cregit-Linux how code gets into the kernel

Release 4.9 drivers/infiniband/hw/hfi1/eprom.c

/*
 * Copyright(c) 2015, 2016 Intel Corporation.
 *
 * This file is provided under a dual BSD/GPLv2 license.  When using or
 * redistributing this file, you may do so under either license.
 *
 * GPL LICENSE SUMMARY
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * 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.
 *
 * BSD LICENSE
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *  - Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *  - Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *  - Neither the name of Intel Corporation nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */
#include <linux/delay.h>
#include "hfi.h"
#include "common.h"
#include "eprom.h"

/*
 * The EPROM is logically divided into three partitions:
 *      partition 0: the first 128K, visible from PCI ROM BAR
 *      partition 1: 4K config file (sector size)
 *      partition 2: the rest
 */

#define P0_SIZE (128 * 1024)

#define P1_SIZE   (4 * 1024)

#define P1_START P0_SIZE

#define P2_START (P0_SIZE + P1_SIZE)

/* controller page size, in bytes */

#define EP_PAGE_SIZE 256

#define EP_PAGE_MASK (EP_PAGE_SIZE - 1)

#define EP_PAGE_DWORDS (EP_PAGE_SIZE / sizeof(u32))

/* controller commands */

#define CMD_SHIFT 24

#define CMD_NOP			    (0)

#define CMD_READ_DATA(addr)	    ((0x03 << CMD_SHIFT) | addr)

#define CMD_RELEASE_POWERDOWN_NOID  ((0xab << CMD_SHIFT))

/* controller interface speeds */

#define EP_SPEED_FULL 0x2	
/* full speed */

/*
 * How long to wait for the EPROM to become available, in ms.
 * The spec 32 Mb EPROM takes around 40s to erase then write.
 * Double it for safety.
 */

#define EPROM_TIMEOUT 80000 
/* ms */

/*
 * Read a 256 byte (64 dword) EPROM page.
 * All callers have verified the offset is at a page boundary.
 */

static void read_page(struct hfi1_devdata *dd, u32 offset, u32 *result) { int i; write_csr(dd, ASIC_EEP_ADDR_CMD, CMD_READ_DATA(offset)); for (i = 0; i < EP_PAGE_DWORDS; i++) result[i] = (u32)read_csr(dd, ASIC_EEP_DATA); write_csr(dd, ASIC_EEP_ADDR_CMD, CMD_NOP); /* close open page */ }

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/* * Read length bytes starting at offset from the start of the EPROM. */
static int read_length(struct hfi1_devdata *dd, u32 start, u32 len, void *dest) { u32 buffer[EP_PAGE_DWORDS]; u32 end; u32 start_offset; u32 read_start; u32 bytes; if (len == 0) return 0; end = start + len; /* * Make sure the read range is not outside of the controller read * command address range. Note that '>' is correct below - the end * of the range is OK if it stops at the limit, but no higher. */ if (end > (1 << CMD_SHIFT)) return -EINVAL; /* read the first partial page */ start_offset = start & EP_PAGE_MASK; if (start_offset) { /* partial starting page */ /* align and read the page that contains the start */ read_start = start & ~EP_PAGE_MASK; read_page(dd, read_start, buffer); /* the rest of the page is available data */ bytes = EP_PAGE_SIZE - start_offset; if (len <= bytes) { /* end is within this page */ memcpy(dest, (u8 *)buffer + start_offset, len); return 0; } memcpy(dest, (u8 *)buffer + start_offset, bytes); start += bytes; len -= bytes; dest += bytes; } /* start is now page aligned */ /* read whole pages */ while (len >= EP_PAGE_SIZE) { read_page(dd, start, buffer); memcpy(dest, buffer, EP_PAGE_SIZE); start += EP_PAGE_SIZE; len -= EP_PAGE_SIZE; dest += EP_PAGE_SIZE; } /* read the last partial page */ if (len) { read_page(dd, start, buffer); memcpy(dest, buffer, len); } return 0; }

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dean luickdean luick229100.00%1100.00%
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/* * Initialize the EPROM handler. */
int eprom_init(struct hfi1_devdata *dd) { int ret = 0; /* only the discrete chip has an EPROM */ if (dd->pcidev->device != PCI_DEVICE_ID_INTEL0) return 0; /* * It is OK if both HFIs reset the EPROM as long as they don't * do it at the same time. */ ret = acquire_chip_resource(dd, CR_EPROM, EPROM_TIMEOUT); if (ret) { dd_dev_err(dd, "%s: unable to acquire EPROM resource, no EPROM support\n", __func__); goto done_asic; } /* reset EPROM to be sure it is in a good state */ /* set reset */ write_csr(dd, ASIC_EEP_CTL_STAT, ASIC_EEP_CTL_STAT_EP_RESET_SMASK); /* clear reset, set speed */ write_csr(dd, ASIC_EEP_CTL_STAT, EP_SPEED_FULL << ASIC_EEP_CTL_STAT_RATE_SPI_SHIFT); /* wake the device with command "release powerdown NoID" */ write_csr(dd, ASIC_EEP_ADDR_CMD, CMD_RELEASE_POWERDOWN_NOID); dd->eprom_available = true; release_chip_resource(dd, CR_EPROM); done_asic: return ret; }

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/* magic character sequence that trails an image */ #define IMAGE_TRAIL_MAGIC "egamiAPO" /* * Read all of partition 1. The actual file is at the front. Adjust * the returned size if a trailing image magic is found. */
static int read_partition_platform_config(struct hfi1_devdata *dd, void **data, u32 *size) { void *buffer; void *p; u32 length; int ret; buffer = kmalloc(P1_SIZE, GFP_KERNEL); if (!buffer) return -ENOMEM; ret = read_length(dd, P1_START, P1_SIZE, buffer); if (ret) { kfree(buffer); return ret; } /* scan for image magic that may trail the actual data */ p = strnstr(buffer, IMAGE_TRAIL_MAGIC, P1_SIZE); if (p) length = p - buffer; else length = P1_SIZE; *data = buffer; *size = length; return 0; }

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dean luickdean luick119100.00%1100.00%
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/* * Read the platform configuration file from the EPROM. * * On success, an allocated buffer containing the data and its size are * returned. It is up to the caller to free this buffer. * * Return value: * 0 - success * -ENXIO - no EPROM is available * -EBUSY - not able to acquire access to the EPROM * -ENOENT - no recognizable file written * -ENOMEM - buffer could not be allocated */
int eprom_read_platform_config(struct hfi1_devdata *dd, void **data, u32 *size) { u32 directory[EP_PAGE_DWORDS]; /* aligned buffer */ int ret; if (!dd->eprom_available) return -ENXIO; ret = acquire_chip_resource(dd, CR_EPROM, EPROM_TIMEOUT); if (ret) return -EBUSY; /* read the last page of P0 for the EPROM format magic */ ret = read_length(dd, P1_START - EP_PAGE_SIZE, EP_PAGE_SIZE, directory); if (ret) goto done; /* last dword of P0 contains a magic indicator */ if (directory[EP_PAGE_DWORDS - 1] == 0) { /* partition format */ ret = read_partition_platform_config(dd, data, size); goto done; } /* nothing recognized */ ret = -ENOENT; done: release_chip_resource(dd, CR_EPROM); return ret; }

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dean luickdean luick61983.31%466.67%
mike marciniszynmike marciniszyn12316.55%116.67%
jubin johnjubin john10.13%116.67%
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