IRQ: Maintain regs pointer globally rather than passing to IRQ handlers
Maintain a per-CPU global "struct pt_regs *" variable which can be used instead
of passing regs around manually through all ~1800 interrupt handlers in the
Linux kernel.
The regs pointer is used in few places, but it potentially costs both stack
space and code to pass it around. On the FRV arch, removing the regs parameter
from all the genirq function results in a 20% speed up of the IRQ exit path
(ie: from leaving timer_interrupt() to leaving do_IRQ()).
Where appropriate, an arch may override the generic storage facility and do
something different with the variable. On FRV, for instance, the address is
maintained in GR28 at all times inside the kernel as part of general exception
handling.
Having looked over the code, it appears that the parameter may be handed down
through up to twenty or so layers of functions. Consider a USB character
device attached to a USB hub, attached to a USB controller that posts its
interrupts through a cascaded auxiliary interrupt controller. A character
device driver may want to pass regs to the sysrq handler through the input
layer which adds another few layers of parameter passing.
I've build this code with allyesconfig for x86_64 and i386. I've runtested the
main part of the code on FRV and i386, though I can't test most of the drivers.
I've also done partial conversion for powerpc and MIPS - these at least compile
with minimal configurations.
This will affect all archs. Mostly the changes should be relatively easy.
Take do_IRQ(), store the regs pointer at the beginning, saving the old one:
struct pt_regs *old_regs = set_irq_regs(regs);
And put the old one back at the end:
set_irq_regs(old_regs);
Don't pass regs through to generic_handle_irq() or __do_IRQ().
In timer_interrupt(), this sort of change will be necessary:
- update_process_times(user_mode(regs));
- profile_tick(CPU_PROFILING, regs);
+ update_process_times(user_mode(get_irq_regs()));
+ profile_tick(CPU_PROFILING);
I'd like to move update_process_times()'s use of get_irq_regs() into itself,
except that i386, alone of the archs, uses something other than user_mode().
Some notes on the interrupt handling in the drivers:
(*) input_dev() is now gone entirely. The regs pointer is no longer stored in
the input_dev struct.
(*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking. It does
something different depending on whether it's been supplied with a regs
pointer or not.
(*) Various IRQ handler function pointers have been moved to type
irq_handler_t.
Signed-Off-By: David Howells <dhowells@redhat.com>
(cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
diff --git a/drivers/net/wireless/airo.c b/drivers/net/wireless/airo.c
index 39d0934..0a33c8a 100644
--- a/drivers/net/wireless/airo.c
+++ b/drivers/net/wireless/airo.c
@@ -1120,8 +1120,7 @@
static void mpi_receive_802_11(struct airo_info *ai);
static int waitbusy (struct airo_info *ai);
-static irqreturn_t airo_interrupt( int irq, void* dev_id, struct pt_regs
- *regs);
+static irqreturn_t airo_interrupt( int irq, void* dev_id);
static int airo_thread(void *data);
static void timer_func( struct net_device *dev );
static int airo_ioctl(struct net_device *dev, struct ifreq *rq, int cmd);
@@ -3151,7 +3150,7 @@
return 0;
}
-static irqreturn_t airo_interrupt ( int irq, void* dev_id, struct pt_regs *regs) {
+static irqreturn_t airo_interrupt ( int irq, void* dev_id) {
struct net_device *dev = (struct net_device *)dev_id;
u16 status;
u16 fid;
diff --git a/drivers/net/wireless/arlan-main.c b/drivers/net/wireless/arlan-main.c
index bb6bea4..4688e56 100644
--- a/drivers/net/wireless/arlan-main.c
+++ b/drivers/net/wireless/arlan-main.c
@@ -78,7 +78,7 @@
static int arlan_open(struct net_device *dev);
static int arlan_tx(struct sk_buff *skb, struct net_device *dev);
-static irqreturn_t arlan_interrupt(int irq, void *dev_id, struct pt_regs *regs);
