![David Howells](/assets/img/avatar_default.png)
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)
450 lines
14 KiB
C
450 lines
14 KiB
C
/*
|
|
* Description of Z8530 Z85C30 and Z85230 communications chips
|
|
*
|
|
* Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
|
|
* Copyright (C) 1998 Alan Cox <alan@redhat.com>
|
|
*/
|
|
|
|
#ifndef _Z8530_H
|
|
#define _Z8530_H
|
|
|
|
#include <linux/tty.h>
|
|
#include <linux/interrupt.h>
|
|
|
|
/* Conversion routines to/from brg time constants from/to bits
|
|
* per second.
|
|
*/
|
|
#define BRG_TO_BPS(brg, freq) ((freq) / 2 / ((brg) + 2))
|
|
#define BPS_TO_BRG(bps, freq) ((((freq) + (bps)) / (2 * (bps))) - 2)
|
|
|
|
/* The Zilog register set */
|
|
|
|
#define FLAG 0x7e
|
|
|
|
/* Write Register 0 */
|
|
#define R0 0 /* Register selects */
|
|
#define R1 1
|
|
#define R2 2
|
|
#define R3 3
|
|
#define R4 4
|
|
#define R5 5
|
|
#define R6 6
|
|
#define R7 7
|
|
#define R8 8
|
|
#define R9 9
|
|
#define R10 10
|
|
#define R11 11
|
|
#define R12 12
|
|
#define R13 13
|
|
#define R14 14
|
|
#define R15 15
|
|
|
|
#define RPRIME 16 /* Indicate a prime register access on 230 */
|
|
|
|
#define NULLCODE 0 /* Null Code */
|
|
#define POINT_HIGH 0x8 /* Select upper half of registers */
|
|
#define RES_EXT_INT 0x10 /* Reset Ext. Status Interrupts */
|
|
#define SEND_ABORT 0x18 /* HDLC Abort */
|
|
#define RES_RxINT_FC 0x20 /* Reset RxINT on First Character */
|
|
#define RES_Tx_P 0x28 /* Reset TxINT Pending */
|
|
#define ERR_RES 0x30 /* Error Reset */
|
|
#define RES_H_IUS 0x38 /* Reset highest IUS */
|
|
|
|
#define RES_Rx_CRC 0x40 /* Reset Rx CRC Checker */
|
|
#define RES_Tx_CRC 0x80 /* Reset Tx CRC Checker */
|
|
#define RES_EOM_L 0xC0 /* Reset EOM latch */
|
|
|
|
/* Write Register 1 */
|
|
|
|
#define EXT_INT_ENAB 0x1 /* Ext Int Enable */
|
|
#define TxINT_ENAB 0x2 /* Tx Int Enable */
|
|
#define PAR_SPEC 0x4 /* Parity is special condition */
|
|
|
|
#define RxINT_DISAB 0 /* Rx Int Disable */
|
|
#define RxINT_FCERR 0x8 /* Rx Int on First Character Only or Error */
|
|
#define INT_ALL_Rx 0x10 /* Int on all Rx Characters or error */
|
|
#define INT_ERR_Rx 0x18 /* Int on error only */
|
|
|
|
#define WT_RDY_RT 0x20 /* Wait/Ready on R/T */
|
|
#define WT_FN_RDYFN 0x40 /* Wait/FN/Ready FN */
|
|
#define WT_RDY_ENAB 0x80 /* Wait/Ready Enable */
|
|
|
|
/* Write Register #2 (Interrupt Vector) */
|
|
|
|
/* Write Register 3 */
|
|
|
|
#define RxENABLE 0x1 /* Rx Enable */
|
|
#define SYNC_L_INH 0x2 /* Sync Character Load Inhibit */
|
|
#define ADD_SM 0x4 /* Address Search Mode (SDLC) */
|
|
#define RxCRC_ENAB 0x8 /* Rx CRC Enable */
|
|
#define ENT_HM 0x10 /* Enter Hunt Mode */
|
|
#define AUTO_ENAB 0x20 /* Auto Enables */
|
|
#define Rx5 0x0 /* Rx 5 Bits/Character */
|
|
#define Rx7 0x40 /* Rx 7 Bits/Character */
|
|
#define Rx6 0x80 /* Rx 6 Bits/Character */
|
|
#define Rx8 0xc0 /* Rx 8 Bits/Character */
|
|
|
|
/* Write Register 4 */
|
|
|
|
#define PAR_ENA 0x1 /* Parity Enable */
|
|
#define PAR_EVEN 0x2 /* Parity Even/Odd* */
|
|
|
|
