The patch introduces support of VFIO on POWER.
The patch consists of:
1. IOMMU driver for VFIO.
It does not use IOMMU API at all, instead it calls POWER
IOMMU API directly (ppc_md callbacks).
2. A piece of code (module_init) which creates IOMMU groups.
TBD: what is a better place for it?
The patch is made on top of
git://github.com/awilliam/linux-vfio.git iommu-group-vfio-20120523
(which is iommu-group-vfio-20120521 + some fixes)
Signed-off-by: Alexey Kardashevskiy <a...@ozlabs.ru>
---
arch/powerpc/Kconfig | 6 +
arch/powerpc/include/asm/iommu.h | 3 +
arch/powerpc/kernel/Makefile | 1 +
arch/powerpc/kernel/iommu_vfio.c | 371 ++++++++++++++++++++++++++++++++++++++
4 files changed, 381 insertions(+), 0 deletions(-)
create mode 100644 arch/powerpc/kernel/iommu_vfio.c
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index feab3ba..13d12ac 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -319,6 +319,12 @@ config 8XX_MINIMAL_FPEMU
config IOMMU_HELPER
def_bool PPC64
+config IOMMU_VFIO
+ select IOMMU_API
+ depends on PPC64
+ tristate "Enable IOMMU chardev to support user-space PCI"
+ default n
+
config SWIOTLB
bool "SWIOTLB support"
default n
diff --git a/arch/powerpc/include/asm/iommu.h b/arch/powerpc/include/asm/iommu.h
index 957a83f..c64bce7 100644
--- a/arch/powerpc/include/asm/iommu.h
+++ b/arch/powerpc/include/asm/iommu.h
@@ -66,6 +66,9 @@ struct iommu_table {
unsigned long it_halfpoint; /* Breaking point for small/large allocs */
spinlock_t it_lock; /* Protects it_map */
unsigned long *it_map; /* A simple allocation bitmap for now */
+#ifdef CONFIG_IOMMU_API
+ struct iommu_group *it_group;
+#endif
};
struct scatterlist;
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index f5808a3..7cfd68e 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -90,6 +90,7 @@ obj-$(CONFIG_RELOCATABLE_PPC32) += reloc_32.o
obj-$(CONFIG_PPC32) += entry_32.o setup_32.o
obj-$(CONFIG_PPC64) += dma-iommu.o iommu.o
+obj-$(CONFIG_IOMMU_VFIO) += iommu_vfio.o
obj-$(CONFIG_KGDB) += kgdb.o
obj-$(CONFIG_PPC_OF_BOOT_TRAMPOLINE) += prom_init.o
obj-$(CONFIG_MODULES) += ppc_ksyms.o
diff --git a/arch/powerpc/kernel/iommu_vfio.c b/arch/powerpc/kernel/iommu_vfio.c
new file mode 100644
index 0000000..68a93dd
--- /dev/null
+++ b/arch/powerpc/kernel/iommu_vfio.c
@@ -0,0 +1,371 @@
+/*
+ * VFIO: IOMMU DMA mapping support for TCE on POWER
+ *
+ * Copyright (C) 2012 IBM Corp. All rights reserved.
+ * Author: Alexey Kardashevskiy <a...@ozlabs.ru>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Derived from original vfio_iommu_x86.c:
+ * Copyright (C) 2012 Red Hat, Inc. All rights reserved.
