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linux-next/drivers/net/de600.h
David Howells 7d12e780e0 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)
2006-10-05 15:10:12 +01:00

170 lines
5.5 KiB
C
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/**************************************************
* *
* Definition of D-Link Ethernet Pocket adapter *
* *
**************************************************/
/*
* D-Link Ethernet pocket adapter ports
*/
/*
* OK, so I'm cheating, but there are an awful lot of
* reads and writes in order to get anything in and out
* of the DE-600 with 4 bits at a time in the parallel port,
* so every saved instruction really helps :-)
*/
#ifndef DE600_IO
#define DE600_IO 0x378
#endif
#define DATA_PORT (DE600_IO)
#define STATUS_PORT (DE600_IO + 1)
#define COMMAND_PORT (DE600_IO + 2)
#ifndef DE600_IRQ
#define DE600_IRQ 7
#endif
/*
* It really should look like this, and autoprobing as well...
*
#define DATA_PORT (dev->base_addr + 0)
#define STATUS_PORT (dev->base_addr + 1)
#define COMMAND_PORT (dev->base_addr + 2)
#define DE600_IRQ dev->irq
*/
/*
* D-Link COMMAND_PORT commands
*/
#define SELECT_NIC 0x04 /* select Network Interface Card */
#define SELECT_PRN 0x1c /* select Printer */
#define NML_PRN 0xec /* normal Printer situation */
#define IRQEN 0x10 /* enable IRQ line */
/*
* D-Link STATUS_PORT
*/
#define RX_BUSY 0x80
#define RX_GOOD 0x40
#define TX_FAILED16 0x10
#define TX_BUSY 0x08
/*
* D-Link DATA_PORT commands
* command in low 4 bits
* data in high 4 bits
* select current data nibble with HI_NIBBLE bit
*/
#define WRITE_DATA 0x00 /* write memory */
#define READ_DATA 0x01 /* read memory */
#define STATUS 0x02 /* read status register */
#define COMMAND 0x03 /* write command register (see COMMAND below) */
#define NULL_COMMAND 0x04 /* null command */
#define RX_LEN 0x05 /* read received packet length */
#define TX_ADDR 0x06 /* set adapter transmit memory address */
#define RW_ADDR 0x07 /* set adapter read/write memory address */
#define HI_NIBBLE 0x08 /* read/write the high nibble of data,
or-ed with rest of command */
/*
* command register, accessed through DATA_PORT with low bits = COMMAND
*/
#define RX_ALL 0x01 /* PROMISCUOUS */
#define RX_BP 0x02 /* default: BROADCAST & PHYSICAL ADDRESS */
#define RX_MBP 0x03 /* MULTICAST, BROADCAST & PHYSICAL ADDRESS */
#define TX_ENABLE 0x04 /* bit 2 */
#define RX_ENABLE 0x08 /* bit 3 */
#define RESET 0x80 /* set bit 7 high */
#define STOP_RESET 0x00 /* set bit 7 low */
/*
* data to command register
* (high 4 bits in write to DATA_PORT)
*/
#define RX_PAGE2_SELECT 0x10 /* bit 4, only 2 pages to select */
#define RX_BASE_PAGE 0x20 /* bit 5, always set when specifying RX_ADDR */
#define FLIP_IRQ 0x40 /* bit 6 */
/*
* D-Link adapter internal memory:
*
* 0-2K 1:st transmit page (send from pointer up to 2K)
* 2-4K 2:nd transmit page (send from pointer up to 4K)
*
* 4-6K 1:st receive page (data from 4K upwards)
* 6-8K 2:nd receive page (data from 6K upwards)
*
* 8K+ Adapter ROM (contains magic code and last 3 bytes of Ethernet address)
*/
#define MEM_2K 0x0800 /* 2048 */
#define MEM_4K 0x1000 /* 4096 */
#define MEM_6K 0x1800 /* 6144 */
#define NODE_ADDRESS 0x2000 /* 8192 */
#define RUNT 60 /* Too small Ethernet packet */
/**************************************************
* *
* End of definition *
* *
**************************************************/
/*
* Index to functions, as function prototypes.
*/
/* Routines used internally. (See "convenience macros") */
static u8 de600_read_status(struct net_device *dev);
static u8 de600_read_byte(unsigned char type, struct net_device *dev);
/* Put in the device structure. */
static int de600_open(struct net_device *dev);
static int de600_close(struct net_device *dev);
static struct net_device_stats *get_stats(struct net_device *dev);
static int de600_start_xmit(struct sk_buff *skb, struct net_device *dev);
/* Dispatch from interrupts. */
static irqreturn_t de600_interrupt(int irq, void *dev_id);
static int de600_tx_intr(struct net_device *dev, int irq_status);
static void de600_rx_intr(struct net_device *dev);
/* Initialization */
static void trigger_interrupt(struct net_device *dev);
static int adapter_init(struct net_device *dev);
/*
* Convenience macros/functions for D-Link adapter
*/
#define select_prn() outb_p(SELECT_PRN, COMMAND_PORT); DE600_SLOW_DOWN
#define select_nic() outb_p(SELECT_NIC, COMMAND_PORT); DE600_SLOW_DOWN
/* Thanks for hints from Mark Burton <markb@ordern.demon.co.uk> */
#define de600_put_byte(data) ( \
outb_p(((data) << 4) | WRITE_DATA , DATA_PORT), \
outb_p(((data) & 0xf0) | WRITE_DATA | HI_NIBBLE, DATA_PORT))
/*
* The first two outb_p()'s below could perhaps be deleted if there
* would be more delay in the last two. Not certain about it yet...
*/
#define de600_put_command(cmd) ( \
outb_p(( rx_page << 4) | COMMAND , DATA_PORT), \
outb_p(( rx_page & 0xf0) | COMMAND | HI_NIBBLE, DATA_PORT), \
outb_p(((rx_page | cmd) << 4) | COMMAND , DATA_PORT), \
outb_p(((rx_page | cmd) & 0xf0) | COMMAND | HI_NIBBLE, DATA_PORT))
#define de600_setup_address(addr,type) ( \
outb_p((((addr) << 4) & 0xf0) | type , DATA_PORT), \
outb_p(( (addr) & 0xf0) | type | HI_NIBBLE, DATA_PORT), \
outb_p((((addr) >> 4) & 0xf0) | type , DATA_PORT), \
outb_p((((addr) >> 8) & 0xf0) | type | HI_NIBBLE, DATA_PORT))
#define rx_page_adr() ((rx_page & RX_PAGE2_SELECT)?(MEM_6K):(MEM_4K))
/* Flip bit, only 2 pages */
#define next_rx_page() (rx_page ^= RX_PAGE2_SELECT)
#define tx_page_adr(a) (((a) + 1) * MEM_2K)
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