dev->msi_enabled ? "MSI" : "",
		dev->msix_enabled ? "MSI/X" : "",
		enable ? (dev_data->isr_on ? "enabled" : "failed to enable") :
			(dev_data->isr_on ? "failed to disable" : "disabled"));
}

/* Ensure a device is "turned off" and ready to be exported.
 * (Also see xen_pcibk_config_reset to ensure virtual configuration space is
 * ready to be re-exported)
 */
void xen_pcibk_reset_device(struct pci_dev *dev)
{
	u16 cmd;

	xen_pcibk_control_isr(dev, 1 /* reset device */);

	/* Disable devices (but not bridges) */
	if (dev->hdr_type == PCI_HEADER_TYPE_NORMAL) {
#ifdef CONFIG_PCI_MSI
		/* The guest could have been abruptly killed without
		 * disabling MSI/MSI-X interrupts.*/
		if (dev->msix_enabled)
			pci_disable_msix(dev);
		if (dev->msi_enabled)
			pci_disable_msi(dev);
#endif
		if (pci_is_enabled(dev))
			pci_disable_device(dev);

		dev->is_busmaster = 0;
	} else {
		pci_read_config_word(dev, PCI_COMMAND, &cmd);
		if (cmd & (PCI_COMMAND_INVALIDATE)) {
			cmd &= ~(PCI_COMMAND_INVALIDATE);
			pci_write_config_word(dev, PCI_COMMAND, cmd);

			dev->is_busmaster = 0;
		}
	}
}

#ifdef CONFIG_PCI_MSI
static
int xen_pcibk_enable_msi(struct xen_pcibk_device *pdev,
			 struct pci_dev *dev, struct xen_pci_op *op)
{
	struct xen_pcibk_dev_data *dev_data;
	int status;

	if (dev->msi_enabled)
		status = -EALREADY;
	else if (dev->msix_enabled)
		status = -ENXIO;
	else
		status = pci_enable_msi(dev);

	if (status) {
		dev_warn_ratelimited(&dev->dev, "error enabling MSI for guest %u: err %d\n",
				     pdev->xdev->otherend_id, status);
		op->value = 0;
		return XEN_PCI_ERR_op_failed;
	}

	/* The value the guest needs is actually the IDT vector, not the
	 * the local domain's IRQ number. */

	op->value = dev->irq ? xen_pirq_from_irq(dev->irq) : 0;

	dev_dbg(&dev->dev, "MSI: %d\n", op->value);

	dev_data = pci_get_drvdata(dev);
	if (dev_data)
		dev_data->ack_intr = 0;

	return 0;
}

static
int xen_pcibk_disable_msi(struct xen_pcibk_device *pdev,
			  struct pci_dev *dev, struct xen_pci_op *op)
{
	if (dev->msi_enabled) {
		struct xen_pcibk_dev_data *dev_data;

		pci_disable_msi(dev);

		dev_data = pci_get_drvdata(dev);
		if (dev_data)
			dev_data->ack_intr = 1;
	}
	op->value = dev->irq ? xen_pirq_from_irq(dev->irq) : 0;

	dev_dbg(&dev->dev, "MSI: %d\n", op->value);

	return 0;
}

static
int xen_pcibk_enable_msix(struct xen_pcibk_device *pdev,
			  struct pci_dev *dev, struct xen_pci_op *op)
{
	struct xen_pcibk_dev_data *dev_data;
	int i, result;
	struct msix_entry *entries;
	u16 cmd;

	dev_dbg(&dev->dev, "enable MSI-X\n");

	if (op->value > SH_INFO_MAX_VEC)
		return -EINVAL;

	if (dev->msix_enabled)
		return -EALREADY;

