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USB: net2280: update dma buffer allocation
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This updates the code handling dma-coherent buffer allocations, basically
reusing code from the musb_hdrc driver.  Instead of trying to work around two
significant limitations of the dma framework (memory wastage for buffers
smaller than a page, and inconsistency between calling context requirements
for allocation and free) this just works around one of them (the latter).

So count this as two steps forward (bugfixes:  the latter issue could cause
errors on some platforms, and some MIPS changes broke code for the former), 
and one step back (increasing cross-platform memory wastage).

Plus linelength and whitespace fixes; and minor data segment shrinkage.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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David Brownell authored and Greg Kroah-Hartman committed Sep 27, 2006
1 parent 80f8af0 commit 901b3d7
Showing 1 changed file with 88 additions and 68 deletions.
156 changes: 88 additions & 68 deletions drivers/usb/gadget/net2280.c
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Original file line number Diff line number Diff line change
Expand Up @@ -2,7 +2,7 @@
* Driver for the PLX NET2280 USB device controller.
* Specs and errata are available from <http://www.plxtech.com>.
*
* PLX Technology Inc. (formerly NetChip Technology) supported the
* PLX Technology Inc. (formerly NetChip Technology) supported the
* development of this driver.
*
*
Expand All @@ -26,7 +26,8 @@
* Copyright (C) 2003 David Brownell
* Copyright (C) 2003-2005 PLX Technology, Inc.
*
* Modified Seth Levy 2005 PLX Technology, Inc. to provide compatibility with 2282 chip
* Modified Seth Levy 2005 PLX Technology, Inc. to provide compatibility
* with 2282 chip
*
* 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
Expand Down Expand Up @@ -85,7 +86,7 @@ static const char driver_name [] = "net2280";
static const char driver_desc [] = DRIVER_DESC;

static const char ep0name [] = "ep0";
static const char *ep_name [] = {
static const char *const ep_name [] = {
ep0name,
"ep-a", "ep-b", "ep-c", "ep-d",
"ep-e", "ep-f",
Expand Down Expand Up @@ -225,7 +226,9 @@ net2280_enable (struct usb_ep *_ep, const struct usb_endpoint_descriptor *desc)
if (!ep->is_in)
writel ((1 << SET_NAK_OUT_PACKETS), &ep->regs->ep_rsp);
else if (dev->pdev->device != 0x2280) {
/* Added for 2282, Don't use nak packets on an in endpoint, this was ignored on 2280 */
/* Added for 2282, Don't use nak packets on an in endpoint,
* this was ignored on 2280
*/
writel ((1 << CLEAR_NAK_OUT_PACKETS)
| (1 << CLEAR_NAK_OUT_PACKETS_MODE), &ep->regs->ep_rsp);
}
Expand Down Expand Up @@ -288,7 +291,7 @@ static int handshake (u32 __iomem *ptr, u32 mask, u32 done, int usec)
return -ETIMEDOUT;
}

static struct usb_ep_ops net2280_ep_ops;
static const struct usb_ep_ops net2280_ep_ops;

static void ep_reset (struct net2280_regs __iomem *regs, struct net2280_ep *ep)
{
Expand Down Expand Up @@ -449,34 +452,15 @@ net2280_free_request (struct usb_ep *_ep, struct usb_request *_req)

/*-------------------------------------------------------------------------*/

#undef USE_KMALLOC

/* many common platforms have dma-coherent caches, which means that it's
* safe to use kmalloc() memory for all i/o buffers without using any
* cache flushing calls. (unless you're trying to share cache lines
* between dma and non-dma activities, which is a slow idea in any case.)
/*
* dma-coherent memory allocation (for dma-capable endpoints)
*
* other platforms need more care, with 2.5 having a moderately general
* solution (which falls down for allocations smaller than one page)
* that improves significantly on the 2.4 PCI allocators by removing
* the restriction that memory never be freed in_interrupt().
* NOTE: the dma_*_coherent() API calls suck. Most implementations are
* (a) page-oriented, so small buffers lose big; and (b) asymmetric with
* respect to calls with irqs disabled: alloc is safe, free is not.
* We currently work around (b), but not (a).
*/
#if defined(CONFIG_X86)
#define USE_KMALLOC

#elif defined(CONFIG_PPC) && !defined(CONFIG_NOT_COHERENT_CACHE)
#define USE_KMALLOC

#elif defined(CONFIG_MIPS) && !defined(CONFIG_DMA_NONCOHERENT)
#define USE_KMALLOC

/* FIXME there are other cases, including an x86-64 one ... */
#endif

/* allocating buffers this way eliminates dma mapping overhead, which
* on some platforms will mean eliminating a per-io buffer copy. with
* some kinds of system caches, further tweaks may still be needed.
*/
static void *
net2280_alloc_buffer (
struct usb_ep *_ep,
Expand All @@ -493,43 +477,71 @@ net2280_alloc_buffer (
return NULL;
*dma = DMA_ADDR_INVALID;

