patch-2.3.99-pre8 linux/drivers/s390/block/dasd_ccwstuff.c

• Lines: 420
• Date: Fri May 12 11:41:44 2000
• Orig file: v2.3.99-pre7/linux/drivers/s390/block/dasd_ccwstuff.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.3.99-pre7/linux/drivers/s390/block/dasd_ccwstuff.c linux/drivers/s390/block/dasd_ccwstuff.c
@@ -0,0 +1,419 @@
+/* 
+ * File...........: linux/drivers/s390/block/dasd_ccwstuff.c
+ * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
+ * Bugreports.to..: <Linux390@de.ibm.com>
+ * (C) IBM Corporation, IBM Deutschland Entwicklung GmbH, 1999,2000
+ */
+
+#include <linux/stddef.h>
+#include <linux/kernel.h>
+#include <linux/malloc.h>
+#include <linux/dasd.h>
+#include <asm/atomic.h>
+
+#include "dasd_types.h"
+
+#define PRINTK_HEADER "dasd_ccw:"
+#define MAX_CP_POWER 9		/* Maximum allowed index */
+#define CP_PER_PAGE_POWER 9	/* Maximum index, fitting on page */
+
+#define get_free_pages __get_free_pages
+
+/* Stuff for the handling task_list */
+dasd_chanq_t *cq_head = NULL;	/* head of task_list */
+atomic_t chanq_tasks;
+
+/* Array of freelists for the channel programs' -space */
+static ccw1_t *ccwarea[CP_PER_PAGE_POWER + 1] =
+{NULL,};
+
+/* array of pages retrieved for internal use */
+#define MAX_DASD_PAGES 64
+static int dasd_page_count = 0;
+static long dasd_page[MAX_DASD_PAGES];
+
+static spinlock_t ccw_lock=SPIN_LOCK_UNLOCKED;	/* spinlock for ccwareas */
+static spinlock_t cq_lock=SPIN_LOCK_UNLOCKED;	/* spinlock for cq_head */
+
+void
+ccwarea_enq (int index, ccw1_t * area)
+{
+	FUNCTION_ENTRY ("ccwarea_enq");
+#if DASD_PARANOIA > 2
+	if (!area) {
+		INTERNAL_CHECK ("zero area %s\n", "");
+	}
+	if (index > CP_PER_PAGE_POWER) {
+		INTERNAL_CHECK ("index too large %d\n", index);
+	}
+#endif
+	*(ccw1_t **) area = ccwarea[index];
+	ccwarea[index] = area;
+	FUNCTION_EXIT ("ccwarea_enq");
+	return;
+}
+
+ccw1_t *
+ccwarea_deq (int index)
+{
+	ccw1_t *cp;
+	FUNCTION_ENTRY ("ccwarea_deq");
+#if DASD_PARANOIA > 2
+	if (index > CP_PER_PAGE_POWER) {
+		INTERNAL_CHECK ("index too large %d\n", index);
+	}
+#endif
+	cp = ccwarea[index];
+	ccwarea[index] = *(ccw1_t **) ccwarea[index];
+#if DASD_PARANOIA > 2
+	if (!cp) {
+		INTERNAL_CHECK ("returning NULL %s\n", "");
+	}
+#endif
+	FUNCTION_EXIT ("ccwarea_deq");
+	return cp;
+}
+
+ccw1_t *
+request_cpa (int index)
+{
+	ccw1_t *freeblk;
+	FUNCTION_ENTRY ("request_cpa");
+	if (index > MAX_CP_POWER) {
+		INTERNAL_ERROR ("index too large %d\n", index);
+		freeblk = NULL;
+		goto exit;
+	}
+	if (index > CP_PER_PAGE_POWER) {
+		int pc = 1 << (index - CP_PER_PAGE_POWER);
+		do {
+			freeblk = (ccw1_t *) get_free_pages (GFP_ATOMIC, index - CP_PER_PAGE_POWER);
+			if (dasd_page_count + pc >= MAX_DASD_PAGES) {
+				PRINT_WARN ("Requesting too many pages...");
+			} else {
+				int i;
+				for (i = 0; i < pc; i++)
+					dasd_page[dasd_page_count++] =
+						(long) freeblk + i * PAGE_SIZE;
+			}
+			FUNCTION_CONTROL ("requesting index %d", index);
+			if ( ! freeblk ) {
+				panic ("No memory received\n");
+			}
+		} while (!freeblk);
+		memset(freeblk,0,PAGE_SIZE<<(index-CP_PER_PAGE_POWER));
+		goto exit;
+	}
+	while (ccwarea[index] == NULL) {
+		ccw1_t *blk;
+		if (index == CP_PER_PAGE_POWER) {
+			do {
+				blk = (ccw1_t *) get_free_page (GFP_ATOMIC);
+				if (dasd_page_count + 1 >= MAX_DASD_PAGES) {
