path: root/sim/ppc/device.maybe

/*  This file is part of the program psim.

    Copyright (C) 1994-1996, Andrew Cagney <cagney@highland.com.au>

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.
 
    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 
    */


#ifndef _DEVICE_H_
#define _DEVICE_H_

#ifndef INLINE_DEVICE
#define INLINE_DEVICE
#endif

/* declared in basics.h, this object is used everywhere */
/* typedef struct _device device; */


/* Device templates:

   *** THIS SECTION DESCRIBES HOW A DEVICE HAS A STATIC AND DYNAMIC
   COMPONENT ** on the device in the tree is dynamic. *****

   A device node is created from its template.  The only valid
   operation on a template is to create a device node from it: */

INLINE_DEVICE\
(device *) device_template_create_device
(device *parent,
 const char *name,
 const char *unit_address,
 const char *args);

/* The create is paramaterized by both the devices unit address (a
   string that is converted into numeric form by the devices parent)
   and optionally extra argument information.

   The actual device node is constructed by a number of pieces provided
   by the template function: */

typedef struct _device_callbacks device_callbacks;

INLINE_DEVICE\
(device *) device_create_from
(const char *name,
 const device_unit *unit_address,
 void *data,
 const device_callbacks *callbacks,
 device *parent);

/* OpenBoot discusses the creation of packages (devices). */


/* Devices:

   As with OpenBoot, all nodes in the device tree are considered to be
   devices. Each node then has associated with it a number of methods
   and properties (duscussed later).

   OpenBoot documentation refers to devices, device nodes, packages,
   package instances, methods, static methods and properties.  This
   device implementation uses its own termonology. Where ever it
   exists, the notes will indicate a correspondance between PSIM terms
   and those found in OpenBoot.

   device:

   A device is the basic building block in this model.  A device can
   be further categorized into one of three classes - template, node
   and instance.

   device-node (aka device):

   The device tree is constructed from device-nodes.  Each node has
   both local state (data), a relationship with the device nodes
   around it and an address (unit-address) on the parents bus `bus' */

INLINE_DEVICE\
(device *) device_parent
(device *me);

INLINE_DEVICE\
(device *) device_sibling
(device *me);

INLINE_DEVICE\
(device *) device_child
(device *me);

INLINE_DEVICE\
(const char *) device_name
(device *me);

INLINE_DEVICE\
(const char *) device_path
(device *me);

INLINE_DEVICE\
(void *) device_data
(device *me);

INLINE_DEVICE\
(psim *) device_system
(device *me);

typedef struct _device_unit {
  int nr_cells;
  unsigned32 cells[4]; /* unused cells are zero */
} device_unit;

INLINE_DEVICE\
(const device_unit *) device_unit_address
(device *me);

/* Each device-node normally corresponds to a hardware component of
   the system being modeled.  Leaf nodes matching external devices and
   intermediate nodes matching bridges and controllers.
   
   Device nodes also support methods that are an abstraction of the
   transactions that occure in real hardware.  These operations
   (io/dma read/writes and interrupts) are discussed separatly.

   OpenBoot refers to device nodes by many names.  The most common are
   device, device node and package. */


/* Properties:

   In IEEE1275 many of the the characteristics of a device are stored
   in the device tree as properties.  Each property consists of a name
   and an associated (implicitly typed) value.  A device will have a
   list of properties attached to it.  The user is able to manipulate
   the list, adding and removing properties and set/modify the value
   of each property.

   PSIM's device tree follows this model but with the addition of
   strongly typing each property's value.  The simulator will detect
   at run time, the incorrect use of a property.

   In addition to the standard use of properties, Both PSIM and
   individual devices will use properties to record simulation
   configuration information.  For instance, a disk device might store
   in a string property called <<file>> the name of the file that
   contains the disk image to use. */

/* The following are valid property types.  The property `array' is a
   for generic untyped data. */

typedef enum {
  array_property,
  boolean_property,
  ihandle_property,
  integer_property,
  string_property,
} device_property_type;

typedef struct _device_property device_property;
struct _device_property {
  device *owner;
  const char *name;
  device_property_type type;
  unsigned sizeof_array;
  const void *array;
  const device_property *original;
  object_disposition disposition;
};


/* iterate through the properties attached to a device */

INLINE_DEVICE\
(const device_property *) device_next_property
(const device_property *previous);

INLINE_DEVICE\
(const device_property *) device_find_property
(device *me,
 const char *property); /* NULL for first property */


/* Manipulate the properties belonging to a given device.

