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Diffstat (limited to 'arch/riscv/kernel/cpufeature.c')
-rw-r--r--arch/riscv/kernel/cpufeature.c115
1 files changed, 93 insertions, 22 deletions
diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
index e12cd22755..b3785ffc15 100644
--- a/arch/riscv/kernel/cpufeature.c
+++ b/arch/riscv/kernel/cpufeature.c
@@ -8,6 +8,7 @@
#include <linux/acpi.h>
#include <linux/bitmap.h>
+#include <linux/cpuhotplug.h>
#include <linux/ctype.h>
#include <linux/log2.h>
#include <linux/memory.h>
@@ -29,6 +30,7 @@
#define MISALIGNED_ACCESS_JIFFIES_LG2 1
#define MISALIGNED_BUFFER_SIZE 0x4000
+#define MISALIGNED_BUFFER_ORDER get_order(MISALIGNED_BUFFER_SIZE)
#define MISALIGNED_COPY_SIZE ((MISALIGNED_BUFFER_SIZE / 2) - 0x80)
unsigned long elf_hwcap __read_mostly;
@@ -93,10 +95,10 @@ static bool riscv_isa_extension_check(int id)
return true;
case RISCV_ISA_EXT_ZICBOZ:
if (!riscv_cboz_block_size) {
- pr_err("Zicboz detected in ISA string, but no cboz-block-size found\n");
+ pr_err("Zicboz detected in ISA string, disabling as no cboz-block-size found\n");
return false;
} else if (!is_power_of_2(riscv_cboz_block_size)) {
- pr_err("cboz-block-size present, but is not a power-of-2\n");
+ pr_err("Zicboz disabled as cboz-block-size present, but is not a power-of-2\n");
return false;
}
return true;
@@ -167,6 +169,7 @@ const struct riscv_isa_ext_data riscv_isa_ext[] = {
__RISCV_ISA_EXT_DATA(zicbom, RISCV_ISA_EXT_ZICBOM),
__RISCV_ISA_EXT_DATA(zicboz, RISCV_ISA_EXT_ZICBOZ),
__RISCV_ISA_EXT_DATA(zicntr, RISCV_ISA_EXT_ZICNTR),
+ __RISCV_ISA_EXT_DATA(zicond, RISCV_ISA_EXT_ZICOND),
__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),
@@ -175,6 +178,7 @@ const struct riscv_isa_ext_data riscv_isa_ext[] = {
__RISCV_ISA_EXT_DATA(zbb, RISCV_ISA_EXT_ZBB),
__RISCV_ISA_EXT_DATA(zbs, RISCV_ISA_EXT_ZBS),
__RISCV_ISA_EXT_DATA(smaia, RISCV_ISA_EXT_SMAIA),
+ __RISCV_ISA_EXT_DATA(smstateen, RISCV_ISA_EXT_SMSTATEEN),
__RISCV_ISA_EXT_DATA(ssaia, RISCV_ISA_EXT_SSAIA),
__RISCV_ISA_EXT_DATA(sscofpmf, RISCV_ISA_EXT_SSCOFPMF),
__RISCV_ISA_EXT_DATA(sstc, RISCV_ISA_EXT_SSTC),
@@ -204,10 +208,11 @@ static void __init riscv_parse_isa_string(unsigned long *this_hwcap, struct risc
switch (*ext) {
case 's':
/*
- * Workaround for invalid single-letter 's' & 'u'(QEMU).
+ * Workaround for invalid single-letter 's' & 'u' (QEMU).
* No need to set the bit in riscv_isa as 's' & 'u' are
- * not valid ISA extensions. It works until multi-letter
- * extension starting with "Su" appears.
