kernel-ark/drivers/scsi/ibmvscsi/rpa_vscsi.c
FUJITA Tomonori 8d8bb39b9e dma-mapping: add the device argument to dma_mapping_error()
Add per-device dma_mapping_ops support for CONFIG_X86_64 as POWER
architecture does:

This enables us to cleanly fix the Calgary IOMMU issue that some devices
are not behind the IOMMU (http://lkml.org/lkml/2008/5/8/423).

I think that per-device dma_mapping_ops support would be also helpful for
KVM people to support PCI passthrough but Andi thinks that this makes it
difficult to support the PCI passthrough (see the above thread).  So I
CC'ed this to KVM camp.  Comments are appreciated.

A pointer to dma_mapping_ops to struct dev_archdata is added.  If the
pointer is non NULL, DMA operations in asm/dma-mapping.h use it.  If it's
NULL, the system-wide dma_ops pointer is used as before.

If it's useful for KVM people, I plan to implement a mechanism to register
a hook called when a new pci (or dma capable) device is created (it works
with hot plugging).  It enables IOMMUs to set up an appropriate
dma_mapping_ops per device.

The major obstacle is that dma_mapping_error doesn't take a pointer to the
device unlike other DMA operations.  So x86 can't have dma_mapping_ops per
device.  Note all the POWER IOMMUs use the same dma_mapping_error function
so this is not a problem for POWER but x86 IOMMUs use different
dma_mapping_error functions.

The first patch adds the device argument to dma_mapping_error.  The patch
is trivial but large since it touches lots of drivers and dma-mapping.h in
all the architecture.

This patch:

dma_mapping_error() doesn't take a pointer to the device unlike other DMA
operations.  So we can't have dma_mapping_ops per device.

Note that POWER already has dma_mapping_ops per device but all the POWER
IOMMUs use the same dma_mapping_error function.  x86 IOMMUs use device
argument.

[akpm@linux-foundation.org: fix sge]
[akpm@linux-foundation.org: fix svc_rdma]
[akpm@linux-foundation.org: build fix]
[akpm@linux-foundation.org: fix bnx2x]
[akpm@linux-foundation.org: fix s2io]
[akpm@linux-foundation.org: fix pasemi_mac]
[akpm@linux-foundation.org: fix sdhci]
[akpm@linux-foundation.org: build fix]
[akpm@linux-foundation.org: fix sparc]
[akpm@linux-foundation.org: fix ibmvscsi]
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Muli Ben-Yehuda <muli@il.ibm.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Avi Kivity <avi@qumranet.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-26 12:00:03 -07:00

