c715a38bb7
We exit staging rar! rar! rar!... Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Matthew Garrett <mjg@redhat.com> Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
671 lines
17 KiB
C
671 lines
17 KiB
C
/*
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* rar_register.c - An Intel Restricted Access Region register driver
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*
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* Copyright(c) 2009 Intel Corporation. All rights reserved.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation; either version 2 of the
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* License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
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* 02111-1307, USA.
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*
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* -------------------------------------------------------------------
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* 20091204 Mark Allyn <mark.a.allyn@intel.com>
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* Ossama Othman <ossama.othman@intel.com>
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* Cleanup per feedback from Alan Cox and Arjan Van De Ven
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*
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* 20090806 Ossama Othman <ossama.othman@intel.com>
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* Return zero high address if upper 22 bits is zero.
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* Cleaned up checkpatch errors.
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* Clarified that driver is dealing with bus addresses.
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*
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* 20090702 Ossama Othman <ossama.othman@intel.com>
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* Removed unnecessary include directives
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* Cleaned up spinlocks.
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* Cleaned up logging.
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* Improved invalid parameter checks.
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* Fixed and simplified RAR address retrieval and RAR locking
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* code.
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*
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* 20090626 Mark Allyn <mark.a.allyn@intel.com>
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* Initial publish
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*/
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#include <linux/module.h>
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#include <linux/pci.h>
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#include <linux/spinlock.h>
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#include <linux/device.h>
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#include <linux/kernel.h>
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#include <linux/rar_register.h>
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/* === Lincroft Message Bus Interface === */
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#define LNC_MCR_OFFSET 0xD0 /* Message Control Register */
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#define LNC_MDR_OFFSET 0xD4 /* Message Data Register */
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/* Message Opcodes */
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#define LNC_MESSAGE_READ_OPCODE 0xD0
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#define LNC_MESSAGE_WRITE_OPCODE 0xE0
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/* Message Write Byte Enables */
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#define LNC_MESSAGE_BYTE_WRITE_ENABLES 0xF
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/* B-unit Port */
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#define LNC_BUNIT_PORT 0x3
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/* === Lincroft B-Unit Registers - Programmed by IA32 firmware === */
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#define LNC_BRAR0L 0x10
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#define LNC_BRAR0H 0x11
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#define LNC_BRAR1L 0x12
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#define LNC_BRAR1H 0x13
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/* Reserved for SeP */
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#define LNC_BRAR2L 0x14
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#define LNC_BRAR2H 0x15
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/* Moorestown supports three restricted access regions. */
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#define MRST_NUM_RAR 3
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/* RAR Bus Address Range */
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struct rar_addr {
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dma_addr_t low;
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dma_addr_t high;
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};
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/*
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* We create one of these for each RAR
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*/
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struct client {
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int (*callback)(unsigned long data);
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unsigned long driver_priv;
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bool busy;
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};
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static DEFINE_MUTEX(rar_mutex);
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static DEFINE_MUTEX(lnc_reg_mutex);
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/*
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* One per RAR device (currently only one device)
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*/
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struct rar_device {
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struct rar_addr rar_addr[MRST_NUM_RAR];
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struct pci_dev *rar_dev;
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bool registered;
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bool allocated;
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struct client client[MRST_NUM_RAR];
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};
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/* Current platforms have only one rar_device for 3 rar regions */
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static struct rar_device my_rar_device;
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/*
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* Abstract out multiple device support. Current platforms only
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* have a single RAR device.
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*/
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/**
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* alloc_rar_device - return a new RAR structure
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*
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* Return a new (but not yet ready) RAR device object
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*/
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static struct rar_device *alloc_rar_device(void)
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{
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if (my_rar_device.allocated)
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return NULL;
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my_rar_device.allocated = 1;
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return &my_rar_device;
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}
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/**
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* free_rar_device - free a RAR object
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* @rar: the RAR device being freed
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*
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* Release a RAR object and any attached resources
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*/
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static void free_rar_device(struct rar_device *rar)
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{
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pci_dev_put(rar->rar_dev);
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rar->allocated = 0;
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}
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/**
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* _rar_to_device - return the device handling this RAR
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* @rar: RAR number
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* @off: returned offset
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*
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* Internal helper for looking up RAR devices. This and alloc are the
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* two functions that need touching to go to multiple RAR devices.