   SET on the other hand will force the properties value.  The
   simulation is aborted if the property was present but of a
   conflicting type.

   FIND returns the specified properties value, aborting the
   simulation if the property is missing.  Code locating a property
   should first check its type (using device_find_property above) and
   then obtain its value using the below. */


INLINE_DEVICE\
(void) device_set_array_property
(device *me,
 const char *property,
 const void *array,
 int sizeof_array);

INLINE_DEVICE\
(const device_property *) device_find_array_property
(device *me,
 const char *property);


#if 0
INLINE_DEVICE\
(void) device_set_boolean_property
(device *me,
 const char *property,
 int bool);
#endif

INLINE_DEVICE\
(int) device_find_boolean_property
(device *me,
 const char *property);


#if 0
INLINE_DEVICE\
(void) device_set_ihandle_property
(device *me,
 const char *property,
 device_instance *ihandle);
#endif

INLINE_DEVICE\
(device_instance *) device_find_ihandle_property
(device *me,
 const char *property);


#if 0
INLINE_DEVICE\
(void) device_set_integer_property
(device *me,
 const char *property,
 signed_word integer);
#endif

INLINE_DEVICE\
(signed_word) device_find_integer_property
(device *me,
 const char *property);


#if 0
INLINE_DEVICE\
(void) device_set_string_property
(device *me,
 const char *property,
 const char *string);
#endif

INLINE_DEVICE\
(const char *) device_find_string_property
(device *me,
 const char *property);


/* Instances:

   As with IEEE1275, a device can be opened, creating an instance.
   Instances provide more abstract interfaces to the underlying
   hardware.  For example, the instance methods for a disk may include
   code that is able to interpret file systems found on disks.  Such
   methods would there for allow the manipulation of files on the
   disks file system.  The operations would be implemented using the
   basic block I/O model provided by the disk.

   This model includes methods that faciliate the creation of device
   instance and (should a given device support it) standard operations
   on those instances. */

   *** device-instance ***

   Devices support an abstract I/O model. A unique I/O instance can be
   created from a device node and then this instance used to perform
   I/O that is independant of other instances. */

typedef struct _device_instance_callbacks device_instance_callbacks;

INLINE_DEVICE\
(device_instance *) device_create_instance_from
(device *me, /*OR*/ device_instance *parent,
 void *data,
 const char *path,
 const char *args,
 const device_instance_callbacks *callbacks);

INLINE_DEVICE\
(device_instance *) device_create_instance
(device *me,
 const char *device_specifier);

INLINE_DEVICE\
(void) device_instance_delete
(device_instance *instance);

INLINE_DEVICE\
(int) device_instance_read
(device_instance *instance,
 void *addr,
 unsigned_word len);

INLINE_DEVICE\
(int) device_instance_write
(device_instance *instance,
 const void *addr,
 unsigned_word len);

INLINE_DEVICE\
(int) device_instance_seek
(device_instance *instance,
 unsigned_word pos_hi,
 unsigned_word pos_lo);

INLINE_DEVICE\
(unsigned_word) device_instance_claim
(device_instance *instance,
 unsigned_word address,
 unsigned_word length,
 unsigned_word alignment);

INLINE_DEVICE\
(void) device_instance_release
(device_instance *instance,
 unsigned_word address,
 unsigned_word length);

INLINE_DEVICE\
(device *) device_instance_device
(device_instance *instance);

INLINE_DEVICE\
(const char *) device_instance_path
(device_instance *instance);

INLINE_DEVICE\
(void *) device_instance_data
(device_instance *instance);

/* A device instance can be marked (when created) as being permenant.
   Such instances are assigned a reserved address and are *not*
   deleted between simulation runs.

   OpenBoot refers to a device instace as a package instance */


/* PIO:

   *** DESCRIBE HERE WHAT A PIO OPERATION IS and how, broadly it is
   modeled ****


   During initialization, each device attaches its self to is parent
   registering the address spaces that it is interested in:

   a.	The <<com>> device attaches its self to its parent <<phb>>
   	device at address <<0x3f8>> through to address <<0x3f8 + 16>>.

   b.   The <<phb>> has in turn attached its self to addresses
        <<0xf0000000 .. 0xf0100000>>.

