[PATCH v3 -mm 4/7] I/OAT: Split PCI startup from DMA handling code

From: Shannon Nelson
Date: Wed Aug 29 2007 - 15:02:46 EST

Split the general PCI startup from the DMA handling code in order to
prepare for adding support for DCA services and future versions of the
ioatdma device.

[Rusty Russell] Removal of __unsafe() usage.

Signed-off-by: Shannon Nelson <shannon.nelson@xxxxxxxxx>
Acked-by: David S. Miller <davem@xxxxxxxxxxxxx>
---

drivers/dma/Makefile | 2
drivers/dma/ioat.c | 196 ++++++++++++++++++++++++++++++++++++++++++++++
drivers/dma/ioat_dma.c | 180 ++++++++++--------------------------------
drivers/dma/ioatdma.h | 20 +++--
drivers/dma/ioatdma_hw.h | 2
5 files changed, 254 insertions(+), 146 deletions(-)

diff --git a/drivers/dma/Makefile b/drivers/dma/Makefile
index 77bee99..cec0c9c 100644
--- a/drivers/dma/Makefile
+++ b/drivers/dma/Makefile
@@ -1,5 +1,5 @@
obj-$(CONFIG_DMA_ENGINE) += dmaengine.o
obj-$(CONFIG_NET_DMA) += iovlock.o
obj-$(CONFIG_INTEL_IOATDMA) += ioatdma.o
-ioatdma-objs := ioat_dma.o
+ioatdma-objs := ioat.o ioat_dma.o
obj-$(CONFIG_INTEL_IOP_ADMA) += iop-adma.o
diff --git a/drivers/dma/ioat.c b/drivers/dma/ioat.c
new file mode 100644
index 0000000..ae5817b
--- /dev/null
+++ b/drivers/dma/ioat.c
@@ -0,0 +1,196 @@
+/*
+ * Intel I/OAT DMA Linux driver
+ * Copyright(c) 2004 - 2007 Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * The full GNU General Public License is included in this distribution in
+ * the file called "COPYING".
+ *
+ */
+
+/*
+ * This driver supports an Intel I/OAT DMA engine, which does asynchronous
+ * copy operations.
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/interrupt.h>
+#include "ioatdma.h"
+#include "ioatdma_registers.h"
+#include "ioatdma_hw.h"
+
+MODULE_VERSION("1.24");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Intel Corporation");
+
+static struct pci_device_id ioat_pci_tbl[] = {
+ { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_IOAT) },
+ { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_IOAT_CNB) },
+ { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_IOAT_SCNB) },
+ { PCI_DEVICE(PCI_VENDOR_ID_UNISYS, PCI_DEVICE_ID_UNISYS_DMA_DIRECTOR) },
+ { 0, }
+};
+
+struct ioat_device {
+ struct pci_dev *pdev;
+ void __iomem *iobase;
+ struct ioatdma_device *dma;
+};
+
+static int __devinit ioat_probe(struct pci_dev *pdev,
+ const struct pci_device_id *id);
+#ifdef IOAT_DMA_REMOVE
+static void __devexit ioat_remove(struct pci_dev *pdev);
+#endif
+
+static int ioat_setup_functionality(struct pci_dev *pdev, void __iomem *iobase)
+{
+ struct ioat_device *device = pci_get_drvdata(pdev);
+ u8 version;
+ int err = 0;
+
+ version = readb(iobase + IOAT_VER_OFFSET);
+ switch (version) {
+ case IOAT_VER_1_2:
+ device->dma = ioat_dma_probe(pdev, iobase);
+ break;
+ default:
+ err = -ENODEV;
+ break;
+ }
+ return err;
+}
+