	/*
	 * PCI_COMMAND_MEMORY must be enabled, otherwise we may not be able
	 * to access the BARs where the MSI-X entries reside.
	 * But VF devices are unique in which the PF needs to be checked.
	 */
	pci_read_config_word(pci_physfn(dev), PCI_COMMAND, &cmd);
	if (dev->msi_enabled || !(cmd & PCI_COMMAND_MEMORY))
		return -ENXIO;

	entries = kmalloc_array(op->value, sizeof(*entries), GFP_KERNEL);
	if (entries == NULL)
		return -ENOMEM;

	for (i = 0; i < op->value; i++) {
		entries[i].entry = op->msix_entries[i].entry;
		entries[i].vector = op->msix_entries[i].vector;
	}

	result = pci_enable_msix_exact(dev, entries, op->value);
	if (result == 0) {
		for (i = 0; i < op->value; i++) {
			op->msix_entries[i].entry = entries[i].entry;
			if (entries[i].vector) {
				op->msix_entries[i].vector =
					xen_pirq_from_irq(entries[i].vector);
				dev_dbg(&dev->dev, "MSI-X[%d]: %d\n", i,
					op->msix_entries[i].vector);
			}
		}
	} else
		dev_warn_ratelimited(&dev->dev, "error enabling MSI-X for guest %u: err %d!\n",
				     pdev->xdev->otherend_id, result);
	kfree(entries);

	op->value = result;
	dev_data = pci_get_drvdata(dev);
	if (dev_data)
		dev_data->ack_intr = 0;

	return result > 0 ? 0 : result;
}

static
int xen_pcibk_disable_msix(struct xen_pcibk_device *pdev,
			   struct pci_dev *dev, struct xen_pci_op *op)
{
	if (dev->msix_enabled) {
		struct xen_pcibk_dev_data *dev_data;

		pci_disable_msix(dev);

		dev_data = pci_get_drvdata(dev);
		if (dev_data)
			dev_data->ack_intr = 1;
	}
	/*
	 * SR-IOV devices (which don't have any legacy IRQ) have
	 * an undefined IRQ value of zero.
	 */
	op->value = dev->irq ? xen_pirq_from_irq(dev->irq) : 0;

	dev_dbg(&dev->dev, "MSI-X: %d\n", op->value);

	return 0;
}
#endif

static inline bool xen_pcibk_test_op_pending(struct xen_pcibk_device *pdev)
{
	return test_bit(_XEN_PCIF_active,
			(unsigned long *)&pdev->sh_info->flags) &&
	       !test_and_set_bit(_PDEVF_op_active, &pdev->flags);
}

/*
* Now the same evtchn is used for both pcifront conf_read_write request
* as well as pcie aer front end ack. We use a new work_queue to schedule
* xen_pcibk conf_read_write service for avoiding confict with aer_core
* do_recovery job which also use the system default work_queue
*/
static void xen_pcibk_test_and_schedule_op(struct xen_pcibk_device *pdev)
{
	bool eoi = true;

	/* Check that frontend is requesting an operation and that we are not
	 * already processing a request */
	if (xen_pcibk_test_op_pending(pdev)) {
		schedule_work(&pdev->op_work);
		eoi = false;
	}
	/*_XEN_PCIB_active should have been cleared by pcifront. And also make
	sure xen_pcibk is waiting for ack by checking _PCIB_op_pending*/
	if (!test_bit(_XEN_PCIB_active, (unsigned long *)&pdev->sh_info->flags)
	    && test_bit(_PCIB_op_pending, &pdev->flags)) {
		wake_up(&xen_pcibk_aer_wait_queue);
		eoi = false;
	}

	/* EOI if there was nothing to do. */
	if (eoi)
		xen_pcibk_lateeoi(pdev, XEN_EOI_FLAG_SPURIOUS);
}

/* Performing the configuration space reads/writes must not be done in atomic
 * context because some of the pci_* functions can sleep (mostly due to ACPI
 * use of semaphores). This function is intended to be called from a work
 * queue in process context taking a struct xen_pcibk_device as a parameter */

static void xen_pcibk_do_one_op(struct xen_pcibk_device *pdev)
{
	struct pci_dev *dev;
	struct xen_pcibk_dev_data *dev_data = NULL;
	struct xen_pci_op *op = &pdev->op;
	int test_intx = 0;
#ifdef CONFIG_PCI_MSI
	unsigned int nr = 0;
#endif