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*/
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static struct rar_device *_rar_to_device(int rar, int *off)
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{
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if (rar >= 0 && rar <= 3) {
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*off = rar;
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return &my_rar_device;
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}
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return NULL;
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}
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/**
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* rar_to_device - return the device handling this RAR
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* @rar: RAR number
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* @off: returned offset
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*
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* Return the device this RAR maps to if one is present, otherwise
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* returns NULL. Reports the offset relative to the base of this
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* RAR device in off.
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*/
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static struct rar_device *rar_to_device(int rar, int *off)
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{
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struct rar_device *rar_dev = _rar_to_device(rar, off);
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if (rar_dev == NULL || !rar_dev->registered)
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return NULL;
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return rar_dev;
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}
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/**
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* rar_to_client - return the client handling this RAR
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* @rar: RAR number
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*
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* Return the client this RAR maps to if a mapping is known, otherwise
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* returns NULL.
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*/
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static struct client *rar_to_client(int rar)
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{
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int idx;
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struct rar_device *r = _rar_to_device(rar, &idx);
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if (r != NULL)
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return &r->client[idx];
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return NULL;
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}
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/**
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* rar_read_addr - retrieve a RAR mapping
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* @pdev: PCI device for the RAR
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* @offset: offset for message
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* @addr: returned address
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*
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* Reads the address of a given RAR register. Returns 0 on success
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* or an error code on failure.
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*/
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static int rar_read_addr(struct pci_dev *pdev, int offset, dma_addr_t *addr)
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{
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/*
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* ======== The Lincroft Message Bus Interface ========
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* Lincroft registers may be obtained via PCI from
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* the host bridge using the Lincroft Message Bus
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* Interface. That message bus interface is generally
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* comprised of two registers: a control register (MCR, 0xDO)
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* and a data register (MDR, 0xD4).
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*
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* The MCR (message control register) format is the following:
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* 1. [31:24]: Opcode
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* 2. [23:16]: Port
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* 3. [15:8]: Register Offset
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* 4. [7:4]: Byte Enables (use 0xF to set all of these bits
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* to 1)
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* 5. [3:0]: reserved
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*
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* Read (0xD0) and write (0xE0) opcodes are written to the
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* control register when reading and writing to Lincroft
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* registers, respectively.
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*
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* We're interested in registers found in the Lincroft
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* B-unit. The B-unit port is 0x3.
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*
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* The six B-unit RAR register offsets we use are listed
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* earlier in this file.
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*
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* Lastly writing to the MCR register requires the "Byte
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* enables" bits to be set to 1. This may be achieved by
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* writing 0xF at bit 4.
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*
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* The MDR (message data register) format is the following:
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* 1. [31:0]: Read/Write Data
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*
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* Data being read from this register is only available after
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* writing the appropriate control message to the MCR
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* register.
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*
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* Data being written to this register must be written before
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* writing the appropriate control message to the MCR
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* register.
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*/
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int result;
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u32 addr32;
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/* Construct control message */
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u32 const message =
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(LNC_MESSAGE_READ_OPCODE << 24)
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| (LNC_BUNIT_PORT << 16)
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| (offset << 8)
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| (LNC_MESSAGE_BYTE_WRITE_ENABLES << 4);
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dev_dbg(&pdev->dev, "Offset for 'get' LNC MSG is %x\n", offset);
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/*
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* We synchronize access to the Lincroft MCR and MDR registers
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* until BOTH the command is issued through the MCR register
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* and the corresponding data is read from the MDR register.
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* Otherwise a race condition would exist between accesses to
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* both registers.
