Implement fixed-point hash instructions #437
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These are done in loadstore1. The HashDigest function is computed in 9 cycles; for 8 cycles, a state machine does 4 steps of key expansion per cycle, and for each of 4 lanes of data, does 4 steps of ciphering; then there is 1 cycle to combine the results into the final hash value. At present, hashcmp does not overlap the computation of the hash with fetching of data from memory (in the case of a cache miss). The 'is_signed' field in the instruction decode table is used to distinguish hashst and hashcmp from ordinary loads and stores. We have a new 'RBC' value for input_reg_c_t which says that we are reading RB but we want the value to come in via the C port; this is because we want the 5-bit immediate offset on the B port. Note that in the list of insn_code values, hashst/chk have been put in the section for instructions with an RB operand, which is not strictly correct given that the B port is used for the immediate D operand; however, adding them to the section for instructions without an RB operand would have made that section exceed 128 entries, causing changes to the padding needed. The only downside to having hashst/cmp where they are is that the debug logic can't use the RB port to read GPR/FPRs when a hashst/cmp instruction is being decoded. Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Previously the computation of whether an instruction is privileged or not was done based on the insn_type. However, that meant that l*cix (OP_LOAD) and st*cix (OP_STORE) couldn't be made privileged, and neither could tlbsync (OP_NOP). Instead, this adds a field to the main instruction decode table to indicate privileged instructions, and makes the cache-inhibited loads and stores privileged, along with tlbsync. Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
These provide facilities similar to hashstp, hashchk and HASHKEYR, but restricted to privileged mode. Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
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This implements hashst, hashchk, hashstp and haschkp, which were added in ISA v3.1B. They are used to provide protection against return-oriented programming attacks.