+ * Author: Alex Williamson <alex.william...@redhat.com>
+ */
+
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <linux/vfio.h>
+#include <linux/err.h>
+#include <linux/spinlock.h>
+#include <asm/iommu.h>
+
+#define DRIVER_VERSION "0.1"
+#define DRIVER_AUTHOR "a...@ozlabs.ru"
+#define DRIVER_DESC "POWER IOMMU chardev for VFIO"
+
+#define IOMMU_CHECK_EXTENSION _IO(VFIO_TYPE, VFIO_BASE + 1)
+
+/* -------- API for POWERPC IOMMU -------- */
+
+#define POWERPC_IOMMU 2
+
+struct tce_iommu_info {
+ __u32 argsz;
+ __u32 dma32_window_start;
+ __u32 dma32_window_size;
+};
+
+#define POWERPC_IOMMU_GET_INFO _IO(VFIO_TYPE, VFIO_BASE + 12)
+
+struct tce_iommu_dma_map {
+ __u32 argsz;
+ __u64 va;
+ __u64 dmaaddr;
+};
+
+#define POWERPC_IOMMU_MAP_DMA _IO(VFIO_TYPE, VFIO_BASE + 13)
+#define POWERPC_IOMMU_UNMAP_DMA _IO(VFIO_TYPE, VFIO_BASE + 14)
+
+/* ***************************************************************** */
+
+struct tce_iommu {
+ struct iommu_table *tbl;
+};
+
+static int tce_iommu_attach_group(void *iommu_data,
+ struct iommu_group *iommu_group)
+{
+ struct tce_iommu *tceiommu = iommu_data;
+
+ if (tceiommu->tbl) {
+ printk(KERN_ERR "Only one group per IOMMU instance is
allowed\n");
+ return -EFAULT;
+ }
+ tceiommu->tbl = iommu_group_get_iommudata(iommu_group);
+
+ return 0;
+}
+
+static void tce_iommu_detach_group(void *iommu_data,
+ struct iommu_group *iommu_group)
+{
+ struct tce_iommu *tceiommu = iommu_data;
+
+ if (!tceiommu->tbl) {
+ printk(KERN_ERR "IOMMU already released\n");
+ return;
+ }
+ tceiommu->tbl = NULL;
+}
+
+static void *tce_iommu_open(unsigned long arg)
+{
+ struct tce_iommu *tceiommu;
+
+ if (arg != POWERPC_IOMMU)
+ return ERR_PTR(-EINVAL);
+
+ tceiommu = kzalloc(sizeof(*tceiommu), GFP_KERNEL);
+ if (!tceiommu)
+ return ERR_PTR(-ENOMEM);
+
+ return tceiommu;
+}
+
+static void tce_iommu_release(void *iommu_data)
+{
+ struct tce_iommu *tceiommu = iommu_data;
+ kfree(tceiommu);
+}
+
+static int tce_iommu_map(struct iommu_table *tbl, unsigned long iova,
+ phys_addr_t paddr)
+{
+ unsigned long entry, flags;
+ int build_fail;
+
+ spin_lock_irqsave(&(tbl->it_lock), flags);
+ entry = iova >> IOMMU_PAGE_SHIFT;
+ build_fail = ppc_md.tce_build(tbl, entry, 1/*pages*/,
+ (unsigned long)paddr & IOMMU_PAGE_MASK,
+ DMA_BIDIRECTIONAL, NULL/*attrs*/);
+
+ /* ppc_md.tce_build() only returns non-zero for transient errors.
+ * Clean up the table bitmap in this case and return
+ * DMA_ERROR_CODE. For all other errors the functionality is
+ * not altered.