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*/
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mutex_lock(&lnc_reg_mutex);
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/* Send the control message */
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result = pci_write_config_dword(pdev, LNC_MCR_OFFSET, message);
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if (!result) {
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/* Read back the address as a 32bit value */
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result = pci_read_config_dword(pdev, LNC_MDR_OFFSET, &addr32);
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*addr = (dma_addr_t)addr32;
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}
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mutex_unlock(&lnc_reg_mutex);
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return result;
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}
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/**
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* rar_set_addr - Set a RAR mapping
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* @pdev: PCI device for the RAR
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* @offset: offset for message
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* @addr: address to set
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*
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* Sets the address of a given RAR register. Returns 0 on success
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* or an error code on failure.
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*/
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static int rar_set_addr(struct pci_dev *pdev,
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int offset,
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dma_addr_t addr)
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{
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/*
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* Data being written to this register must be written before
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* writing the appropriate control message to the MCR
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* register.
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* See rar_get_addrs() for a description of the
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* message bus interface being used here.
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*/
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int result;
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/* Construct control message */
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u32 const message = (LNC_MESSAGE_WRITE_OPCODE << 24)
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| (LNC_BUNIT_PORT << 16)
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| (offset << 8)
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| (LNC_MESSAGE_BYTE_WRITE_ENABLES << 4);
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/*
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* We synchronize access to the Lincroft MCR and MDR registers
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* until BOTH the command is issued through the MCR register
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* and the corresponding data is read from the MDR register.
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* Otherwise a race condition would exist between accesses to
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* both registers.
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*/
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mutex_lock(&lnc_reg_mutex);
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/* Send the control message */
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result = pci_write_config_dword(pdev, LNC_MDR_OFFSET, addr);
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if (!result)
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/* And address */
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result = pci_write_config_dword(pdev, LNC_MCR_OFFSET, message);
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mutex_unlock(&lnc_reg_mutex);
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return result;
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}
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/*
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* rar_init_params - Initialize RAR parameters
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* @rar: RAR device to initialise
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*
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* Initialize RAR parameters, such as bus addresses, etc. Returns 0
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* on success, or an error code on failure.
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*/
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static int init_rar_params(struct rar_device *rar)
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{
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struct pci_dev *pdev = rar->rar_dev;
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unsigned int i;
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int result = 0;
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int offset = 0x10; /* RAR 0 to 2 in order low/high/low/high/... */
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/* Retrieve RAR start and end bus addresses.
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* Access the RAR registers through the Lincroft Message Bus
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* Interface on PCI device: 00:00.0 Host bridge.
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*/
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for (i = 0; i < MRST_NUM_RAR; ++i) {
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struct rar_addr *addr = &rar->rar_addr[i];
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result = rar_read_addr(pdev, offset++, &addr->low);
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if (result != 0)
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return result;
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result = rar_read_addr(pdev, offset++, &addr->high);
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if (result != 0)
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return result;
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/*
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* Only the upper 22 bits of the RAR addresses are
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* stored in their corresponding RAR registers so we
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* must set the lower 10 bits accordingly.
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* The low address has its lower 10 bits cleared, and
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* the high address has all its lower 10 bits set,
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* e.g.:
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* low = 0x2ffffc00
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*/
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addr->low &= (dma_addr_t)0xfffffc00u;
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/*
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* Set bits 9:0 on uppser address if bits 31:10 are non
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* zero; otherwize clear all bits
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*/
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if ((addr->high & 0xfffffc00u) == 0)
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addr->high = 0;
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else
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addr->high |= 0x3ffu;
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}
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/* Done accessing the device. */
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if (result == 0) {
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for (i = 0; i != MRST_NUM_RAR; ++i) {
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/*
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* "BRAR" refers to the RAR registers in the
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* Lincroft B-unit.
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*/
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dev_info(&pdev->dev, "BRAR[%u] bus address range = "
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"[%lx, %lx]\n", i,
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(unsigned long)rar->rar_addr[i].low,
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(unsigned long)rar->rar_addr[i].high);
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}
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}
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return result;
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}
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/**
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* rar_get_address - get the bus address in a RAR
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* @start: return value of start address of block
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* @end: return value of end address of block
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*
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* The rar_get_address function is used by other device drivers
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* to obtain RAR address information on a RAR. It takes three
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* parameters:
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*
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* The function returns a 0 upon success or an error if there is no RAR
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* facility on this system.