#if defined(USE_KMALLOC)
retval = kmalloc(bytes, gfp_flags);
if (retval)
*dma = virt_to_phys(retval);
#else
if (ep->dma) {
/* the main problem with this call is that it wastes memory
* on typical 1/N page allocations: it allocates 1-N pages.
*/
#warning Using dma_alloc_coherent even with buffers smaller than a page.
if (ep->dma)
retval = dma_alloc_coherent(&ep->dev->pdev->dev,
bytes, dma, gfp_flags);
} else
else
retval = kmalloc(bytes, gfp_flags);
#endif
return retval;
}

static DEFINE_SPINLOCK(buflock);
static LIST_HEAD(buffers);

struct free_record {
struct list_head list;
struct device *dev;
unsigned bytes;
dma_addr_t dma;
};

static void do_free(unsigned long ignored)
{
spin_lock_irq(&buflock);
while (!list_empty(&buffers)) {
struct free_record *buf;

buf = list_entry(buffers.next, struct free_record, list);
list_del(&buf->list);
spin_unlock_irq(&buflock);

dma_free_coherent(buf->dev, buf->bytes, buf, buf->dma);

spin_lock_irq(&buflock);
}
spin_unlock_irq(&buflock);
}

static DECLARE_TASKLET(deferred_free, do_free, 0);

static void
net2280_free_buffer (
struct usb_ep *_ep,
void *buf,
void *address,
dma_addr_t dma,
unsigned bytes
) {
/* free memory into the right allocator */
#ifndef USE_KMALLOC
if (dma != DMA_ADDR_INVALID) {
struct net2280_ep *ep;
struct free_record *buf = address;
unsigned long flags;

ep = container_of(_ep, struct net2280_ep, ep);
if (!_ep)
return;
dma_free_coherent(&ep->dev->pdev->dev, bytes, buf, dma);

ep = container_of (_ep, struct net2280_ep, ep);
buf->dev = &ep->dev->pdev->dev;
buf->bytes = bytes;
buf->dma = dma;

spin_lock_irqsave(&buflock, flags);
list_add_tail(&buf->list, &buffers);
tasklet_schedule(&deferred_free);
spin_unlock_irqrestore(&buflock, flags);
} else
#endif
kfree (buf);
kfree (address);
}

/*-------------------------------------------------------------------------*/
Expand Down Expand Up @@ -737,7 +749,8 @@ fill_dma_desc (struct net2280_ep *ep, struct net2280_request *req, int valid)
*/
if (ep->is_in)
dmacount |= (1 << DMA_DIRECTION);
if ((!ep->is_in && (dmacount % ep->ep.maxpacket) != 0) || ep->dev->pdev->device != 0x2280)
if ((!ep->is_in && (dmacount % ep->ep.maxpacket) != 0)
|| ep->dev->pdev->device != 0x2280)
dmacount |= (1 << END_OF_CHAIN);

req->valid = valid;
Expand Down Expand Up @@ -812,7 +825,7 @@ static void start_dma (struct net2280_ep *ep, struct net2280_request *req)

/* previous OUT packet might have been short */
if (!ep->is_in && ((tmp = readl (&ep->regs->ep_stat))
& (1 << NAK_OUT_PACKETS)) != 0) {
& (1 << NAK_OUT_PACKETS)) != 0) {
writel ((1 << SHORT_PACKET_TRANSFERRED_INTERRUPT),
&ep->regs->ep_stat);

Expand Down Expand Up @@ -1373,7 +1386,7 @@ net2280_fifo_flush (struct usb_ep *_ep)
(void) readl (&ep->regs->ep_rsp);
}

static struct usb_ep_ops net2280_ep_ops = {
static const struct usb_ep_ops net2280_ep_ops = {
.enable = net2280_enable,
.disable = net2280_disable,

Expand Down Expand Up @@ -1631,7 +1644,7 @@ show_registers (struct device *_dev, struct device_attribute *attr, char *buf)
}