	*op = pdev->sh_info->op;
	barrier();
	dev = xen_pcibk_get_pci_dev(pdev, op->domain, op->bus, op->devfn);

	if (dev == NULL)
		op->err = XEN_PCI_ERR_dev_not_found;
	else {
		dev_data = pci_get_drvdata(dev);
		if (dev_data)
			test_intx = dev_data->enable_intx;
		switch (op->cmd) {
		case XEN_PCI_OP_conf_read:
			op->err = xen_pcibk_config_read(dev,
				  op->offset, op->size, &op->value);
			break;
		case XEN_PCI_OP_conf_write:
			op->err = xen_pcibk_config_write(dev,
				  op->offset, op->size,	op->value);
			break;
#ifdef CONFIG_PCI_MSI
		case XEN_PCI_OP_enable_msi:
			op->err = xen_pcibk_enable_msi(pdev, dev, op);
			break;
		case XEN_PCI_OP_disable_msi:
			op->err = xen_pcibk_disable_msi(pdev, dev, op);
			break;
		case XEN_PCI_OP_enable_msix:
			nr = op->value;
			op->err = xen_pcibk_enable_msix(pdev, dev, op);
			break;
		case XEN_PCI_OP_disable_msix:
			op->err = xen_pcibk_disable_msix(pdev, dev, op);
			break;
#endif
		default:
			op->err = XEN_PCI_ERR_not_implemented;
			break;
		}
	}
	if (!op->err && dev && dev_data) {
		/* Transition detected */
		if ((dev_data->enable_intx != test_intx))
			xen_pcibk_control_isr(dev, 0 /* no reset */);
	}
	pdev->sh_info->op.err = op->err;
	pdev->sh_info->op.value = op->value;
#ifdef CONFIG_PCI_MSI
	if (op->cmd == XEN_PCI_OP_enable_msix && op->err == 0) {
		unsigned int i;

		for (i = 0; i < nr; i++)
			pdev->sh_info->op.msix_entries[i].vector =
				op->msix_entries[i].vector;
	}
#endif
	/* Tell the driver domain that we're done. */
	wmb();
	clear_bit(_XEN_PCIF_active, (unsigned long *)&pdev->sh_info->flags);
	notify_remote_via_irq(pdev->evtchn_irq);

	/* Mark that we're done. */
	smp_mb__before_atomic(); /* /after/ clearing PCIF_active */
	clear_bit(_PDEVF_op_active, &pdev->flags);
	smp_mb__after_atomic(); /* /before/ final check for work */
}

void xen_pcibk_do_op(struct work_struct *data)
{
	struct xen_pcibk_device *pdev =
		container_of(data, struct xen_pcibk_device, op_work);

	do {
		xen_pcibk_do_one_op(pdev);
	} while (xen_pcibk_test_op_pending(pdev));

	xen_pcibk_lateeoi(pdev, 0);
}

irqreturn_t xen_pcibk_handle_event(int irq, void *dev_id)
{
	struct xen_pcibk_device *pdev = dev_id;
	bool eoi;

	/* IRQs might come in before pdev->evtchn_irq is written. */
	if (unlikely(pdev->evtchn_irq != irq))
		pdev->evtchn_irq = irq;

	eoi = test_and_set_bit(_EOI_pending, &pdev->flags);
	WARN(eoi, "IRQ while EOI pending\n");

	xen_pcibk_test_and_schedule_op(pdev);

	return IRQ_HANDLED;
}
static irqreturn_t xen_pcibk_guest_interrupt(int irq, void *dev_id)
{
	struct pci_dev *dev = (struct pci_dev *)dev_id;
	struct xen_pcibk_dev_data *dev_data = pci_get_drvdata(dev);

