[S390] cio: provide functions for fcx enabled I/O

Provide functions for assembling and starting fcx enabled I/O request
blocks.

Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>

1 files changed, 350 insertions, 0 deletions

diff --git a/drivers/s390/cio/fcx.c b/drivers/s390/cio/fcx.c
new file mode 100644
index 000000000000..61677dfbdc9b
--- /dev/null
+++ b/drivers/s390/cio/fcx.c
@@ -0,0 +1,350 @@
+/*
+ *  Functions for assembling fcx enabled I/O control blocks.
+ *
+ *    Copyright IBM Corp. 2008
+ *    Author(s): Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/err.h>
+#include <linux/module.h>
+#include <asm/fcx.h>
+#include "cio.h"
+
+/**
+ * tcw_get_intrg - return pointer to associated interrogate tcw
+ * @tcw: pointer to the original tcw
+ *
+ * Return a pointer to the interrogate tcw associated with the specified tcw
+ * or %NULL if there is no associated interrogate tcw.
+ */
+struct tcw *tcw_get_intrg(struct tcw *tcw)
+{
+	return (struct tcw *) ((addr_t) tcw->intrg);
+}
+EXPORT_SYMBOL(tcw_get_intrg);
+
+/**
+ * tcw_get_data - return pointer to input/output data associated with tcw
+ * @tcw: pointer to the tcw
+ *
+ * Return the input or output data address specified in the tcw depending
+ * on whether the r-bit or the w-bit is set. If neither bit is set, return
+ * %NULL.
+ */
+void *tcw_get_data(struct tcw *tcw)
+{
+	if (tcw->r)
+		return (void *) ((addr_t) tcw->input);
+	if (tcw->w)
+		return (void *) ((addr_t) tcw->output);
+	return NULL;
+}
+EXPORT_SYMBOL(tcw_get_data);
+
+/**
+ * tcw_get_tccb - return pointer to tccb associated with tcw
+ * @tcw: pointer to the tcw
+ *
+ * Return pointer to the tccb associated with this tcw.
+ */
+struct tccb *tcw_get_tccb(struct tcw *tcw)
+{
+	return (struct tccb *) ((addr_t) tcw->tccb);
+}
+EXPORT_SYMBOL(tcw_get_tccb);
+
+/**
+ * tcw_get_tsb - return pointer to tsb associated with tcw
+ * @tcw: pointer to the tcw
+ *
+ * Return pointer to the tsb associated with this tcw.
+ */
+struct tsb *tcw_get_tsb(struct tcw *tcw)
+{
+	return (struct tsb *) ((addr_t) tcw->tsb);
+}
+EXPORT_SYMBOL(tcw_get_tsb);
+
+/**
+ * tcw_init - initialize tcw data structure
+ * @tcw: pointer to the tcw to be initialized
+ * @r: initial value of the r-bit
+ * @w: initial value of the w-bit
+ *
+ * Initialize all fields of the specified tcw data structure with zero and
+ * fill in the format, flags, r and w fields.
+ */
+void tcw_init(struct tcw *tcw, int r, int w)
+{
+	memset(tcw, 0, sizeof(struct tcw));
+	tcw->format = TCW_FORMAT_DEFAULT;
+	tcw->flags = TCW_FLAGS_TIDAW_FORMAT(TCW_TIDAW_FORMAT_DEFAULT);
+	if (r)
+		tcw->r = 1;
+	if (w)
+		tcw->w = 1;
+}
+EXPORT_SYMBOL(tcw_init);
+
+static inline size_t tca_size(struct tccb *tccb)
+{
+	return tccb->tcah.tcal - 12;
+}
+
+static u32 calc_dcw_count(struct tccb *tccb)
+{
+	int offset;
+	struct dcw *dcw;
+	u32 count = 0;
+	size_t size;
+
+	size = tca_size(tccb);
+	for (offset = 0; offset < size;) {
+		dcw = (struct dcw *) &tccb->tca[offset];
+		count += dcw->count;
+		if (!(dcw->flags & DCW_FLAGS_CC))
+			break;
+		offset += sizeof(struct dcw) + ALIGN((int) dcw->cd_count, 4);
+	}
+	return count;
+}
+
+static u32 calc_cbc_size(struct tidaw *tidaw, int num)
+{
+	int i;
+	u32 cbc_data;
+	u32 cbc_count = 0;
+	u64 data_count = 0;
+
+	for (i = 0; i < num; i++) {
+		if (tidaw[i].flags & TIDAW_FLAGS_LAST)
+			break;
+		/* TODO: find out if padding applies to total of data
+		 * transferred or data transferred by this tidaw. Assumption:
+		 * applies to total. */
+		data_count += tidaw[i].count;
+		if (tidaw[i].flags & TIDAW_FLAGS_INSERT_CBC) {
+			cbc_data = 4 + ALIGN(data_count, 4) - data_count;
+			cbc_count += cbc_data;
+			data_count += cbc_data;
+		}
+	}
+	return cbc_count;
+}
+
+/**
+ * tcw_finalize - finalize tcw length fields and tidaw list
+ * @tcw: pointer to the tcw
+ * @num_tidaws: the number of tidaws used to address input/output data or zero
+ * if no tida is used
+ *
+ * Calculate the input-/output-count and tccbl field in the tcw, add a
+ * tcat the tccb and terminate the data tidaw list if used.
