@@ -1,3 +1,4 @@
+obj-y += cpufeature.o
obj-$(CONFIG_EARLY_PRINTK) += early_printk.o
obj-y += entry.o
obj-y += mm.o
new file mode 100644
@@ -0,0 +1,479 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Originally taken for Linux kernel v6.12-rc3.
+ *
+ * Copyright (C) 2015 ARM Ltd.
+ * Copyright (C) 2017 SiFive
+ * Copyright (C) 2024 Vates
+ */
+
+#include <xen/bitmap.h>
+#include <xen/ctype.h>
+#include <xen/device_tree.h>
+#include <xen/errno.h>
+#include <xen/init.h>
+#include <xen/lib.h>
+#include <xen/sections.h>
+
+#include <asm/cpufeature.h>
+
+#ifdef CONFIG_ACPI
+# error "cpufeature.c functions should be updated to support ACPI"
+#endif
+
+struct riscv_isa_ext_data {
+ unsigned int id;
+ const char *name;
+};
+
+#define RISCV_ISA_EXT_DATA(ext_name, ext_id) \
+{ \
+ .id = ext_id, \
+ .name = #ext_name, \
+}
+
+/* Host ISA bitmap */
+static __ro_after_init DECLARE_BITMAP(riscv_isa, RISCV_ISA_EXT_MAX);
+
+static int __init dt_get_cpuid_from_node(const struct dt_device_node *cpu,
+ unsigned long *dt_cpuid)
+{
+ const __be32 *prop;
+ unsigned int reg_len;
+
+ /*
+ * For debug purpose check dt_n_size_cells(cpu) value.
+ *
+ * Based on DT's bindings [1] and RISC-V's DTS files in kernel #size-cells
+ * for cpu node is expected to be 0.
+ *
+ * [1] https://www.kernel.org/doc/Documentation/devicetree/bindings/riscv/cpus.txt
+ */
+ if ( dt_n_size_cells(cpu) != 0 )
+ printk("DT's cpu node `%s`: #size-cells %d\n",
+ dt_node_full_name(cpu), dt_n_size_cells(cpu));
+
+ prop = dt_get_property(cpu, "reg", ®_len);
+ if ( !prop )
+ {
+ printk("cpu node `%s`: has no reg property\n", dt_node_full_name(cpu));
+ return -EINVAL;
+ }
+
+ if ( reg_len < dt_cells_to_size(dt_n_addr_cells(cpu)) )
+ {
+ printk("cpu node `%s`: reg property too short\n",
+ dt_node_full_name(cpu));
+ return -EINVAL;
+ }
+
+ /*
+ * It is safe to convert `paddr_t` to `unsigned long` as dt_read_paddr()
+ * in the context of this function returns cpuid which according to RISC-V
+ * specification could be from 0 to ((1ULL << (MXLEN)) - 1), where
+ * MXLEN=32 for RV32 and MXLEN=64 for RV64.
+ */
+ *dt_cpuid = dt_read_paddr(prop, dt_n_addr_cells(cpu));
+
+ return 0;
+}
+
+/*
+ * The canonical order of ISA extension names in the ISA string is defined in
+ * chapter 27 of the unprivileged specification.
+ *
+ * The specification uses vague wording, such as should, when it comes to
+ * ordering, so for our purposes the following rules apply:
+ *
+ * 1. All multi-letter extensions must be separated from other extensions by an
+ * underscore.
+ *
+ * 2. Additional standard extensions (starting with 'Z') must be sorted after
+ * single-letter extensions and before any higher-privileged extensions.
+ *
+ * 3. The first letter following the 'Z' conventionally indicates the most
+ * closely related alphabetical extension category, IMAFDQLCBKJTPVH.
+ * If multiple 'Z' extensions are named, they must be ordered first by
+ * category, then alphabetically within a category.
+ *
+ * 4. Standard supervisor-level extensions (starting with 'S') must be listed
+ * after standard unprivileged extensions. If multiple supervisor-level
+ * extensions are listed, they must be ordered alphabetically.
+ *
+ * 5. Standard machine-level extensions (starting with 'Zxm') must be listed
+ * after any lower-privileged, standard extensions. If multiple
+ * machine-level extensions are listed, they must be ordered
+ * alphabetically.