+					PRINT_WARN ("Requesting too many pages...");
+				} else {
+					dasd_page[dasd_page_count++] =
+						(long) blk;
+				}
+				if (blk == NULL) {
+					PRINT_WARN ("Can't allocate page!\n");
+				}
+			} while ( ! blk );
+			memset(blk,0,PAGE_SIZE);
+			ccwarea_enq (CP_PER_PAGE_POWER, blk);
+			continue;
+		}
+		blk = request_cpa (index + 1);
+#if DASD_PARANOIA > 1
+		if (!blk) {
+			PRINT_WARN ("retrieved NULL");
+		}
+#endif				/* DASD_PARANOIA */
+		ccwarea_enq (index, blk);
+		ccwarea_enq (index, blk + (1 << index));
+	}
+#if DASD_PARANOIA > 2
+	if (!ccwarea[index]) {
+		INTERNAL_ERROR ("ccwarea is NULL\n%s", "");
+	}
+#endif				/* DASD_PARANOIA */
+
+	freeblk = ccwarea_deq (index);
+#if DASD_PARANOIA > 1
+	if (!freeblk) {
+		INTERNAL_ERROR ("freeblk is NULL\n%s", "");
+	}
+#endif				/* DASD_PARANOIA */
+      exit:
+	FUNCTION_EXIT ("request_cpa");
+	return freeblk;
+}
+
+ccw1_t *
+request_cp (int size)
+{
+	ccw1_t *freeblk;
+	int index;
+	int blksize;
+	/* Determine the index of ccwarea to look at */
+	for (index = 0, blksize = 1;
+	     size > blksize;
+	     index++, blksize = blksize << 1) {
+	}
+	if (index > MAX_CP_POWER) {
+		INTERNAL_ERROR ("index too large %d\n", index);
+	}
+	spin_lock (&ccw_lock);
+	freeblk = request_cpa (index);
+	spin_unlock (&ccw_lock);
+	if (freeblk == NULL) {
+		printk (KERN_WARNING PRINTK_HEADER
+			"No way to deliver free ccw space\n");
+	}
+	return freeblk;
+}
+
+void
+release_cp (int size, ccw1_t * area)
+{
+	int index;
+	int blksize;
+	/* Determine the index of ccwarea to look at */
+	for (index = 0, blksize = 1;
+	     size > blksize;
+	     index++, blksize = blksize << 1) {
+	}
+	if (index > MAX_CP_POWER) {
+		INTERNAL_ERROR ("index too large %d\n", index);
+	} else if (index > CP_PER_PAGE_POWER) {
+		free_pages ((unsigned long) area,
+			    index - CP_PER_PAGE_POWER);
+		INTERNAL_CHECK ("large index used: %d\n", index);
+	} else {
+		spin_lock (&ccw_lock);
+		ccwarea_enq (index, area);
+		spin_unlock (&ccw_lock);
+	}
+	return;
+}
+
+/* ---------------------------------------------------------- */
+
+static cqr_t *cqrp = NULL;
+static spinlock_t cqr_lock=SPIN_LOCK_UNLOCKED;
+
+void
+cqf_enq (cqr_t * cqf)
+{
+	*(cqr_t **) cqf = cqrp;
+	cqrp = cqf;
+}
+
+cqr_t *
+cqf_deq (void)
+{
+	cqr_t *cqr = cqrp;
+	cqrp = *(cqr_t **) cqrp;
+	return cqr;
+}
+
+cqr_t *
+request_cq (void)
+{
+	cqr_t *cqr = NULL;
+	int i;
+	cqr_t *area;
+
+	spin_lock (&cqr_lock);
+	while (cqrp == NULL) {
+		do {
+			area = (cqr_t *) get_free_page (GFP_ATOMIC);
+			if (area == NULL) {
+				printk (KERN_WARNING PRINTK_HEADER
+					"No memory for chanq area\n");
+			}
+		} while ( ! area );
+		memset(area,0,PAGE_SIZE);
+		if (dasd_page_count + 1 >= MAX_DASD_PAGES) {
+			PRINT_WARN ("Requesting too many pages...");
+		} else {
+			dasd_page[dasd_page_count++] =
+				(long) area;
+		}
+		for (i = 0; i < 4096 / sizeof (cqr_t); i++) {
+				cqf_enq (area + i);
+		}
+	}
+	cqr = cqf_deq ();
+	spin_unlock (&cqr_lock);
+	return cqr;
+}
+
+void
+release_cq (cqr_t * cqr)
+{
+	spin_lock (&cqr_lock);
+	cqf_enq (cqr);
+	spin_unlock (&cqr_lock);
+	return;
+}
+
+/* ----------------------------------------------------------- */
+cqr_t *
+request_cqr (int cpsize, int datasize)
+{
+	cqr_t *cqr = NULL;
+	cqr = request_cq ();