+ *
+ * Note: in case input- or output-tida is used, the tidaw-list must be stored
+ * in contiguous storage (no ttic). The tcal field in the tccb must be
+ * up-to-date.
+ */
+void tcw_finalize(struct tcw *tcw, int num_tidaws)
+{
+	struct tidaw *tidaw;
+	struct tccb *tccb;
+	struct tccb_tcat *tcat;
+	u32 count;
+
+	/* Terminate tidaw list. */
+	tidaw = tcw_get_data(tcw);
+	if (num_tidaws > 0)
+		tidaw[num_tidaws - 1].flags |= TIDAW_FLAGS_LAST;
+	/* Add tcat to tccb. */
+	tccb = tcw_get_tccb(tcw);
+	tcat = (struct tccb_tcat *) &tccb->tca[tca_size(tccb)];
+	memset(tcat, 0, sizeof(tcat));
+	/* Calculate tcw input/output count and tcat transport count. */
+	count = calc_dcw_count(tccb);
+	if (tcw->w && (tcw->flags & TCW_FLAGS_OUTPUT_TIDA))
+		count += calc_cbc_size(tidaw, num_tidaws);
+	if (tcw->r)
+		tcw->input_count = count;
+	else if (tcw->w)
+		tcw->output_count = count;
+	tcat->count = ALIGN(count, 4) + 4;
+	/* Calculate tccbl. */
+	tcw->tccbl = (sizeof(struct tccb) + tca_size(tccb) +
+		      sizeof(struct tccb_tcat) - 20) >> 2;
+}
+EXPORT_SYMBOL(tcw_finalize);
+
+/**
+ * tcw_set_intrg - set the interrogate tcw address of a tcw
+ * @tcw: the tcw address
+ * @intrg_tcw: the address of the interrogate tcw
+ *
+ * Set the address of the interrogate tcw in the specified tcw.
+ */
+void tcw_set_intrg(struct tcw *tcw, struct tcw *intrg_tcw)
+{
+	tcw->intrg = (u32) ((addr_t) intrg_tcw);
+}
+EXPORT_SYMBOL(tcw_set_intrg);
+
+/**
+ * tcw_set_data - set data address and tida flag of a tcw
+ * @tcw: the tcw address
+ * @data: the data address
+ * @use_tidal: zero of the data address specifies a contiguous block of data,
+ * non-zero if it specifies a list if tidaws.
+ *
+ * Set the input/output data address of a tcw (depending on the value of the
+ * r-flag and w-flag). If @use_tidal is non-zero, the corresponding tida flag
+ * is set as well.
+ */
+void tcw_set_data(struct tcw *tcw, void *data, int use_tidal)
+{
+	if (tcw->r) {
+		tcw->input = (u64) ((addr_t) data);
+		if (use_tidal)
+			tcw->flags |= TCW_FLAGS_INPUT_TIDA;
+	} else if (tcw->w) {
+		tcw->output = (u64) ((addr_t) data);
+		if (use_tidal)
+			tcw->flags |= TCW_FLAGS_OUTPUT_TIDA;
+	}
+}
+EXPORT_SYMBOL(tcw_set_data);
+
+/**
+ * tcw_set_tccb - set tccb address of a tcw
+ * @tcw: the tcw address
+ * @tccb: the tccb address
+ *
+ * Set the address of the tccb in the specified tcw.
+ */
+void tcw_set_tccb(struct tcw *tcw, struct tccb *tccb)
+{
+	tcw->tccb = (u64) ((addr_t) tccb);
+}
+EXPORT_SYMBOL(tcw_set_tccb);
+
+/**
+ * tcw_set_tsb - set tsb address of a tcw
+ * @tcw: the tcw address
+ * @tsb: the tsb address
+ *
+ * Set the address of the tsb in the specified tcw.