   During the execution of the simulation propper, the following then
   occure:
	
   1.	After any virtual to physical translation, the processor
   	passes the address to be read (or written to the core device).
	(eg address 0xf00003f8).

   2.   The core device then looks up the specified addresses in its
        address to device map, determines that in this case the address
	belongs to the phb and passes it down.

   3.	The <<phb>> in turn determines that the address belongs to the
   	serial port and passes to that device the request for an access
	to location <<0x3f8>>.

   @figure mio

   */

/* Device Hardware

   This model assumes that the data paths of the system being modeled
   have a tree topology.  That is, one or more processors sit at the
   top of a tree.  That tree containing leaf nodes (real devices) and
   branch nodes (bridges).

   For instance, consider the tree:

   /pci                    # PCI-HOST bridge
   /pci/pci1000,1@1        # A pci controller
   /pci/isa8086            # PCI-ISA bridge
   /pci/isa8086/fdc@300    # floppy disk controller on ISA bus

   A processor needing to access the device fdc@300 on the ISA bus
   would do so using a data path that goes through the pci-host bridge
   (pci)and the isa-pci bridge (isa8086) to finally reach the device
   fdc@300.  As the data transfer passes through each intermediate
   bridging node that bridge device is able to (just like with real
   hardware) manipulate either the address or data involved in the
   transfer. */

INLINE_DEVICE\
(unsigned) device_io_read_buffer
(device *me,
 void *dest,
 int space,
 unsigned_word addr,
 unsigned nr_bytes,
 cpu *processor,
 unsigned_word cia);

INLINE_DEVICE\
(unsigned) device_io_write_buffer
(device *me,
 const void *source,
 int space,
 unsigned_word addr,
 unsigned nr_bytes,
 cpu *processor,
 unsigned_word cia);

/* To avoid the need for an intermediate (bridging) node to ask each
   of its child devices in turn if an IO access is intended for them,
   parent nodes maintain a table mapping addresses directly to
   specific devices.  When a device is `connected' to its bus it
   attaches its self to its parent. */

/* Address access attributes */
typedef enum _access_type {
  access_invalid = 0,
  access_read = 1,
  access_write = 2,
  access_read_write = 3,
  access_exec = 4,
  access_read_exec = 5,
  access_write_exec = 6,
  access_read_write_exec = 7,
} access_type;

/* Address attachement types */
typedef enum _attach_type {
  attach_invalid,
  attach_raw_memory,
  attach_callback,
  /* ... */
} attach_type;

INLINE_DEVICE\
(void) device_attach_address
(device *me,
 const char *name,
 attach_type attach,
 int space,
 unsigned_word addr,
 unsigned nr_bytes,
 access_type access,
 device *who); /*callback/default*/

INLINE_DEVICE\
(void) device_detach_address
(device *me,
 const char *name,
 attach_type attach,
 int space,
 unsigned_word addr,
 unsigned nr_bytes,
 access_type access,
 device *who); /*callback/default*/

/* where the attached address space can be any of

   callback - all accesses to that range of addresses are past on to
   the attached child device.  The callback addresses are ordered
   according to the callback level (attach_callback, .. + 1, .. + 2,
   ...).  Lower levels are searched first.  This facilitates the
   implementation of more unusual addressing schema such as
   subtractive decoding (as seen on the PCI bus).  Within a given
   callback level addresses must not overlap.

   memory - the specified address space contains RAM, the node that is
   having the ram attached is responsible for allocating space for and
   maintaining that space.  The device initiating the attach will not
   be notified of accesses to such an attachement.

   The memory attachment is very important.  By giving the parent node
   the responsability (and freedom) of managing the RAM, that node is
   able to implement memory spaces more efficiently.  For instance it
   could `cache' accesses or merge adjacent memory areas.


