IB/ehca: Support large page MRs

Add support for MR pages larger than 4K on eHCA2. This reduces
firmware memory consumption.  If enabled via the mr_largepage module
parameter, the MR page size will be determined based on the MR length
and the hardware capabilities -- if the MR is >= 16M, 16M pages are
used, for example.

Signed-off-by: Joachim Fenkes <fenkes@de.ibm.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

drivers/infiniband/hw/ehca/ehca_classes.h

@@ -100,6 +100,11 @@ struct ehca_sport {
 	struct ehca_sma_attr saved_attr;
 };
 
+#define HCA_CAP_MR_PGSIZE_4K  1
+#define HCA_CAP_MR_PGSIZE_64K 2
+#define HCA_CAP_MR_PGSIZE_1M  4
+#define HCA_CAP_MR_PGSIZE_16M 8
+
 struct ehca_shca {
 	struct ib_device ib_device;
 	struct ibmebus_dev *ibmebus_dev;
@@ -115,6 +120,8 @@ struct ehca_shca {
 	struct h_galpas galpas;
 	struct mutex modify_mutex;
 	u64 hca_cap;
+	/* MR pgsize: bit 0-3 means 4K, 64K, 1M, 16M respectively */
+	u32 hca_cap_mr_pgsize;
 	int max_mtu;
 };
 
@@ -206,6 +213,7 @@ struct ehca_mr {
 	enum ehca_mr_flag flags;
 	u32 num_kpages;		/* number of kernel pages */
 	u32 num_hwpages;	/* number of hw pages to form MR */
+	u64 hwpage_size;	/* hw page size used for this MR */
 	int acl;		/* ACL (stored here for usage in reregister) */
 	u64 *start;		/* virtual start address (stored here for */
 				/* usage in reregister) */
@@ -240,6 +248,7 @@ struct ehca_mr_pginfo {
 	enum ehca_mr_pgi_type type;
 	u64 num_kpages;
 	u64 kpage_cnt;
+	u64 hwpage_size;     /* hw page size used for this MR */
 	u64 num_hwpages;     /* number of hw pages */
 	u64 hwpage_cnt;      /* counter for hw pages */
 	u64 next_hwpage;     /* next hw page in buffer/chunk/listelem */

drivers/infiniband/hw/ehca/ehca_main.c

@@ -63,6 +63,7 @@ int ehca_port_act_time = 30;
 int ehca_poll_all_eqs  = 1;
 int ehca_static_rate   = -1;
 int ehca_scaling_code  = 0;
+int ehca_mr_largepage  = 0;
 
 module_param_named(open_aqp1,     ehca_open_aqp1,     int, 0);
 module_param_named(debug_level,   ehca_debug_level,   int, 0);
@@ -72,7 +73,8 @@ module_param_named(use_hp_mr,     ehca_use_hp_mr,     int, 0);
 module_param_named(port_act_time, ehca_port_act_time, int, 0);
 module_param_named(poll_all_eqs,  ehca_poll_all_eqs,  int, 0);
 module_param_named(static_rate,   ehca_static_rate,   int, 0);
-module_param_named(scaling_code,   ehca_scaling_code,   int, 0);
+module_param_named(scaling_code,  ehca_scaling_code,  int, 0);
+module_param_named(mr_largepage,  ehca_mr_largepage,  int, 0);
 
 MODULE_PARM_DESC(open_aqp1,
 		 "AQP1 on startup (0: no (default), 1: yes)");
@@ -95,6 +97,9 @@ MODULE_PARM_DESC(static_rate,
 		 "set permanent static rate (default: disabled)");
 MODULE_PARM_DESC(scaling_code,
 		 "set scaling code (0: disabled/default, 1: enabled)");
+MODULE_PARM_DESC(mr_largepage,
+		 "use large page for MR (0: use PAGE_SIZE (default), "
+		 "1: use large page depending on MR size");
 
 DEFINE_RWLOCK(ehca_qp_idr_lock);
 DEFINE_RWLOCK(ehca_cq_idr_lock);
@@ -295,6 +300,8 @@ int ehca_sense_attributes(struct ehca_shca *shca)
 		if (EHCA_BMASK_GET(hca_cap_descr[i].mask, shca->hca_cap))
 			ehca_gen_dbg("   %s", hca_cap_descr[i].descr);
 
+	shca->hca_cap_mr_pgsize = rblock->memory_page_size_supported;
+
 	port = (struct hipz_query_port *)rblock;
 	h_ret = hipz_h_query_port(shca->ipz_hca_handle, 1, port);
 	if (h_ret != H_SUCCESS) {
@@ -590,6 +597,14 @@ static ssize_t ehca_show_adapter_handle(struct device *dev,
 }
 static DEVICE_ATTR(adapter_handle, S_IRUGO, ehca_show_adapter_handle, NULL);
 
+static ssize_t ehca_show_mr_largepage(struct device *dev,
+				      struct device_attribute *attr,
+				      char *buf)
+{
+	return sprintf(buf, "%d\n", ehca_mr_largepage);
+}
+static DEVICE_ATTR(mr_largepage, S_IRUGO, ehca_show_mr_largepage, NULL);
+
 static struct attribute *ehca_dev_attrs[] = {
 	&dev_attr_adapter_handle.attr,
 	&dev_attr_num_ports.attr,
@@ -606,6 +621,7 @@ static struct attribute *ehca_dev_attrs[] = {
 	&dev_attr_cur_mw.attr,
 	&dev_attr_max_pd.attr,
 	&dev_attr_max_ah.attr,
+	&dev_attr_mr_largepage.attr,
 	NULL
 };