344 lines
9.6 KiB
C

/* ------------------------------------------------------------
* rpa_vscsi.c
* (C) Copyright IBM Corporation 1994, 2003
* Authors: Colin DeVilbiss (devilbis@us.ibm.com)
* Santiago Leon (santil@us.ibm.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; either version 2 of the License, or
* (at your option) any later version.
*
* 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307
* USA
*
* ------------------------------------------------------------
* RPA-specific functions of the SCSI host adapter for Virtual I/O devices
*
* This driver allows the Linux SCSI peripheral drivers to directly
* access devices in the hosting partition, either on an iSeries
* hypervisor system or a converged hypervisor system.
*/
#include <asm/vio.h>
#include <asm/prom.h>
#include <asm/iommu.h>
#include <asm/hvcall.h>
#include <linux/dma-mapping.h>
#include <linux/interrupt.h>
#include "ibmvscsi.h"
static char partition_name[97] = "UNKNOWN";
static unsigned int partition_number = -1;
/* ------------------------------------------------------------
* Routines for managing the command/response queue
*/
/**
* rpavscsi_handle_event: - Interrupt handler for crq events
* @irq: number of irq to handle, not used
* @dev_instance: ibmvscsi_host_data of host that received interrupt
*
* Disables interrupts and schedules srp_task
* Always returns IRQ_HANDLED
*/
static irqreturn_t rpavscsi_handle_event(int irq, void *dev_instance)
{
struct ibmvscsi_host_data *hostdata =
(struct ibmvscsi_host_data *)dev_instance;
vio_disable_interrupts(to_vio_dev(hostdata->dev));
tasklet_schedule(&hostdata->srp_task);
return IRQ_HANDLED;
}
/**
* release_crq_queue: - Deallocates data and unregisters CRQ
* @queue: crq_queue to initialize and register
* @host_data: ibmvscsi_host_data of host
*
* Frees irq, deallocates a page for messages, unmaps dma, and unregisters
* the crq with the hypervisor.
*/
static void rpavscsi_release_crq_queue(struct crq_queue *queue,
struct ibmvscsi_host_data *hostdata,
int max_requests)
{
long rc;
struct vio_dev *vdev = to_vio_dev(hostdata->dev);
free_irq(vdev->irq, (void *)hostdata);
tasklet_kill(&hostdata->srp_task);
do {
rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address);
} while ((rc == H_BUSY) || (H_IS_LONG_BUSY(rc)));
dma_unmap_single(hostdata->dev,
queue->msg_token,
queue->size * sizeof(*queue->msgs), DMA_BIDIRECTIONAL);
free_page((unsigned long)queue->msgs);
}
/**
* crq_queue_next_crq: - Returns the next entry in message queue
* @queue: crq_queue to use
*
* Returns pointer to next entry in queue, or NULL if there are no new
* entried in the CRQ.
*/
static struct viosrp_crq *crq_queue_next_crq(struct crq_queue *queue)
{
struct viosrp_crq *crq;
unsigned long flags;
spin_lock_irqsave(&queue->lock, flags);
crq = &queue->msgs[queue->cur];
if (crq->valid & 0x80) {
if (++queue->cur == queue->size)
queue->cur = 0;
} else
crq = NULL;
spin_unlock_irqrestore(&queue->lock, flags);
return crq;
}
/**
* rpavscsi_send_crq: - Send a CRQ
* @hostdata: the adapter
* @word1: the first 64 bits of the data
* @word2: the second 64 bits of the data
*/
static int rpavscsi_send_crq(struct ibmvscsi_host_data *hostdata,
u64 word1, u64 word2)
{
struct vio_dev *vdev = to_vio_dev(hostdata->dev);
return plpar_hcall_norets(H_SEND_CRQ, vdev->unit_address, word1, word2);
}
/**
* rpavscsi_task: - Process srps asynchronously
* @data: ibmvscsi_host_data of host
*/
static void rpavscsi_task(void *data)
{
struct ibmvscsi_host_data *hostdata = (struct ibmvscsi_host_data *)data;
struct vio_dev *vdev = to_vio_dev(hostdata->dev);
struct viosrp_crq *crq;
int done = 0;
while (!done) {
/* Pull all the valid messages off the CRQ */
while ((crq = crq_queue_next_crq(&hostdata->queue)) != NULL) {
ibmvscsi_handle_crq(crq, hostdata);
crq->valid = 0x00;
}
vio_enable_interrupts(vdev);
if ((crq = crq_queue_next_crq(&hostdata->queue)) != NULL) {
vio_disable_interrupts(vdev);
ibmvscsi_handle_crq(crq, hostdata);
crq->valid = 0x00;
} else {
done = 1;
}
}
}
static void gather_partition_info(void)
{
struct device_node *rootdn;
const char *ppartition_name;
const unsigned int *p_number_ptr;
/* Retrieve information about this partition */
rootdn = of_find_node_by_path("/");
if (!rootdn) {
return;
}
ppartition_name = of_get_property(rootdn, "ibm,partition-name", NULL);
if (ppartition_name)
strncpy(partition_name, ppartition_name,
sizeof(partition_name));
p_number_ptr = of_get_property(rootdn, "ibm,partition-no", NULL);