   In addition to I/O and DMA, devices interact with the rest of the
   system via interrupts.  Interrupts are discussed separatly. */


/* DMA:

   *** DESCRIBE HERE WHAT A DMA OPERATION IS AND HOW IT IS MODELED,
   include an interation of an access being reflected back down ***

   */

/* Conversly, the device pci1000,1@1 my need to perform a dma transfer
   into the cpu/memory core.  Just as I/O moves towards the leaves,
   dma transfers move towards the core via the initiating devices
   parent nodes.  The root device (special) converts the DMA transfer
   into reads/writes to memory */

INLINE_DEVICE\
(unsigned) device_dma_read_buffer
(device *me,
 void *dest,
 int space,
 unsigned_word addr,
 unsigned nr_bytes);

INLINE_DEVICE\
(unsigned) device_dma_write_buffer
(device *me,
 const void *source,
 int space,
 unsigned_word addr,
 unsigned nr_bytes,
 int violate_read_only_section);


/* Interrupts:

   *** DESCRIBE HERE THE INTERRUPT NETWORK ***

   PSIM models interrupts and their wiring as a directed graph of
   connections between interrupt sources and destinations.  The source
   and destination are both a tupple consisting of a port number and
   device.  Both multiple destinations attached to a single source and
   multiple sources attached to a single destination are allowed.

   When a device drives an interrupt port with multiple destinations a
   broadcast of that interrupt event (message to all destinations)
   occures.  Each of those destination (device/port) are able to
   further propogate the interrupt until it reaches its ultimate
   destination.

   Normally an interrupt source would be a model of a real device
   (such as a keyboard) while an interrupt destination would be an
   interrupt controller.  The facility that allows an interrupt to be
   delivered to multiple devices and to be propogated from device to
   device was designed to support the requirements specified by
   OpenPIC (ISA interrupts go to both OpenPIC and 8259), CHRP (8259
   connected to OpenPIC) and hardware designs such as PCI-PCI
   bridges. */

   
/* Interrupting a processor

   The cpu object provides methods for delivering external interrupts
   to a given processor.

   The problem of synchronizing external interrupt delivery with the
   execution of the cpu is handled internally by the processor object. */



/* Interrupt Source

   A device drives its interrupt line using the call: */

INLINE_DEVICE\
(void) device_interrupt_event
(device *me,
 int my_port,
 int value,
 cpu *processor,
 unsigned_word cia);

/* This interrupt event will then be propogated to any attached
   interrupt destinations.

   Any interpretation of PORT and VALUE is model dependant.  However
   as guidelines the following are recommended: PCI interrupts a-d
   correspond to lines 0-3; level sensative interrupts be requested
   with a value of one and withdrawn with a value of 0; edge sensative
   interrupts always have a value of 1, the event its self is treated
   as the interrupt.


   Interrupt Destinations

   Attached to each interrupt line of a device can be zero or more
   desitinations.  These destinations consist of a device/port pair.
   A destination is attached/detached to a device line using the
   attach and detach calls. */

INLINE_DEVICE\
(void) device_interrupt_attach
(device *me,
 int my_port,
 device *dest,
 int dest_port,
 object_disposition disposition);

INLINE_DEVICE\
(void) device_interrupt_detach
(device *me,
 int my_port,
 device *dest,
 int dest_port);

/* DESTINATION is attached (detached) to LINE of the device ME


   Interrupt conversion

   Users refer to interrupt port numbers symbolically.  For instance a
   device may refer to its `INT' signal which is internally
   represented by port 3.

   To convert to/from the symbolic and internal representation of a
   port name/number.  The following functions are available. */

INLINE_DEVICE\
(int) device_interrupt_decode
(device *me,
 const char *symbolic_name);

INLINE_DEVICE\
(int) device_interrupt_encode
(device *me,
 int port_number,
 char *buf,
 int sizeof_buf);
 


/* Initialization:

   In PSIM, the device tree is created and then initialized in stages.
   When using devices it is important to be clear what initialization
   the simulator assumes is being performed during each of these
   stages.

   Firstly, each device is created in isolation (using the create from
   template method).  Only after it has been created will a device be
   inserted into the tree ready for initialization.

   Once the tree is created, it is initialized as follows:

   	1.      All properties (apart from those containing instances)
                are (re)initialized

        2.      Any interrupts addeded as part of the simulation run
		are removed.

        4.      The initialize address method of each device (in top
		down order) is called.  At this stage the device
		is expected to:

		o	Clear address maps and delete allocated memory
			associated with the devices children.

		o	(Re)attach its own addresses to its parent device.

		o	Ensure that it is otherwize sufficiently
			initialized such that it is ready for a
			device instance create call.

        5.      All properties containing an instance of
                a device are (re)initialized

        6.      The initialize data method for each device is called (in
		top down) order.  At this stage the device is expected to:

		o	Perform any needed data transfers.  Such
			transfers would include the initialization
			of memory created during the address initialization
			stage using DMA.

