arch/arm/mach-spear3xx/include/mach/entry-macro.S

   1 /*
   2  * arch/arm/mach-spear3xx/include/mach/entry-macro.S
   3  *
   4  * Low-level IRQ helper macros for SPEAr3xx machine family
   5  *
   6  * Copyright (C) 2009 ST Microelectronics
   7  * Viresh Kumar<viresh.kumar@st.com>
   8  *
   9  * This file is licensed under the terms of the GNU General Public
  10  * License version 2. This program is licensed "as is" without any
  11  * warranty of any kind, whether express or implied.
  12  */
  13
  14 #include <asm/hardware/vic.h>
  15 #include <mach/hardware.h>
  16
  17                 .macro  disable_fiq
  18                 .endm
  19
  20                 .macro  get_irqnr_preamble, base, tmp
  21                 .endm
  22
  23                 .macro  arch_ret_to_user, tmp1, tmp2
  24                 .endm
  25
  26                 .macro  get_irqnr_and_base, irqnr, irqstat, base, tmp
  27                 ldr     \base, =VA_SPEAR3XX_ML1_VIC_BASE
  28                 ldr     \irqstat, [\base, #VIC_IRQ_STATUS]      @ get status
  29                 teq     \irqstat, #0
  30                 beq     1001f                           @ this will set/reset
  31                                                         @ zero register
  32                 /*
  33                  * Following code will find bit position of least significang
  34                  * bit set in irqstat, using following equation
  35                  * least significant bit set in n = (n & ~(n-1))
  36                  */
  37                 sub     \tmp, \irqstat, #1              @ tmp = irqstat - 1
  38                 mvn     \tmp, \tmp                      @ tmp = ~tmp
  39                 and     \irqstat, \irqstat, \tmp        @ irqstat &= tmp
  40                 /* Now, irqstat is = bit no. of 1st bit set in vic irq status */
  41                 clz     \tmp, \irqstat                  @ tmp = leading zeros
  42                 rsb     \irqnr, \tmp, #0x1F             @ irqnr = 32 - tmp - 1
  43
  44 1001:           /* EQ will be set if no irqs pending */
  45                 .endm