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[REVIEW,ONLY,2/2] NEAR-RATIFICATION RISC-V: Add platform property/capability extensions

Message ID 8083ad9d5339afdeb7f1ba88ee6af0665dcc76d5.1667478033.git.research_trasio@irq.a4lg.com
State Accepted
Headers
Series NEAR RATIFICATION RISC-V: Extensions from the RISC-V Profiles |

Checks

Context Check Description
snail/binutils-gdb-check success Github commit url

Commit Message

Tsukasa OI Nov. 3, 2022, 12:26 p.m. UTC 
  [DO NOT MERGE]
RISC-V Profiles are frozen but -- from my view -- this document will still
change in some way.  Meanwhile, this patch should not be merged upstream.
This commit uses tentative version 1.0 (as there are no versions).

RISC-V Profiles document defines number of "extensions" that indicate
certain platform properties/capabilities just like 'Zkt' extension from the
RISC-V cryptography extensions.

This commit defines 19 platform property/capability extensions as defined
in the RISC-V Profiles documentation.
The version number is tentatively set to 1.0.

The only exception: 'Ssstateen' extension is defined separately because it
defines a subset (supervisor/hypervisor view) of the 'Smstateen' extension.

This is based on the latest version of RISC-V Profiles (version 0.9-draft):
<https://github.com/riscv/riscv-profiles/commit/226b7f643067b29abc6723fac60d5f6d3f9eb901>

[Definition]

"Main memory regions": memory regions with both the cacheability
                       and coherence PMAs.

[New Unprivileged Extensions]

1.  'Ziccif'
    "Main memory regions" support instruction fetch and any instruction
    fetches of naturally aligned power-of-2 sizes up to min(ILEN, XLEN)
    are atomic.
2.  'Ziccrse'
    "Main memory regions" provide the eventual success guarantee for
    LR/SC sequence.
3.  'Ziccamoa'
    "Main memory regions" support all AMO operations including atomic swap,
    logical and arithmetic operations.
4.  'Za64rs'
    For LR/SC instructions, reservation sets are contiguous, naturally
    aligned and at most 64-bytes in size.
5.  'Za128rs'
    Likewise, but reservation sets are at most 128-bytes in size.
6.  'Zicclsm'
    Misaligned loads / stores to "main memory regions" are supported.
    Those include both regular scalar and vector access but does not include
    AMOs and other specialized forms of memory access.
7.  'Zic64b'
    Cache blocks are (exactly) 64-bytes in size and naturally aligned.

[New Privileged Extensions]

1.  'Svbare'
    "satp" mode Bare is supported.
2.  'Ssptead'
    Page-fault exceptions are raised when a page is accessed when A bit is
    clear, or written when D bit is clear.
3.  'Ssccptr'
    "Main memory regions" support hardware page-table reads.
4.  'Sstvecd'
    "stvec" mode Direct is supported.  When "stvec" mode is Direct,
    "stvec.BASE" is capable of holding any valid 4-byte aligned address.
5.  'Sstvala'
    "stval" is always written with a nonzero value whenever possible as
    specified in the Privileged Architecture documentation
    (version 20211203: see section 4.1.9).
6.  'Ssu64xl'
    "sstatus.UXL"=64 [sic].
7.  'Shcounterenw'
    For any "hpmcounter" that is not read-only zero, the corresponding bit
    in "hcounteren" is writable.
8.  'Shvstvala'
    Similar to 'Sstvala' but the same rule applies to "vstval".
9.  'Shtvala'
    "htval" is written with the faulting guest physical address as long as
    permitted by the ISA (a bit similar to 'Sstvala' and 'Shvstvala').
10. 'Shvstvecd'
    Similar to 'Sstvecd' but the same rule applies to "vstvec".
11. 'Shvsatpa'
    All translation modes supported in "satp" are also supported in "vsatp".
12. 'Shgatpa'
    For each supported virtual memory scheme SvNN supported in "satp", the
    corresponding "hgatp" SvNNx4 mode is supported.  The "hgatp" mode Bare
    is also supported.