+ */
+ if (unlikely(build_fail)) {
+ printk("Failed to add TCE\n");
+ spin_unlock_irqrestore(&(tbl->it_lock), flags);
+ return -EFAULT;
+ }
+ /* Flush/invalidate TLB caches if necessary */
+ if (ppc_md.tce_flush)
+ ppc_md.tce_flush(tbl);
+
+ spin_unlock_irqrestore(&(tbl->it_lock), flags);
+
+ /* Make sure updates are seen by hardware */
+ mb();
+
+ return 0;
+}
+
+static void tce_iommu_unmap(struct iommu_table *tbl, unsigned long iova)
+{
+ unsigned long entry, flags;
+ entry = iova >> IOMMU_PAGE_SHIFT;
+
+ spin_lock_irqsave(&(tbl->it_lock), flags);
+ ppc_md.tce_free(tbl, entry, 1);
+ /* Flush/invalidate TLB caches if necessary */
+ if (ppc_md.tce_flush)
+ ppc_md.tce_flush(tbl);
+
+ spin_unlock_irqrestore(&(tbl->it_lock), flags);
+
+ /* Make sure updates are seen by hardware */
+ mb();
+}
+
+static phys_addr_t tce_iommu_iova_to_va(struct iommu_table *tbl,
+ unsigned long iova)
+{
+ unsigned long entry = iova >> IOMMU_PAGE_SHIFT;
+ phys_addr_t ret = 0;
+
+ if (ppc_md.tce_get)
+ ret = ppc_md.tce_get(tbl, entry);
+
+ return ret;
+}
+
+static struct page *tceaddr_to_page(void *addr)
+{
+ return pfn_to_page(__pa(addr) >> PAGE_SHIFT);
+}
+
+static long tce_dmamap_page(struct iommu_table *tbl,
+ uint64_t va, uint64_t dmaaddr)
+{
+ int ret = -EFAULT;
+ phys_addr_t addr;
+ struct page *page[1];
+ int iswrite = 1;
+ void *kva;
+
+ if (NULL == tbl) {
+ printk(KERN_ERR"tce_iommu: (map) IOMMU table has not "
+ "been initialized yet!\n");
+ return -EFAULT;
+ }
+ addr = tce_iommu_iova_to_va(tbl, dmaaddr);
+ if (addr) {
+ printk(KERN_WARNING"tce_iommu: already mapped va=%llx "
+ "da=%llx addr=%llx\n",
+ va, dmaaddr, addr);
+ /*TODO: unmap! */
+ }
+
+ ret = get_user_pages_fast(va, 1, iswrite, page);
+ if (1 != ret) {
+ printk(KERN_ERR"tce_iommu: get_user_pages_fast failed "
+ "va=%llx da=%llx addr=%llx ret=%d\n",
+ va, dmaaddr, addr, ret);
+ return -EFAULT;
+ }
+ ret = -EFAULT;
+ kva = (void *) page_address(page[0]);
+ if (kva) {
+ ret = tce_iommu_map(tbl, dmaaddr, (phys_addr_t) kva);
+ }
+ if (ret) {
+ printk(KERN_ERR"tce_iommu: tce_iommu_map va=%llx "
+ "da=%llx kva=%p\n",
+ va, dmaaddr, kva);
+ if (iswrite)
+ SetPageDirty(page[0]);
+ put_page(page[0]);
+ }
+
+ return ret;
+}
+
+static long tce_dmaunmap_page(struct iommu_table *tbl, uint64_t dmaaddr)
+{
+ int ret = 0;
+ phys_addr_t addr;
+ struct page *page;
+
+ if (NULL == tbl) {
+ printk(KERN_ERR"tce_iommu: (unmap) IOMMU table has not been "
+ "initialized yet!\n");
+ return -EFAULT;
+ }
+ addr = tce_iommu_iova_to_va(tbl, dmaaddr);
+ if (addr) {
+ page = tceaddr_to_page((void*)addr);
+ if (!page) {
+ printk(KERN_ERR"DMAUNMAP error: pfn_to_page(%llx) "
+ "failed\n", addr);
+ ret = -EFAULT;
+ } else {
+ SetPageDirty(page);
+ put_page(page);
+ }
+ }
+ tce_iommu_unmap(tbl, dmaaddr);
+ if (ret)
+ printk(KERN_ERR"Failed to DMAUNMAP: da=%llx pfn=%llx\n",
+ dmaaddr, addr);
+ return ret;
+}
+
+
+static long tce_iommu_ioctl(void *iommu_data,
