drivers/infiniband/core/packer.c

Source file repositories/reference/linux-study-clean/drivers/infiniband/core/packer.c

File Facts

System
Linux kernel
Corpus path
drivers/infiniband/core/packer.c
Extension
.c
Size
6389 bytes
Lines
202
Domain
Driver Families
Bucket
drivers/infiniband
Inferred role
Driver Families: exported/initcall integration point
Status
integration implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

if (desc[i].size_bits <= 32) {
			int shift;
			u32 val;
			__be32 mask;
			__be32 *addr;

			shift = 32 - desc[i].offset_bits - desc[i].size_bits;
			if (desc[i].struct_size_bytes)
				val = value_read(desc[i].struct_offset_bytes,
						 desc[i].struct_size_bytes,
						 structure) << shift;
			else
				val = 0;

			mask = cpu_to_be32(((1ull << desc[i].size_bits) - 1) << shift);
			addr = (__be32 *) buf + desc[i].offset_words;
			*addr = (*addr & ~mask) | (cpu_to_be32(val) & mask);
		} else if (desc[i].size_bits <= 64) {
			int shift;
			u64 val;
			__be64 mask;
			__be64 *addr;

			shift = 64 - desc[i].offset_bits - desc[i].size_bits;
			if (desc[i].struct_size_bytes)
				val = value_read(desc[i].struct_offset_bytes,
						 desc[i].struct_size_bytes,
						 structure) << shift;
			else
				val = 0;

			mask = cpu_to_be64((~0ull >> (64 - desc[i].size_bits)) << shift);
			addr = (__be64 *) ((__be32 *) buf + desc[i].offset_words);
			*addr = (*addr & ~mask) | (cpu_to_be64(val) & mask);
		} else {
			if (desc[i].offset_bits % 8 ||
			    desc[i].size_bits   % 8) {
				pr_warn("Structure field %s of size %d bits is not byte-aligned\n",
					desc[i].field_name, desc[i].size_bits);
			}

			if (desc[i].struct_size_bytes)
				memcpy(buf + desc[i].offset_words * 4 +
				       desc[i].offset_bits / 8,
				       structure + desc[i].struct_offset_bytes,
				       desc[i].size_bits / 8);
			else
				memset(buf + desc[i].offset_words * 4 +
				       desc[i].offset_bits / 8,
				       0,
				       desc[i].size_bits / 8);
		}
	}
}
EXPORT_SYMBOL(ib_pack);

static void value_write(int offset, int size, u64 val, void *structure)
{
	switch (size * 8) {
	case 8:  *(    u8 *) (structure + offset) = val; break;
	case 16: *(__be16 *) (structure + offset) = cpu_to_be16(val); break;
	case 32: *(__be32 *) (structure + offset) = cpu_to_be32(val); break;
	case 64: *(__be64 *) (structure + offset) = cpu_to_be64(val); break;
	default:
		pr_warn("Field size %d bits not handled\n", size * 8);
	}
}

/**
 * ib_unpack - Unpack a buffer into a structure
 * @desc:Array of structure field descriptions
 * @desc_len:Number of entries in @desc
 * @buf:Buffer to unpack from
 * @structure:Structure to unpack into
 *
 * ib_pack() unpacks a list of structure fields from a buffer,
 * controlled by the array of fields in @desc.
 */
void ib_unpack(const struct ib_field        *desc,
	       int                           desc_len,
	       void                         *buf,
	       void                         *structure)
{
	int i;

	for (i = 0; i < desc_len; ++i) {
		if (!desc[i].struct_size_bytes)
			continue;

		if (desc[i].size_bits <= 32) {

Annotation

Implementation Notes