+++ /dev/null
-/*
- * rar_register.c - An Intel Restricted Access Region register driver
- *
- * Copyright(c) 2009 Intel Corporation. All rights reserved.
- *
- * 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.
- *
- * -------------------------------------------------------------------
- * 20091204 Mark Allyn <mark.a.allyn@intel.com>
- * Ossama Othman <ossama.othman@intel.com>
- * Cleanup per feedback from Alan Cox and Arjan Van De Ven
- *
- * 20090806 Ossama Othman <ossama.othman@intel.com>
- * Return zero high address if upper 22 bits is zero.
- * Cleaned up checkpatch errors.
- * Clarified that driver is dealing with bus addresses.
- *
- * 20090702 Ossama Othman <ossama.othman@intel.com>
- * Removed unnecessary include directives
- * Cleaned up spinlocks.
- * Cleaned up logging.
- * Improved invalid parameter checks.
- * Fixed and simplified RAR address retrieval and RAR locking
- * code.
- *
- * 20090626 Mark Allyn <mark.a.allyn@intel.com>
- * Initial publish
- */
-
-#include <linux/module.h>
-#include <linux/pci.h>
-#include <linux/spinlock.h>
-#include <linux/device.h>
-#include <linux/kernel.h>
-#include <linux/rar_register.h>
-
-/* === Lincroft Message Bus Interface === */
-#define LNC_MCR_OFFSET 0xD0 /* Message Control Register */
-#define LNC_MDR_OFFSET 0xD4 /* Message Data Register */
-
-/* Message Opcodes */
-#define LNC_MESSAGE_READ_OPCODE 0xD0
-#define LNC_MESSAGE_WRITE_OPCODE 0xE0
-
-/* Message Write Byte Enables */
-#define LNC_MESSAGE_BYTE_WRITE_ENABLES 0xF
-
-/* B-unit Port */
-#define LNC_BUNIT_PORT 0x3
-
-/* === Lincroft B-Unit Registers - Programmed by IA32 firmware === */
-#define LNC_BRAR0L 0x10
-#define LNC_BRAR0H 0x11
-#define LNC_BRAR1L 0x12
-#define LNC_BRAR1H 0x13
-/* Reserved for SeP */
-#define LNC_BRAR2L 0x14
-#define LNC_BRAR2H 0x15
-
-/* Moorestown supports three restricted access regions. */
-#define MRST_NUM_RAR 3
-
-/* RAR Bus Address Range */
-struct rar_addr {
- dma_addr_t low;
- dma_addr_t high;
-};
-
-/*
- * We create one of these for each RAR
- */
-struct client {
- int (*callback)(unsigned long data);
- unsigned long driver_priv;
- bool busy;
-};
-
-static DEFINE_MUTEX(rar_mutex);
-static DEFINE_MUTEX(lnc_reg_mutex);
-
-/*
- * One per RAR device (currently only one device)
- */
-struct rar_device {
- struct rar_addr rar_addr[MRST_NUM_RAR];
- struct pci_dev *rar_dev;
- bool registered;
- bool allocated;
- struct client client[MRST_NUM_RAR];
-};
-
-/* Current platforms have only one rar_device for 3 rar regions */
-static struct rar_device my_rar_device;
-
-/*
- * Abstract out multiple device support. Current platforms only
- * have a single RAR device.
- */
-
-/**
- * alloc_rar_device - return a new RAR structure
- *
- * Return a new (but not yet ready) RAR device object
- */
-static struct rar_device *alloc_rar_device(void)
-{
- if (my_rar_device.allocated)
- return NULL;
- my_rar_device.allocated = 1;
- return &my_rar_device;
-}
-
-/**
- * free_rar_device - free a RAR object
- * @rar: the RAR device being freed
- *
- * Release a RAR object and any attached resources
- */
-static void free_rar_device(struct rar_device *rar)
-{
- pci_dev_put(rar->rar_dev);
- rar->allocated = 0;
-}
-
-/**
- * _rar_to_device - return the device handling this RAR
- * @rar: RAR number
- * @off: returned offset
- *
- * Internal helper for looking up RAR devices. This and alloc are the
- * two functions that need touching to go to multiple RAR devices.
