drivers/message/fusion/mptscsih.c

Source file repositories/reference/linux-study-clean/drivers/message/fusion/mptscsih.c

File Facts

System
Linux kernel
Corpus path
drivers/message/fusion/mptscsih.c
Extension
.c
Size
92708 bytes
Lines
3260
Domain
Driver Families
Bucket
drivers/message
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 (thisxfer == 0) {
			/* Get next SG element from the OS */
			sg = sg_next(sg);
			sg_done++;
			continue;
		}

		v2 = sg_dma_address(sg);
		ioc->add_sge(psge, sgflags | thisxfer, v2);

		/* Get next SG element from the OS */
		sg = sg_next(sg);
		psge += ioc->SGE_size;
		sgeOffset += ioc->SGE_size;
		sg_done++;
	}

	if (numSgeThisFrame == sges_left) {
		/* Add last element, end of buffer and end of list flags.
		 */
		sgflags |= MPT_SGE_FLAGS_LAST_ELEMENT |
				MPT_SGE_FLAGS_END_OF_BUFFER |
				MPT_SGE_FLAGS_END_OF_LIST;

		/* Add last SGE and set termination flags.
		 * Note: Last SGE may have a length of 0 - which should be ok.
		 */
		thisxfer = sg_dma_len(sg);

		v2 = sg_dma_address(sg);
		ioc->add_sge(psge, sgflags | thisxfer, v2);
		sgeOffset += ioc->SGE_size;
		sg_done++;

		if (chainSge) {
			/* The current buffer is a chain buffer,
			 * but there is not another one.
			 * Update the chain element
			 * Offset and Length fields.
			 */
			ioc->add_chain((char *)chainSge, 0, sgeOffset,
				ioc->ChainBufferDMA + chain_dma_off);
		} else {
			/* The current buffer is the original MF
			 * and there is no Chain buffer.
			 */
			pReq->ChainOffset = 0;
			RequestNB = (((sgeOffset - 1) >> ioc->NBShiftFactor)  + 1) & 0x03;
			dsgprintk(ioc, printk(MYIOC_s_DEBUG_FMT
			    "Single Buffer RequestNB=%x, sgeOffset=%d\n", ioc->name, RequestNB, sgeOffset));
			ioc->RequestNB[req_idx] = RequestNB;
		}
	} else {
		/* At least one chain buffer is needed.
		 * Complete the first MF
		 *  - last SGE element, set the LastElement bit
		 *  - set ChainOffset (words) for orig MF
		 *             (OR finish previous MF chain buffer)
		 *  - update MFStructPtr ChainIndex
		 *  - Populate chain element
		 * Also
		 * Loop until done.
		 */

		dsgprintk(ioc, printk(MYIOC_s_DEBUG_FMT "SG: Chain Required! sg done %d\n",
				ioc->name, sg_done));

		/* Set LAST_ELEMENT flag for last non-chain element
		 * in the buffer. Since psge points at the NEXT
		 * SGE element, go back one SGE element, update the flags
		 * and reset the pointer. (Note: sgflags & thisxfer are already
		 * set properly).
		 */
		if (sg_done) {
			u32 *ptmp = (u32 *) (psge - ioc->SGE_size);
			sgflags = le32_to_cpu(*ptmp);
			sgflags |= MPT_SGE_FLAGS_LAST_ELEMENT;
			*ptmp = cpu_to_le32(sgflags);
		}

		if (chainSge) {
			/* The current buffer is a chain buffer.
			 * chainSge points to the previous Chain Element.
			 * Update its chain element Offset and Length (must
			 * include chain element size) fields.
			 * Old chain element is now complete.
			 */
			u8 nextChain = (u8) (sgeOffset >> 2);
			sgeOffset += ioc->SGE_size;
			ioc->add_chain((char *)chainSge, nextChain, sgeOffset,

Annotation

Implementation Notes