		*/

INLINE_DEVICE\
(void) device_tree_init
(device *root,
 psim *system);



/* IOCTL:

   Very simply, a catch all for any thing that turns up that until now
   either hasn't been thought of or doesn't justify an extra function. */

EXTERN_DEVICE\
(int) device_ioctl
(device *me,
 cpu *processor,
 unsigned_word cia,
 ...);


/* External communcation:

   Devices interface to the external environment */

/* device_error() reports the problem to the console and aborts the
   simulation.  The error message is prefixed with the name of the
   reporting device. */

EXTERN_DEVICE\
(void volatile) device_error
(device *me,
 const char *fmt,
 ...) __attribute__ ((format (printf, 2, 3)));


/* Tree utilities:

   In addition to the standard method of creating a device from a
   device template, the following sortcuts can be used.

   Create a device or property from a textual representation */

EXTERN_DEVICE\
(device *) device_tree_add_parsed
(device *current,
 const char *fmt,
 ...) __attribute__ ((format (printf, 2, 3)));

/* where FMT,... once formatted (using vsprintf) is used to locate and
   create either a device or property.  Its syntax is almost identical
   to that used in OpenBoot documentation - the only extension is in
   allowing properties and their values to be specified vis:

   "/pci/pci1000,1@1/disk@0,0"

   Path:

   The path to a device or property can either be absolute (leading
   `/') or relative (leading `.' or `..').  Relative paths start from
   the CURRENT node.  The new current node is returned as the result.
   In addition, a path may start with a leading alias (resolved by
   looking in /aliases).

   Device name:

   <name> "@" <unit> [ ":" <args> ]

   Where <name> is the name of the template device, <unit> is a
   textual specification of the devices unit address (that is
   converted into a numeric form by the devices parent) and <args> are
   optional additional information to be passed to the device-template
   when it creates the device.

   Properties:

   Properties are specified in a similar way to devices except that
   the last element on the path (which would have been the device) is
   the property name. This path is then followed by the property
   value. Unlike OpenBoot, the property values in the device tree are
   strongly typed.

   String property:

     <property-name> " " <text>
     <property-name> " " "\"" <text>
   
   Boolean property:

     <property-name> " " [ "true" | "false" ]
   Integer property or integer array property:

     <property-name> " " <number> { <number> }

   Phandle property:

     <property-name> " " "&" <path-to-device>

   Ihandle property:

     <property-name> " " "*" <path-to-device-to-open>

   Duplicate existing property:

     <property-name> " " "!" <path-to-original-property>


   In addition to properties, the wiring of interrupts can be
   specified:

   Attach interrupt <line> of <device> to <controller>:

     <device> " " ">" <my-port>  <dest-port> <dest-device>


   Once created, a device tree can be traversed in various orders: */

typedef void (device_tree_traverse_function)
     (device *device,
      void *data);

INLINE_DEVICE\
(void) device_tree_traverse
(device *root,
 device_tree_traverse_function *prefix,
 device_tree_traverse_function *postfix,
 void *data);

/* Or dumped out in a format that can be read back in using
   device_add_parsed() */

INLINE_DEVICE\
(void) device_tree_print_device
(device *device,
 void *ignore_data_argument);

/* Individual nodes can be located using */

INLINE_DEVICE\
(device *) device_tree_find_device
(device *root,
 const char *path);

/* And the current list of devices can be listed */

INLINE_DEVICE\
(void) device_usage
(int verbose);


/* ihandles and phandles:

   Both device nodes and device instances, in OpenBoot firmware have
   an external representation (phandles and ihandles) and these values
   are both stored in the device tree in property nodes and passed
   between the client program and the simulator during emulation
   calls.

   To limit the potential risk associated with trusing `data' from the
   client program, the following mapping operators `safely' convert
   between the two representations: */

INLINE_DEVICE\
(device *) external_to_device
(device *tree_member,
 unsigned32 phandle);

INLINE_DEVICE\
(unsigned32) device_to_external
(device *me);

INLINE_DEVICE\
(device_instance *) external_to_device_instance
(device *tree_member,
 unsigned32 ihandle);

INLINE_DEVICE\
(unsigned32) device_instance_to_external
(device_instance *me);

#endif /* _DEVICE_H_ */