[PATCH v3 08/17] riscv: Introduce vendor variants of extension helpers
Charlie Jenkins
charlie at rivosinc.com
Sat Apr 20 18:04:40 PDT 2024
Vendor extensions are maintained in per-vendor structs (separate from
standard extensions which live in riscv_isa). Create vendor variants for
the existing extension helpers to interface with the riscv_isa_vendor
bitmaps. There is a good amount of overlap between these functions, so
the alternative checking code can be factored out.
Signed-off-by: Charlie Jenkins <charlie at rivosinc.com>
---
arch/riscv/errata/sifive/errata.c | 3 ++
arch/riscv/errata/thead/errata.c | 3 ++
arch/riscv/include/asm/cpufeature.h | 86 +++++++++++++++++-------------
arch/riscv/include/asm/vendor_extensions.h | 56 +++++++++++++++++++
arch/riscv/kernel/cpufeature.c | 20 ++++---
arch/riscv/kernel/vendor_extensions.c | 40 ++++++++++++++
6 files changed, 164 insertions(+), 44 deletions(-)
diff --git a/arch/riscv/errata/sifive/errata.c b/arch/riscv/errata/sifive/errata.c
index 3d9a32d791f7..b29b6e405ff2 100644
--- a/arch/riscv/errata/sifive/errata.c
+++ b/arch/riscv/errata/sifive/errata.c
@@ -12,6 +12,7 @@
#include <asm/alternative.h>
#include <asm/vendorid_list.h>
#include <asm/errata_list.h>
+#include <asm/vendor_extensions.h>
struct errata_info_t {
char name[32];
@@ -99,6 +100,8 @@ void sifive_errata_patch_func(struct alt_entry *begin, struct alt_entry *end,
for (alt = begin; alt < end; alt++) {
if (alt->vendor_id != SIFIVE_VENDOR_ID)
continue;
+ if (alt->patch_id >= RISCV_VENDOR_EXT_ALTERNATIVES_BASE)
+ continue;
if (alt->patch_id >= ERRATA_SIFIVE_NUMBER) {
WARN(1, "This errata id:%d is not in kernel errata list", alt->patch_id);
continue;
diff --git a/arch/riscv/errata/thead/errata.c b/arch/riscv/errata/thead/errata.c
index b1c410bbc1ae..d8e78cc687bc 100644
--- a/arch/riscv/errata/thead/errata.c
+++ b/arch/riscv/errata/thead/errata.c
@@ -18,6 +18,7 @@
#include <asm/io.h>
#include <asm/patch.h>
#include <asm/vendorid_list.h>
+#include <asm/vendor_extensions.h>
static bool errata_probe_pbmt(unsigned int stage,
unsigned long arch_id, unsigned long impid)
@@ -163,6 +164,8 @@ void thead_errata_patch_func(struct alt_entry *begin, struct alt_entry *end,
for (alt = begin; alt < end; alt++) {
if (alt->vendor_id != THEAD_VENDOR_ID)
continue;
+ if (alt->patch_id >= RISCV_VENDOR_EXT_ALTERNATIVES_BASE)
+ continue;
if (alt->patch_id >= ERRATA_THEAD_NUMBER)
continue;
diff --git a/arch/riscv/include/asm/cpufeature.h b/arch/riscv/include/asm/cpufeature.h
index db6a6d7d6b2e..83e1143db9ad 100644
--- a/arch/riscv/include/asm/cpufeature.h
+++ b/arch/riscv/include/asm/cpufeature.h
@@ -103,22 +103,13 @@ bool __riscv_isa_extension_available(const unsigned long *isa_bitmap, unsigned i
__riscv_isa_extension_available(isa_bitmap, RISCV_ISA_EXT_##ext)
static __always_inline bool