+static irqreturn_t arlan_interrupt(int irq, void *dev_id);
static int arlan_close(struct net_device *dev);
static struct net_device_stats *
arlan_statistics (struct net_device *dev);
@@ -1651,7 +1651,7 @@
return;
}
-static irqreturn_t arlan_interrupt(int irq, void *dev_id, struct pt_regs *regs)
+static irqreturn_t arlan_interrupt(int irq, void *dev_id)
{
struct net_device *dev = dev_id;
struct arlan_private *priv = netdev_priv(dev);
diff --git a/drivers/net/wireless/atmel.c b/drivers/net/wireless/atmel.c
index 0fc267d..31eed85 100644
--- a/drivers/net/wireless/atmel.c
+++ b/drivers/net/wireless/atmel.c
@@ -1145,7 +1145,7 @@
}
}
-static irqreturn_t service_interrupt(int irq, void *dev_id, struct pt_regs *regs)
+static irqreturn_t service_interrupt(int irq, void *dev_id)
{
struct net_device *dev = (struct net_device *) dev_id;
struct atmel_private *priv = netdev_priv(dev);
diff --git a/drivers/net/wireless/bcm43xx/bcm43xx_main.c b/drivers/net/wireless/bcm43xx/bcm43xx_main.c
index eb65db7..bad3452 100644
--- a/drivers/net/wireless/bcm43xx/bcm43xx_main.c
+++ b/drivers/net/wireless/bcm43xx/bcm43xx_main.c
@@ -1834,7 +1834,7 @@
}
/* Interrupt handler top-half */
-static irqreturn_t bcm43xx_interrupt_handler(int irq, void *dev_id, struct pt_regs *regs)
+static irqreturn_t bcm43xx_interrupt_handler(int irq, void *dev_id)
{
irqreturn_t ret = IRQ_HANDLED;
struct bcm43xx_private *bcm = dev_id;
@@ -3963,7 +3963,7 @@
local_irq_save(flags);
if (bcm43xx_status(bcm) == BCM43xx_STAT_INITIALIZED)
- bcm43xx_interrupt_handler(bcm->irq, bcm, NULL);
+ bcm43xx_interrupt_handler(bcm->irq, bcm);
local_irq_restore(flags);
}
#endif /* CONFIG_NET_POLL_CONTROLLER */
diff --git a/drivers/net/wireless/hostap/hostap_hw.c b/drivers/net/wireless/hostap/hostap_hw.c
index d500012..ed00ebb 100644
--- a/drivers/net/wireless/hostap/hostap_hw.c
+++ b/drivers/net/wireless/hostap/hostap_hw.c
@@ -2622,7 +2622,7 @@
/* Called only from hardware IRQ */
-static irqreturn_t prism2_interrupt(int irq, void *dev_id, struct pt_regs *regs)
+static irqreturn_t prism2_interrupt(int irq, void *dev_id)
{
struct net_device *dev = (struct net_device *) dev_id;
struct hostap_interface *iface;
diff --git a/drivers/net/wireless/ipw2100.c b/drivers/net/wireless/ipw2100.c
index 599e2fe..4e4eaa2 100644
--- a/drivers/net/wireless/ipw2100.c
+++ b/drivers/net/wireless/ipw2100.c
@@ -3255,7 +3255,7 @@
IPW_DEBUG_ISR("exit\n");
}
-static irqreturn_t ipw2100_interrupt(int irq, void *data, struct pt_regs *regs)
+static irqreturn_t ipw2100_interrupt(int irq, void *data)
{
struct ipw2100_priv *priv = data;
u32 inta, inta_mask;
diff --git a/drivers/net/wireless/ipw2200.c b/drivers/net/wireless/ipw2200.c
index 5685d7b..1f74281 100644
--- a/drivers/net/wireless/ipw2200.c
+++ b/drivers/net/wireless/ipw2200.c
@@ -10467,7 +10467,7 @@
.set_eeprom = ipw_ethtool_set_eeprom,
};
-static irqreturn_t ipw_isr(int irq, void *data, struct pt_regs *regs)
+static irqreturn_t ipw_isr(int irq, void *data)
{
struct ipw_priv *priv = data;
u32 inta, inta_mask;
diff --git a/drivers/net/wireless/netwave_cs.c b/drivers/net/wireless/netwave_cs.c
index 36b5e00..6714e0d 100644
--- a/drivers/net/wireless/netwave_cs.c
+++ b/drivers/net/wireless/netwave_cs.c
@@ -207,7 +207,7 @@
static int netwave_rx( struct net_device *dev);
/* Interrupt routines */
-static irqreturn_t netwave_interrupt(int irq, void *dev_id, struct pt_regs *regs);
+static irqreturn_t netwave_interrupt(int irq, void *dev_id);
static void netwave_watchdog(struct net_device *);
/* Statistics */
@@ -1072,7 +1072,7 @@
} /* netwave_start_xmit */
/*
- * Function netwave_interrupt (irq, dev_id, regs)
+ * Function netwave_interrupt (irq, dev_id)
*
* This function is the interrupt handler for the Netwave card. This
* routine will be called whenever:
@@ -1081,7 +1081,7 @@
* ready to transmit another packet.
* 3. A command has completed execution.