[Implications]

(Due to reservation set size constraints)
-   'Za64rs' -> 'Za128rs'

(Due to the fact that a privileged "extension" directly refers a CSR)
-   'Svbare'       -> 'Zicsr'
-   'Sstvecd'      -> 'Zicsr'
-   'Sstvala'      -> 'Zicsr'
-   'Ssu64xl'      -> 'Zicsr'

(Due to the fact that a privileged "extension" indirectly depends on CSRs)
-   'Ssptead' -> 'Zicsr'
-   'Ssccptr' -> 'Zicsr'

(Due to the fact that a privileged "extension" is a hypervisor property)
-   'Shcounterenw' -> 'H'
-   'Shvstvala'    -> 'H'
-   'Shtvala'      -> 'H'
-   'Shvstvecd'    -> 'H'
-   'Shvsatpa'     -> 'H'
-   'Shgatpa'      -> 'H'

bfd/ChangeLog:

	* elfxx-riscv.c
	(riscv_implicit_subsets): Add 13 implication rules.
	(riscv_supported_std_z_ext) Add 7 property/capability extensions.
	(riscv_supported_std_s_ext) Add 12 property/capability extensions.
---
 bfd/elfxx-riscv.c | 34 +++++++++++++++++++++++++++++++++-
 1 file changed, 33 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/bfd/elfxx-riscv.c b/bfd/elfxx-riscv.c
index 781b57cbd98..64811a138a3 100644
--- a/bfd/elfxx-riscv.c
+++ b/bfd/elfxx-riscv.c
@@ -1047,7 +1047,6 @@  static struct riscv_implicit_subset riscv_implicit_subsets[] =
   {"g", "zicsr",	check_implicit_always},
   {"g", "zifencei",	check_implicit_always},
   {"m", "zmmul",	check_implicit_always},
-  {"h", "zicsr",	check_implicit_always},
   {"q", "d",		check_implicit_always},
   {"v", "d",		check_implicit_always},
   {"v", "zve64d",	check_implicit_always},
@@ -1083,6 +1082,7 @@  static struct riscv_implicit_subset riscv_implicit_subsets[] =
   {"zhinx", "zhinxmin",	check_implicit_always},
   {"zhinxmin", "zfinx",	check_implicit_always},
   {"zfinx", "zicsr",	check_implicit_always},
+  {"za64rs", "za128rs",	check_implicit_always},
   {"zk", "zkn",		check_implicit_always},
   {"zk", "zkr",		check_implicit_always},
   {"zk", "zkt",		check_implicit_always},
@@ -1099,9 +1099,22 @@  static struct riscv_implicit_subset riscv_implicit_subsets[] =
   {"zks", "zksh",	check_implicit_always},
   {"smstateen", "ssstateen",	check_implicit_always},
   {"smepmp", "zicsr",		check_implicit_always},
+  {"shcounterenw", "h",		check_implicit_always},
+  {"shgatpa", "h",		check_implicit_always},
+  {"shtvala", "h",		check_implicit_always},
+  {"shvsatpa", "h",		check_implicit_always},
+  {"shvstvala", "h",		check_implicit_always},
+  {"shvstvecd", "h",		check_implicit_always},
+  {"h", "zicsr",		check_implicit_always},
+  {"ssccptr", "zicsr",		check_implicit_always},
   {"sscofpmf", "zicsr",		check_implicit_always},
+  {"ssptead", "zicsr",		check_implicit_always},
   {"ssstateen", "zicsr",	check_implicit_always},
   {"sstc", "zicsr",		check_implicit_always},
+  {"sstvala", "zicsr",		check_implicit_always},
+  {"sstvecd", "zicsr",		check_implicit_always},
+  {"ssu64xl", "zicsr",		check_implicit_always},
+  {"svbare", "zicsr",		check_implicit_always},
   {NULL, NULL, NULL}
 };
 