+static void ioat_shutdown_functionality(struct pci_dev *pdev)
+{
+ struct ioat_device *device = pci_get_drvdata(pdev);
+
+ if (device->dma) {
+ ioat_dma_remove(device->dma);
+ device->dma = NULL;
+ }
+}
+
+static struct pci_driver ioat_pci_drv = {
+ .name = "ioatdma",
+ .id_table = ioat_pci_tbl,
+ .probe = ioat_probe,
+ .shutdown = ioat_shutdown_functionality,
+#ifdef IOAT_DMA_REMOVE
+ .remove = __devexit_p(ioat_remove),
+#endif
+};
+
+static int __devinit ioat_probe(struct pci_dev *pdev,
+ const struct pci_device_id *id)
+{
+ void __iomem *iobase;
+ struct ioat_device *device;
+ unsigned long mmio_start, mmio_len;
+ int err;
+
+ err = pci_enable_device(pdev);
+ if (err)
+ goto err_enable_device;
+
+ err = pci_request_regions(pdev, ioat_pci_drv.name);
+ if (err)
+ goto err_request_regions;
+
+ err = pci_set_dma_mask(pdev, DMA_64BIT_MASK);
+ if (err)
+ err = pci_set_dma_mask(pdev, DMA_32BIT_MASK);
+ if (err)
+ goto err_set_dma_mask;
+
+ err = pci_set_consistent_dma_mask(pdev, DMA_64BIT_MASK);
+ if (err)
+ err = pci_set_consistent_dma_mask(pdev, DMA_32BIT_MASK);
+ if (err)
+ goto err_set_dma_mask;
+
+ mmio_start = pci_resource_start(pdev, 0);
+ mmio_len = pci_resource_len(pdev, 0);
+ iobase = ioremap(mmio_start, mmio_len);
+ if (!iobase) {
+ err = -ENOMEM;
+ goto err_ioremap;
+ }
+
+ device = kzalloc(sizeof(*device), GFP_KERNEL);
+ if (!device) {
+ err = -ENOMEM;
+ goto err_kzalloc;
+ }
+ device->pdev = pdev;
+ pci_set_drvdata(pdev, device);
+ device->iobase = iobase;
+
+ pci_set_master(pdev);
+
+ err = ioat_setup_functionality(pdev, iobase);
+ if (err)
+ goto err_version;
+
+ return 0;
+
+err_version:
+ kfree(device);
+err_kzalloc:
+ iounmap(iobase);
+err_ioremap:
+err_set_dma_mask:
+ pci_release_regions(pdev);
+ pci_disable_device(pdev);
+err_request_regions:
+err_enable_device:
+ return err;
+}
+
+#ifdef IOAT_DMA_REMOVE
+/*
+ * It is unsafe to remove this module: if removed while a requested
+ * dma is outstanding, esp. from tcp, it is possible to hang while
+ * waiting for something that will never finish, thus hanging at
+ * least one cpu. However, if you're feeling lucky and need to do
+ * some testing, this usually works just fine.
+ */
+static void __devexit ioat_remove(struct pci_dev *pdev)
+{
+ struct ioat_device *device = pci_get_drvdata(pdev);
+
+ ioat_shutdown_functionality(pdev);
+
+ kfree(device);
+
+ iounmap(device->iobase);
+ pci_release_regions(pdev);
+ pci_disable_device(pdev);
+}
+#endif
+
+static int __init ioat_init_module(void)
+{
+ return pci_register_driver(&ioat_pci_drv);
+}
+module_init(ioat_init_module);
+
+static void __exit ioat_exit_module(void)
+{
+ pci_unregister_driver(&ioat_pci_drv);
+}
+module_exit(ioat_exit_module);
diff --git a/drivers/dma/ioat_dma.c b/drivers/dma/ioat_dma.c
index 2db05f6..eef83ea 100644
--- a/drivers/dma/ioat_dma.c
+++ b/drivers/dma/ioat_dma.c
@@ -39,19 +39,15 @@
#define INITIAL_IOAT_DESC_COUNT 128