*/
-static irqreturn_t netwave_interrupt(int irq, void* dev_id, struct pt_regs *regs)
+static irqreturn_t netwave_interrupt(int irq, void* dev_id)
{
kio_addr_t iobase;
u_char __iomem *ramBase;
diff --git a/drivers/net/wireless/orinoco.c b/drivers/net/wireless/orinoco.c
index 9e19a96..793da5f 100644
--- a/drivers/net/wireless/orinoco.c
+++ b/drivers/net/wireless/orinoco.c
@@ -1952,7 +1952,7 @@
dev->name);
}
-irqreturn_t orinoco_interrupt(int irq, void *dev_id, struct pt_regs *regs)
+irqreturn_t orinoco_interrupt(int irq, void *dev_id)
{
struct net_device *dev = (struct net_device *)dev_id;
struct orinoco_private *priv = netdev_priv(dev);
diff --git a/drivers/net/wireless/orinoco.h b/drivers/net/wireless/orinoco.h
index fb5700d..4720fb2 100644
--- a/drivers/net/wireless/orinoco.h
+++ b/drivers/net/wireless/orinoco.h
@@ -128,7 +128,7 @@
extern int __orinoco_up(struct net_device *dev);
extern int __orinoco_down(struct net_device *dev);
extern int orinoco_reinit_firmware(struct net_device *dev);
-extern irqreturn_t orinoco_interrupt(int irq, void * dev_id, struct pt_regs *regs);
+extern irqreturn_t orinoco_interrupt(int irq, void * dev_id);
/********************************************************************/
/* Locking and synchronization functions */
diff --git a/drivers/net/wireless/prism54/islpci_dev.c b/drivers/net/wireless/prism54/islpci_dev.c
index ab3c5a2..ec1c00f 100644
--- a/drivers/net/wireless/prism54/islpci_dev.c
+++ b/drivers/net/wireless/prism54/islpci_dev.c
@@ -182,7 +182,7 @@
******************************************************************************/
irqreturn_t
-islpci_interrupt(int irq, void *config, struct pt_regs *regs)
+islpci_interrupt(int irq, void *config)
{
u32 reg;
islpci_private *priv = config;
diff --git a/drivers/net/wireless/prism54/islpci_dev.h b/drivers/net/wireless/prism54/islpci_dev.h
index 5049f37..2f7e525d 100644
--- a/drivers/net/wireless/prism54/islpci_dev.h
+++ b/drivers/net/wireless/prism54/islpci_dev.h
@@ -198,7 +198,7 @@
#define ISLPCI_TX_TIMEOUT (2*HZ)
-irqreturn_t islpci_interrupt(int, void *, struct pt_regs *);
+irqreturn_t islpci_interrupt(int, void *);
int prism54_post_setup(islpci_private *, int);
int islpci_reset(islpci_private *, int);
diff --git a/drivers/net/wireless/ray_cs.c b/drivers/net/wireless/ray_cs.c
index e82548e..0b381d7 100644
--- a/drivers/net/wireless/ray_cs.c
+++ b/drivers/net/wireless/ray_cs.c
@@ -130,7 +130,7 @@
static void verify_dl_startup(u_long);
/* Prototypes for interrpt time functions **********************************/
-static irqreturn_t ray_interrupt (int reg, void *dev_id, struct pt_regs *regs);
+static irqreturn_t ray_interrupt (int reg, void *dev_id);
static void clear_interrupt(ray_dev_t *local);
static void rx_deauthenticate(ray_dev_t *local, struct rcs __iomem *prcs,
unsigned int pkt_addr, int rx_len);
@@ -1940,7 +1940,7 @@
/*=============================================================================
* All routines below here are run at interrupt time.
