powerpc/powernv/vas: Define copy/paste interfaces

Define interfaces (wrappers) to the 'copy' and 'paste'
instructions (which are new in PowerISA 3.0). These are intended to be
used to by NX driver(s) to submit Coprocessor Request Blocks (CRBs) to
the NX hardware engines.

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

3 files changed, 109 insertions, 2 deletions

diff --git a/arch/powerpc/platforms/powernv/copy-paste.h b/arch/powerpc/platforms/powernv/copy-paste.h
new file mode 100644
index 000000000000..c9a503623431
--- /dev/null
+++ b/arch/powerpc/platforms/powernv/copy-paste.h
@@ -0,0 +1,46 @@
+/*
+ * Copyright 2016-17 IBM Corp.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+#include <asm/ppc-opcode.h>
+
+#define CR0_SHIFT	28
+#define CR0_MASK	0xF
+/*
+ * Copy/paste instructions:
+ *
+ *	copy RA,RB
+ *		Copy contents of address (RA) + effective_address(RB)
+ *		to internal copy-buffer.
+ *
+ *	paste RA,RB
+ *		Paste contents of internal copy-buffer to the address
+ *		(RA) + effective_address(RB)
+ */
+static inline int vas_copy(void *crb, int offset)
+{
+	asm volatile(PPC_COPY(%0, %1)";"
+		:
+		: "b" (offset), "b" (crb)
+		: "memory");
+
+	return 0;
+}
+
+static inline int vas_paste(void *paste_address, int offset)
+{
+	u32 cr;
+
+	cr = 0;
+	asm volatile(PPC_PASTE(%1, %2)";"
+		"mfocrf %0, 0x80;"
+		: "=r" (cr)
+		: "b" (offset), "b" (paste_address)
+		: "memory", "cr0");
+
+	return (cr >> CR0_SHIFT) & CR0_MASK;
+}
diff --git a/arch/powerpc/platforms/powernv/vas-window.c b/arch/powerpc/platforms/powernv/vas-window.c
index 6992e304156b..5aae845b8cd9 100644
--- a/arch/powerpc/platforms/powernv/vas-window.c
+++ b/arch/powerpc/platforms/powernv/vas-window.c
@@ -18,6 +18,7 @@
 #include <linux/cred.h>
 
 #include "vas.h"
+#include "copy-paste.h"
 
 /*
  * Compute the paste address region for the window @window using the
@@ -997,6 +998,52 @@ put_rxwin:
 }
 EXPORT_SYMBOL_GPL(vas_tx_win_open);
 
+int vas_copy_crb(void *crb, int offset)
+{
+	return vas_copy(crb, offset);
+}
+EXPORT_SYMBOL_GPL(vas_copy_crb);
+
+#define RMA_LSMP_REPORT_ENABLE PPC_BIT(53)
+int vas_paste_crb(struct vas_window *txwin, int offset, bool re)
+{
+	int rc;
+	void *addr;
+	uint64_t val;
+
+	/*
+	 * Only NX windows are supported for now and hardware assumes
+	 * report-enable flag is set for NX windows. Ensure software
+	 * complies too.
+	 */
+	WARN_ON_ONCE(txwin->nx_win && !re);
+
+	addr = txwin->paste_kaddr;
+	if (re) {
+		/*
+		 * Set the REPORT_ENABLE bit (equivalent to writing
+		 * to 1K offset of the paste address)
+		 */
+		val = SET_FIELD(RMA_LSMP_REPORT_ENABLE, 0ULL, 1);
+		addr += val;
+	}
+
+	/*
+	 * Map the raw CR value from vas_paste() to an error code (there
+	 * is just pass or fail for now though).
+	 */
+	rc = vas_paste(addr, offset);
+	if (rc == 2)
+		rc = 0;
+	else
+		rc = -EINVAL;
+
+	print_fifo_msg_count(txwin);
+
+	return rc;
+}
+EXPORT_SYMBOL_GPL(vas_paste_crb);
+
 static void poll_window_busy_state(struct vas_window *window)
 {
 	int busy;
diff --git a/arch/powerpc/platforms/powernv/vas.h b/arch/powerpc/platforms/powernv/vas.h
index d3e4f554a11c..38dee5d50f31 100644
--- a/arch/powerpc/platforms/powernv/vas.h
+++ b/arch/powerpc/platforms/powernv/vas.h
@@ -398,11 +398,11 @@ extern struct vas_instance *find_vas_instance(int vasid);
 #ifdef vas_debug
 static inline void dump_rx_win_attr(struct vas_rx_win_attr *attr)
 {
-	pr_err("VAS: fault %d, notify %d, intr %d early %d\n",
+	pr_err("fault %d, notify %d, intr %d early %d\n",
 			attr->fault_win, attr->notify_disable,
 			attr->intr_disable, attr->notify_early);
 
-	pr_err("VAS: rx_fifo_size %d, max value %d\n",
+	pr_err("rx_fifo_size %d, max value %d\n",
 				attr->rx_fifo_size, VAS_RX_FIFO_SIZE_MAX);
 }
 
@@ -450,4 +450,18 @@ static inline u64 read_hvwc_reg(struct vas_window *win,
 	return in_be64(win->hvwc_map+reg);
 }
 
+#ifdef vas_debug
+
+static void print_fifo_msg_count(struct vas_window *txwin)
+{
+	uint64_t read_hvwc_reg(struct vas_window *w, char *n, uint64_t o);
+	pr_devel("Winid %d, Msg count %llu\n", txwin->winid,
+			(uint64_t)read_hvwc_reg(txwin, VREG(LRFIFO_PUSH)));
+}
+#else	/* vas_debug */
+
+#define print_fifo_msg_count(window)
+
+#endif	/* vas_debug */
+
 #endif /* _VAS_H */