if (p_number_ptr)
partition_number = *p_number_ptr;
of_node_put(rootdn);
}
static void set_adapter_info(struct ibmvscsi_host_data *hostdata)
{
memset(&hostdata->madapter_info, 0x00,
sizeof(hostdata->madapter_info));
dev_info(hostdata->dev, "SRP_VERSION: %s\n", SRP_VERSION);
strcpy(hostdata->madapter_info.srp_version, SRP_VERSION);
strncpy(hostdata->madapter_info.partition_name, partition_name,
sizeof(hostdata->madapter_info.partition_name));
hostdata->madapter_info.partition_number = partition_number;
hostdata->madapter_info.mad_version = 1;
hostdata->madapter_info.os_type = 2;
}
/**
* reset_crq_queue: - resets a crq after a failure
* @queue: crq_queue to initialize and register
* @hostdata: ibmvscsi_host_data of host
*
*/
static int rpavscsi_reset_crq_queue(struct crq_queue *queue,
struct ibmvscsi_host_data *hostdata)
{
int rc;
struct vio_dev *vdev = to_vio_dev(hostdata->dev);
/* Close the CRQ */
do {
rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address);
} while ((rc == H_BUSY) || (H_IS_LONG_BUSY(rc)));
/* Clean out the queue */
memset(queue->msgs, 0x00, PAGE_SIZE);
queue->cur = 0;
set_adapter_info(hostdata);
/* And re-open it again */
rc = plpar_hcall_norets(H_REG_CRQ,
vdev->unit_address,
queue->msg_token, PAGE_SIZE);
if (rc == 2) {
/* Adapter is good, but other end is not ready */
dev_warn(hostdata->dev, "Partner adapter not ready\n");
} else if (rc != 0) {
dev_warn(hostdata->dev, "couldn't register crq--rc 0x%x\n", rc);
}
return rc;
}
/**
* initialize_crq_queue: - Initializes and registers CRQ with hypervisor
* @queue: crq_queue to initialize and register
* @hostdata: ibmvscsi_host_data of host
*
* Allocates a page for messages, maps it for dma, and registers
* the crq with the hypervisor.
* Returns zero on success.
*/
static int rpavscsi_init_crq_queue(struct crq_queue *queue,
struct ibmvscsi_host_data *hostdata,
int max_requests)
{
int rc;
int retrc;
struct vio_dev *vdev = to_vio_dev(hostdata->dev);
queue->msgs = (struct viosrp_crq *)get_zeroed_page(GFP_KERNEL);
if (!queue->msgs)
goto malloc_failed;
queue->size = PAGE_SIZE / sizeof(*queue->msgs);
queue->msg_token = dma_map_single(hostdata->dev, queue->msgs,
queue->size * sizeof(*queue->msgs),
DMA_BIDIRECTIONAL);
if (dma_mapping_error(hostdata->dev, queue->msg_token))
goto map_failed;
gather_partition_info();
set_adapter_info(hostdata);
retrc = rc = plpar_hcall_norets(H_REG_CRQ,
vdev->unit_address,
queue->msg_token, PAGE_SIZE);
if (rc == H_RESOURCE)
/* maybe kexecing and resource is busy. try a reset */
rc = rpavscsi_reset_crq_queue(queue,
hostdata);
if (rc == 2) {
/* Adapter is good, but other end is not ready */
dev_warn(hostdata->dev, "Partner adapter not ready\n");
retrc = 0;
} else if (rc != 0) {
dev_warn(hostdata->dev, "Error %d opening adapter\n", rc);
goto reg_crq_failed;
}
if (request_irq(vdev->irq,
rpavscsi_handle_event,
0, "ibmvscsi", (void *)hostdata) != 0) {
dev_err(hostdata->dev, "couldn't register irq 0x%x\n",
vdev->irq);
goto req_irq_failed;
}
rc = vio_enable_interrupts(vdev);
if (rc != 0) {
dev_err(hostdata->dev, "Error %d enabling interrupts!!!\n", rc);
goto req_irq_failed;
}
queue->cur = 0;
spin_lock_init(&queue->lock);
tasklet_init(&hostdata->srp_task, (void *)rpavscsi_task,
(unsigned long)hostdata);
return retrc;
req_irq_failed:
do {
rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address);
} while ((rc == H_BUSY) || (H_IS_LONG_BUSY(rc)));
reg_crq_failed:
dma_unmap_single(hostdata->dev,
queue->msg_token,
queue->size * sizeof(*queue->msgs), DMA_BIDIRECTIONAL);
map_failed:
free_page((unsigned long)queue->msgs);
malloc_failed:
return -1;
}
/**
* reenable_crq_queue: - reenables a crq after
* @queue: crq_queue to initialize and register
* @hostdata: ibmvscsi_host_data of host
*
*/
static int rpavscsi_reenable_crq_queue(struct crq_queue *queue,
struct ibmvscsi_host_data *hostdata)
{
int rc;
struct vio_dev *vdev = to_vio_dev(hostdata->dev);
/* Re-enable the CRQ */
do {
rc = plpar_hcall_norets(H_ENABLE_CRQ, vdev->unit_address);
} while ((rc == H_IN_PROGRESS) || (rc == H_BUSY) || (H_IS_LONG_BUSY(rc)));
if (rc)
dev_err(hostdata->dev, "Error %d enabling adapter\n", rc);
return rc;
}
struct ibmvscsi_ops rpavscsi_ops = {
.init_crq_queue = rpavscsi_init_crq_queue,
.release_crq_queue = rpavscsi_release_crq_queue,
.reset_crq_queue = rpavscsi_reset_crq_queue,
.reenable_crq_queue = rpavscsi_reenable_crq_queue,
.send_crq = rpavscsi_send_crq,
};