/* Indexed Registers */
// none yet
// none yet

/* Statistics */
t = scnprintf (next, size, "\nirqs: ");
Expand Down Expand Up @@ -1691,11 +1704,11 @@ show_queues (struct device *_dev, struct device_attribute *attr, char *buf)
({ char *val;
switch (d->bmAttributes & 0x03) {
case USB_ENDPOINT_XFER_BULK:
val = "bulk"; break;
val = "bulk"; break;
case USB_ENDPOINT_XFER_INT:
val = "intr"; break;
val = "intr"; break;
default:
val = "iso"; break;
val = "iso"; break;
}; val; }),
le16_to_cpu (d->wMaxPacketSize) & 0x1fff,
ep->dma ? "dma" : "pio", ep->fifo_size
Expand Down Expand Up @@ -1808,8 +1821,8 @@ extern int net2280_set_fifo_mode (struct usb_gadget *gadget, int mode);
* net2280_set_fifo_mode - change allocation of fifo buffers
* @gadget: access to the net2280 device that will be updated
* @mode: 0 for default, four 1kB buffers (ep-a through ep-d);
* 1 for two 2kB buffers (ep-a and ep-b only);
* 2 for one 2kB buffer (ep-a) and two 1kB ones (ep-b, ep-c).
* 1 for two 2kB buffers (ep-a and ep-b only);
* 2 for one 2kB buffer (ep-a) and two 1kB ones (ep-b, ep-c).
*
* returns zero on success, else negative errno. when this succeeds,
* the contents of gadget->ep_list may have changed.
Expand Down Expand Up @@ -2241,7 +2254,8 @@ static void handle_ep_small (struct net2280_ep *ep)
req->td->dmacount = 0;
t = readl (&ep->regs->ep_avail);
dma_done (ep, req, count,
(ep->out_overflow || t) ? -EOVERFLOW : 0);
(ep->out_overflow || t)
? -EOVERFLOW : 0);
}

/* also flush to prevent erratum 0106 trouble */
Expand Down Expand Up @@ -2411,7 +2425,7 @@ static void handle_stat0_irqs (struct net2280 *dev, u32 stat)
, &ep->regs->ep_stat);
u.raw [0] = readl (&dev->usb->setup0123);
u.raw [1] = readl (&dev->usb->setup4567);

cpu_to_le32s (&u.raw [0]);
cpu_to_le32s (&u.raw [1]);

Expand Down Expand Up @@ -2578,14 +2592,16 @@ static void handle_stat1_irqs (struct net2280 *dev, u32 stat)

/* VBUS disconnect is indicated by VBUS_PIN and VBUS_INTERRUPT set.
* Root Port Reset is indicated by ROOT_PORT_RESET_INTERRRUPT set and
* both HIGH_SPEED and FULL_SPEED clear (as ROOT_PORT_RESET_INTERRUPT
* both HIGH_SPEED and FULL_SPEED clear (as ROOT_PORT_RESET_INTERRUPT
* only indicates a change in the reset state).
*/
if (stat & tmp) {
writel (tmp, &dev->regs->irqstat1);
if ((((stat & (1 << ROOT_PORT_RESET_INTERRUPT)) &&
((readl (&dev->usb->usbstat) & mask) == 0))
|| ((readl (&dev->usb->usbctl) & (1 << VBUS_PIN)) == 0)
if ((((stat & (1 << ROOT_PORT_RESET_INTERRUPT))
&& ((readl (&dev->usb->usbstat) & mask)
== 0))
|| ((readl (&dev->usb->usbctl)
& (1 << VBUS_PIN)) == 0)
) && ( dev->gadget.speed != USB_SPEED_UNKNOWN)) {
DEBUG (dev, "disconnect %s\n",
dev->driver->driver.name);
Expand Down Expand Up @@ -2852,7 +2868,7 @@ static int net2280_probe (struct pci_dev *pdev, const struct pci_device_id *id)

/* now all the pci goodies ... */
if (pci_enable_device (pdev) < 0) {
retval = -ENODEV;
retval = -ENODEV;
goto done;
}
dev->enabled = 1;
Expand All @@ -2870,6 +2886,10 @@ static int net2280_probe (struct pci_dev *pdev, const struct pci_device_id *id)
}
dev->region = 1;

/* FIXME provide firmware download interface to put
* 8051 code into the chip, e.g. to turn on PCI PM.
*/

base = ioremap_nocache (resource, len);
if (base == NULL) {
DEBUG (dev, "can't map memory\n");
Expand Down Expand Up @@ -2984,16 +3004,16 @@ static void net2280_shutdown (struct pci_dev *pdev)

/*-------------------------------------------------------------------------*/

static struct pci_device_id pci_ids [] = { {
.class = ((PCI_CLASS_SERIAL_USB << 8) | 0xfe),
.class_mask = ~0,
static const struct pci_device_id pci_ids [] = { {
.class = ((PCI_CLASS_SERIAL_USB << 8) | 0xfe),
.class_mask = ~0,
.vendor = 0x17cc,
.device = 0x2280,
.subvendor = PCI_ANY_ID,
.subdevice = PCI_ANY_ID,
}, {
.class = ((PCI_CLASS_SERIAL_USB << 8) | 0xfe),
.class_mask = ~0,
.class = ((PCI_CLASS_SERIAL_USB << 8) | 0xfe),
.class_mask = ~0,
.vendor = 0x17cc,
.device = 0x2282,
.subvendor = PCI_ANY_ID,
Expand Down

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