linux-stable.git/include/linux/serial_core.h, branch linux-2.6.19.y Linux kernel stable tree IRQ: Maintain regs pointer globally rather than passing to IRQ handlers 2006-10-05T14:10:12+00:00 David Howells dhowells@redhat.com 2006-10-05T13:55:46+00:00 7d12e780e003f93433d49ce78cfedf4b4c52adc5 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) 
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)
[PATCH] serial: Rename PORT_AT91 -> PORT_ATMEL 2006-10-04T17:25:05+00:00 Haavard Skinnemoen hskinnemoen@atmel.com 2006-10-04T14:02:06+00:00 9ab4f88b7ffdf338773e7755f923bc6b9e079834 The at91_serial driver can be used with both AT32 and AT91 devices from Atmel and has therefore been renamed atmel_serial. The only thing left is to rename PORT_AT91 PORT_ATMEL. Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com> Acked-by: Andrew Victor <andrew@sanpeople.com> Signed-off-by: Linus Torvalds <torvalds@osdl.org> 
The at91_serial driver can be used with both AT32 and AT91 devices
from Atmel and has therefore been renamed atmel_serial. The only
thing left is to rename PORT_AT91 PORT_ATMEL.

Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Acked-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
[SERIAL] Magic SysRq SAK does nothing on serial consoles 2006-10-01T19:03:20+00:00 Simon Tatham anakin@pobox.com 2006-09-25T23:51:28+00:00 d8d64d6b29d331f1217c77999f5104fe68b0ef3a Make sysrq-K work on serial console by passing in the tty. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> 
Make sysrq-K work on serial console by passing in the tty.

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
[SERIAL] Fix oops when removing suspended serial port 2006-10-01T16:17:40+00:00 Russell King rmk@dyn-67.arm.linux.org.uk 2006-10-01T16:17:40+00:00 a6b93a908508810c5d51dd9b390283345af6f2d9 A serial card might have been removed when the system is resumed. This results in a suspended port being shut down, which results in the ports shutdown method being called twice in a row. This causes BUGs. Avoid this by tracking the suspended state separately from the initialised state. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> 
A serial card might have been removed when the system is resumed.
This results in a suspended port being shut down, which results in
the ports shutdown method being called twice in a row.  This causes
BUGs.  Avoid this by tracking the suspended state separately from
the initialised state.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
[SERIAL] 8250: add tsi108 serial support 2006-07-09T20:11:09+00:00 Zang Roy-r61911 tie-fei.zang@freescale.com 2006-06-30T09:29:58+00:00 3be91ec7388bae3cf1bfb4febcee5ab6c65f409f The following patch gets rid of CONFIG_TSI108_BRIDGE. I add UPIO_TSI to handle IIR and IER register in serial_in and serial_out. (1) the reason to rewrite serial_in: TSI108 rev Z1 version ERRATA. Reading the UART's Interrupt Identification Register (IIR) clears the Transmit Holding Register Empty (THRE) and Transmit buffer Empty (TEMP) interrupts even if they are not enabled in the Interrupt Enable Register (IER). This leads to loss of the interrupts. Interrupts are not cleared when reading UART registers as 32-bit word. (2) the reason to rewrite serial_out: Check for UART_IER_UUE bit in the autoconfig routine. This section of autoconfig is excluded for Tsi108/109 because bits 7 and 6 are reserved for internal use. They are R/W bits. In addition to incorrect identification, changing these bits (from 00) will make Tsi108/109 UART non-functional. Signed-off-by: Roy Zang <tie-fei.zang@freescale.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> 
The following patch gets rid of CONFIG_TSI108_BRIDGE.  I add UPIO_TSI to
handle IIR and IER register in serial_in and serial_out.

(1) the reason to rewrite serial_in:

    TSI108 rev Z1 version ERRATA.  Reading the UART's Interrupt
    Identification Register (IIR) clears the Transmit Holding Register
    Empty (THRE) and Transmit buffer Empty (TEMP) interrupts even if they
    are not enabled in the Interrupt Enable Register (IER).  This leads to
    loss of the interrupts.  Interrupts are not cleared when reading UART
    registers as 32-bit word.

(2) the reason to rewrite serial_out:

    Check for UART_IER_UUE bit in the autoconfig routine.  This section
    of autoconfig is excluded for Tsi108/109 because bits 7 and 6 are
    reserved for internal use.  They are R/W bits.  In addition to
    incorrect identification, changing these bits (from 00) will make
    Tsi108/109 UART non-functional.