+ *
+ * 6. Non-standard extensions (starting with 'X') must be listed after all
+ * standard extensions. If multiple non-standard extensions are listed, they
+ * must be ordered alphabetically.
+ *
+ * An example string following the order is:
+ * rv64imadc_zifoo_zigoo_zafoo_sbar_scar_zxmbaz_xqux_xrux
+ *
+ * New entries to this struct should follow the ordering rules described above.
+ *
+ * Extension name must be all lowercase (according to device-tree binding)
+ * and strncmp() is used in match_isa_ext() to compare extension names instead
+ * of strncasecmp().
+ */
+const struct riscv_isa_ext_data __initconst riscv_isa_ext[] = {
+ RISCV_ISA_EXT_DATA(i, RISCV_ISA_EXT_i),
+ RISCV_ISA_EXT_DATA(m, RISCV_ISA_EXT_m),
+ RISCV_ISA_EXT_DATA(a, RISCV_ISA_EXT_a),
+ RISCV_ISA_EXT_DATA(f, RISCV_ISA_EXT_f),
+ RISCV_ISA_EXT_DATA(d, RISCV_ISA_EXT_d),
+ RISCV_ISA_EXT_DATA(q, RISCV_ISA_EXT_q),
+ RISCV_ISA_EXT_DATA(h, RISCV_ISA_EXT_h),
+ RISCV_ISA_EXT_DATA(zicntr, RISCV_ISA_EXT_ZICNTR),
+ RISCV_ISA_EXT_DATA(zicsr, RISCV_ISA_EXT_ZICSR),
+ RISCV_ISA_EXT_DATA(zifencei, RISCV_ISA_EXT_ZIFENCEI),
+ RISCV_ISA_EXT_DATA(zihintpause, RISCV_ISA_EXT_ZIHINTPAUSE),
+ RISCV_ISA_EXT_DATA(zihpm, RISCV_ISA_EXT_ZIHPM),
+ RISCV_ISA_EXT_DATA(zbb, RISCV_ISA_EXT_ZBB),
+ RISCV_ISA_EXT_DATA(smaia, RISCV_ISA_EXT_SMAIA),
+ RISCV_ISA_EXT_DATA(ssaia, RISCV_ISA_EXT_SSAIA),
+};
+
+static const struct riscv_isa_ext_data __initconst required_extensions[] = {
+ RISCV_ISA_EXT_DATA(zicsr, RISCV_ISA_EXT_ZICSR),
+ RISCV_ISA_EXT_DATA(zihintpause, RISCV_ISA_EXT_ZIHINTPAUSE),
+ RISCV_ISA_EXT_DATA(zbb, RISCV_ISA_EXT_ZBB),
+};
+
+static bool is_lowercase_extension_name(const char *str)
+{
+ /*
+ * `str` could contain full riscv,isa string from device tree so one
+ * of the stop condionitions is checking for '_' as extensions are
+ * separated by '_'.
+ */
+ for ( unsigned int i = 0; (str[i] != '\0') && (str[i] != '_'); i++ )
+ if ( !isdigit(str[i]) && !islower(str[i]) )
+ return false;
+
+ return true;
+}
+
+static void __init match_isa_ext(const char *name, const char *name_end,
+ unsigned long *bitmap)
+{
+ const size_t riscv_isa_ext_count = ARRAY_SIZE(riscv_isa_ext);
+
+ for ( unsigned int i = 0; i < riscv_isa_ext_count; i++ )
+ {
+ const struct riscv_isa_ext_data *ext = &riscv_isa_ext[i];
+
+ /*
+ * `ext->name` (according to initialization of riscv_isa_ext[]
+ * elements) must be all in lowercase.