#define SYNC_ENAB 0 /* Sync Modes Enable */
|
|
#define SB1 0x4 /* 1 stop bit/char */
|
|
#define SB15 0x8 /* 1.5 stop bits/char */
|
|
#define SB2 0xc /* 2 stop bits/char */
|
|
|
|
#define MONSYNC 0 /* 8 Bit Sync character */
|
|
#define BISYNC 0x10 /* 16 bit sync character */
|
|
#define SDLC 0x20 /* SDLC Mode (01111110 Sync Flag) */
|
|
#define EXTSYNC 0x30 /* External Sync Mode */
|
|
|
|
#define X1CLK 0x0 /* x1 clock mode */
|
|
#define X16CLK 0x40 /* x16 clock mode */
|
|
#define X32CLK 0x80 /* x32 clock mode */
|
|
#define X64CLK 0xC0 /* x64 clock mode */
|
|
|
|
/* Write Register 5 */
|
|
|
|
#define TxCRC_ENAB 0x1 /* Tx CRC Enable */
|
|
#define RTS 0x2 /* RTS */
|
|
#define SDLC_CRC 0x4 /* SDLC/CRC-16 */
|
|
#define TxENAB 0x8 /* Tx Enable */
|
|
#define SND_BRK 0x10 /* Send Break */
|
|
#define Tx5 0x0 /* Tx 5 bits (or less)/character */
|
|
#define Tx7 0x20 /* Tx 7 bits/character */
|
|
#define Tx6 0x40 /* Tx 6 bits/character */
|
|
#define Tx8 0x60 /* Tx 8 bits/character */
|
|
#define DTR 0x80 /* DTR */
|
|
|
|
/* Write Register 6 (Sync bits 0-7/SDLC Address Field) */
|
|
|
|
/* Write Register 7 (Sync bits 8-15/SDLC 01111110) */
|
|
|
|
/* Write Register 8 (transmit buffer) */
|
|
|
|
/* Write Register 9 (Master interrupt control) */
|
|
#define VIS 1 /* Vector Includes Status */
|
|
#define NV 2 /* No Vector */
|
|
#define DLC 4 /* Disable Lower Chain */
|
|
#define MIE 8 /* Master Interrupt Enable */
|
|
#define STATHI 0x10 /* Status high */
|
|
#define NORESET 0 /* No reset on write to R9 */
|
|
#define CHRB 0x40 /* Reset channel B */
|
|
#define CHRA 0x80 /* Reset channel A */
|
|
#define FHWRES 0xc0 /* Force hardware reset */
|
|
|
|
/* Write Register 10 (misc control bits) */
|
|
#define BIT6 1 /* 6 bit/8bit sync */
|
|
#define LOOPMODE 2 /* SDLC Loop mode */
|
|
#define ABUNDER 4 /* Abort/flag on SDLC xmit underrun */
|
|
#define MARKIDLE 8 /* Mark/flag on idle */
|
|
#define GAOP 0x10 /* Go active on poll */
|
|
#define NRZ 0 /* NRZ mode */
|
|
#define NRZI 0x20 /* NRZI mode */
|
|
#define FM1 0x40 /* FM1 (transition = 1) */
|
|
#define FM0 0x60 /* FM0 (transition = 0) */
|
|
#define CRCPS 0x80 /* CRC Preset I/O */
|
|
|
|
/* Write Register 11 (Clock Mode control) */
|
|
#define TRxCXT 0 /* TRxC = Xtal output */
|
|
#define TRxCTC 1 /* TRxC = Transmit clock */
|
|
#define TRxCBR 2 /* TRxC = BR Generator Output */
|
|
#define TRxCDP 3 /* TRxC = DPLL output */
|
|
#define TRxCOI 4 /* TRxC O/I */
|
|
#define TCRTxCP 0 /* Transmit clock = RTxC pin */
|
|
#define TCTRxCP 8 /* Transmit clock = TRxC pin */
|
|
#define TCBR 0x10 /* Transmit clock = BR Generator output */
|
|
#define TCDPLL 0x18 /* Transmit clock = DPLL output */
|
|
#define RCRTxCP 0 /* Receive clock = RTxC pin */
|
|
#define RCTRxCP 0x20 /* Receive clock = TRxC pin */
|
|
#define RCBR 0x40 /* Receive clock = BR Generator output */
|
|
#define RCDPLL 0x60 /* Receive clock = DPLL output */
|
|
#define RTxCX 0x80 /* RTxC Xtal/No Xtal */
|
|
|
|
/* Write Register 12 (lower byte of baud rate generator time constant) */
|
|
|
|