Signed-off-by: Roy Zang	<tie-fei.zang@freescale.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Merge branch 'devel' of master.kernel.org:/home/rmk/linux-2.6-serial 2006-07-04T04:31:05+00:00 Linus Torvalds torvalds@g5.osdl.org 2006-07-04T04:31:05+00:00 075395d228641646159dae3dd170fa3fc6ff477a * 'devel' of master.kernel.org:/home/rmk/linux-2.6-serial: [SERIAL] Ensure 8250_pci quirks are not marked __devinit [SERIAL] Convert fifosize to an unsigned int 
* 'devel' of master.kernel.org:/home/rmk/linux-2.6-serial:
  [SERIAL] Ensure 8250_pci quirks are not marked __devinit
  [SERIAL] Convert fifosize to an unsigned int
[SERIAL] Convert fifosize to an unsigned int 2006-07-02T19:45:51+00:00 Russell King rmk@dyn-67.arm.linux.org.uk 2006-07-02T19:45:51+00:00 947deee8904b3c2edc7f59ab6e6242499e4dc434 Some UARTs have more than 255 bytes of FIFO, which can't be represented by an unsigned char. Change the kernel's internal structure to be an unsigned int, but still export an unsigned char via the TIOCGSERIAL ioctl. If the TIOCSSERIAL ioctl provides a fifo size of 0, assume this means "don't change" otherwise we'll corrupt the larger fifo sizes. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> 
Some UARTs have more than 255 bytes of FIFO, which can't be
represented by an unsigned char.  Change the kernel's internal
structure to be an unsigned int, but still export an unsigned char
via the TIOCGSERIAL ioctl.  If the TIOCSSERIAL ioctl provides a
fifo size of 0, assume this means "don't change" otherwise we'll
corrupt the larger fifo sizes.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
[PATCH] devfs: Remove devfs support from the serial subsystem 2006-06-26T19:25:05+00:00 Greg Kroah-Hartman gregkh@suse.de 2005-06-21T04:15:16+00:00 aa4148cfc7b3b93eeaf755a7d14f10afaffe9a96 Also fixes all serial drivers. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> 
Also fixes all serial drivers.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
[ARM] 3639/1: S3C2412: serial port support 2006-06-24T20:21:32+00:00 Ben Dooks ben-linux@fluff.org 2006-06-24T20:21:32+00:00 73e55cb3b3549d0174d1dadb755200938232e8d0 Patch from Ben Dooks Serial port support for the on-board UART blocks on the Samsung S3C2412 and S3C2413 UARTs. Signed-off-by: Ben Dooks <ben-linux@fluff.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> 
Patch from Ben Dooks

Serial port support for the on-board UART blocks
on the Samsung S3C2412 and S3C2413 UARTs.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Merge branch 'devel' of master.kernel.org:/home/rmk/linux-2.6-arm 2006-06-21T00:52:36+00:00 Linus Torvalds torvalds@g5.osdl.org 2006-06-21T00:52:36+00:00 050335db2a777ffaa859d77beb05fffe9e8c5ae9 * 'devel' of master.kernel.org:/home/rmk/linux-2.6-arm: (42 commits) [ARM] Fix tosa build error [ARM] 3610/1: Make reboot work on Versatile [ARM] 3609/1: S3C24XX: defconfig update for s3c2410_defconfig [ARM] 3591/1: Anubis: IDE device definitions [ARM] Include asm/hardware.h not asm/arch/hardware.h [ARM] 3594/1: Poodle: Add touchscreen support + other updates [ARM] 3564/1: sharpsl_pm: Abstract some machine specific parameters [ARM] 3561/1: Poodle: Correct the MMC/SD power control [ARM] 3593/1: Add reboot and shutdown handlers for Zaurus handhelds [ARM] 3599/1: AT91RM9200 remove global variables [ARM] 3607/1: AT91RM9200 misc fixes [ARM] 3605/1: AT91RM9200 Power Management [ARM] 3604/1: AT91RM9200 New boards [ARM] 3603/1: AT91RM9200 remove old files [ARM] 3592/1: AT91RM9200 Serial driver update [ARM] 3590/1: AT91RM9200 Platform devices support [ARM] 3589/1: AT91RM9200 DK/EK board update [ARM] 3588/1: AT91RM9200 CSB337/637 board update [ARM] 3587/1: AT91RM9200 hardware headers [ARM] 3586/1: AT91RM9200 header update ... 
* 'devel' of master.kernel.org:/home/rmk/linux-2.6-arm: (42 commits)
  [ARM] Fix tosa build error
  [ARM] 3610/1: Make reboot work on Versatile
  [ARM] 3609/1: S3C24XX: defconfig update for s3c2410_defconfig
  [ARM] 3591/1: Anubis: IDE device definitions
  [ARM] Include asm/hardware.h not asm/arch/hardware.h
  [ARM] 3594/1: Poodle: Add touchscreen support + other updates
  [ARM] 3564/1: sharpsl_pm: Abstract some machine specific parameters
  [ARM] 3561/1: Poodle: Correct the MMC/SD power control
  [ARM] 3593/1: Add reboot and shutdown handlers for Zaurus handhelds
  [ARM] 3599/1: AT91RM9200 remove global variables
  [ARM] 3607/1: AT91RM9200 misc fixes
  [ARM] 3605/1: AT91RM9200 Power Management
  [ARM] 3604/1: AT91RM9200 New boards
  [ARM] 3603/1: AT91RM9200 remove old files
  [ARM] 3592/1: AT91RM9200 Serial driver update
  [ARM] 3590/1: AT91RM9200 Platform devices support
  [ARM] 3589/1: AT91RM9200 DK/EK board update
  [ARM] 3588/1: AT91RM9200 CSB337/637 board update
  [ARM] 3587/1: AT91RM9200 hardware headers
  [ARM] 3586/1: AT91RM9200 header update
  ...