	if (dev_data->isr_on && dev_data->ack_intr) {
		dev_data->handled++;
		if ((dev_data->handled % 1000) == 0) {
			if (xen_test_irq_shared(irq)) {
				dev_info(&dev->dev, "%s IRQ line is not shared "
					"with other domains. Turning ISR off\n",
					 dev_data->irq_name);
				dev_data->ack_intr = 0;
			}
		}
		return IRQ_HANDLED;
	}
	return IRQ_NONE;
}
Commit	Line	Data
b2441318	1	// SPDX-License-Identifier: GPL-2.0
30edc14b KRW	2	/*
	3	* PCI Backend Operations - respond to PCI requests from Frontend
	4	*
	5	* Author: Ryan Wilson <hap9@epoch.ncsc.mil>
	6	*/
283c0972 JP	7
283c0972 JP	8	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
69049454	9	#define dev_fmt pr_fmt
283c0972	10
59aa56bf	11	#include <linux/moduleparam.h>
30edc14b KRW	12	#include <linux/wait.h>
	13	#include <linux/bitops.h>
	14	#include <xen/events.h>
	15	#include <linux/sched.h>
	16	#include "pciback.h"
	17
a92336a1 KRW	18	static irqreturn_t xen_pcibk_guest_interrupt(int irq, void *dev_id);
a92336a1 KRW	19
0513fe9e	20	/* Ensure a device is has the fake IRQ handler "turned on/off" and is
a92336a1	21	* ready to be exported. This MUST be run after xen_pcibk_reset_device
0513fe9e KRW	22	* which does the actual PCI device enable/disable.
0513fe9e KRW	23	*/
a92336a1	24	static void xen_pcibk_control_isr(struct pci_dev *dev, int reset)
0513fe9e	25	{
a92336a1	26	struct xen_pcibk_dev_data *dev_data;
0513fe9e KRW	27	int rc;
	28	int enable = 0;
	29
	30	dev_data = pci_get_drvdata(dev);
	31	if (!dev_data)
	32	return;
	33
	34	/* We don't deal with bridges */
	35	if (dev->hdr_type != PCI_HEADER_TYPE_NORMAL)
	36	return;
	37
	38	if (reset) {
	39	dev_data->enable_intx = 0;
	40	dev_data->ack_intr = 0;
	41	}
	42	enable = dev_data->enable_intx;
	43
	44	/* Asked to disable, but ISR isn't runnig */
	45	if (!enable && !dev_data->isr_on)
	46	return;
	47
	48	/* Squirrel away the IRQs in the dev_data. We need this
	49	* b/c when device transitions to MSI, the dev->irq is
	50	* overwritten with the MSI vector.
	51	*/
	52	if (enable)
	53	dev_data->irq = dev->irq;
	54
e17ab35f KRW	55	/*
	56	* SR-IOV devices in all use MSI-X and have no legacy
	57	* interrupts, so inhibit creating a fake IRQ handler for them.
	58	*/
	59	if (dev_data->irq == 0)
	60	goto out;
	61
0513fe9e KRW	62	dev_dbg(&dev->dev, "%s: #%d %s %s%s %s-> %s\n",
	63	dev_data->irq_name,
	64	dev_data->irq,
	65	pci_is_enabled(dev) ? "on" : "off",
	66	dev->msi_enabled ? "MSI" : "",
	67	dev->msix_enabled ? "MSI/X" : "",
	68	dev_data->isr_on ? "enable" : "disable",
	69	enable ? "enable" : "disable");
	70
	71	if (enable) {
a396f3a2 KRW	72	/*
	73	* The MSI or MSI-X should not have an IRQ handler. Otherwise
	74	* if the guest terminates we BUG_ON in free_msi_irqs.
	75	*/
	76	if (dev->msi_enabled \|\| dev->msix_enabled)
	77	goto out;
	78
0513fe9e	79	rc = request_irq(dev_data->irq,
a92336a1	80	xen_pcibk_guest_interrupt, IRQF_SHARED,
0513fe9e KRW	81	dev_data->irq_name, dev);
	82	if (rc) {
	83	dev_err(&dev->dev, "%s: failed to install fake IRQ " \
	84	"handler for IRQ %d! (rc:%d)\n",
	85	dev_data->irq_name, dev_data->irq, rc);