- */
-static struct rar_device *_rar_to_device(int rar, int *off)
-{
- if (rar >= 0 && rar < MRST_NUM_RAR) {
- *off = rar;
- return &my_rar_device;
- }
- return NULL;
-}
-
-/**
- * rar_to_device - return the device handling this RAR
- * @rar: RAR number
- * @off: returned offset
- *
- * Return the device this RAR maps to if one is present, otherwise
- * returns NULL. Reports the offset relative to the base of this
- * RAR device in off.
- */
-static struct rar_device *rar_to_device(int rar, int *off)
-{
- struct rar_device *rar_dev = _rar_to_device(rar, off);
- if (rar_dev == NULL || !rar_dev->registered)
- return NULL;
- return rar_dev;
-}
-
-/**
- * rar_to_client - return the client handling this RAR
- * @rar: RAR number
- *
- * Return the client this RAR maps to if a mapping is known, otherwise
- * returns NULL.
- */
-static struct client *rar_to_client(int rar)
-{
- int idx;
- struct rar_device *r = _rar_to_device(rar, &idx);
- if (r != NULL)
- return &r->client[idx];
- return NULL;
-}
-
-/**
- * rar_read_addr - retrieve a RAR mapping
- * @pdev: PCI device for the RAR
- * @offset: offset for message
- * @addr: returned address
- *
- * Reads the address of a given RAR register. Returns 0 on success
- * or an error code on failure.
- */
-static int rar_read_addr(struct pci_dev *pdev, int offset, dma_addr_t *addr)
-{
- /*
- * ======== The Lincroft Message Bus Interface ========
- * Lincroft registers may be obtained via PCI from
- * the host bridge using the Lincroft Message Bus
- * Interface. That message bus interface is generally
- * comprised of two registers: a control register (MCR, 0xDO)
- * and a data register (MDR, 0xD4).
- *
- * The MCR (message control register) format is the following:
- * 1. [31:24]: Opcode
- * 2. [23:16]: Port
- * 3. [15:8]: Register Offset
- * 4. [7:4]: Byte Enables (use 0xF to set all of these bits
- * to 1)
- * 5. [3:0]: reserved
- *
- * Read (0xD0) and write (0xE0) opcodes are written to the
- * control register when reading and writing to Lincroft
- * registers, respectively.
- *
- * We're interested in registers found in the Lincroft
- * B-unit. The B-unit port is 0x3.
- *
- * The six B-unit RAR register offsets we use are listed
- * earlier in this file.
- *
- * Lastly writing to the MCR register requires the "Byte
- * enables" bits to be set to 1. This may be achieved by
- * writing 0xF at bit 4.
- *
- * The MDR (message data register) format is the following:
- * 1. [31:0]: Read/Write Data
- *
- * Data being read from this register is only available after
- * writing the appropriate control message to the MCR
- * register.
- *
- * Data being written to this register must be written before
- * writing the appropriate control message to the MCR
- * register.
- */
-
- int result;
- u32 addr32;
-
- /* Construct control message */
- u32 const message =
- (LNC_MESSAGE_READ_OPCODE << 24)
- | (LNC_BUNIT_PORT << 16)
- | (offset << 8)
- | (LNC_MESSAGE_BYTE_WRITE_ENABLES << 4);
-
- dev_dbg(&pdev->dev, "Offset for 'get' LNC MSG is %x\n", offset);
-
- /*
- * We synchronize access to the Lincroft MCR and MDR registers
- * until BOTH the command is issued through the MCR register
- * and the corresponding data is read from the MDR register.
- * Otherwise a race condition would exist between accesses to
- * both registers.