+	if (cqr == NULL) {
+		printk (KERN_WARNING PRINTK_HEADER __FILE__
+			"No memory for chanq request\n");
+		goto exit;
+	}
+	memset (cqr, 0, sizeof (cqr_t));
+	cqr -> magic = DASD_MAGIC;
+	if (cpsize) {
+		cqr->cpaddr = request_cp (cpsize);
+		if (cqr->cpaddr == NULL) {
+			printk (KERN_WARNING PRINTK_HEADER __FILE__
+				"No memory for channel program\n");
+			goto nocp;
+		}
+		cqr->cplength = cpsize;
+	}
+	if (datasize) {
+		do {
+			cqr->data = (char *) kmalloc (datasize, GFP_ATOMIC);
+			if (cqr->data == NULL) {
+				printk (KERN_WARNING PRINTK_HEADER __FILE__
+					"No memory for cqr data area\n");
+			}
+		} while (!cqr->data);
+		memset (cqr->data,0,datasize);
+	}
+	goto exit;
+ nocp:
+	release_cq (cqr);
+	cqr = NULL;
+ exit:
+	return cqr;
+}
+
+int
+release_cqr (cqr_t * cqr)
+{
+	int rc = 0;
+	if (cqr == NULL) {
+		rc = -ENOENT;
+		return rc;
+	}
+	if (cqr->data) {
+		kfree (cqr->data);
+	}
+	if (cqr->dstat) {
+		kfree (cqr->dstat);
+	}
+	if (cqr->cpaddr) {
+		release_cp (cqr->cplength, cqr->cpaddr);
+	}
+	cqr -> magic = dasd_MAGIC;
+	release_cq (cqr);
+	return rc;
+}
+
+/* -------------------------------------------------------------- */
+void
+dasd_chanq_enq (dasd_chanq_t * q, cqr_t * cqr)
+{
+	if (q->head != NULL) {
+		q->tail->next = cqr;
+	} else
+		q->head = cqr;
+	cqr->next = NULL;
+	q->tail = cqr;
+	q->queued_requests ++;
+	if (atomic_compare_and_swap(CQR_STATUS_FILLED,
+				    CQR_STATUS_QUEUED,
+				    &cqr->status)) {
+		PRINT_WARN ("q_cqr: %p status changed %d\n", 
+			    cqr,atomic_read(&cqr->status));
+		atomic_set(&cqr->status,CQR_STATUS_QUEUED);
+	}
+}
+
+int
+dasd_chanq_deq (dasd_chanq_t * q, cqr_t * cqr)
+{
+	cqr_t *prev;
+
+	if (cqr == NULL)
+		return -ENOENT;
+	if (cqr == (cqr_t *) q->head) {
+		q->head = cqr->next;
+		if (q->head == NULL)
+			q->tail = NULL;
+	} else {
+		prev = (cqr_t *) q->head; 
+		while (prev && prev->next != cqr)
+			prev = prev->next;
+		if (prev == NULL)
+			return -ENOENT;
+		prev->next = cqr->next;
+		if (prev->next == NULL)
+			q->tail = prev;
+	}
+	cqr->next = NULL;
+	q->queued_requests --;
+	return release_cqr(cqr);
+}
+
+/* -------------------------------------------------------------------------- */
+void
+cql_enq_head (dasd_chanq_t * q)
+{
+	if (q == NULL) {
+		INTERNAL_ERROR ("NULL queue passed%s\n", "");
+		return;
+	}
+	if (atomic_read(&q->flags) & DASD_CHANQ_ACTIVE) {
+		PRINT_WARN("Queue already active");
+		return;
+	}
+	spin_lock(&cq_lock);
+	atomic_set_mask(DASD_CHANQ_ACTIVE,&q->flags);
+	q->next_q = cq_head;
+	cq_head = q;
+	spin_unlock(&cq_lock);
+}
+
+void
+cql_deq (dasd_chanq_t * q)
+{
+	dasd_chanq_t *c;
+
+        if (cq_head == NULL) {
+                INTERNAL_ERROR ("Channel queue is empty%s\n", "");
+		return;
+	}
+	if (q == NULL) {
+		INTERNAL_ERROR ("NULL queue passed%s\n", "");
+		return;
+	}
+	spin_lock(&cq_lock);
+	if (! (atomic_read(&q->flags) & DASD_CHANQ_ACTIVE)) {
+		PRINT_WARN("Queue not active\n");
+	}
+	else if (cq_head == q) {
+		cq_head = q->next_q;
+	} else {
+		c = cq_head;
+		while (c->next_q && c->next_q != q)
+			c = c->next_q;
+		if (c->next_q != q)
+			INTERNAL_ERROR ("Entry not in queue%s\n", "");
+		else
+			c->next_q = q->next_q;
+	}
+	q->next_q = NULL;
+	atomic_clear_mask(DASD_CHANQ_ACTIVE,&q->flags);
+	spin_unlock(&cq_lock);
+}