	86	goto out;
	87	}
	88	} else {
	89	free_irq(dev_data->irq, dev);
	90	dev_data->irq = 0;
	91	}
	92	dev_data->isr_on = enable;
	93	dev_data->ack_intr = enable;
	94	out:
	95	dev_dbg(&dev->dev, "%s: #%d %s %s%s %s\n",
	96	dev_data->irq_name,
	97	dev_data->irq,
	98	pci_is_enabled(dev) ? "on" : "off",
	99	dev->msi_enabled ? "MSI" : "",
	100	dev->msix_enabled ? "MSI/X" : "",
	101	enable ? (dev_data->isr_on ? "enabled" : "failed to enable") :
	102	(dev_data->isr_on ? "failed to disable" : "disabled"));
	103	}
	104
30edc14b	105	/* Ensure a device is "turned off" and ready to be exported.
a92336a1	106	* (Also see xen_pcibk_config_reset to ensure virtual configuration space is
30edc14b KRW	107	* ready to be re-exported)
30edc14b KRW	108	*/
a92336a1	109	void xen_pcibk_reset_device(struct pci_dev *dev)
30edc14b KRW	110	{
	111	u16 cmd;
	112
a92336a1	113	xen_pcibk_control_isr(dev, 1 /* reset device */);
0513fe9e	114
30edc14b KRW	115	/* Disable devices (but not bridges) */
30edc14b KRW	116	if (dev->hdr_type == PCI_HEADER_TYPE_NORMAL) {
a2be65fd KRW	117	#ifdef CONFIG_PCI_MSI
	118	/* The guest could have been abruptly killed without
	119	* disabling MSI/MSI-X interrupts.*/
	120	if (dev->msix_enabled)
	121	pci_disable_msix(dev);
	122	if (dev->msi_enabled)
	123	pci_disable_msi(dev);
	124	#endif
bdc5c181 KRW	125	if (pci_is_enabled(dev))
bdc5c181 KRW	126	pci_disable_device(dev);
30edc14b	127
30edc14b KRW	128	dev->is_busmaster = 0;
	129	} else {
	130	pci_read_config_word(dev, PCI_COMMAND, &cmd);
	131	if (cmd & (PCI_COMMAND_INVALIDATE)) {
	132	cmd &= ~(PCI_COMMAND_INVALIDATE);
	133	pci_write_config_word(dev, PCI_COMMAND, cmd);
	134
	135	dev->is_busmaster = 0;
	136	}
	137	}
	138	}
a92336a1 KRW	139
	140	#ifdef CONFIG_PCI_MSI
	141	static
	142	int xen_pcibk_enable_msi(struct xen_pcibk_device *pdev,
	143	struct pci_dev dev, struct xen_pci_op op)
	144	{
	145	struct xen_pcibk_dev_data *dev_data;
a92336a1 KRW	146	int status;
a92336a1 KRW	147
56441f3c KRW	148	if (dev->msi_enabled)
	149	status = -EALREADY;
	150	else if (dev->msix_enabled)
	151	status = -ENXIO;
	152	else
	153	status = pci_enable_msi(dev);
a92336a1 KRW	154
a92336a1 KRW	155	if (status) {
69049454 BH	156	dev_warn_ratelimited(&dev->dev, "error enabling MSI for guest %u: err %d\n",
69049454 BH	157	pdev->xdev->otherend_id, status);
a92336a1 KRW	158	op->value = 0;
	159	return XEN_PCI_ERR_op_failed;
	160	}
	161
	162	/* The value the guest needs is actually the IDT vector, not the
	163	* the local domain's IRQ number. */
	164
	165	op->value = dev->irq ? xen_pirq_from_irq(dev->irq) : 0;
4969a3a2 BO	166
4969a3a2 BO	167	dev_dbg(&dev->dev, "MSI: %d\n", op->value);
a92336a1 KRW	168
	169	dev_data = pci_get_drvdata(dev);
	170	if (dev_data)
	171	dev_data->ack_intr = 0;
	172
	173	return 0;
	174	}
	175
	176	static
	177	int xen_pcibk_disable_msi(struct xen_pcibk_device *pdev,
	178	struct pci_dev dev, struct xen_pci_op op)
	179	{
7cfb905b KRW	180	if (dev->msi_enabled) {
	181	struct xen_pcibk_dev_data *dev_data;
	182
	183	pci_disable_msi(dev);
	184
	185	dev_data = pci_get_drvdata(dev);