+ unsigned int cmd, unsigned long arg)
+{
+ struct tce_iommu *tceiommu = iommu_data;
+ unsigned long minsz;
+
+ if (cmd == IOMMU_CHECK_EXTENSION) {
+ switch (arg) {
+ case POWERPC_IOMMU:
+ return 1;
+ default:
+ return 0;
+ }
+ } else if (cmd == POWERPC_IOMMU_GET_INFO) {
+ struct tce_iommu_info info;
+
+ minsz = offsetofend(struct tce_iommu_info, dma32_window_size);
+
+ if (copy_from_user(&info, (void __user *)arg, minsz))
+ return -EFAULT;
+
+ if (info.argsz < minsz)
+ return -EINVAL;
+
+ info.dma32_window_start =
+ tceiommu->tbl->it_offset << IOMMU_PAGE_SHIFT;
+ info.dma32_window_size =
+ tceiommu->tbl->it_size << IOMMU_PAGE_SHIFT;
+
+ return copy_to_user((void __user *)arg, &info, minsz);
+
+ } else if (cmd == POWERPC_IOMMU_MAP_DMA) {
+ struct tce_iommu_dma_map map;
+
+ minsz = offsetofend(struct tce_iommu_dma_map, dmaaddr);
+
+ if (copy_from_user(&map, (void __user *)arg, minsz))
+ return -EFAULT;
+
+ if (map.argsz < minsz)
+ return -EINVAL;
+
+ return tce_dmamap_page(tceiommu->tbl, map.va, map.dmaaddr);
+
+ } else if (cmd == POWERPC_IOMMU_UNMAP_DMA) {
+ struct tce_iommu_dma_map unmap;
+
+ minsz = offsetofend(struct tce_iommu_dma_map, dmaaddr);
+
+ if (copy_from_user(&unmap, (void __user *)arg, minsz))
+ return -EFAULT;
+
+ if (unmap.argsz < minsz)
+ return -EINVAL;
+
+ return tce_dmaunmap_page(tceiommu->tbl, unmap.dmaaddr);
+ }
+
+ return -ENOTTY;
+}
+
+const struct vfio_iommu_driver_ops tce_iommu_driver_ops = {
+ .name = "vfio-iommu-powerpc",
+ .owner = THIS_MODULE,
+ .open = tce_iommu_open,
+ .release = tce_iommu_release,
+ .ioctl = tce_iommu_ioctl,
+ .attach_group = tce_iommu_attach_group,
+ .detach_group = tce_iommu_detach_group,
+};
+
+static int __init tce_iommu_init(void)
+{
+ struct pci_dev *pdev = NULL;
+ struct iommu_table *tbl = NULL;
+ struct iommu_group *grp = NULL;
+ int ret = 0;
+
+ /* TODO: Do this for all devices, not just for PCI */
+ for_each_pci_dev(pdev) {
+
+ tbl = get_iommu_table_base(&pdev->dev);
+ if (NULL == tbl) {
+ printk("Skipping device %s\n", pdev->dev.kobj.name);
+ continue;
+ }
+ if (!tbl->it_group) {
+ struct iommu_group *tmp = iommu_group_alloc();
+ if (IS_ERR(tmp)) {
+ printk("Failed to create new IOMMU group, "
+ "ret = %ld\n", PTR_ERR(tmp));
+ break;
+ }
+ tbl->it_group = tmp;
+ iommu_group_set_iommudata(tmp, tbl, NULL);
+ }
+
+ grp = iommu_group_get(&pdev->dev);
+ if (!grp) {
+ ret = iommu_group_add_device(tbl->it_group, &pdev->dev);
+ if (ret < 0)
+ printk("iommu_group_add_device(%s) failed "
+ "with %d\n",
+ pdev->dev.kobj.name, ret);
+ }
+ }
+
+ return vfio_register_iommu_driver(&tce_iommu_driver_ops);
+}
+
+static void __exit tce_iommu_cleanup(void)
+{
+ vfio_unregister_iommu_driver(&tce_iommu_driver_ops);
+}
+
+module_init(tce_iommu_init);
+module_exit(tce_iommu_cleanup);
+
+MODULE_VERSION(DRIVER_VERSION);
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR(DRIVER_AUTHOR);
+MODULE_DESCRIPTION(DRIVER_DESC);
+
--
1.7.7.3