+ */
+ ASSERT(is_lowercase_extension_name(ext->name));
+
+ if ( (name_end - name == strlen(ext->name)) &&
+ !strncmp(name, ext->name, name_end - name) )
+ {
+ __set_bit(ext->id, bitmap);
+ break;
+ }
+ }
+}
+
+static int __init riscv_isa_parse_string(const char *isa,
+ unsigned long *out_bitmap)
+{
+ if ( (isa[0] != 'r') && (isa[1] != 'v') )
+ return -EINVAL;
+
+#if defined(CONFIG_RISCV_32)
+ if ( isa[2] != '3' && isa[3] != '2' )
+ return -EINVAL;
+#elif defined(CONFIG_RISCV_64)
+ if ( isa[2] != '6' && isa[3] != '4' )
+ return -EINVAL;
+#else
+# error "unsupported RISC-V bitness"
+#endif
+
+ isa += 4;
+
+ while ( *isa )
+ {
+ const char *ext = isa++;
+ const char *ext_end = isa;
+ bool ext_err = false;
+
+ switch ( *ext )
+ {
+ case 'x':
+ printk_once("Vendor extensions are ignored in riscv,isa\n");
+ /*
+ * To skip an extension, we find its end.
+ * As multi-letter extensions must be split from other multi-letter
+ * extensions with an "_", the end of a multi-letter extension will
+ * either be the null character or the "_" at the start of the next
+ * multi-letter extension.
+ */
+ for ( ; *isa && *isa != '_'; ++isa )
+ ;
+ ext_err = true;
+ break;
+
+ case 's':
+ /*
+ * Workaround for invalid single-letter 's' & 'u' (QEMU):
+ * Before QEMU 7.1 it was an issue with misa to ISA string
+ * conversion:
+ * https://patchwork.kernel.org/project/qemu-devel/patch/dee09d708405075420b29115c1e9e87910b8da55.1648270894.git.research_trasio@irq.a4lg.com/#24792587
+ * Additional details of the workaround on Linux kernel side:
+ * https://lore.kernel.org/linux-riscv/ae93358e-e117-b43d-faad-772c529f846c@irq.a4lg.com/#t
+ *
+ * No need to set the bit in riscv_isa as 's' & 'u' are
+ * not valid ISA extensions. It works unless the first
+ * multi-letter extension in the ISA string begins with
+ * "Su" and is not prefixed with an underscore.
+ */
+ if ( ext[-1] != '_' && ext[1] == 'u' )
+ {
+ ++isa;
+ ext_err = true;
+ break;
+ }
+ fallthrough;
+ case 'z':
+ /*
+ * Before attempting to parse the extension itself, we find its end.
+ * As multi-letter extensions must be split from other multi-letter
+ * extensions with an "_", the end of a multi-letter extension will
+ * either be the null character or the "_" at the start of the next
+ * multi-letter extension.
+ *
+ * Next, as the extensions version is currently ignored, we
+ * eliminate that portion. This is done by parsing backwards from
+ * the end of the extension, removing any numbers. This may be a
+ * major or minor number however, so the process is repeated if a
+ * minor number was found.
+ *
+ * ext_end is intended to represent the first character *after* the
+ * name portion of an extension, but will be decremented to the last
+ * character itself while eliminating the extensions version number.
+ * A simple re-increment solves this problem.
+ */
+ for ( ; *isa && *isa != '_'; ++isa )
+ if ( unlikely(!isalnum(*isa)) )
+ ext_err = true;
+
+ ext_end = isa;
+ if ( unlikely(ext_err) )
+ break;
+
+ if ( !isdigit(ext_end[-1]) )
+ break;
+
+ while ( isdigit(*--ext_end) )
+ ;
+
+ if ( tolower(ext_end[0]) != 'p' || !isdigit(ext_end[-1]) )
+ {
+ ++ext_end;
+ break;
+ }
+
+ while ( isdigit(*--ext_end) )
+ ;
+
+ ++ext_end;
+ break;
+
+ default:
+ /*
+ * Things are a little easier for single-letter extensions, as they
+ * are parsed forwards.
+ *
+ * After checking that our starting position is valid, we need to
+ * ensure that, when isa was incremented at the start of the loop,
+ * that it arrived at the start of the next extension.
+ *
+ * If we are already on a non-digit, there is nothing to do. Either
+ * we have a multi-letter extension's _, or the start of an
+ * extension.
+ *
+ * Otherwise we have found the current extension's major version
+ * number. Parse past it, and a subsequent p/minor version number
+ * if present. The `p` extension must not appear immediately after
+ * a number, so there is no fear of missing it.