/* Write Register 13 (upper byte of baud rate generator time constant) */
|
|
|
|
/* Write Register 14 (Misc control bits) */
|
|
#define BRENABL 1 /* Baud rate generator enable */
|
|
#define BRSRC 2 /* Baud rate generator source */
|
|
#define DTRREQ 4 /* DTR/Request function */
|
|
#define AUTOECHO 8 /* Auto Echo */
|
|
#define LOOPBAK 0x10 /* Local loopback */
|
|
#define SEARCH 0x20 /* Enter search mode */
|
|
#define RMC 0x40 /* Reset missing clock */
|
|
#define DISDPLL 0x60 /* Disable DPLL */
|
|
#define SSBR 0x80 /* Set DPLL source = BR generator */
|
|
#define SSRTxC 0xa0 /* Set DPLL source = RTxC */
|
|
#define SFMM 0xc0 /* Set FM mode */
|
|
#define SNRZI 0xe0 /* Set NRZI mode */
|
|
|
|
/* Write Register 15 (external/status interrupt control) */
|
|
#define PRIME 1 /* R5' etc register access (Z85C30/230 only) */
|
|
#define ZCIE 2 /* Zero count IE */
|
|
#define FIFOE 4 /* Z85230 only */
|
|
#define DCDIE 8 /* DCD IE */
|
|
#define SYNCIE 0x10 /* Sync/hunt IE */
|
|
#define CTSIE 0x20 /* CTS IE */
|
|
#define TxUIE 0x40 /* Tx Underrun/EOM IE */
|
|
#define BRKIE 0x80 /* Break/Abort IE */
|
|
|
|
|
|
/* Read Register 0 */
|
|
#define Rx_CH_AV 0x1 /* Rx Character Available */
|
|
#define ZCOUNT 0x2 /* Zero count */
|
|
#define Tx_BUF_EMP 0x4 /* Tx Buffer empty */
|
|
#define DCD 0x8 /* DCD */
|
|
#define SYNC_HUNT 0x10 /* Sync/hunt */
|
|
#define CTS 0x20 /* CTS */
|
|
#define TxEOM 0x40 /* Tx underrun */
|
|
#define BRK_ABRT 0x80 /* Break/Abort */
|
|
|
|
/* Read Register 1 */
|
|
#define ALL_SNT 0x1 /* All sent */
|
|
/* Residue Data for 8 Rx bits/char programmed */
|
|
#define RES3 0x8 /* 0/3 */
|
|
#define RES4 0x4 /* 0/4 */
|
|
#define RES5 0xc /* 0/5 */
|
|
#define RES6 0x2 /* 0/6 */
|
|
#define RES7 0xa /* 0/7 */
|
|
#define RES8 0x6 /* 0/8 */
|
|
#define RES18 0xe /* 1/8 */
|
|
#define RES28 0x0 /* 2/8 */
|
|
/* Special Rx Condition Interrupts */
|
|
#define PAR_ERR 0x10 /* Parity error */
|
|
#define Rx_OVR 0x20 /* Rx Overrun Error */
|
|
#define CRC_ERR 0x40 /* CRC/Framing Error */
|
|
#define END_FR 0x80 /* End of Frame (SDLC) */
|
|
|
|
/* Read Register 2 (channel b only) - Interrupt vector */
|
|
|
|
/* Read Register 3 (interrupt pending register) ch a only */
|
|
#define CHBEXT 0x1 /* Channel B Ext/Stat IP */
|
|
#define CHBTxIP 0x2 /* Channel B Tx IP */
|
|
#define CHBRxIP 0x4 /* Channel B Rx IP */
|
|
#define CHAEXT 0x8 /* Channel A Ext/Stat IP */
|
|
#define CHATxIP 0x10 /* Channel A Tx IP */
|
|
#define CHARxIP 0x20 /* Channel A Rx IP */
|
|
|
|
/* Read Register 8 (receive data register) */
|
|
|
|
/* Read Register 10 (misc status bits) */
|
|
#define ONLOOP 2 /* On loop */
|
|
#define LOOPSEND 0x10 /* Loop sending */
|
|
#define CLK2MIS 0x40 /* Two clocks missing */
|
|
#define CLK1MIS 0x80 /* One clock missing */
|
|
|
|
/* Read Register 12 (lower byte of baud rate generator constant) */
|
|
|
|
/* Read Register 13 (upper byte of baud rate generator constant) */
|
|
|
|
/* Read Register 15 (value of WR 15) */
|
|
|
|
|
|
/*
|
|
* Interrupt handling functions for this SCC
|
|
*/
|
|
|
|