- */
-
- mutex_lock(&lnc_reg_mutex);
-
- /* Send the control message */
- result = pci_write_config_dword(pdev, LNC_MCR_OFFSET, message);
- if (!result) {
- /* Read back the address as a 32bit value */
- result = pci_read_config_dword(pdev, LNC_MDR_OFFSET, &addr32);
- *addr = (dma_addr_t)addr32;
- }
- mutex_unlock(&lnc_reg_mutex);
- return result;
-}
-
-/**
- * rar_set_addr - Set a RAR mapping
- * @pdev: PCI device for the RAR
- * @offset: offset for message
- * @addr: address to set
- *
- * Sets the address of a given RAR register. Returns 0 on success
- * or an error code on failure.
- */
-static int rar_set_addr(struct pci_dev *pdev,
- int offset,
- dma_addr_t addr)
-{
- /*
- * Data being written to this register must be written before
- * writing the appropriate control message to the MCR
- * register.
- * See rar_get_addrs() for a description of the
- * message bus interface being used here.
- */
-
- int result;
-
- /* Construct control message */
- u32 const message = (LNC_MESSAGE_WRITE_OPCODE << 24)
- | (LNC_BUNIT_PORT << 16)
- | (offset << 8)
- | (LNC_MESSAGE_BYTE_WRITE_ENABLES << 4);
-
- /*
- * We synchronize access to the Lincroft MCR and MDR registers
- * until BOTH the command is issued through the MCR register
- * and the corresponding data is read from the MDR register.
- * Otherwise a race condition would exist between accesses to
- * both registers.
- */
-
- mutex_lock(&lnc_reg_mutex);
-
- /* Send the control message */
- result = pci_write_config_dword(pdev, LNC_MDR_OFFSET, addr);
- if (!result)
- /* And address */
- result = pci_write_config_dword(pdev, LNC_MCR_OFFSET, message);
-
- mutex_unlock(&lnc_reg_mutex);
- return result;
-}
-
-/*
- * rar_init_params - Initialize RAR parameters
- * @rar: RAR device to initialise
- *
- * Initialize RAR parameters, such as bus addresses, etc. Returns 0
- * on success, or an error code on failure.
- */
-static int init_rar_params(struct rar_device *rar)
-{
- struct pci_dev *pdev = rar->rar_dev;
- unsigned int i;
- int result = 0;
- int offset = 0x10; /* RAR 0 to 2 in order low/high/low/high/... */
-
- /* Retrieve RAR start and end bus addresses.
- * Access the RAR registers through the Lincroft Message Bus
- * Interface on PCI device: 00:00.0 Host bridge.
- */
-
- for (i = 0; i < MRST_NUM_RAR; ++i) {
- struct rar_addr *addr = &rar->rar_addr[i];
-
- result = rar_read_addr(pdev, offset++, &addr->low);
- if (result != 0)
- return result;
-
- result = rar_read_addr(pdev, offset++, &addr->high);
- if (result != 0)
- return result;
-
-
- /*
- * Only the upper 22 bits of the RAR addresses are
- * stored in their corresponding RAR registers so we
- * must set the lower 10 bits accordingly.
-
- * The low address has its lower 10 bits cleared, and
- * the high address has all its lower 10 bits set,
- * e.g.:
- * low = 0x2ffffc00
- */
-
- addr->low &= (dma_addr_t)0xfffffc00u;
-
- /*
- * Set bits 9:0 on uppser address if bits 31:10 are non
- * zero; otherwize clear all bits
- */
-
- if ((addr->high & 0xfffffc00u) == 0)
- addr->high = 0;
- else
- addr->high |= 0x3ffu;
- }
- /* Done accessing the device. */
-
- if (result == 0) {
- for (i = 0; i != MRST_NUM_RAR; ++i) {
- /*
- * "BRAR" refers to the RAR registers in the
- * Lincroft B-unit.