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*/
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int rar_get_address(int rar_index, dma_addr_t *start, dma_addr_t *end)
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{
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int idx;
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struct rar_device *rar = rar_to_device(rar_index, &idx);
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if (rar == NULL) {
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WARN_ON(1);
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return -ENODEV;
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}
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*start = rar->rar_addr[idx].low;
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*end = rar->rar_addr[idx].high;
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return 0;
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}
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EXPORT_SYMBOL(rar_get_address);
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/**
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* rar_lock - lock a RAR register
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* @rar_index: RAR to lock (0-2)
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*
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* The rar_lock function is ued by other device drivers to lock an RAR.
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* once a RAR is locked, it stays locked until the next system reboot.
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*
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* The function returns a 0 upon success or an error if there is no RAR
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* facility on this system, or the locking fails
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*/
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int rar_lock(int rar_index)
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{
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struct rar_device *rar;
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int result;
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int idx;
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dma_addr_t low, high;
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rar = rar_to_device(rar_index, &idx);
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if (rar == NULL) {
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WARN_ON(1);
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return -EINVAL;
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}
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low = rar->rar_addr[idx].low & 0xfffffc00u;
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high = rar->rar_addr[idx].high & 0xfffffc00u;
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/*
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* Only allow I/O from the graphics and Langwell;
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* not from the x86 processor
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*/
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if (rar_index == RAR_TYPE_VIDEO) {
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low |= 0x00000009;
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high |= 0x00000015;
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} else if (rar_index == RAR_TYPE_AUDIO) {
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/* Only allow I/O from Langwell; nothing from x86 */
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low |= 0x00000008;
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high |= 0x00000018;
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} else
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/* Read-only from all agents */
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high |= 0x00000018;
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/*
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* Now program the register using the Lincroft message
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* bus interface.
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*/
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result = rar_set_addr(rar->rar_dev,
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2 * idx, low);
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if (result == 0)
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result = rar_set_addr(rar->rar_dev,
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2 * idx + 1, high);
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return result;
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}
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EXPORT_SYMBOL(rar_lock);
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/**
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* register_rar - register a RAR handler
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* @num: RAR we wish to register for
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* @callback: function to call when RAR support is available
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* @data: data to pass to this function
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*
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* The register_rar function is to used by other device drivers
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* to ensure that this driver is ready. As we cannot be sure of
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* the compile/execute order of drivers in ther kernel, it is
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* best to give this driver a callback function to call when
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* it is ready to give out addresses. The callback function
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* would have those steps that continue the initialization of
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* a driver that do require a valid RAR address. One of those
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* steps would be to call rar_get_address()
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*
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* This function return 0 on success or an error code on failure.
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*/
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int register_rar(int num, int (*callback)(unsigned long data),
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unsigned long data)
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{
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/* For now we hardcode a single RAR device */
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struct rar_device *rar;
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struct client *c;
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int idx;
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int retval = 0;
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mutex_lock(&rar_mutex);
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/* Do we have a client mapping for this RAR number ? */
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c = rar_to_client(num);
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if (c == NULL) {
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retval = -ERANGE;
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goto done;
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}
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/* Is it claimed ? */
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if (c->busy) {
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retval = -EBUSY;
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goto done;
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}
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c->busy = 1;
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/* See if we have a handler for this RAR yet, if we do then fire it */
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rar = rar_to_device(num, &idx);
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if (rar) {
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/*
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* if the driver already registered, then we can simply
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* call the callback right now
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*/
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(*callback)(data);
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goto done;
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}
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/* 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;
|
|
}
|
|
|
|
const struct pci_device_id rar_pci_id_tbl[] = {
|
|
{ PCI_VDEVICE(INTEL, 0x4110) },
|
|
{ 0 }
|
|
};
|
|
|
|
MODULE_DEVICE_TABLE(pci, rar_pci_id_tbl);
|
|
|
|
const struct pci_device_id *my_id_table = 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");
|