-riscv_has_extension_likely(const unsigned long ext)
+__riscv_has_extension_likely_alternatives(const unsigned long vendor, const unsigned long ext)
{
- compiletime_assert(ext < RISCV_ISA_EXT_MAX,
- "ext must be < RISCV_ISA_EXT_MAX");
-
- if (IS_ENABLED(CONFIG_RISCV_ALTERNATIVE)) {
- asm goto(
- ALTERNATIVE("j %l[l_no]", "nop", 0, %[ext], 1)
- :
- : [ext] "i" (ext)
- :
- : l_no);
- } else {
- if (!__riscv_isa_extension_available(NULL, ext))
- goto l_no;
- }
+ asm goto(ALTERNATIVE("j %l[l_no]", "nop", %[vendor], %[ext], 1)
+ :
+ : [vendor] "i" (vendor), [ext] "i" (ext)
+ :
+ : l_no);
return true;
l_no:
@@ -126,42 +117,65 @@ riscv_has_extension_likely(const unsigned long ext)
}
static __always_inline bool
-riscv_has_extension_unlikely(const unsigned long ext)
+__riscv_has_extension_unlikely_alternatives(const unsigned long vendor, const unsigned long ext)
{
- compiletime_assert(ext < RISCV_ISA_EXT_MAX,
- "ext must be < RISCV_ISA_EXT_MAX");
-
- if (IS_ENABLED(CONFIG_RISCV_ALTERNATIVE)) {
- asm goto(
- ALTERNATIVE("nop", "j %l[l_yes]", 0, %[ext], 1)
- :
- : [ext] "i" (ext)
- :
- : l_yes);
- } else {
- if (__riscv_isa_extension_available(NULL, ext))
- goto l_yes;
- }
+ asm goto(ALTERNATIVE("nop", "j %l[l_yes]", %[vendor], %[ext], 1)
+ :
+ : [vendor] "i" (vendor), [ext] "i" (ext)
+ :
+ : l_yes);
return false;
l_yes:
return true;
}
+static __always_inline bool
+riscv_has_extension_likely(const unsigned long ext)
+{
+ compiletime_assert(ext < RISCV_ISA_EXT_MAX,
+ "ext must be < RISCV_ISA_EXT_MAX");
+
+ if (IS_ENABLED(CONFIG_RISCV_ALTERNATIVE))
+ return __riscv_has_extension_likely_alternatives(0, ext);
+ else
+ return __riscv_isa_extension_available(NULL, ext);
+}
+
+static __always_inline bool
+riscv_has_extension_unlikely(const unsigned long ext)
+{
+ compiletime_assert(ext < RISCV_ISA_EXT_MAX,
+ "ext must be < RISCV_ISA_EXT_MAX");
+
+ if (IS_ENABLED(CONFIG_RISCV_ALTERNATIVE))
+ return __riscv_has_extension_unlikely_alternatives(0, ext);
+ else
+ return __riscv_isa_extension_available(NULL, ext);
+}
+
static __always_inline bool riscv_cpu_has_extension_likely(int cpu, const unsigned long ext)
{
- if (IS_ENABLED(CONFIG_RISCV_ALTERNATIVE) && riscv_has_extension_likely(ext))
- return true;
+ compiletime_assert(ext < RISCV_ISA_EXT_MAX,
+ "ext must be < RISCV_ISA_EXT_MAX");
- return __riscv_isa_extension_available(hart_isa[cpu].isa, ext);
+ if (IS_ENABLED(CONFIG_RISCV_ALTERNATIVE) &&
+ __riscv_has_extension_likely_alternatives(0, ext))
+ return true;
+ else
+ return __riscv_isa_extension_available(hart_isa[cpu].isa, ext);
}
static __always_inline bool riscv_cpu_has_extension_unlikely(int cpu, const unsigned long ext)
{
- if (IS_ENABLED(CONFIG_RISCV_ALTERNATIVE) && riscv_has_extension_unlikely(ext))
- return true;
+ compiletime_assert(ext < RISCV_ISA_EXT_MAX,
+ "ext must be < RISCV_ISA_EXT_MAX");
