cregit-Linux how code gets into the kernel

Release 4.7 arch/sh/boards/mach-x3proto/ilsel.c

/*
 * arch/sh/boards/mach-x3proto/ilsel.c
 *
 * Helper routines for SH-X3 proto board ILSEL.
 *
 * Copyright (C) 2007 - 2010  Paul Mundt
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/bitmap.h>
#include <linux/io.h>
#include <mach/ilsel.h>

/*
 * ILSEL is split across:
 *
 *      ILSEL0 - 0xb8100004 [ Levels  1 -  4 ]
 *      ILSEL1 - 0xb8100006 [ Levels  5 -  8 ]
 *      ILSEL2 - 0xb8100008 [ Levels  9 - 12 ]
 *      ILSEL3 - 0xb810000a [ Levels 13 - 15 ]
 *
 * With each level being relative to an ilsel_source_t.
 */

#define ILSEL_BASE	0xb8100004

#define ILSEL_LEVELS	15

/*
 * ILSEL level map, in descending order from the highest level down.
 *
 * Supported levels are 1 - 15 spread across ILSEL0 - ILSEL4, mapping
 * directly to IRLs. As the IRQs are numbered in reverse order relative
 * to the interrupt level, the level map is carefully managed to ensure a
 * 1:1 mapping between the bit position and the IRQ number.
 *
 * This careful constructions allows ilsel_enable*() to be referenced
 * directly for hooking up an ILSEL set and getting back an IRQ which can
 * subsequently be used for internal accounting in the (optional) disable
 * path.
 */

static unsigned long ilsel_level_map;


static inline unsigned int ilsel_offset(unsigned int bit) { return ILSEL_LEVELS - bit - 1; }

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paul mundtpaul mundt19100.00%1100.00%
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static inline unsigned long mk_ilsel_addr(unsigned int bit) { return ILSEL_BASE + ((ilsel_offset(bit) >> 1) & ~0x1); }

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paul mundtpaul mundt29100.00%1100.00%
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static inline unsigned int mk_ilsel_shift(unsigned int bit) { return (ilsel_offset(bit) & 0x3) << 2; }

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static void __ilsel_enable(ilsel_source_t set, unsigned int bit) { unsigned int tmp, shift; unsigned long addr; pr_notice("enabling ILSEL set %d\n", set); addr = mk_ilsel_addr(bit); shift = mk_ilsel_shift(bit); pr_debug("%s: bit#%d: addr - 0x%08lx (shift %d, set %d)\n", __func__, bit, addr, shift, set); tmp = __raw_readw(addr); tmp &= ~(0xf << shift); tmp |= set << shift; __raw_writew(tmp, addr); }

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paul mundtpaul mundt8798.86%375.00%
harvey harrisonharvey harrison11.14%125.00%
Total88100.00%4100.00%

/** * ilsel_enable - Enable an ILSEL set. * @set: ILSEL source (see ilsel_source_t enum in include/asm-sh/ilsel.h). * * Enables a given non-aliased ILSEL source (<= ILSEL_KEY) at the highest * available interrupt level. Callers should take care to order callsites * noting descending interrupt levels. Aliasing FPGA and external board * IRQs need to use ilsel_enable_fixed(). * * The return value is an IRQ number that can later be taken down with * ilsel_disable(). */
int ilsel_enable(ilsel_source_t set) { unsigned int bit; if (unlikely(set > ILSEL_KEY)) { pr_err("Aliased sources must use ilsel_enable_fixed()\n"); return -EINVAL; } do { bit = find_first_zero_bit(&ilsel_level_map, ILSEL_LEVELS); } while (test_and_set_bit(bit, &ilsel_level_map)); __ilsel_enable(set, bit); return bit; }

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paul mundtpaul mundt66100.00%2100.00%
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EXPORT_SYMBOL_GPL(ilsel_enable); /** * ilsel_enable_fixed - Enable an ILSEL set at a fixed interrupt level * @set: ILSEL source (see ilsel_source_t enum in include/asm-sh/ilsel.h). * @level: Interrupt level (1 - 15) * * Enables a given ILSEL source at a fixed interrupt level. Necessary * both for level reservation as well as for aliased sources that only * exist on special ILSEL#s. * * Returns an IRQ number (as ilsel_enable()). */
int ilsel_enable_fixed(ilsel_source_t set, unsigned int level) { unsigned int bit = ilsel_offset(level - 1); if (test_and_set_bit(bit, &ilsel_level_map)) return -EBUSY; __ilsel_enable(set, bit); return bit; }

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paul mundtpaul mundt47100.00%1100.00%
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EXPORT_SYMBOL_GPL(ilsel_enable_fixed); /** * ilsel_disable - Disable an ILSEL set * @irq: Bit position for ILSEL set value (retval from enable routines) * * Disable a previously enabled ILSEL set. */
void ilsel_disable(unsigned int irq) { unsigned long addr; unsigned int tmp; pr_notice("disabling ILSEL set %d\n", irq); addr = mk_ilsel_addr(irq); tmp = __raw_readw(addr); tmp &= ~(0xf << mk_ilsel_shift(irq)); __raw_writew(tmp, addr); clear_bit(irq, &ilsel_level_map); }

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paul mundtpaul mundt65100.00%4100.00%
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EXPORT_SYMBOL_GPL(ilsel_disable);

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paul mundtpaul mundt39699.75%583.33%
harvey harrisonharvey harrison10.25%116.67%
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