[PATCH] Revert "caam: Fix CAAM error on startup"

[Fabio Estevam]

This reverts commit 159b6f0e119962ce5da645f548cefe9196c8778e.

Since commit 159b6f0e1199 ("caam: Fix CAAM error on startup") the following
regression was reported by Tim Harvey:

"I've found that this patch causes a regression on an imx8mm board
(imx8mm_venice_defconfig) where the first call to caam_rng_read fails
here in jr_dequeue but if you call it again it works. With some
debugging added:
SEC0:  RNG instantiated
...
Hit any key to stop autoboot:  0
u-boot=> rng list
RNG #0 - caam-rng
u-boot=> rng 0 10
caam_rng_read caam-rng len=16
run_descriptor_jr_idx idx=0
Error in SEC deq: -1
caam_rng_read_one run_descriptor_jr failed: -1
caam_rng_read caam-rng caam_rng_read_one failed: -5
Reading RNG failed
u-boot=> rng 0 10
caam_rng_read caam-rng len=16
run_descriptor_jr_idx idx=0
00000000: ad 2e ad c0 2a 12 27 c4 65 82 66 19 be ef f6 07  ....*.'.e.f.....

If I revert your patch caam_rng_read works initially and on subsequent
calls."

" I ran into this when I was testing
lwIP HTTPS as it causes anything that uses dm_rng to fail the first
time (such as HTTPS)."

Revert it for now to avoid the regression.

Reported-by: Tim Harvey <tharvey at gateworks.com>
Signed-off-by: Fabio Estevam <festevam at gmail.com>
---
 drivers/crypto/fsl/jr.c | 25 +++++++++++--------------
 drivers/crypto/fsl/jr.h |  4 ++++
 2 files changed, 15 insertions(+), 14 deletions(-)

diff --git a/drivers/crypto/fsl/jr.c b/drivers/crypto/fsl/jr.c
index 1d95d2bff278..8f7a821ebf3d 100644
--- a/drivers/crypto/fsl/jr.c
+++ b/drivers/crypto/fsl/jr.c
@@ -217,6 +217,13 @@ static int jr_enqueue(uint32_t *desc_addr,
 
 	jr->head = (head + 1) & (jr->size - 1);
 
+	/* Invalidate output ring */
+	start = (unsigned long)jr->output_ring &
+					~(ARCH_DMA_MINALIGN - 1);
+	end = ALIGN((unsigned long)jr->output_ring + jr->op_size,
+		    ARCH_DMA_MINALIGN);
+	invalidate_dcache_range(start, end);
+
 	sec_out32(&regs->irja, 1);
 
 	return 0;
@@ -236,7 +243,6 @@ static int jr_dequeue(int sec_idx, struct caam_regs *caam)
 #else
 	uint32_t *addr;
 #endif
-	unsigned long start, end;
 
 	while (sec_in32(&regs->orsf) && CIRC_CNT(jr->head, jr->tail,
 						 jr->size)) {
@@ -244,11 +250,6 @@ static int jr_dequeue(int sec_idx, struct caam_regs *caam)
 		found = 0;
 
 		caam_dma_addr_t op_desc;
-
-		/* Invalidate output ring */
-		start = (unsigned long)jr->output_ring & ~(ARCH_DMA_MINALIGN - 1);
-		end = ALIGN((unsigned long)jr->output_ring + jr->op_size, ARCH_DMA_MINALIGN);
-		invalidate_dcache_range(start, end);
 	#ifdef CONFIG_CAAM_64BIT
 		/* Read the 64 bit Descriptor address from Output Ring.
 		 * The 32 bit hign and low part of the address will
@@ -282,13 +283,8 @@ static int jr_dequeue(int sec_idx, struct caam_regs *caam)
 		}
 
 		/* Error condition if match not found */
-		if (!found) {
-			int slots_full = sec_in32(&regs->orsf);
-
-			jr->tail = (jr->tail + slots_full) & (jr->size - 1);
-			sec_out32(&regs->orjr, slots_full);
+		if (!found)
 			return -1;
-		}
 
 		jr->info[idx].op_done = 1;
 		callback = (void *)jr->info[idx].callback;
@@ -300,14 +296,14 @@ static int jr_dequeue(int sec_idx, struct caam_regs *caam)
 		 */
 		if (idx == tail)
 			do {
-				jr->info[tail].op_done = 0;
 				tail = (tail + 1) & (jr->size - 1);
 			} while (jr->info[tail].op_done);
 
 		jr->tail = tail;
-
+		jr->read_idx = (jr->read_idx + 1) & (jr->size - 1);
 
 		sec_out32(&regs->orjr, 1);
+		jr->info[idx].op_done = 0;
 
 		callback(status, arg);
 	}
@@ -382,6 +378,7 @@ static int jr_sw_cleanup(uint8_t sec_idx, struct caam_regs *caam)
 
 	jr->head = 0;
 	jr->tail = 0;
+	jr->read_idx = 0;
 	jr->write_idx = 0;
 	memset(jr->info, 0, sizeof(jr->info));
 	memset(jr->input_ring, 0, jr->size * sizeof(caam_dma_addr_t));
diff --git a/drivers/crypto/fsl/jr.h b/drivers/crypto/fsl/jr.h
index 8d5ca03e5015..b136cd8d05a9 100644
--- a/drivers/crypto/fsl/jr.h
+++ b/drivers/crypto/fsl/jr.h
@@ -83,6 +83,10 @@ struct jobring {
 	 * in-order job completion
 	 */
 	int tail;
+	/* Read index of the output ring. It may not match with tail in case
+	 * of out of order completetion
+	 */
+	int read_idx;
 	/* Write index to input ring. Would be always equal to head */
 	int write_idx;
 	/* Size of the rings. */
-- 
2.34.1