This patch allows a context (different from kernel context)
to reserve a MSI bank for itself. And then the devices in the
context will share the MSI bank.
VFIO meta driver is one of typical user of these APIs. It will
reserve a MSI bank for MSI interrupt support of direct assignment
PCI devices to a Guest. Patches for same will follow this patch.
Signed-off-by: Bharat Bhushan <bharat.bhus...@freescale.com>
---
arch/powerpc/include/asm/device.h | 2 +
arch/powerpc/include/asm/fsl_msi.h | 26 ++++++
arch/powerpc/sysdev/fsl_msi.c | 169 +++++++++++++++++++++++++++++++------
arch/powerpc/sysdev/fsl_msi.h | 1 +
4 files changed, 173 insertions(+), 25 deletions(-)
create mode 100644 arch/powerpc/include/asm/fsl_msi.h
diff --git a/arch/powerpc/include/asm/device.h
b/arch/powerpc/include/asm/device.h
index 38faede..1c2bfd7 100644
--- a/arch/powerpc/include/asm/device.h
+++ b/arch/powerpc/include/asm/device.h
@@ -40,6 +40,8 @@ struct dev_archdata {
#ifdef CONFIG_FAIL_IOMMU
int fail_iommu;
#endif
+
+ void *context;
};
struct pdev_archdata {
diff --git a/arch/powerpc/include/asm/fsl_msi.h
b/arch/powerpc/include/asm/fsl_msi.h
new file mode 100644
index 0000000..e9041c2
--- /dev/null
+++ b/arch/powerpc/include/asm/fsl_msi.h
@@ -0,0 +1,26 @@
+/*
+ * Copyright (C) 2014 Freescale Semiconductor, Inc. All rights reserved.
+ *
+ * Author: Bharat Bhushan <bharat.bhus...@freescale.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; version 2 of the
+ * License.
+ *
+ */
+
+#ifndef _POWERPC_FSL_MSI_H
+#define _POWERPC_FSL_MSI_H
+
+extern int fsl_msi_set_msi_bank_region(struct iommu_domain *domain,
+ void *context, int win,
+ dma_addr_t iova, int prot);
+extern int fsl_msi_clear_msi_bank_region(struct iommu_domain *domain,
+ struct iommu_group *iommu_group,
+ int win, dma_addr_t iova);
+extern struct fsl_msi *fsl_msi_reserve_msi_bank(void *context);
+extern int fsl_msi_unreserve_msi_bank(void *context);
+extern int fsl_msi_set_msi_bank_in_dev(struct device *dev, void *data);
+
+#endif /* _POWERPC_FSL_MSI_H */
diff --git a/arch/powerpc/sysdev/fsl_msi.c b/arch/powerpc/sysdev/fsl_msi.c
index 027aeeb..75cd196 100644
--- a/arch/powerpc/sysdev/fsl_msi.c
+++ b/arch/powerpc/sysdev/fsl_msi.c
@@ -25,6 +25,7 @@
#include <asm/ppc-pci.h>
#include <asm/mpic.h>
#include <asm/fsl_hcalls.h>
+#include <linux/iommu.h>
#include "fsl_msi.h"
#include "fsl_pci.h"
@@ -172,22 +173,6 @@ static struct fsl_msi *fsl_msi_allocate_msi_bank(void
*context)
return NULL;
}
-/* FIXME: Assumption that host kernel will allocate only one MSI bank */
- __attribute__ ((unused)) static int fsl_msi_free_msi_bank(void *context)
-{
- struct fsl_msi *msi_data;
-
- list_for_each_entry(msi_data, &msi_head, list) {
- if ((msi_data->reserved == MSI_RESERVED) &&
- (msi_data->context == context)) {
- msi_data->reserved = MSI_FREE;
- msi_data->context = NULL;
- return 0;
- }
- }
- return -ENODEV;
-}
-
/* This API returns the allocated MSI bank of "context"
* to which "pdev" device belongs.
* All kernel owned devices have NULL context. All devices
@@ -200,6 +185,12 @@ static struct fsl_msi
*fsl_msi_get_reserved_msi_bank(struct pci_dev *pdev)
{
struct fsl_msi *msi_data = NULL;
void *context = NULL;
+ struct device *dev = &pdev->dev;
+
+ /* Device assigned to userspace if there is valid context */
+ if (dev->archdata.context) {
+ context = dev->archdata.context;
+ }
list_for_each_entry(msi_data, &msi_head, list) {
if ((msi_data->reserved == MSI_RESERVED) &&
@@ -208,13 +199,133 @@ static struct fsl_msi
*fsl_msi_get_reserved_msi_bank(struct pci_dev *pdev)
}
/* If no MSI bank allocated for kernel owned device, allocate one */
- msi_data = fsl_msi_allocate_msi_bank(NULL);
- if (msi_data)
- return msi_data;
+ if (!context) {
+ msi_data = fsl_msi_allocate_msi_bank(NULL);
+ if (msi_data)
+ return msi_data;
+ }
return NULL;
}
+/* API to set "context" to which the device belongs */
+int fsl_msi_set_msi_bank_in_dev(struct device *dev, void *data)
+{
+ dev->archdata.context = data;
+ return 0;
+}
+
+/* This API Allows a MSI bank to be reserved for a "context".