#define to_ioat_chan(chan) container_of(chan, struct ioat_dma_chan, common)
-#define to_ioat_device(dev) container_of(dev, struct ioat_device, common)
+#define to_ioatdma_device(dev) container_of(dev, struct ioatdma_device, common)
#define to_ioat_desc(lh) container_of(lh, struct ioat_desc_sw, node)
#define tx_to_ioat_desc(tx) container_of(tx, struct ioat_desc_sw, async_tx)

/* internal functions */
static void ioat_dma_start_null_desc(struct ioat_dma_chan *ioat_chan);
static void ioat_dma_memcpy_cleanup(struct ioat_dma_chan *ioat_chan);
-static int __devinit ioat_probe(struct pci_dev *pdev,
- const struct pci_device_id *ent);
-static void ioat_shutdown(struct pci_dev *pdev);
-static void __devexit ioat_remove(struct pci_dev *pdev);

-static int ioat_dma_enumerate_channels(struct ioat_device *device)
+static int ioat_dma_enumerate_channels(struct ioatdma_device *device)
{
u8 xfercap_scale;
u32 xfercap;
@@ -158,17 +154,17 @@ static struct ioat_desc_sw *ioat_dma_alloc_descriptor(
{
struct ioat_dma_descriptor *desc;
struct ioat_desc_sw *desc_sw;
- struct ioat_device *ioat_device;
+ struct ioatdma_device *ioatdma_device;
dma_addr_t phys;

- ioat_device = to_ioat_device(ioat_chan->common.device);
- desc = pci_pool_alloc(ioat_device->dma_pool, flags, &phys);
+ ioatdma_device = to_ioatdma_device(ioat_chan->common.device);
+ desc = pci_pool_alloc(ioatdma_device->dma_pool, flags, &phys);
if (unlikely(!desc))
return NULL;

desc_sw = kzalloc(sizeof(*desc_sw), flags);
if (unlikely(!desc_sw)) {
- pci_pool_free(ioat_device->dma_pool, desc, phys);
+ pci_pool_free(ioatdma_device->dma_pool, desc, phys);
return NULL;
}

@@ -245,9 +241,8 @@ static int ioat_dma_alloc_chan_resources(struct dma_chan *chan)
static void ioat_dma_free_chan_resources(struct dma_chan *chan)
{
struct ioat_dma_chan *ioat_chan = to_ioat_chan(chan);
- struct ioat_device *ioat_device = to_ioat_device(chan->device);
+ struct ioatdma_device *ioatdma_device = to_ioatdma_device(chan->device);
struct ioat_desc_sw *desc, *_desc;
- u16 chanctrl;
int in_use_descs = 0;

ioat_dma_memcpy_cleanup(ioat_chan);
@@ -258,19 +253,19 @@ static void ioat_dma_free_chan_resources(struct dma_chan *chan)
list_for_each_entry_safe(desc, _desc, &ioat_chan->used_desc, node) {
in_use_descs++;
list_del(&desc->node);
- pci_pool_free(ioat_device->dma_pool, desc->hw,
+ pci_pool_free(ioatdma_device->dma_pool, desc->hw,
desc->async_tx.phys);
kfree(desc);
}
list_for_each_entry_safe(desc, _desc, &ioat_chan->free_desc, node) {
list_del(&desc->node);
- pci_pool_free(ioat_device->dma_pool, desc->hw,
+ pci_pool_free(ioatdma_device->dma_pool, desc->hw,
desc->async_tx.phys);
kfree(desc);
}
spin_unlock_bh(&ioat_chan->desc_lock);

- pci_pool_free(ioat_device->completion_pool,
+ pci_pool_free(ioatdma_device->completion_pool,
ioat_chan->completion_virt,
ioat_chan->completion_addr);

@@ -514,25 +509,9 @@ static enum dma_status ioat_dma_is_complete(struct dma_chan *chan,

/* PCI API */

-static struct pci_device_id ioat_pci_tbl[] = {
- { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_IOAT) },
- { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_IOAT_CNB) },
- { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_IOAT_SCNB) },
- { PCI_DEVICE(PCI_VENDOR_ID_UNISYS, PCI_DEVICE_ID_UNISYS_DMA_DIRECTOR) },
- { 0, }
-};
-
-static struct pci_driver ioat_pci_driver = {
- .name = "ioatdma",
- .id_table = ioat_pci_tbl,
- .probe = ioat_probe,
- .shutdown = ioat_shutdown,
- .remove = __devexit_p(ioat_remove),
-};
-
static irqreturn_t ioat_do_interrupt(int irq, void *data)
{
- struct ioat_device *instance = data;
+ struct ioatdma_device *instance = data;
unsigned long attnstatus;
u8 intrctrl;

@@ -592,7 +571,7 @@ static void ioat_dma_start_null_desc(struct ioat_dma_chan *ioat_chan)
*/
#define IOAT_TEST_SIZE 2000

-static int ioat_self_test(struct ioat_device *device)
+static int ioat_self_test(struct ioatdma_device *device)
{
int i;
u8 *src;
@@ -660,46 +639,25 @@ out:
return err;
}