	186	if (dev_data)
	187	dev_data->ack_intr = 1;
	188	}
a92336a1	189	op->value = dev->irq ? xen_pirq_from_irq(dev->irq) : 0;
4969a3a2 BO	190
	191	dev_dbg(&dev->dev, "MSI: %d\n", op->value);
	192
a92336a1 KRW	193	return 0;
	194	}
	195
	196	static
	197	int xen_pcibk_enable_msix(struct xen_pcibk_device *pdev,
	198	struct pci_dev dev, struct xen_pci_op op)
	199	{
	200	struct xen_pcibk_dev_data *dev_data;
	201	int i, result;
	202	struct msix_entry *entries;
408fb0e5	203	u16 cmd;
a92336a1	204
4969a3a2	205	dev_dbg(&dev->dev, "enable MSI-X\n");
5e0ce145	206
a92336a1 KRW	207	if (op->value > SH_INFO_MAX_VEC)
	208	return -EINVAL;
	209
5e0ce145 KRW	210	if (dev->msix_enabled)
	211	return -EALREADY;
	212
408fb0e5 KRW	213	/*
	214	* PCI_COMMAND_MEMORY must be enabled, otherwise we may not be able
	215	* to access the BARs where the MSI-X entries reside.
8d47065f	216	* But VF devices are unique in which the PF needs to be checked.
408fb0e5	217	*/
8d47065f	218	pci_read_config_word(pci_physfn(dev), PCI_COMMAND, &cmd);
408fb0e5	219	if (dev->msi_enabled \|\| !(cmd & PCI_COMMAND_MEMORY))
5e0ce145 KRW	220	return -ENXIO;
5e0ce145 KRW	221
6da2ec56	222	entries = kmalloc_array(op->value, sizeof(*entries), GFP_KERNEL);
a92336a1 KRW	223	if (entries == NULL)
	224	return -ENOMEM;
	225
	226	for (i = 0; i < op->value; i++) {
	227	entries[i].entry = op->msix_entries[i].entry;
	228	entries[i].vector = op->msix_entries[i].vector;
	229	}
	230
efdfa3ed	231	result = pci_enable_msix_exact(dev, entries, op->value);
a92336a1 KRW	232	if (result == 0) {
	233	for (i = 0; i < op->value; i++) {
	234	op->msix_entries[i].entry = entries[i].entry;
c0914e61	235	if (entries[i].vector) {
a92336a1 KRW	236	op->msix_entries[i].vector =
a92336a1 KRW	237	xen_pirq_from_irq(entries[i].vector);
4969a3a2 BO	238	dev_dbg(&dev->dev, "MSI-X[%d]: %d\n", i,
4969a3a2 BO	239	op->msix_entries[i].vector);
c0914e61	240	}
a92336a1	241	}
51ac8893	242	} else
69049454 BH	243	dev_warn_ratelimited(&dev->dev, "error enabling MSI-X for guest %u: err %d!\n",
69049454 BH	244	pdev->xdev->otherend_id, result);
a92336a1 KRW	245	kfree(entries);
	246
	247	op->value = result;
	248	dev_data = pci_get_drvdata(dev);
	249	if (dev_data)
	250	dev_data->ack_intr = 0;
	251
0ee46eca	252	return result > 0 ? 0 : result;
a92336a1 KRW	253	}
	254
	255	static
	256	int xen_pcibk_disable_msix(struct xen_pcibk_device *pdev,
	257	struct pci_dev dev, struct xen_pci_op op)
	258	{
7cfb905b KRW	259	if (dev->msix_enabled) {
	260	struct xen_pcibk_dev_data *dev_data;
	261
	262	pci_disable_msix(dev);
	263
	264	dev_data = pci_get_drvdata(dev);
	265	if (dev_data)
	266	dev_data->ack_intr = 1;
	267	}
a92336a1 KRW	268	/*
	269	* SR-IOV devices (which don't have any legacy IRQ) have
	270	* an undefined IRQ value of zero.
	271	*/
	272	op->value = dev->irq ? xen_pirq_from_irq(dev->irq) : 0;
4969a3a2 BO	273
	274	dev_dbg(&dev->dev, "MSI-X: %d\n", op->value);
	275
a92336a1 KRW	276	return 0;
	277	}
	278	#endif
c2711441 JG	279
	280	static inline bool xen_pcibk_test_op_pending(struct xen_pcibk_device *pdev)
	281	{