+ */
+void tcw_set_tsb(struct tcw *tcw, struct tsb *tsb)
+{
+	tcw->tsb = (u64) ((addr_t) tsb);
+}
+EXPORT_SYMBOL(tcw_set_tsb);
+
+/**
+ * tccb_init - initialize tccb
+ * @tccb: the tccb address
+ * @size: the maximum size of the tccb
+ * @sac: the service-action-code to be user
+ *
+ * Initialize the header of the specified tccb by resetting all values to zero
+ * and filling in defaults for format, sac and initial tcal fields.
+ */
+void tccb_init(struct tccb *tccb, size_t size, u32 sac)
+{
+	memset(tccb, 0, size);
+	tccb->tcah.format = TCCB_FORMAT_DEFAULT;
+	tccb->tcah.sac = sac;
+	tccb->tcah.tcal = 12;
+}
+EXPORT_SYMBOL(tccb_init);
+
+/**
+ * tsb_init - initialize tsb
+ * @tsb: the tsb address
+ *
+ * Initialize the specified tsb by resetting all values to zero.
+ */
+void tsb_init(struct tsb *tsb)
+{
+	memset(tsb, 0, sizeof(tsb));
+}
+EXPORT_SYMBOL(tsb_init);
+
+/**
+ * tccb_add_dcw - add a dcw to the tccb
+ * @tccb: the tccb address
+ * @tccb_size: the maximum tccb size
+ * @cmd: the dcw command
+ * @flags: flags for the dcw
+ * @cd: pointer to control data for this dcw or NULL if none is required
+ * @cd_count: number of control data bytes for this dcw
+ * @count: number of data bytes for this dcw
+ *
+ * Add a new dcw to the specified tccb by writing the dcw information specified
+ * by @cmd, @flags, @cd, @cd_count and @count to the tca of the tccb. Return
+ * a pointer to the newly added dcw on success or -%ENOSPC if the new dcw
+ * would exceed the available space as defined by @tccb_size.
+ *
+ * Note: the tcal field of the tccb header will be updates to reflect added
+ * content.
+ */
+struct dcw *tccb_add_dcw(struct tccb *tccb, size_t tccb_size, u8 cmd, u8 flags,
+			 void *cd, u8 cd_count, u32 count)
+{
+	struct dcw *dcw;
+	int size;
+	int tca_offset;
+
+	/* Check for space. */
+	tca_offset = tca_size(tccb);
+	size = ALIGN(sizeof(struct dcw) + cd_count, 4);
+	if (sizeof(struct tccb_tcah) + tca_offset + size +
+	    sizeof(struct tccb_tcat) > tccb_size)
+		return ERR_PTR(-ENOSPC);
+	/* Add dcw to tca. */
+	dcw = (struct dcw *) &tccb->tca[tca_offset];
+	memset(dcw, 0, size);
+	dcw->cmd = cmd;
+	dcw->flags = flags;
+	dcw->count = count;
+	dcw->cd_count = cd_count;
+	if (cd)
+		memcpy(&dcw->cd[0], cd, cd_count);
+	tccb->tcah.tcal += size;
+	return dcw;
+}
+EXPORT_SYMBOL(tccb_add_dcw);
+
+/**
+ * tcw_add_tidaw - add a tidaw to a tcw
+ * @tcw: the tcw address
+ * @num_tidaws: the current number of tidaws
+ * @flags: flags for the new tidaw
+ * @addr: address value for the new tidaw
+ * @count: count value for the new tidaw
+ *
+ * Add a new tidaw to the input/output data tidaw-list of the specified tcw
+ * (depending on the value of the r-flag and w-flag) and return a pointer to
+ * the new tidaw.
+ *
+ * Note: the tidaw-list is assumed to be contiguous with no ttics. The caller
+ * must ensure that there is enough space for the new tidaw. The last-tidaw
+ * flag for the last tidaw in the list will be set by tcw_finalize.
+ */
+struct tidaw *tcw_add_tidaw(struct tcw *tcw, int num_tidaws, u8 flags,
+			    void *addr, u32 count)
+{
+	struct tidaw *tidaw;
+
+	/* Add tidaw to tidaw-list. */
+	tidaw = ((struct tidaw *) tcw_get_data(tcw)) + num_tidaws;
+	memset(tidaw, 0, sizeof(struct tidaw));
+	tidaw->flags = flags;
+	tidaw->count = count;
+	tidaw->addr = (u64) ((addr_t) addr);
+	return tidaw;
+}
+EXPORT_SYMBOL(tcw_add_tidaw);