-static int __devinit ioat_probe(struct pci_dev *pdev,
- const struct pci_device_id *ent)
+struct ioatdma_device *ioat_dma_probe(struct pci_dev *pdev,
+ void __iomem *iobase)
{
int err;
- unsigned long mmio_start, mmio_len;
- void __iomem *reg_base;
- struct ioat_device *device;
-
- err = pci_enable_device(pdev);
- if (err)
- goto err_enable_device;
-
- err = pci_set_dma_mask(pdev, DMA_64BIT_MASK);
- if (err)
- err = pci_set_dma_mask(pdev, DMA_32BIT_MASK);
- if (err)
- goto err_set_dma_mask;
-
- err = pci_request_regions(pdev, ioat_pci_driver.name);
- if (err)
- goto err_request_regions;
-
- mmio_start = pci_resource_start(pdev, 0);
- mmio_len = pci_resource_len(pdev, 0);
-
- reg_base = ioremap(mmio_start, mmio_len);
- if (!reg_base) {
- err = -ENOMEM;
- goto err_ioremap;
- }
+ struct ioatdma_device *device;

device = kzalloc(sizeof(*device), GFP_KERNEL);
if (!device) {
err = -ENOMEM;
goto err_kzalloc;
}
+ device->pdev = pdev;
+ device->reg_base = iobase;
+ device->version = readb(device->reg_base + IOAT_VER_OFFSET);

/* DMA coherent memory pool for DMA descriptor allocations */
device->dma_pool = pci_pool_create("dma_desc_pool", pdev,
- sizeof(struct ioat_dma_descriptor), 64, 0);
+ sizeof(struct ioat_dma_descriptor),
+ 64, 0);
if (!device->dma_pool) {
err = -ENOMEM;
goto err_dma_pool;
@@ -713,26 +671,6 @@ static int __devinit ioat_probe(struct pci_dev *pdev,
goto err_completion_pool;
}

- device->pdev = pdev;
- pci_set_drvdata(pdev, device);
-#ifdef CONFIG_PCI_MSI
- if (pci_enable_msi(pdev) == 0) {
- device->msi = 1;
- } else {
- device->msi = 0;
- }
-#endif
- err = request_irq(pdev->irq, &ioat_do_interrupt, IRQF_SHARED, "ioat",
- device);
- if (err)
- goto err_irq;
-
- device->reg_base = reg_base;
-
- writeb(IOAT_INTRCTRL_MASTER_INT_EN,
- device->reg_base + IOAT_INTRCTRL_OFFSET);
- pci_set_master(pdev);
-
INIT_LIST_HEAD(&device->common.channels);
ioat_dma_enumerate_channels(device);

@@ -746,9 +684,19 @@ static int __devinit ioat_probe(struct pci_dev *pdev,
device->common.device_issue_pending = ioat_dma_memcpy_issue_pending;
device->common.device_dependency_added = ioat_dma_dependency_added;
device->common.dev = &pdev->dev;
- printk(KERN_INFO
- "ioatdma: Intel(R) I/OAT DMA Engine found, %d channels\n",
- device->common.chancnt);
+ printk(KERN_INFO "ioatdma: Intel(R) I/OAT DMA Engine found,"
+ " %d channels, device version 0x%02x\n",
+ device->common.chancnt, device->version);
+
+ pci_set_drvdata(pdev, device);
+ err = request_irq(pdev->irq, &ioat_do_interrupt, IRQF_SHARED, "ioat",
+ device);
+ if (err)
+ goto err_irq;
+
+ writeb(IOAT_INTRCTRL_MASTER_INT_EN,
+ device->reg_base + IOAT_INTRCTRL_OFFSET);
+ pci_set_master(pdev);

err = ioat_self_test(device);
if (err)
@@ -756,9 +704,10 @@ static int __devinit ioat_probe(struct pci_dev *pdev,

dma_async_device_register(&device->common);

- return 0;
+ return device;

err_self_test:
+ free_irq(device->pdev->irq, device);
err_irq:
pci_pool_destroy(device->completion_pool);
err_completion_pool:
@@ -766,47 +715,24 @@ err_completion_pool:
err_dma_pool:
kfree(device);
err_kzalloc:
- iounmap(reg_base);
-err_ioremap:
- pci_release_regions(pdev);
-err_request_regions:
-err_set_dma_mask:
- pci_disable_device(pdev);
-err_enable_device:
-
- printk(KERN_INFO
- "ioatdma: Intel(R) I/OAT DMA Engine initialization failed\n");
-
- return err;
-}
-
-static void ioat_shutdown(struct pci_dev *pdev)
-{
- struct ioat_device *device;
- device = pci_get_drvdata(pdev);
-
- dma_async_device_unregister(&device->common);
+ iounmap(iobase);
+ printk(KERN_ERR
+ "ioatdma: Intel(R) I/OAT DMA Engine initialization failed\n");
+ return NULL;
}