=============================================================================*/
-static irqreturn_t ray_interrupt(int irq, void *dev_id, struct pt_regs * regs)
+static irqreturn_t ray_interrupt(int irq, void *dev_id)
{
struct net_device *dev = (struct net_device *)dev_id;
struct pcmcia_device *link;
diff --git a/drivers/net/wireless/wavelan.c b/drivers/net/wireless/wavelan.c
index 5b69befd..24221e4 100644
--- a/drivers/net/wireless/wavelan.c
+++ b/drivers/net/wireless/wavelan.c
@@ -3768,7 +3768,7 @@
* This function is the interrupt handler for the WaveLAN card. This
* routine will be called whenever:
*/
-static irqreturn_t wavelan_interrupt(int irq, void *dev_id, struct pt_regs *regs)
+static irqreturn_t wavelan_interrupt(int irq, void *dev_id)
{
struct net_device *dev;
unsigned long ioaddr;
diff --git a/drivers/net/wireless/wavelan.p.h b/drivers/net/wireless/wavelan.p.h
index 5cb0bc8..72b646c 100644
--- a/drivers/net/wireless/wavelan.p.h
+++ b/drivers/net/wireless/wavelan.p.h
@@ -642,8 +642,7 @@
/* ---------------------- INTERRUPT HANDLING ---------------------- */
static irqreturn_t
wavelan_interrupt(int, /* interrupt handler */
- void *,
- struct pt_regs *);
+ void *);
static void
wavelan_watchdog(struct net_device *); /* transmission watchdog */
/* ------------------- CONFIGURATION CALLBACKS ------------------- */
diff --git a/drivers/net/wireless/wavelan_cs.c b/drivers/net/wireless/wavelan_cs.c
index 0065f05..cadfe13 100644
--- a/drivers/net/wireless/wavelan_cs.c
+++ b/drivers/net/wireless/wavelan_cs.c
@@ -4117,8 +4117,7 @@
*/
static irqreturn_t
wavelan_interrupt(int irq,
- void * dev_id,
- struct pt_regs * regs)
+ void * dev_id)
{
struct net_device * dev;
net_local * lp;
diff --git a/drivers/net/wireless/wavelan_cs.p.h b/drivers/net/wireless/wavelan_cs.p.h
index f34a36b..4d1c490 100644
--- a/drivers/net/wireless/wavelan_cs.p.h
+++ b/drivers/net/wireless/wavelan_cs.p.h
@@ -738,8 +738,7 @@
/* ---------------------- INTERRUPT HANDLING ---------------------- */
static irqreturn_t
wavelan_interrupt(int, /* Interrupt handler */
- void *,
- struct pt_regs *);
+ void *);
static void
wavelan_watchdog(struct net_device *); /* Transmission watchdog */
/* ------------------- CONFIGURATION CALLBACKS ------------------- */
diff --git a/drivers/net/wireless/wl3501_cs.c b/drivers/net/wireless/wl3501_cs.c
index e3ae5f6..a143035 100644
--- a/drivers/net/wireless/wl3501_cs.c
+++ b/drivers/net/wireless/wl3501_cs.c
@@ -1145,7 +1145,6 @@
* wl3501_interrupt - Hardware interrupt from card.
* @irq - Interrupt number
* @dev_id - net_device
- * @regs - registers
*
* We must acknowledge the interrupt as soon as possible, and block the
* interrupt from the same card immediately to prevent re-entry.
@@ -1154,7 +1153,7 @@
* On the other hand, to prevent SUTRO from malfunctioning, we must
* unlock the SUTRO as soon as possible.
*/
-static irqreturn_t wl3501_interrupt(int irq, void *dev_id, struct pt_regs *regs)
+static irqreturn_t wl3501_interrupt(int irq, void *dev_id)
{
struct net_device *dev = (struct net_device *)dev_id;
struct wl3501_card *this;
diff --git a/drivers/net/wireless/zd1201.c b/drivers/net/wireless/zd1201.c
index 80af9a9..30057a3 100644
--- a/drivers/net/wireless/zd1201.c
+++ b/drivers/net/wireless/zd1201.c
@@ -112,7 +112,7 @@
return err;
}
-static void zd1201_usbfree(struct urb *urb, struct pt_regs *regs)
+static void zd1201_usbfree(struct urb *urb)
{
struct zd1201 *zd = urb->context;
@@ -177,7 +177,7 @@
}
/* Callback after sending out a packet */
-static void zd1201_usbtx(struct urb *urb, struct pt_regs *regs)
+static void zd1201_usbtx(struct urb *urb)
{
struct zd1201 *zd = urb->context;
netif_wake_queue(zd->dev);
@@ -185,7 +185,7 @@
}
/* Incoming data */
-static void zd1201_usbrx(struct urb *urb, struct pt_regs *regs)
+static void zd1201_usbrx(struct urb *urb)
{
struct zd1201 *zd = urb->context;
int free = 0;
diff --git a/drivers/net/wireless/zd1211rw/zd_usb.c b/drivers/net/wireless/zd1211rw/zd_usb.c
index 5c265ad..3faaeb2 100644
--- a/drivers/net/wireless/zd1211rw/zd_usb.c
+++ b/drivers/net/wireless/zd1211rw/zd_usb.c
@@ -408,7 +408,7 @@
}
-static void int_urb_complete(struct urb *urb, struct pt_regs *pt_regs)
+static void int_urb_complete(struct urb *urb)
{
int r;
struct usb_int_header *hdr;
@@ -609,7 +609,7 @@
}
}
-static void rx_urb_complete(struct urb *urb, struct pt_regs *pt_regs)
+static void rx_urb_complete(struct urb *urb)
{
struct zd_usb *usb;
struct zd_usb_rx *rx;
@@ -779,7 +779,7 @@
spin_unlock_irqrestore(&rx->lock, flags);
}
-static void tx_urb_complete(struct urb *urb, struct pt_regs *pt_regs)
+static void tx_urb_complete(struct urb *urb)
{
int r;