+ */
+ if ( unlikely(!isalpha(*ext)) )
+ {
+ ext_err = true;
+ break;
+ }
+
+ if ( !isdigit(*isa) )
+ break;
+
+ while ( isdigit(*++isa) )
+ ;
+
+ if ( tolower(*isa) != 'p' )
+ break;
+
+ if ( !isdigit(*++isa) )
+ {
+ --isa;
+ break;
+ }
+
+ while ( isdigit(*++isa) )
+ ;
+
+ break;
+ }
+
+ /*
+ * The parser expects that at the start of an iteration isa points to the
+ * first character of the next extension. As we stop parsing an extension
+ * on meeting a non-alphanumeric character, an extra increment is needed
+ * where the succeeding extension is a multi-letter prefixed with an "_".
+ */
+ if ( *isa == '_' )
+ ++isa;
+
+ if ( unlikely(ext_err) )
+ continue;
+
+ match_isa_ext(ext, ext_end, out_bitmap);
+ }
+
+ return 0;
+}
+
+static void __init riscv_fill_hwcap_from_isa_string(void)
+{
+ const struct dt_device_node *cpus = dt_find_node_by_path("/cpus");
+ const struct dt_device_node *cpu;
+
+ if ( !cpus )
+ {
+ printk("Missing /cpus node in the device tree?\n");
+ return;
+ }
+
+ dt_for_each_child_node(cpus, cpu)
+ {
+ DECLARE_BITMAP(this_isa, RISCV_ISA_EXT_MAX);
+ const char *isa;
+ unsigned long cpuid;
+
+ if ( !dt_device_type_is_equal(cpu, "cpu") )
+ continue;
+
+ if ( dt_get_cpuid_from_node(cpu, &cpuid) < 0 )
+ continue;
+
+ if ( dt_property_read_string(cpu, "riscv,isa", &isa) )
+ {
+ printk("Unable to find \"riscv,isa\" devicetree entry "
+ "for DT's cpu%ld node\n", cpuid);
+ continue;
+ }
+
+ for ( unsigned int i = 0; (isa[i] != '\0'); i++ )
+ if ( !isdigit(isa[i]) && (isa[i] != '_') && !islower(isa[i]) )
+ panic("According to DT binding riscv,isa must be lowercase\n");
+
+ riscv_isa_parse_string(isa, this_isa);
+
+ /*
+ * In the unpriv. spec is mentioned:
+ * A RISC-V ISA is defined as a base integer ISA, which must be
+ * present in any implementation, plus optional extensions to
+ * the base ISA.
+ * What means that isa should contain, at least, I or E thereby
+ * this_isa can't be empty too.
+ *
+ * Ensure that this_isa is not empty, so riscv_isa won't be empty
+ * during initialization. This prevents ending up with extensions
+ * not supported by one of the CPUs.
+ */
+ ASSERT(!bitmap_empty(this_isa, RISCV_ISA_EXT_MAX));
+
+ if ( bitmap_empty(riscv_isa, RISCV_ISA_EXT_MAX) )
+ bitmap_copy(riscv_isa, this_isa, RISCV_ISA_EXT_MAX);
+ else
+ bitmap_and(riscv_isa, riscv_isa, this_isa, RISCV_ISA_EXT_MAX);
+ }
+}
+
+static bool __init has_isa_extensions_property(void)
+{
+ const struct dt_device_node *cpus = dt_find_node_by_path("/cpus");
+ const struct dt_device_node *cpu;
+
+ if ( !cpus )
+ {
+ printk("Missing /cpus node in the device tree?\n");
+ return false;
+ }
+
+ dt_for_each_child_node(cpus, cpu)
+ {
+ const char *isa;
+
+ if ( !dt_device_type_is_equal(cpu, "cpu") )
+ continue;
+
+ if ( dt_property_read_string(cpu, "riscv,isa-extensions", &isa) )
+ continue;
+
+ return true;
+ }
+
+ return false;
+}
+
+bool riscv_isa_extension_available(const unsigned long *isa_bitmap,
+ enum riscv_isa_ext_id id)
+{
+ if ( !isa_bitmap )
+ isa_bitmap = riscv_isa;
+
+ if ( id >= RISCV_ISA_EXT_MAX )
+ return false;
+
+ return test_bit(id, isa_bitmap);
+}
+
+void __init riscv_fill_hwcap(void)
+{
+ unsigned int i;
+ size_t req_extns_amount = ARRAY_SIZE(required_extensions);
+ bool all_extns_available = true;
+
+ riscv_fill_hwcap_from_isa_string();
+
+ if ( bitmap_empty(riscv_isa, RISCV_ISA_EXT_MAX) )
+ {
+ const char *failure_msg = has_isa_extensions_property() ?
