arch/alpha/kernel/core_tsunami.c

Source file repositories/reference/linux-study-clean/arch/alpha/kernel/core_tsunami.c

File Facts

System
Linux kernel
Corpus path
arch/alpha/kernel/core_tsunami.c
Extension
.c
Size
13261 bytes
Lines
485
Domain
Architecture Layer
Bucket
arch/alpha
Inferred role
Architecture Layer: exported/initcall integration point
Status
integration implementation candidate

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0
/*
 *	linux/arch/alpha/kernel/core_tsunami.c
 *
 * Based on code written by David A. Rusling (david.rusling@reo.mts.dec.com).
 *
 * Code common to all TSUNAMI core logic chips.
 */

#define __EXTERN_INLINE inline
#include <asm/io.h>
#include <asm/core_tsunami.h>
#undef __EXTERN_INLINE

#include <linux/module.h>
#include <linux/types.h>
#include <linux/pci.h>
#include <linux/sched.h>
#include <linux/init.h>
#include <linux/memblock.h>

#include <asm/ptrace.h>
#include <asm/smp.h>
#include <asm/vga.h>

#include "proto.h"
#include "pci_impl.h"

/* Save Tsunami configuration data as the console had it set up.  */

struct 
{
	unsigned long wsba[4];
	unsigned long wsm[4];
	unsigned long tba[4];
} saved_config[2] __attribute__((common));

/*
 * NOTE: Herein lie back-to-back mb instructions.  They are magic. 
 * One plausible explanation is that the I/O controller does not properly
 * handle the system transaction.  Another involves timing.  Ho hum.
 */

/*
 * BIOS32-style PCI interface:
 */

#define DEBUG_CONFIG 0

#if DEBUG_CONFIG
# define DBG_CFG(args)	printk args
#else
# define DBG_CFG(args)
#endif


/*
 * Given a bus, device, and function number, compute resulting
 * configuration space address
 * accordingly.  It is therefore not safe to have concurrent
 * invocations to configuration space access routines, but there
 * really shouldn't be any need for this.
 *
 * Note that all config space accesses use Type 1 address format.
 *
 * Note also that type 1 is determined by non-zero bus number.
 *
 * Type 1:
 *
 *  3 3|3 3 2 2|2 2 2 2|2 2 2 2|1 1 1 1|1 1 1 1|1 1 
 *  3 2|1 0 9 8|7 6 5 4|3 2 1 0|9 8 7 6|5 4 3 2|1 0 9 8|7 6 5 4|3 2 1 0
 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 * | | | | | | | | | | |B|B|B|B|B|B|B|B|D|D|D|D|D|F|F|F|R|R|R|R|R|R|0|1|
 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *
 *	31:24	reserved
 *	23:16	bus number (8 bits = 128 possible buses)
 *	15:11	Device number (5 bits)
 *	10:8	function number
 *	 7:2	register number
 *  
 * Notes:
 *	The function number selects which function of a multi-function device 
 *	(e.g., SCSI and Ethernet).
 * 
 *	The register selects a DWORD (32 bit) register offset.  Hence it
 *	doesn't get shifted by 2 bits as we want to "drop" the bottom two
 *	bits.
 */

Annotation

Implementation Notes