- */
- dev_info(&pdev->dev, "BRAR[%u] bus address range = "
- "[%lx, %lx]\n", i,
- (unsigned long)rar->rar_addr[i].low,
- (unsigned long)rar->rar_addr[i].high);
- }
- }
- return result;
-}
-
-/**
- * rar_get_address - get the bus address in a RAR
- * @start: return value of start address of block
- * @end: return value of end address of block
- *
- * The rar_get_address function is used by other device drivers
- * to obtain RAR address information on a RAR. It takes three
- * parameters:
- *
- * The function returns a 0 upon success or an error if there is no RAR
- * facility on this system.
- */
-int rar_get_address(int rar_index, dma_addr_t *start, dma_addr_t *end)
-{
- int idx;
- struct rar_device *rar = rar_to_device(rar_index, &idx);
-
- if (rar == NULL) {
- WARN_ON(1);
- return -ENODEV;
- }
-
- *start = rar->rar_addr[idx].low;
- *end = rar->rar_addr[idx].high;
- return 0;
-}
-EXPORT_SYMBOL(rar_get_address);
-
-/**
- * rar_lock - lock a RAR register
- * @rar_index: RAR to lock (0-2)
- *
- * The rar_lock function is ued by other device drivers to lock an RAR.
- * once a RAR is locked, it stays locked until the next system reboot.
- *
- * The function returns a 0 upon success or an error if there is no RAR
- * facility on this system, or the locking fails
- */
-int rar_lock(int rar_index)
-{
- struct rar_device *rar;
- int result;
- int idx;
- dma_addr_t low, high;
-
- rar = rar_to_device(rar_index, &idx);
-
- if (rar == NULL) {
- WARN_ON(1);
- return -EINVAL;
- }
-
- low = rar->rar_addr[idx].low & 0xfffffc00u;
- high = rar->rar_addr[idx].high & 0xfffffc00u;
-
- /*
- * Only allow I/O from the graphics and Langwell;
- * not from the x86 processor
- */
-
- if (rar_index == RAR_TYPE_VIDEO) {
- low |= 0x00000009;
- high |= 0x00000015;
- } else if (rar_index == RAR_TYPE_AUDIO) {
- /* Only allow I/O from Langwell; nothing from x86 */
- low |= 0x00000008;
- high |= 0x00000018;
- } else
- /* Read-only from all agents */
- high |= 0x00000018;
-
- /*
- * Now program the register using the Lincroft message
- * bus interface.
- */
- result = rar_set_addr(rar->rar_dev,
- 2 * idx, low);
-
- if (result == 0)
- result = rar_set_addr(rar->rar_dev,
- 2 * idx + 1, high);
-
- return result;
-}
-EXPORT_SYMBOL(rar_lock);
-
-/**
- * register_rar - register a RAR handler
- * @num: RAR we wish to register for
- * @callback: function to call when RAR support is available
- * @data: data to pass to this function
- *
- * The register_rar function is to used by other device drivers
- * to ensure that this driver is ready. As we cannot be sure of
- * the compile/execute order of drivers in the kernel, it is
- * best to give this driver a callback function to call when
- * it is ready to give out addresses. The callback function
- * would have those steps that continue the initialization of
- * a driver that do require a valid RAR address. One of those
- * steps would be to call rar_get_address()
- *
- * This function return 0 on success or an error code on failure.
- */
-int register_rar(int num, int (*callback)(unsigned long data),
- unsigned long data)
-{
- /* For now we hardcode a single RAR device */
- struct rar_device *rar;
- struct client *c;
- int idx;
- int retval = 0;
-
- mutex_lock(&rar_mutex);
-
- /* Do we have a client mapping for this RAR number ? */
- c = rar_to_client(num);
- if (c == NULL) {
- retval = -ERANGE;
- goto done;
- }
- /* Is it claimed ? */
- if (c->busy) {
- retval = -EBUSY;
- goto done;
- }
- c->busy = 1;
-
- /* See if we have a handler for this RAR yet, if we do then fire it */
- rar = rar_to_device(num, &idx);
-
- if (rar) {
- /*
- * if the driver already registered, then we can simply
- * call the callback right now
- */
- (*callback)(data);
- goto done;
- }
-
- /* Arrange to be called back when the hardware is found */
- c->callback = callback;
- c->driver_priv = data;
-done:
- mutex_unlock(&rar_mutex);
- return retval;
-}
-EXPORT_SYMBOL(register_rar);
-
-/**
- * unregister_rar - release a RAR allocation
- * @num: RAR number
- *
- * Releases a RAR allocation, or pending allocation. If a callback is
- * pending then this function will either complete before the unregister
- * returns or not at all.