+ "\"riscv,isa-extension\" isn't supported" :
+ "\"riscv,isa\" parsing failed";
+
+ panic("HW capabilities parsing failed: %s\n", failure_msg);
+ }
+
+ for ( i = 0; i < req_extns_amount; i++ )
+ {
+ const struct riscv_isa_ext_data ext = required_extensions[i];
+
+ if ( !riscv_isa_extension_available(NULL, ext.id) )
+ {
+ printk("Xen requires extension: %s\n", ext.name);
+ all_extns_available = false;
+ }
+ }
+
+ if ( !all_extns_available )
+ panic("Look why the extensions above are needed in "
+ "https://xenbits.xenproject.org/docs/unstable/misc/riscv/booting.txt\n");
+}
new file mode 100644
@@ -0,0 +1,57 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef ASM__RISCV__CPUFEATURE_H
+#define ASM__RISCV__CPUFEATURE_H
+
+#ifndef __ASSEMBLY__
+
+#include <xen/stdbool.h>
+
+/*
+ * These macros represent the logical IDs of each multi-letter RISC-V ISA
+ * extension and are used in the ISA bitmap. The logical IDs start from
+ * RISCV_ISA_EXT_BASE, which allows the 0-25 range to be reserved for single
+ * letter extensions and are used in enum riscv_isa_ext_id.
+ *
+ * New extensions should just be added to the bottom, rather than added
+ * alphabetically, in order to avoid unnecessary shuffling.
+ */
+#define RISCV_ISA_EXT_BASE 26
+
+enum riscv_isa_ext_id {
+ RISCV_ISA_EXT_a,
+ RISCV_ISA_EXT_c,
+ RISCV_ISA_EXT_d,
+ RISCV_ISA_EXT_f,
+ RISCV_ISA_EXT_h,
+ RISCV_ISA_EXT_i,
+ RISCV_ISA_EXT_m,
+ RISCV_ISA_EXT_q,
+ RISCV_ISA_EXT_v,
+ RISCV_ISA_EXT_ZICNTR = RISCV_ISA_EXT_BASE,
+ RISCV_ISA_EXT_ZICSR,
+ RISCV_ISA_EXT_ZIFENCEI,
+ RISCV_ISA_EXT_ZIHINTPAUSE,
+ RISCV_ISA_EXT_ZIHPM,
+ RISCV_ISA_EXT_ZBB,
+ RISCV_ISA_EXT_SMAIA,
+ RISCV_ISA_EXT_SSAIA,
+ RISCV_ISA_EXT_MAX
+};
+
+void riscv_fill_hwcap(void);
+
+bool riscv_isa_extension_available(const unsigned long *isa_bitmap,
+ enum riscv_isa_ext_id id);
+
+#endif /* __ASSEMBLY__ */
+
+#endif /* ASM__RISCV__CPUFEATURE_H */
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
@@ -13,6 +13,7 @@
#include <public/version.h>
+#include <asm/cpufeature.h>
#include <asm/early_printk.h>
#include <asm/fixmap.h>
#include <asm/sbi.h>
@@ -121,6 +122,8 @@ void __init noreturn start_xen(unsigned long bootcpu_id,
panic("Booting using ACPI isn't supported\n");
}
+ riscv_fill_hwcap();
+
printk("All set up\n");
machine_halt();
Supported ISA extensions are specified in the device tree within the CPU node, using two properties: `riscv,isa-extensions` and `riscv,isa`. Currently, Xen does not support the `riscv,isa-extensions` property, as all available device tree source (DTS) files in the Linux kernel (v6.12-rc3) and DTBs generated by QEMU use only the `riscv,isa` property. Therefore, only `riscv,isa` parsing is implemented. The `riscv,isa` property is parsed for each CPU, and the common extensions are stored in the `host_riscv_isa` bitmap. This bitmap is then used by `riscv_isa_extension_available()` to check if a specific extension is supported. The current implementation is based on Linux kernel v6.12-rc3 implementation with the following changes: - Drop unconditional setting of {RISCV_ISA_EXT_ZICSR, RISCV_ISA_EXT_ZIFENCEI, RISCV_ISA_EXT_ZICNTR, RISCV_ISA_EXT_ZIHPM} as they are now part of the riscv,isa string. - Remove saving of the ISA for each CPU, only the common available ISA is saved. - Remove ACPI-related code as ACPI is not supported by Xen. - Drop handling of elf_hwcap, since Xen does not provide hwcap to userspace. - Replace of_cpu_device_node_get() API, which is not available in Xen, with a combination of dt_for_each_child_node(), dt_device_type_is_equal(), and dt_get_cpuid_from_node() to retrieve cpuid and riscv,isa in riscv_fill_hwcap_from_isa_string(). - Rename arguments of __RISCV_ISA_EXT_DATA() from _name to ext_name, and _id to ext_id for clarity. - Replace instances of __RISCV_ISA_EXT_DATA with RISCV_ISA_EXT_DATA. - Replace instances of __riscv_isa_extension_available with riscv_isa_extension_available for consistency. Also, update the type of `bit` argument of riscv_isa_extension_available(). - Redefine RISCV_ISA_EXT_DATA() to work only with ext_name and ext_id, as other fields are not used in Xen currently. - Add check of first 4 letters of riscv,isa string to riscv_isa_parse_string() as Xen doesn't do this check before so it is necessary to check correctness of riscv,isa string. ( it should start with rv{32,64} with taking into account upper and lower case of "rv"). - Drop an argument of riscv_fill_hwcap() and riscv_fill_hwcap_from_isa_string() as it isn't used, at the moment. - Update the comment message about QEMU workaround. - Apply Xen coding style. - s/pr_info/printk. - Drop handling of uppercase letters of riscv,isa in riscv_isa_parse_string() as Xen checks that riscv,isa should be in lowercase according to the device tree bindings. Signed-off-by: Oleksii Kurochko <oleksii.kurochko@gmail.com> --- Changes in V4: - Add "Originally ... " at the start of cpufeature.c. - Sync required_extensions[] with riscv_isa_ext[] in terms of element sorting/ordering. - Fix identations. - s/#error/# error. - With insisting on ISA string being all lowercase, drop handling the uppercases in riscv_isa_parse_string(). - check riscv,isa recieved from device tree; it must be in lowercase. - Update ASSERT() in match_isa_ext(): drop checking of riscv,isa recieved from device tree as this check was moved to riscv_fill_hwcap(). - Update is_lowercase_extension_name() to ignore digits as they could be used for extension version which is part of the extension name so should be skipped. - Alight ternanry operator properly in riscv_fill_hwcap(). - Update the commit message: add information that handling of uppercase letters in riscv,isa are dropped in riscv_isa_parsing_string() becase Xen checks that riscv,isa must be all in lowercase according to device tree binding. --- Changes in V3: - Drop description of changes in cpufeature.c and leave only in the commit message to not deal with possible staleness of them in the future. - Update for dt_get_cpuid_from_node(): - update printk() message. - add some explanation about if-condition on the start of the function. - add dt_cpuid argument for function dt_get_cpuid_from_node() to deal with potential truncation issue from paddr_t (dt_read_paddr() returns that ) to int. - Add Zicsr to required_extensions[]. - Drop an argument check at the start of is_lowercase_extension_name() as function is static and callers are expected to pass a good pointer. - Add a comment with some additional explanation about the stop condition of checking a case of extension name. - Omit blanks after opening and closing parentheses in the comments. - Add missed parentheses in match_isa_ext(). - Drop ASSERT() which checks that first two letters of `isa` string are in lower case as after this ASSERT() there is an if-condition which does the same. - Cut part of printk_once()'s message in riscv_isa_parse_string() related to riscv,isa-extension as it isn't supported for now and usage of it will lead to panic(). - Drop function riscv_fill_hwcap_from_ext_list() at all as Xen isn't going to support riscv,isa-extensions for now. - Clarify printk()'s message when riscv,isa property wasn't found in cpu node. Now it contains "for DT's cpu%d node", where %d is cpuid, instead of "for cpu%d" to not confuse cpuid number ( if it Xen's cpu id and physical cpu's id). - Updates in riscv_isa_extension_available(): - Drop