- return __riscv_isa_extension_available(hart_isa[cpu].isa, ext);
+ if (IS_ENABLED(CONFIG_RISCV_ALTERNATIVE) &&
+ __riscv_has_extension_unlikely_alternatives(0, ext))
+ return true;
+ else
+ return __riscv_isa_extension_available(hart_isa[cpu].isa, ext);
}
#endif
diff --git a/arch/riscv/include/asm/vendor_extensions.h b/arch/riscv/include/asm/vendor_extensions.h
index 0af1ddd0af70..3e676a96016e 100644
--- a/arch/riscv/include/asm/vendor_extensions.h
+++ b/arch/riscv/include/asm/vendor_extensions.h
@@ -23,4 +23,60 @@ extern const struct riscv_isa_vendor_ext_data_list *riscv_isa_vendor_ext_list[];
extern const size_t riscv_isa_vendor_ext_list_size;
+/*
+ * The alternatives need some way of distinguishing between vendor extensions
+ * and errata. Incrementing all of the vendor extension keys so they are at
+ * least 0x8000 accomplishes that.
+ */
+#define RISCV_VENDOR_EXT_ALTERNATIVES_BASE 0x8000
+
+bool __riscv_isa_vendor_extension_available(int cpu, unsigned long vendor, unsigned int bit);
+#define riscv_cpu_isa_vendor_extension_available(cpu, vendor, ext) \
+ __riscv_isa_vendor_extension_available(cpu, vendor, RISCV_ISA_VENDOR_EXT_##ext)
+#define riscv_isa_vendor_extension_available(vendor, ext) \
+ __riscv_isa_vendor_extension_available(-1, vendor, RISCV_ISA_VENDOR_EXT_##ext)
+
+static __always_inline bool
+riscv_has_vendor_extension_likely(const unsigned long vendor, const unsigned long ext)
+{
+ if (IS_ENABLED(CONFIG_RISCV_ALTERNATIVE))
+ return __riscv_has_extension_likely_alternatives(vendor,
+ ext + RISCV_VENDOR_EXT_ALTERNATIVES_BASE);
+ else
+ return __riscv_isa_vendor_extension_available(-1, vendor, ext);
+}
+
+static __always_inline bool
+riscv_has_vendor_extension_unlikely(const unsigned long vendor, const unsigned long ext)
+{
+ if (IS_ENABLED(CONFIG_RISCV_ALTERNATIVE))
+ return __riscv_has_extension_unlikely_alternatives(vendor,
+ ext + RISCV_VENDOR_EXT_ALTERNATIVES_BASE);
+ else
+ return __riscv_isa_vendor_extension_available(-1, vendor, ext);
+}
+
+static __always_inline bool riscv_cpu_has_vendor_extension_likely(const unsigned long vendor,
+ int cpu, const unsigned long ext)
+{
+ if (IS_ENABLED(CONFIG_RISCV_ALTERNATIVE) &&
+ __riscv_has_extension_likely_alternatives(vendor,
+ ext + RISCV_VENDOR_EXT_ALTERNATIVES_BASE))
+ return true;
+ else
+ return __riscv_isa_vendor_extension_available(cpu, vendor, ext);
+}
+
+static __always_inline bool riscv_cpu_has_vendor_extension_unlikely(const unsigned long vendor,
+ int cpu,
+ const unsigned long ext)
+{
+ if (IS_ENABLED(CONFIG_RISCV_ALTERNATIVE) &&
+ __riscv_has_extension_unlikely_alternatives(vendor,
+ ext + RISCV_VENDOR_EXT_ALTERNATIVES_BASE))
+ return true;
+ else
+ return __riscv_isa_vendor_extension_available(cpu, vendor, ext);
+}
+
#endif /* _ASM_VENDOR_EXTENSIONS_H */
diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
index c9f36822e337..17371887abcc 100644
--- a/arch/riscv/kernel/cpufeature.c
+++ b/arch/riscv/kernel/cpufeature.c
@@ -833,25 +833,29 @@ void __init_or_module riscv_cpufeature_patch_func(struct alt_entry *begin,
{
struct alt_entry *alt;
void *oldptr, *altptr;
- u16 id, value;
+ u16 id, value, vendor;
if (stage == RISCV_ALTERNATIVES_EARLY_BOOT)
return;
for (alt = begin; alt < end; alt++) {
- if (alt->vendor_id != 0)
- continue;
-
id = PATCH_ID_CPUFEATURE_ID(alt->patch_id);
+ vendor = PATCH_ID_CPUFEATURE_ID(alt->vendor_id);
- if (id >= RISCV_ISA_EXT_MAX) {
+ if (id < RISCV_ISA_EXT_MAX) {
+ if (alt->vendor_id != 0)
+ continue;
+
+ if (!__riscv_isa_extension_available(NULL, id))
+ continue;
+ } else if (id >= RISCV_VENDOR_EXT_ALTERNATIVES_BASE) {
+ if (!__riscv_isa_vendor_extension_available(-1, vendor, id))
+ continue;
+ } else {
WARN(1, "This extension id:%d is not in ISA extension list", id);
continue;
}
- if (!__riscv_isa_extension_available(NULL, id))
- continue;
-
value = PATCH_ID_CPUFEATURE_VALUE(alt->patch_id);
if (!riscv_cpufeature_patch_check(id, value))
continue;
diff --git a/arch/riscv/kernel/vendor_extensions.c b/arch/riscv/kernel/vendor_extensions.c
index f76cb3013c2d..eced93eec5a6 100644
--- a/arch/riscv/kernel/vendor_extensions.c
+++ b/arch/riscv/kernel/vendor_extensions.c
@@ -3,6 +3,7 @@
* Copyright 2024 Rivos, Inc
*/
+#include <asm/vendorid_list.h>
#include <asm/vendor_extensions.h>
#include <asm/vendor_extensions/thead.h>
@@ -16,3 +17,42 @@ const struct riscv_isa_vendor_ext_data_list *riscv_isa_vendor_ext_list[] = {
};
const size_t riscv_isa_vendor_ext_list_size = ARRAY_SIZE(riscv_isa_vendor_ext_list);
+
+/**
+ * __riscv_isa_vendor_extension_available() - Check whether given vendor
+ * extension is available or not.
+ *
+ * @cpu: check if extension is available on this cpu
+ * @vendor: vendor that the extension is a member of
+ * @bit: bit position of the desired extension
+ * Return: true or false
+ *
+ * NOTE: When cpu is -1, will check if extension is available on all cpus
+ */
+bool __riscv_isa_vendor_extension_available(int cpu, unsigned long vendor, unsigned int bit)
+{
+ unsigned long *bmap;
+ struct riscv_isainfo *cpu_bmap;
+ size_t bmap_size;
+
+ switch (vendor) {
+#ifdef CONFIG_RISCV_ISA_VENDOR_EXT_THEAD
+ case THEAD_VENDOR_ID:
+ bmap = riscv_isa_vendor_ext_list_thead.vendor_bitmap;
+ cpu_bmap = riscv_isa_vendor_ext_list_thead.per_hart_vendor_bitmap;
+ bmap_size = riscv_isa_vendor_ext_list_thead.bitmap_size;
+ break;
+#endif
+ default:
+ return false;
+ }
+
+ if (cpu != -1)
+ bmap = cpu_bmap[cpu].isa;
+
+ if (bit >= bmap_size)
+ return false;
+
+ return test_bit(bit, bmap) ? true : false;
+}
+EXPORT_SYMBOL_GPL(__riscv_isa_vendor_extension_available);
--
2.44.0
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