From 62aeddbf28fa63872e8f13f47177338b0f1fd8b5 Mon Sep 17 00:00:00 2001 From: Dean Luick Date: Wed, 7 Dec 2016 19:32:15 -0800 Subject: [PATCH] IB/hfi1: Read new EPROM format Add the ability to read the new EPROM format. Reviewed-by: Easwar Hariharan Signed-off-by: Dean Luick Signed-off-by: Dennis Dalessandro Signed-off-by: Doug Ledford --- drivers/infiniband/hw/hfi1/eprom.c | 211 +++++++++++++++++++++++++++-- 1 file changed, 203 insertions(+), 8 deletions(-) diff --git a/drivers/infiniband/hw/hfi1/eprom.c b/drivers/infiniband/hw/hfi1/eprom.c index e70c223801b4..26da124c88e2 100644 --- a/drivers/infiniband/hw/hfi1/eprom.c +++ b/drivers/infiniband/hw/hfi1/eprom.c @@ -207,6 +207,40 @@ done_asic: /* magic character sequence that trails an image */ #define IMAGE_TRAIL_MAGIC "egamiAPO" +/* EPROM file types */ +#define HFI1_EFT_PLATFORM_CONFIG 2 + +/* segment size - 128 KiB */ +#define SEG_SIZE (128 * 1024) + +struct hfi1_eprom_footer { + u32 oprom_size; /* size of the oprom, in bytes */ + u16 num_table_entries; + u16 version; /* version of this footer */ + u32 magic; /* must be last */ +}; + +struct hfi1_eprom_table_entry { + u32 type; /* file type */ + u32 offset; /* file offset from start of EPROM */ + u32 size; /* file size, in bytes */ +}; + +/* + * Calculate the max number of table entries that will fit within a directory + * buffer of size 'dir_size'. + */ +#define MAX_TABLE_ENTRIES(dir_size) \ + (((dir_size) - sizeof(struct hfi1_eprom_footer)) / \ + sizeof(struct hfi1_eprom_table_entry)) + +#define DIRECTORY_SIZE(n) (sizeof(struct hfi1_eprom_footer) + \ + (sizeof(struct hfi1_eprom_table_entry) * (n))) + +#define MAGIC4(a, b, c, d) ((d) << 24 | (c) << 16 | (b) << 8 | (a)) +#define FOOTER_MAGIC MAGIC4('e', 'p', 'r', 'm') +#define FOOTER_VERSION 1 + /* * Read all of partition 1. The actual file is at the front. Adjust * the returned size if a trailing image magic is found. @@ -241,6 +275,167 @@ static int read_partition_platform_config(struct hfi1_devdata *dd, void **data, return 0; } +/* + * The segment magic has been checked. There is a footer and table of + * contents present. + * + * directory is a u32 aligned buffer of size EP_PAGE_SIZE. + */ +static int read_segment_platform_config(struct hfi1_devdata *dd, + void *directory, void **data, u32 *size) +{ + struct hfi1_eprom_footer *footer; + struct hfi1_eprom_table_entry *table; + struct hfi1_eprom_table_entry *entry; + void *buffer = NULL; + void *table_buffer = NULL; + int ret, i; + u32 directory_size; + u32 seg_base, seg_offset; + u32 bytes_available, ncopied, to_copy; + + /* the footer is at the end of the directory */ + footer = (struct hfi1_eprom_footer *) + (directory + EP_PAGE_SIZE - sizeof(*footer)); + + /* make sure the structure version is supported */ + if (footer->version != FOOTER_VERSION) + return -EINVAL; + + /* oprom size cannot be larger than a segment */ + if (footer->oprom_size >= SEG_SIZE) + return -EINVAL; + + /* the file table must fit in a segment with the oprom */ + if (footer->num_table_entries > + MAX_TABLE_ENTRIES(SEG_SIZE - footer->oprom_size)) + return -EINVAL; + + /* find the file table start, which precedes the footer */ + directory_size = DIRECTORY_SIZE(footer->num_table_entries); + if (directory_size <= EP_PAGE_SIZE) { + /* the file table fits into the directory buffer handed in */ + table = (struct hfi1_eprom_table_entry *) + (directory + EP_PAGE_SIZE - directory_size); + } else { + /* need to allocate and read more */ + table_buffer = kmalloc(directory_size, GFP_KERNEL); + if (!table_buffer) + return -ENOMEM; + ret = read_length(dd, SEG_SIZE - directory_size, + directory_size, table_buffer); + if (ret) + goto