- */
-
-void unregister_rar(int num)
-{
- struct client *c;
-
- mutex_lock(&rar_mutex);
- c = rar_to_client(num);
- if (c == NULL || !c->busy)
- WARN_ON(1);
- else
- c->busy = 0;
- mutex_unlock(&rar_mutex);
-}
-EXPORT_SYMBOL(unregister_rar);
-
-/**
- * rar_callback - Process callbacks
- * @rar: new RAR device
- *
- * Process the callbacks for a newly found RAR device.
- */
-
-static void rar_callback(struct rar_device *rar)
-{
- struct client *c = &rar->client[0];
- int i;
-
- mutex_lock(&rar_mutex);
-
- rar->registered = 1; /* Ensure no more callbacks queue */
-
- for (i = 0; i < MRST_NUM_RAR; i++) {
- if (c->callback && c->busy) {
- c->callback(c->driver_priv);
- c->callback = NULL;
- }
- c++;
- }
- mutex_unlock(&rar_mutex);
-}
-
-/**
- * rar_probe - PCI probe callback
- * @dev: PCI device
- * @id: matching entry in the match table
- *
- * A RAR device has been discovered. Initialise it and if successful
- * process any pending callbacks that can now be completed.
- */
-static int rar_probe(struct pci_dev *dev, const struct pci_device_id *id)
-{
- int error;
- struct rar_device *rar;
-
- dev_dbg(&dev->dev, "PCI probe starting\n");
-
- rar = alloc_rar_device();
- if (rar == NULL)
- return -EBUSY;
-
- /* Enable the device */
- error = pci_enable_device(dev);
- if (error) {
- dev_err(&dev->dev,
- "Error enabling RAR register PCI device\n");
- goto end_function;
- }
-
- /* Fill in the rar_device structure */
- rar->rar_dev = pci_dev_get(dev);
- pci_set_drvdata(dev, rar);
-
- /*
- * Initialize the RAR parameters, which have to be retrieved
- * via the message bus interface.
- */
- error = init_rar_params(rar);
- if (error) {
- pci_disable_device(dev);
- dev_err(&dev->dev, "Error retrieving RAR addresses\n");
- goto end_function;
- }
- /* now call anyone who has registered (using callbacks) */
- rar_callback(rar);
- return 0;
-end_function:
- free_rar_device(rar);
- return error;
-}
-
-static DEFINE_PCI_DEVICE_TABLE(rar_pci_id_tbl) = {
- { PCI_VDEVICE(INTEL, 0x4110) },
- { 0 }
-};
-
-MODULE_DEVICE_TABLE(pci, rar_pci_id_tbl);
-
-/* field for registering driver to PCI device */
-static struct pci_driver rar_pci_driver = {
- .name = "rar_register_driver",
- .id_table = rar_pci_id_tbl,
- .probe = rar_probe,
- /* Cannot be unplugged - no remove */
-};
-
-static int __init rar_init_handler(void)
-{
- return pci_register_driver(&rar_pci_driver);
-}
-
-static void __exit rar_exit_handler(void)
-{
- pci_unregister_driver(&rar_pci_driver);
-}
-
-module_init(rar_init_handler);
-module_exit(rar_exit_handler);
-
-MODULE_LICENSE("GPL");
-MODULE_DESCRIPTION("Intel Restricted Access Region Register Driver");
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