	282	return test_bit(_XEN_PCIF_active,
	283	(unsigned long *)&pdev->sh_info->flags) &&
	284	!test_and_set_bit(_PDEVF_op_active, &pdev->flags);
	285	}
	286
30edc14b KRW	287	/*
	288	* Now the same evtchn is used for both pcifront conf_read_write request
	289	* as well as pcie aer front end ack. We use a new work_queue to schedule
a92336a1	290	* xen_pcibk conf_read_write service for avoiding confict with aer_core
30edc14b KRW	291	* do_recovery job which also use the system default work_queue
30edc14b KRW	292	*/
c2711441	293	static void xen_pcibk_test_and_schedule_op(struct xen_pcibk_device *pdev)
30edc14b	294	{
c2711441 JG	295	bool eoi = true;
c2711441 JG	296
30edc14b KRW	297	/* Check that frontend is requesting an operation and that we are not
30edc14b KRW	298	* already processing a request */
c2711441	299	if (xen_pcibk_test_op_pending(pdev)) {
429eafe6	300	schedule_work(&pdev->op_work);
c2711441	301	eoi = false;
30edc14b KRW	302	}
30edc14b KRW	303	/*_XEN_PCIB_active should have been cleared by pcifront. And also make
a92336a1	304	sure xen_pcibk is waiting for ack by checking _PCIB_op_pending*/
30edc14b KRW	305	if (!test_bit(_XEN_PCIB_active, (unsigned long *)&pdev->sh_info->flags)
30edc14b KRW	306	&& test_bit(_PCIB_op_pending, &pdev->flags)) {
a92336a1	307	wake_up(&xen_pcibk_aer_wait_queue);
c2711441	308	eoi = false;
30edc14b	309	}
c2711441 JG	310
	311	/* EOI if there was nothing to do. */
	312	if (eoi)
	313	xen_pcibk_lateeoi(pdev, XEN_EOI_FLAG_SPURIOUS);
30edc14b KRW	314	}
	315
	316	/* Performing the configuration space reads/writes must not be done in atomic
	317	* context because some of the pci_* functions can sleep (mostly due to ACPI
	318	* use of semaphores). This function is intended to be called from a work
a92336a1	319	* queue in process context taking a struct xen_pcibk_device as a parameter */
30edc14b	320
c2711441	321	static void xen_pcibk_do_one_op(struct xen_pcibk_device *pdev)
30edc14b	322	{
30edc14b	323	struct pci_dev *dev;
a92336a1	324	struct xen_pcibk_dev_data *dev_data = NULL;
8135cf8b	325	struct xen_pci_op *op = &pdev->op;
0513fe9e	326	int test_intx = 0;
d159457b KRW	327	#ifdef CONFIG_PCI_MSI
	328	unsigned int nr = 0;
	329	#endif
30edc14b	330
8135cf8b KRW	331	*op = pdev->sh_info->op;
8135cf8b KRW	332	barrier();
a92336a1	333	dev = xen_pcibk_get_pci_dev(pdev, op->domain, op->bus, op->devfn);
30edc14b KRW	334
	335	if (dev == NULL)
	336	op->err = XEN_PCI_ERR_dev_not_found;
	337	else {
0513fe9e KRW	338	dev_data = pci_get_drvdata(dev);
	339	if (dev_data)
	340	test_intx = dev_data->enable_intx;
30edc14b KRW	341	switch (op->cmd) {
30edc14b KRW	342	case XEN_PCI_OP_conf_read:
a92336a1	343	op->err = xen_pcibk_config_read(dev,
30edc14b KRW	344	op->offset, op->size, &op->value);
	345	break;
	346	case XEN_PCI_OP_conf_write:
a92336a1	347	op->err = xen_pcibk_config_write(dev,
30edc14b KRW	348	op->offset, op->size, op->value);
	349	break;
	350	#ifdef CONFIG_PCI_MSI
	351	case XEN_PCI_OP_enable_msi:
a92336a1	352	op->err = xen_pcibk_enable_msi(pdev, dev, op);
30edc14b KRW	353	break;