struct z8530_channel;
|
|
|
|
struct z8530_irqhandler
|
|
{
|
|
void (*rx)(struct z8530_channel *);
|
|
void (*tx)(struct z8530_channel *);
|
|
void (*status)(struct z8530_channel *);
|
|
};
|
|
|
|
/*
|
|
* A channel of the Z8530
|
|
*/
|
|
|
|
struct z8530_channel
|
|
{
|
|
struct z8530_irqhandler *irqs; /* IRQ handlers */
|
|
/*
|
|
* Synchronous
|
|
*/
|
|
u16 count; /* Buyes received */
|
|
u16 max; /* Most we can receive this frame */
|
|
u16 mtu; /* MTU of the device */
|
|
u8 *dptr; /* Pointer into rx buffer */
|
|
struct sk_buff *skb; /* Buffer dptr points into */
|
|
struct sk_buff *skb2; /* Pending buffer */
|
|
u8 status; /* Current DCD */
|
|
u8 dcdcheck; /* which bit to check for line */
|
|
u8 sync; /* Set if in sync mode */
|
|
|
|
u8 regs[32]; /* Register map for the chip */
|
|
u8 pendregs[32]; /* Pending register values */
|
|
|
|
struct sk_buff *tx_skb; /* Buffer being transmitted */
|
|
struct sk_buff *tx_next_skb; /* Next transmit buffer */
|
|
u8 *tx_ptr; /* Byte pointer into the buffer */
|
|
u8 *tx_next_ptr; /* Next pointer to use */
|
|
u8 *tx_dma_buf[2]; /* TX flip buffers for DMA */
|
|
u8 tx_dma_used; /* Flip buffer usage toggler */
|
|
u16 txcount; /* Count of bytes to transmit */
|
|
|
|
void (*rx_function)(struct z8530_channel *, struct sk_buff *);
|
|
|
|
/*
|
|
* Sync DMA
|
|
*/
|
|
|
|
u8 rxdma; /* DMA channels */
|
|
u8 txdma;
|
|
u8 rxdma_on; /* DMA active if flag set */
|
|
u8 txdma_on;
|
|
u8 dma_num; /* Buffer we are DMAing into */
|
|
u8 dma_ready; /* Is the other buffer free */
|
|
u8 dma_tx; /* TX is to use DMA */
|
|
u8 *rx_buf[2]; /* The flip buffers */
|
|
|
|
/*
|
|
* System
|
|
*/
|
|
|
|
struct z8530_dev *dev; /* Z85230 chip instance we are from */
|
|
unsigned long ctrlio; /* I/O ports */
|
|
unsigned long dataio;
|
|
|
|
/*
|
|
* For PC we encode this way.
|
|
*/
|
|
#define Z8530_PORT_SLEEP 0x80000000
|
|
#define Z8530_PORT_OF(x) ((x)&0xFFFF)
|
|
|
|
u32 rx_overrun; /* Overruns - not done yet */
|
|
u32 rx_crc_err;
|
|
|
|
/*
|
|
* Bound device pointers
|
|
*/
|
|
|
|
void *private; /* For our owner */
|
|
struct net_device *netdevice; /* Network layer device */
|
|
struct net_device_stats stats; /* Network layer statistics */
|
|
|
|
/*
|
|
* Async features
|
|
*/
|
|
|
|
struct tty_struct *tty; /* Attached terminal */
|
|
int line; /* Minor number */
|
|
wait_queue_head_t open_wait; /* Tasks waiting to open */
|
|
wait_queue_head_t close_wait; /* and for close to end */
|
|
unsigned long event; /* Pending events */
|
|
int fdcount; /* # of fd on device */
|
|
int blocked_open; /* # of blocked opens */
|
|
int x_char; /* XON/XOF char */
|
|
unsigned char *xmit_buf; /* Transmit pointer */
|
|
int xmit_head; /* Transmit ring */
|
|
int xmit_tail;
|
|
int xmit_cnt;
|
|
int flags;
|
|
int timeout;
|
|
int xmit_fifo_size; /* Transmit FIFO info */
|
|
|
|
int close_delay; /* Do we wait for drain on close ? */
|
|
unsigned short closing_wait;
|
|
|
|
/* We need to know the current clock divisor
|
|
* to read the bps rate the chip has currently
|
|
* loaded.