+ * 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;
@@ -556,27 +561,21 @@ unsigned long riscv_get_elf_hwcap(void)
return hwcap;
}
-void check_unaligned_access(int cpu)
+static int check_unaligned_access(void *param)
{
+ int cpu = smp_processor_id();
u64 start_cycles, end_cycles;
u64 word_cycles;
u64 byte_cycles;
int ratio;
unsigned long start_jiffies, now;
- struct page *page;
+ struct page *page = param;
void *dst;
void *src;
long speed = RISCV_HWPROBE_MISALIGNED_SLOW;
- /* We are already set since the last check */
- if (per_cpu(misaligned_access_speed, cpu) != RISCV_HWPROBE_MISALIGNED_UNKNOWN)
- return;
-
- page = alloc_pages(GFP_NOWAIT, get_order(MISALIGNED_BUFFER_SIZE));
- if (!page) {
- pr_warn("Can't alloc pages to measure memcpy performance");
- return;
- }
+ if (check_unaligned_access_emulated(cpu))
+ return 0;
/* Make an unaligned destination buffer. */
dst = (void *)((unsigned long)page_address(page) | 0x1);
@@ -630,7 +629,7 @@ void check_unaligned_access(int cpu)
pr_warn("cpu%d: rdtime lacks granularity needed to measure unaligned access speed\n",
cpu);
- goto out;
+ return 0;
}
if (word_cycles < byte_cycles)
@@ -644,18 +643,90 @@ void check_unaligned_access(int cpu)
(speed == RISCV_HWPROBE_MISALIGNED_FAST) ? "fast" : "slow");
per_cpu(misaligned_access_speed, cpu) = speed;
+ return 0;
+}
-out:
- __free_pages(page, get_order(MISALIGNED_BUFFER_SIZE));
+static void check_unaligned_access_nonboot_cpu(void *param)
+{
+ unsigned int cpu = smp_processor_id();
+ struct page **pages = param;
+
+ if (smp_processor_id() != 0)
+ check_unaligned_access(pages[cpu]);
}
-static int check_unaligned_access_boot_cpu(void)
+static int riscv_online_cpu(unsigned int cpu)
{
- check_unaligned_access(0);
+ static struct page *buf;
+
+ /* We are already set since the last check */
+ if (per_cpu(misaligned_access_speed, cpu) != RISCV_HWPROBE_MISALIGNED_UNKNOWN)
+ return 0;
+
+ buf = alloc_pages(GFP_KERNEL, MISALIGNED_BUFFER_ORDER);
+ if (!buf) {
+ pr_warn("Allocation failure, not measuring misaligned performance\n");
+ return -ENOMEM;
+ }
+
+ check_unaligned_access(buf);
+ __free_pages(buf, MISALIGNED_BUFFER_ORDER);
return 0;
}
-arch_initcall(check_unaligned_access_boot_cpu);
+/* Measure unaligned access on all CPUs present at boot in parallel. */
+static int check_unaligned_access_all_cpus(void)
+{
+ unsigned int cpu;
+ unsigned int cpu_count = num_possible_cpus();
+ struct page **bufs = kzalloc(cpu_count * sizeof(struct page *),
+ GFP_KERNEL);
+
+ if (!bufs) {
+ pr_warn("Allocation failure, not measuring misaligned performance\n");
+ return 0;
+ }
+
+ /*
+ * Allocate separate buffers for each CPU so there's no fighting over
+ * cache lines.
+ */
+ for_each_cpu(cpu, cpu_online_mask) {
+ bufs[cpu] = alloc_pages(GFP_KERNEL, MISALIGNED_BUFFER_ORDER);
+ if (!bufs[cpu]) {
+ pr_warn("Allocation failure, not measuring misaligned performance\n");
+ goto out;
+ }
+ }
+
+ /* Check everybody except 0, who stays behind to tend jiffies. */
+ on_each_cpu(check_unaligned_access_nonboot_cpu, bufs, 1);
+
+ /* Check core 0. */
+ smp_call_on_cpu(0, check_unaligned_access, bufs[0], true);
+
+ /* Setup hotplug callback for any new CPUs that come online. */
+ cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, "riscv:online",
+ riscv_online_cpu, NULL);
+
+out:
+ unaligned_emulation_finish();
+ for_each_cpu(cpu, cpu_online_mask) {
+ if (bufs[cpu])
+ __free_pages(bufs[cpu], MISALIGNED_BUFFER_ORDER);
+ }
+
+ kfree(bufs);
+ return 0;
+}
+
+arch_initcall(check_unaligned_access_all_cpus);
+
+void riscv_user_isa_enable(void)
+{
+ if (riscv_cpu_has_extension_unlikely(smp_processor_id(), RISCV_ISA_EXT_ZICBOZ))
+ csr_set(CSR_SENVCFG, ENVCFG_CBZE);
+}
#ifdef CONFIG_RISCV_ALTERNATIVE
/*