-static void __devexit ioat_remove(struct pci_dev *pdev)
+void ioat_dma_remove(struct ioatdma_device *device)
{
- struct ioat_device *device;
struct dma_chan *chan, *_chan;
struct ioat_dma_chan *ioat_chan;

- device = pci_get_drvdata(pdev);
dma_async_device_unregister(&device->common);

free_irq(device->pdev->irq, device);
-#ifdef CONFIG_PCI_MSI
- if (device->msi)
- pci_disable_msi(device->pdev);
-#endif
+
pci_pool_destroy(device->dma_pool);
pci_pool_destroy(device->completion_pool);
- iounmap(device->reg_base);
- pci_release_regions(pdev);
- pci_disable_device(pdev);
+
list_for_each_entry_safe(chan, _chan,
&device->common.channels, device_node) {
ioat_chan = to_ioat_chan(chan);
@@ -816,25 +742,3 @@ static void __devexit ioat_remove(struct pci_dev *pdev)
kfree(device);
}

-/* MODULE API */
-MODULE_VERSION("1.9");
-MODULE_LICENSE("GPL");
-MODULE_AUTHOR("Intel Corporation");
-
-static int __init ioat_init_module(void)
-{
- /* it's currently unsafe to unload this module */
- /* if forced, worst case is that rmmod hangs */
- __unsafe(THIS_MODULE);
-
- return pci_register_driver(&ioat_pci_driver);
-}
-
-module_init(ioat_init_module);
-
-static void __exit ioat_exit_module(void)
-{
- pci_unregister_driver(&ioat_pci_driver);
-}
-
-module_exit(ioat_exit_module);
diff --git a/drivers/dma/ioatdma.h b/drivers/dma/ioatdma.h
index bf4dad7..0b8ffbd 100644
--- a/drivers/dma/ioatdma.h
+++ b/drivers/dma/ioatdma.h
@@ -31,22 +31,21 @@
#define IOAT_LOW_COMPLETION_MASK 0xffffffc0

/**
- * struct ioat_device - internal representation of a IOAT device
+ * struct ioatdma_device - internal representation of a IOAT device
* @pdev: PCI-Express device
* @reg_base: MMIO register space base address
* @dma_pool: for allocating DMA descriptors
* @common: embedded struct dma_device
- * @msi: Message Signaled Interrupt number
+ * @version: version of ioatdma device
*/

-struct ioat_device {
+struct ioatdma_device {
struct pci_dev *pdev;
void __iomem *reg_base;
struct pci_pool *dma_pool;
struct pci_pool *completion_pool;
-
struct dma_device common;
- u8 msi;
+ u8 version;
};

/**
@@ -84,7 +83,7 @@ struct ioat_dma_chan {

int pending;

- struct ioat_device *device;
+ struct ioatdma_device *device;
struct dma_chan common;

dma_addr_t completion_addr;
@@ -117,4 +116,13 @@ struct ioat_desc_sw {
struct dma_async_tx_descriptor async_tx;
};

+#if defined(CONFIG_INTEL_IOATDMA) || defined(CONFIG_INTEL_IOATDMA_MODULE)
+struct ioatdma_device *ioat_dma_probe(struct pci_dev *pdev,
+ void __iomem *iobase);
+void ioat_dma_remove(struct ioatdma_device *device);
+#else
+#define ioat_dma_probe(pdev, iobase) NULL
+#define ioat_dma_remove(device) do { } while (0)
+#endif
+
#endif /* IOATDMA_H */
diff --git a/drivers/dma/ioatdma_hw.h b/drivers/dma/ioatdma_hw.h
index 4d7a128..9e7434e 100644
--- a/drivers/dma/ioatdma_hw.h
+++ b/drivers/dma/ioatdma_hw.h
@@ -27,7 +27,7 @@
#define IOAT_PCI_RID 0x00
#define IOAT_PCI_SVID 0x8086
#define IOAT_PCI_SID 0x8086
-#define IOAT_VER 0x12 /* Version 1.2 */
+#define IOAT_VER_1_2 0x12 /* Version 1.2 */

struct ioat_dma_descriptor {
uint32_t size;
-
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