local varible `bmap` and initialize `isa_bitmap` in more readable way. - Rename argument `bit` of riscv_isa_extension_available() to `id` for clearness. - Update handling of failure of h/w capabilities parsing in riscv_fill_hwcap(). - Introduce has_isa_extensions_property() to check if "riscv,isa-extension" is present in any device tree cpu node. --- Changes in V2: - Update the list of changes in comparison with Linux on the top of cpufeature.c. - Now really drop all ACPI-related stuff. Add #ifdef CONFIG_ACPI #error ... #endif instead. - Make `id` ( member of riscv_isa_ext_data structure ) not const. - s/__read_mostly/__ro_after_init for riscv_isa bitmap. - Update the comment above riscv_isa_ext[] declaration: - Drop Linux details. - Revised the numbering of the ordering rules for RISC-V ISA extensions. - Add comment that extension name must be all lowercase according to device tree binding. - Add __initconst for declarations of riscv_isa_ext[] and required_extensions[]. - Move riscv_isa_ext_count for global declaration to match_isa_ext where it is really used. - Add new function is_lowercase_extension_name(). - Updates for match_isa_ext(): - Move last argument of match_isa_ext() to new line to not violate line length. - s/int/unsigned int for cycle varible `i`. - s/set_bit/__set_bit as no need for atomicity at this stage of boot. - Add ASSERT() to be sure that extension name is in lowercase. - s/strncasecmp/strncasecmp as extension name must be in a lowercase. - Updates for riscv_isa_parse_string(): - Move last argument of riscv_isa_parse_string() to new line to not violate line length. - Update the checks at the start of the function. Now if CONFIG_RISCV_32=y the only rv32 is accepted, or rv64 for CONFIG_RISCV_64=y. - Drop ACPI-related stuff. - Add blank lines between non-fall-through case blocks. - Add blanks in `for loops` before ')'. - Update the comment about QEMU workaround for invalid single-letter 's' & 'u'. - Updates for riscv_fill_hwcap_from_ext_list(): - Drop initilizer of cpuid inside dt_for_each_child_node() {...}. - Introduce res and return it instead of -EINVAL. - Drop `else` and change printk("riscv,isa-extensions isnt supported\n") to panic("riscv,isa-extensions isnt supported\n"). - Drop ( cpuid >= NR_CPUS ) check as cpuid technically could be any number. Only cpuid=0 is guaranteed to be. - Updates for riscv_fill_hwcap_from_isa_string(): - move cpuid and isa variables to dt_for_each_child_node() {...}. - Drop initilizer of cpuid inside dt_for_each_child_node() {...}. - Drop ( cpuid >= NR_CPUS ) check as cpuid technically could be any number. Only cpuid=0 is guaranteed to be. - Add ASSERT() to be sure that `this_isa` isn't null to prevent ending up with extensions not supported by one of the CPUs. - Updates for riscv_isa_extension_available(): - Code style fixes. - Drop conditional operator used in return as functions returns bool. - s/extenstion/extensions, s/extenstion/extenstion. - Drop RISCV_ISA_EXT_SxAIA as it isn't used. - Move definitions of RISCV_ISA_EXT_{a,c,d,...,v} to enum riscv_isa_ext_id. - Move macros RISCV_ISA_EXT_MAX to enum riscv_isa_ext_id. - Update the comment above definition of RISCV_ISA_EXT_BASE. - Fix code style ( violation of line length ) for riscv_isa_extension_available(). - Sync commit message with the comment on the start of cpufeature.c --- xen/arch/riscv/Makefile | 1 + xen/arch/riscv/cpufeature.c | 479 ++++++++++++++++++++++++ xen/arch/riscv/include/asm/cpufeature.h | 57 +++ xen/arch/riscv/setup.c | 3 + 4 files changed, 540 insertions(+) create mode 100644 xen/arch/riscv/cpufeature.c create mode 100644 xen/arch/riscv/include/asm/cpufeature.h