+ * All devices in same "context" will share the allocated
+ * MSI bank.
+ * Typically this function will be called from meta
+ * driver like VFIO with a valid "context".
+ */
+struct fsl_msi *fsl_msi_reserve_msi_bank(void *context)
+{
+ struct fsl_msi *msi_data;
+
+ if (!context)
+ return NULL;
+
+ /* Check if msi-bank already allocated for the context */
+ list_for_each_entry(msi_data, &msi_head, list) {
+ if (msi_data->reserved == MSI_FREE)
+ continue;
+
+ if (context == msi_data->context)
+ return msi_data;
+ }
+
+ msi_data = fsl_msi_allocate_msi_bank(context);
+ return msi_data;
+}
+
+/* Free reserved MSI bank for a given valid context */
+int fsl_msi_unreserve_msi_bank(void *context)
+{
+ struct fsl_msi *msi_data;
+
+ if (!context)
+ return -EINVAL;
+
+ list_for_each_entry(msi_data, &msi_head, list) {
+ if ((context == msi_data->context) &&
+ (msi_data->reserved == MSI_RESERVED)) {
+ msi_data->reserved = MSI_FREE;
+ msi_data->context = NULL;
+ return 0;
+ }
+ }
+ return -ENODEV;
+}
+
+static int is_msi_bank_reserved(struct fsl_msi *msi)
+{
+ return msi->reserved != MSI_FREE;
+}
+
+/*
+ * This function configures PAMU window for MSI page with
+ * given iova. Also same iova will be used as "msi-address"
+ * when configuring msi-message in the devices using this
+ * msi bank.
+ */
+int fsl_msi_set_msi_bank_region(struct iommu_domain *domain,
+ void *context , int win,
+ dma_addr_t iova, int prot)
+{
+ struct fsl_msi *msi_data;
+ dma_addr_t addr;
+ u64 size;
+ int ret;
+
+ if (!context)
+ return -EINVAL;
+
+ list_for_each_entry(msi_data, &msi_head, list) {
+ if (msi_data->reserved == MSI_FREE)
+ continue;
+
+ if (context != msi_data->context)
+ continue;
+
+ size = PAGE_SIZE;
+ addr = msi_data->msiir & ~(size - 1);
+ ret = iommu_domain_window_enable(domain, win, addr, size, prot);
+ if (ret) {
+ pr_err("%s Error: unable to map msi region\n",
__func__);
+ return ret;
+ }
+ msi_data->iova = iova | (msi_data->msiir & (size - 1));
+ return 0;
+ }
+
+ return -ENODEV;
+}
+
+/* This allows to undo what is done in fsl_msi_set_msi_bank_region() */
+int fsl_msi_clear_msi_bank_region(struct iommu_domain *domain, void *context,
+ int win)
+{
+ struct fsl_msi *msi_data;
+
+ if (!context)
+ return -EINVAL;
+
+ list_for_each_entry(msi_data, &msi_head, list) {
+ if (msi_data->reserved == MSI_FREE)
+ continue;
+
+ if (context == msi_data->context) {
+ iommu_domain_window_disable(domain, win);
+ msi_data->iova = 0;
+ return 0;
+ }
+ }
+ return -ENODEV;
+}
+
static void fsl_compose_msi_msg(struct pci_dev *pdev, int hwirq,
struct msi_msg *msg,
struct fsl_msi *fsl_msi_data)
@@ -225,12 +336,17 @@ static void fsl_compose_msi_msg(struct pci_dev *pdev, int
hwirq,
int len;
const __be64 *reg;
- /* If the msi-address-64 property exists, then use it */
- reg = of_get_property(hose->dn, "msi-address-64", &len);
- if (reg && (len == sizeof(u64)))
- address = be64_to_cpup(reg);
- else
- address = msi_data->msiir;
+ if (pdev->dev.archdata.context) {
+ address = msi_data->iova;
+ } else {
+ /* If the msi-address-64 property exists, then use it */
+ reg = of_get_property(hose->dn, "msi-address-64", &len);
+ if (reg && (len == sizeof(u64)))
+ address = be64_to_cpup(reg);
+ else
+ address = fsl_pci_immrbar_base(hose) +
+ (msi_data->msiir & 0xfffff);
+ }
msg->address_lo = lower_32_bits(address);
msg->address_hi = upper_32_bits(address);
@@ -401,6 +517,9 @@ static int fsl_of_msi_remove(struct platform_device *ofdev)
struct fsl_msi *msi = platform_get_drvdata(ofdev);
int virq, i;
+ if (is_msi_bank_reserved(msi))
+ return -EBUSY;
+
if (msi->list.prev != NULL)
list_del(&msi->list);
for (i = 0; i < NR_MSI_REG_MAX; i++) {
diff --git a/arch/powerpc/sysdev/fsl_msi.h b/arch/powerpc/sysdev/fsl_msi.h
index c69702b..7dc6f35 100644
--- a/arch/powerpc/sysdev/fsl_msi.h
+++ b/arch/powerpc/sysdev/fsl_msi.h
@@ -50,6 +50,7 @@ struct fsl_msi {
#define MSI_RESERVED 1
int reserved;
void *context;
+ dma_addr_t iova;
};
#endif /* _POWERPC_SYSDEV_FSL_MSI_H */
--
1.9.3
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