30edc14b KRW	354	case XEN_PCI_OP_disable_msi:
a92336a1	355	op->err = xen_pcibk_disable_msi(pdev, dev, op);
30edc14b KRW	356	break;
30edc14b KRW	357	case XEN_PCI_OP_enable_msix:
d159457b	358	nr = op->value;
a92336a1	359	op->err = xen_pcibk_enable_msix(pdev, dev, op);
30edc14b KRW	360	break;
30edc14b KRW	361	case XEN_PCI_OP_disable_msix:
a92336a1	362	op->err = xen_pcibk_disable_msix(pdev, dev, op);
30edc14b KRW	363	break;
	364	#endif
	365	default:
	366	op->err = XEN_PCI_ERR_not_implemented;
	367	break;
	368	}
	369	}
0513fe9e KRW	370	if (!op->err && dev && dev_data) {
	371	/* Transition detected */
	372	if ((dev_data->enable_intx != test_intx))
a92336a1	373	xen_pcibk_control_isr(dev, 0 /* no reset */);
0513fe9e	374	}
8135cf8b KRW	375	pdev->sh_info->op.err = op->err;
	376	pdev->sh_info->op.value = op->value;
	377	#ifdef CONFIG_PCI_MSI
	378	if (op->cmd == XEN_PCI_OP_enable_msix && op->err == 0) {
	379	unsigned int i;
	380
d159457b	381	for (i = 0; i < nr; i++)
8135cf8b KRW	382	pdev->sh_info->op.msix_entries[i].vector =
	383	op->msix_entries[i].vector;
	384	}
	385	#endif
30edc14b KRW	386	/* Tell the driver domain that we're done. */
	387	wmb();
	388	clear_bit(_XEN_PCIF_active, (unsigned long *)&pdev->sh_info->flags);
	389	notify_remote_via_irq(pdev->evtchn_irq);
	390
	391	/* Mark that we're done. */
4e857c58	392	smp_mb__before_atomic(); /* /after/ clearing PCIF_active */
30edc14b	393	clear_bit(_PDEVF_op_active, &pdev->flags);
4e857c58	394	smp_mb__after_atomic(); /* /before/ final check for work */
c2711441	395	}
30edc14b	396
c2711441 JG	397	void xen_pcibk_do_op(struct work_struct *data)
	398	{
	399	struct xen_pcibk_device *pdev =
	400	container_of(data, struct xen_pcibk_device, op_work);
	401
	402	do {
	403	xen_pcibk_do_one_op(pdev);
	404	} while (xen_pcibk_test_op_pending(pdev));
	405
	406	xen_pcibk_lateeoi(pdev, 0);
30edc14b KRW	407	}
30edc14b KRW	408
a92336a1	409	irqreturn_t xen_pcibk_handle_event(int irq, void *dev_id)
30edc14b	410	{
a92336a1	411	struct xen_pcibk_device *pdev = dev_id;
c2711441 JG	412	bool eoi;
	413
	414	/* IRQs might come in before pdev->evtchn_irq is written. */
	415	if (unlikely(pdev->evtchn_irq != irq))
	416	pdev->evtchn_irq = irq;
	417
	418	eoi = test_and_set_bit(_EOI_pending, &pdev->flags);
	419	WARN(eoi, "IRQ while EOI pending\n");
30edc14b	420
a92336a1	421	xen_pcibk_test_and_schedule_op(pdev);
30edc14b KRW	422
	423	return IRQ_HANDLED;
	424	}
a92336a1	425	static irqreturn_t xen_pcibk_guest_interrupt(int irq, void *dev_id)
0513fe9e KRW	426	{
0513fe9e KRW	427	struct pci_dev dev = (struct pci_dev )dev_id;
a92336a1	428	struct xen_pcibk_dev_data *dev_data = pci_get_drvdata(dev);
0513fe9e KRW	429
	430	if (dev_data->isr_on && dev_data->ack_intr) {
	431	dev_data->handled++;
	432	if ((dev_data->handled % 1000) == 0) {
	433	if (xen_test_irq_shared(irq)) {
69049454	434	dev_info(&dev->dev, "%s IRQ line is not shared "
0513fe9e KRW	435	"with other domains. Turning ISR off\n",
	436	dev_data->irq_name);
	437	dev_data->ack_intr = 0;
	438	}
	439	}
	440	return IRQ_HANDLED;
	441	}
	442	return IRQ_NONE;
	443	}