|
|
*/
|
|
|
|
unsigned char clk_divisor; /* May be 1, 16, 32, or 64 */
|
|
int zs_baud;
|
|
|
|
int magic;
|
|
int baud_base; /* Baud parameters */
|
|
int custom_divisor;
|
|
|
|
|
|
unsigned char tx_active; /* character is being xmitted */
|
|
unsigned char tx_stopped; /* output is suspended */
|
|
|
|
spinlock_t *lock; /* Devicr lock */
|
|
};
|
|
|
|
/*
|
|
* Each Z853x0 device.
|
|
*/
|
|
|
|
struct z8530_dev
|
|
{
|
|
char *name; /* Device instance name */
|
|
struct z8530_channel chanA; /* SCC channel A */
|
|
struct z8530_channel chanB; /* SCC channel B */
|
|
int type;
|
|
#define Z8530 0 /* NMOS dinosaur */
|
|
#define Z85C30 1 /* CMOS - better */
|
|
#define Z85230 2 /* CMOS with real FIFO */
|
|
int irq; /* Interrupt for the device */
|
|
int active; /* Soft interrupt enable - the Mac doesn't
|
|
always have a hard disable on its 8530s... */
|
|
spinlock_t lock;
|
|
};
|
|
|
|
|
|
/*
|
|
* Functions
|
|
*/
|
|
|
|
extern u8 z8530_dead_port[];
|
|
extern u8 z8530_hdlc_kilostream_85230[];
|
|
extern u8 z8530_hdlc_kilostream[];
|
|
extern irqreturn_t z8530_interrupt(int, void *);
|
|
extern void z8530_describe(struct z8530_dev *, char *mapping, unsigned long io);
|
|
extern int z8530_init(struct z8530_dev *);
|
|
extern int z8530_shutdown(struct z8530_dev *);
|
|
extern int z8530_sync_open(struct net_device *, struct z8530_channel *);
|
|
extern int z8530_sync_close(struct net_device *, struct z8530_channel *);
|
|
extern int z8530_sync_dma_open(struct net_device *, struct z8530_channel *);
|
|
extern int z8530_sync_dma_close(struct net_device *, struct z8530_channel *);
|
|
extern int z8530_sync_txdma_open(struct net_device *, struct z8530_channel *);
|
|
extern int z8530_sync_txdma_close(struct net_device *, struct z8530_channel *);
|
|
extern int z8530_channel_load(struct z8530_channel *, u8 *);
|
|
extern int z8530_queue_xmit(struct z8530_channel *c, struct sk_buff *skb);
|
|
extern struct net_device_stats *z8530_get_stats(struct z8530_channel *c);
|
|
extern void z8530_null_rx(struct z8530_channel *c, struct sk_buff *skb);
|
|
|
|
|
|
/*
|
|
* Standard interrupt vector sets
|
|
*/
|
|
|
|
extern struct z8530_irqhandler z8530_sync, z8530_async, z8530_nop;
|
|
|
|
/*
|
|
* Asynchronous Interfacing
|
|
*/
|
|
|
|
#define SERIAL_MAGIC 0x5301
|
|
|
|
/*
|
|
* The size of the serial xmit buffer is 1 page, or 4096 bytes
|
|
*/
|
|
|
|
#define SERIAL_XMIT_SIZE 4096
|
|
#define WAKEUP_CHARS 256
|
|
|
|
/*
|
|
* Events are used to schedule things to happen at timer-interrupt
|
|
* time, instead of at rs interrupt time.
|
|
*/
|
|
#define RS_EVENT_WRITE_WAKEUP 0
|
|
|
|
/* Internal flags used only by kernel/chr_drv/serial.c */
|
|
#define ZILOG_INITIALIZED 0x80000000 /* Serial port was initialized */
|
|
#define ZILOG_CALLOUT_ACTIVE 0x40000000 /* Call out device is active */
|
|
#define ZILOG_NORMAL_ACTIVE 0x20000000 /* Normal device is active */
|
|
#define ZILOG_BOOT_AUTOCONF 0x10000000 /* Autoconfigure port on bootup */
|
|
#define ZILOG_CLOSING 0x08000000 /* Serial port is closing */
|
|
#define ZILOG_CTS_FLOW 0x04000000 /* Do CTS flow control */
|
|
#define ZILOG_CHECK_CD 0x02000000 /* i.e., CLOCAL */
|
|
|
|
#endif /* !(_Z8530_H) */
|