@@ -1159,6 +1172,11 @@  static struct riscv_supported_ext riscv_supported_std_ext[] =
 
 static struct riscv_supported_ext riscv_supported_std_z_ext[] =
 {
+  {"zic64b",		ISA_SPEC_CLASS_DRAFT,		1, 0,  0 },
+  {"ziccamoa",		ISA_SPEC_CLASS_DRAFT,		1, 0,  0 },
+  {"ziccif",		ISA_SPEC_CLASS_DRAFT,		1, 0,  0 },
+  {"zicclsm",		ISA_SPEC_CLASS_DRAFT,		1, 0,  0 },
+  {"ziccrse",		ISA_SPEC_CLASS_DRAFT,		1, 0,  0 },
   {"zicbom",		ISA_SPEC_CLASS_DRAFT,		1, 0,  0 },
   {"zicbop",		ISA_SPEC_CLASS_DRAFT,		1, 0,  0 },
   {"zicboz",		ISA_SPEC_CLASS_DRAFT,		1, 0,  0 },
@@ -1168,6 +1186,8 @@  static struct riscv_supported_ext riscv_supported_std_z_ext[] =
   {"zifencei",		ISA_SPEC_CLASS_20190608,	2, 0,  0 },
   {"zihintpause",	ISA_SPEC_CLASS_DRAFT,		2, 0,  0 },
   {"zmmul",		ISA_SPEC_CLASS_DRAFT,		1, 0,  0 },
+  {"za64rs",		ISA_SPEC_CLASS_DRAFT,		1, 0,  0 },
+  {"za128rs",		ISA_SPEC_CLASS_DRAFT,		1, 0,  0 },
   {"zawrs",		ISA_SPEC_CLASS_DRAFT,		1, 0,  0 },
   {"zfh",		ISA_SPEC_CLASS_DRAFT,		1, 0,  0 },
   {"zfhmin",		ISA_SPEC_CLASS_DRAFT,		1, 0,  0 },
@@ -1217,11 +1237,23 @@  static struct riscv_supported_ext riscv_supported_std_z_ext[] =
 
 static struct riscv_supported_ext riscv_supported_std_s_ext[] =
 {
+  {"shcounterenw",	ISA_SPEC_CLASS_DRAFT,		1, 0, 0 },
+  {"shgatpa",		ISA_SPEC_CLASS_DRAFT,		1, 0, 0 },
+  {"shtvala",		ISA_SPEC_CLASS_DRAFT,		1, 0, 0 },
+  {"shvsatpa",		ISA_SPEC_CLASS_DRAFT,		1, 0, 0 },
+  {"shvstvala",		ISA_SPEC_CLASS_DRAFT,		1, 0, 0 },
+  {"shvstvecd",		ISA_SPEC_CLASS_DRAFT,		1, 0, 0 },
   {"smepmp",		ISA_SPEC_CLASS_DRAFT,		1, 0, 0 },
   {"smstateen",		ISA_SPEC_CLASS_DRAFT,		1, 0, 0 },
+  {"ssccptr",		ISA_SPEC_CLASS_DRAFT,		1, 0, 0 },
   {"sscofpmf",		ISA_SPEC_CLASS_DRAFT,		1, 0, 0 },
+  {"ssptead",		ISA_SPEC_CLASS_DRAFT,		1, 0, 0 },
   {"ssstateen",		ISA_SPEC_CLASS_DRAFT,		1, 0, 0 },
   {"sstc",		ISA_SPEC_CLASS_DRAFT,		1, 0, 0 },
+  {"sstvala",		ISA_SPEC_CLASS_DRAFT,		1, 0, 0 },
+  {"sstvecd",		ISA_SPEC_CLASS_DRAFT,		1, 0, 0 },
+  {"ssu64xl",		ISA_SPEC_CLASS_DRAFT,		1, 0, 0 },
+  {"svbare",		ISA_SPEC_CLASS_DRAFT,		1, 0, 0 },
   {"svinval",		ISA_SPEC_CLASS_DRAFT,		1, 0, 0 },
   {"svnapot",		ISA_SPEC_CLASS_DRAFT,		1, 0, 0 },
   {"svpbmt",		ISA_SPEC_CLASS_DRAFT,		1, 0, 0 },