done; + table = table_buffer; + } + + /* look for the platform configuration file in the table */ + for (entry = NULL, i = 0; i < footer->num_table_entries; i++) { + if (table[i].type == HFI1_EFT_PLATFORM_CONFIG) { + entry = &table[i]; + break; + } + } + if (!entry) { + ret = -ENOENT; + goto done; + } + + /* + * Sanity check on the configuration file size - it should never + * be larger than 4 KiB. + */ + if (entry->size > (4 * 1024)) { + dd_dev_err(dd, "Bad configuration file size 0x%x\n", + entry->size); + ret = -EINVAL; + goto done; + } + + /* check for bogus offset and size that wrap when added together */ + if (entry->offset + entry->size < entry->offset) { + dd_dev_err(dd, + "Bad configuration file start + size 0x%x+0x%x\n", + entry->offset, entry->size); + ret = -EINVAL; + goto done; + } + + /* allocate the buffer to return */ + buffer = kmalloc(entry->size, GFP_KERNEL); + if (!buffer) { + ret = -ENOMEM; + goto done; + } + + /* + * Extract the file by looping over segments until it is fully read. + */ + seg_offset = entry->offset % SEG_SIZE; + seg_base = entry->offset - seg_offset; + ncopied = 0; + while (ncopied < entry->size) { + /* calculate data bytes available in this segment */ + + /* start with the bytes from the current offset to the end */ + bytes_available = SEG_SIZE - seg_offset; + /* subtract off footer and table from segment 0 */ + if (seg_base == 0) { + /* + * Sanity check: should not have a starting point + * at or within the directory. + */ + if (bytes_available <= directory_size) { + dd_dev_err(dd, + "Bad configuration file - offset 0x%x within footer+table\n", + entry->offset); + ret = -EINVAL; + goto done; + } + bytes_available -= directory_size; + } + + /* calculate bytes wanted */ + to_copy = entry->size - ncopied; + + /* max out at the available bytes in this segment */ + if (to_copy > bytes_available) + to_copy = bytes_available; + + /* + * Read from the EPROM. + * + * The sanity check for entry->offset is done in read_length(). + * The EPROM offset is validated against what the hardware + * addressing supports. In addition, if the offset is larger + * than the actual EPROM, it silently wraps. It will work + * fine, though the reader may not get what they expected + * from the EPROM. + */ + ret = read_length(dd, seg_base + seg_offset, to_copy, + buffer + ncopied); + if (ret) + goto done; + + ncopied += to_copy; + + /* set up for next segment */ + seg_offset = footer->oprom_size; + seg_base += SEG_SIZE; + } + + /* success */ + ret = 0; + *data = buffer; + *size = entry->size; + +done: + kfree(table_buffer); + if (ret) + kfree(buffer); + return ret; +} + /* * Read the platform configuration file from the EPROM. * @@ -253,6 +448,7 @@ static int read_partition_platform_config(struct hfi1_devdata *dd, void **data, * -EBUSY - not able to acquire access to the EPROM * -ENOENT - no recognizable file written * -ENOMEM - buffer could not be allocated + * -EINVAL - invalid EPROM contentents found */ int eprom_read_platform_config(struct hfi1_devdata *dd, void **data, u32 *size) { @@ -266,21 +462,20 @@ int eprom_read_platform_config(struct hfi1_devdata *dd, void **data, u32 *size) 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); + /* read the last page of the segment for the EPROM format magic */ + ret = read_length(dd, SEG_SIZE - 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) { + /* last dword of the segment contains a magic value */ + if (directory[EP_PAGE_DWORDS - 1] == FOOTER_MAGIC) { + /* segment format */ + ret = read_segment_platform_config(dd, directory, data, size); + } else { /* 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; -- 2.20.1