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-rw-r--r--drivers/crypto/caam/desc_constr.h27
1 files changed, 27 insertions, 0 deletions
diff --git a/drivers/crypto/caam/desc_constr.h b/drivers/crypto/caam/desc_constr.h
index 536f360bf131..1fe50a4fefaa 100644
--- a/drivers/crypto/caam/desc_constr.h
+++ b/drivers/crypto/caam/desc_constr.h
@@ -18,6 +18,33 @@
#define CAAM_DESC_BYTES_MAX (CAAM_CMD_SZ * MAX_CAAM_DESCSIZE)
#define DESC_JOB_IO_LEN (CAAM_CMD_SZ * 5 + CAAM_PTR_SZ * 3)
+/*
+ * The CAAM QI hardware constructs a job descriptor which points
+ * to shared descriptor (as pointed by context_a of FQ to CAAM).
+ * When the job descriptor is executed by deco, the whole job
+ * descriptor together with shared descriptor gets loaded in
+ * deco buffer which is 64 words long (each 32-bit).
+ *
+ * The job descriptor constructed by QI hardware has layout:
+ *
+ * HEADER (1 word)
+ * Shdesc ptr (1 or 2 words)
+ * SEQ_OUT_PTR (1 word)
+ * Out ptr (1 or 2 words)
+ * Out length (1 word)
+ * SEQ_IN_PTR (1 word)
+ * In ptr (1 or 2 words)
+ * In length (1 word)
+ *
+ * The shdesc ptr is used to fetch shared descriptor contents
+ * into deco buffer.
+ *
+ * Apart from shdesc contents, the total number of words that
+ * get loaded in deco buffer are '8' or '11'. The remaining words
+ * in deco buffer can be used for storing shared descriptor.
+ */
+#define MAX_SDLEN ((CAAM_DESC_BYTES_MAX - DESC_JOB_IO_LEN) / CAAM_CMD_SZ)
+
#ifdef DEBUG
#define PRINT_POS do { printk(KERN_DEBUG "%02d: %s\n", desc_len(desc),\
&__func__[sizeof("append")]); } while (0)