Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/drivers/lightnvm/pblk-rl.c b/drivers/lightnvm/pblk-rl.c
index 6a0616a..a5f8bc2 100644
--- a/drivers/lightnvm/pblk-rl.c
+++ b/drivers/lightnvm/pblk-rl.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Copyright (C) 2016 CNEX Labs
  * Initial release: Javier Gonzalez <javier@cnexlabs.com>
@@ -127,7 +128,7 @@
 	} else if (free_blocks < rl->high) {
 		int shift = rl->high_pw - rl->rb_windows_pw;
 		int user_windows = free_blocks >> shift;
-		int user_max = user_windows << PBLK_MAX_REQ_ADDRS_PW;
+		int user_max = user_windows << ilog2(NVM_MAX_VLBA);
 
 		rl->rb_user_max = user_max;
 		rl->rb_gc_max = max - user_max;
@@ -206,16 +207,14 @@
 	del_timer(&rl->u_timer);
 }
 
-void pblk_rl_init(struct pblk_rl *rl, int budget)
+void pblk_rl_init(struct pblk_rl *rl, int budget, int threshold)
 {
 	struct pblk *pblk = container_of(rl, struct pblk, rl);
 	struct nvm_tgt_dev *dev = pblk->dev;
 	struct nvm_geo *geo = &dev->geo;
 	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
 	struct pblk_line_meta *lm = &pblk->lm;
-	int min_blocks = lm->blk_per_line * PBLK_GC_RSV_LINE;
 	int sec_meta, blk_meta;
-
 	unsigned int rb_windows;
 
 	/* Consider sectors used for metadata */
@@ -225,19 +224,24 @@
 	rl->high = pblk->op_blks - blk_meta - lm->blk_per_line;
 	rl->high_pw = get_count_order(rl->high);
 
-	rl->rsv_blocks = min_blocks;
+	rl->rsv_blocks = pblk_get_min_chks(pblk);
 
 	/* This will always be a power-of-2 */
-	rb_windows = budget / PBLK_MAX_REQ_ADDRS;
+	rb_windows = budget / NVM_MAX_VLBA;
 	rl->rb_windows_pw = get_count_order(rb_windows);
 
 	/* To start with, all buffer is available to user I/O writers */
 	rl->rb_budget = budget;
 	rl->rb_user_max = budget;
-	rl->rb_max_io = budget >> 1;
 	rl->rb_gc_max = 0;
 	rl->rb_state = PBLK_RL_HIGH;
 
+	/* Maximize I/O size and ansure that back threshold is respected */
+	if (threshold)
+		rl->rb_max_io = budget - pblk->min_write_pgs_data - threshold;
+	else
+		rl->rb_max_io = budget - pblk->min_write_pgs_data - 1;
+
 	atomic_set(&rl->rb_user_cnt, 0);
 	atomic_set(&rl->rb_gc_cnt, 0);
 	atomic_set(&rl->rb_space, -1);