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authorLinus Torvalds <torvalds@linux-foundation.org>2025-10-25 09:35:26 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2025-10-25 09:35:26 -0700
commit9bb956508c9d94935bedba4f13901fb2b7468e91 (patch)
treed6bcdae2a1da283367a8e1e858e4b7050fa35d56
parent27c0b5c4f67aeb73edd515200bd1e0c82a3ee892 (diff)
parentb7776a802f2f80139f96530a489dd00fd7089eda (diff)
Merge tag 'riscv-for-linus-6.18-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux
Pull RISC-V fixes from Paul Walmsley: - Close a race during boot between userspace vDSO usage and some late-initialized vDSO data - Improve performance on systems with non-CPU-cache-coherent DMA-capable peripherals by enabling write combining on pgprot_dmacoherent() allocations - Add human-readable detail for RISC-V IPI tracing - Provide more information to zsmalloc on 64-bit RISC-V to improve allocation - Silence useless boot messages about CPUs that have been disabled in DT - Resolve some compiler and smatch warnings and remove a redundant macro * tag 'riscv-for-linus-6.18-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: riscv: hwprobe: avoid uninitialized variable use in hwprobe_arch_id() riscv: cpufeature: avoid uninitialized variable in has_thead_homogeneous_vlenb() riscv: hwprobe: Fix stale vDSO data for late-initialized keys at boot riscv: add a forward declaration for cpuinfo_op RISC-V: Don't print details of CPUs disabled in DT riscv: Remove the PER_CPU_OFFSET_SHIFT macro riscv: mm: Define MAX_POSSIBLE_PHYSMEM_BITS for zsmalloc riscv: Register IPI IRQs with unique names ACPI: RIMT: Fix unused function warnings when CONFIG_IOMMU_API is disabled RISC-V: Define pgprot_dmacoherent() for non-coherent devices
-rw-r--r--arch/riscv/include/asm/asm.h8
-rw-r--r--arch/riscv/include/asm/cpufeature.h2
-rw-r--r--arch/riscv/include/asm/hwprobe.h7
-rw-r--r--arch/riscv/include/asm/pgtable-64.h2
-rw-r--r--arch/riscv/include/asm/pgtable.h2
-rw-r--r--arch/riscv/include/asm/vdso/arch_data.h6
-rw-r--r--arch/riscv/kernel/cpu.c4
-rw-r--r--arch/riscv/kernel/cpufeature.c4
-rw-r--r--arch/riscv/kernel/smp.c24
-rw-r--r--arch/riscv/kernel/sys_hwprobe.c76
-rw-r--r--arch/riscv/kernel/unaligned_access_speed.c9
-rw-r--r--arch/riscv/kernel/vdso/hwprobe.c2
-rw-r--r--drivers/acpi/riscv/rimt.c122
13 files changed, 168 insertions, 100 deletions
diff --git a/arch/riscv/include/asm/asm.h b/arch/riscv/include/asm/asm.h
index 8bd2a11382a3..ac28066bb564 100644
--- a/arch/riscv/include/asm/asm.h
+++ b/arch/riscv/include/asm/asm.h
@@ -84,15 +84,9 @@
.endm
#ifdef CONFIG_SMP
-#ifdef CONFIG_32BIT
-#define PER_CPU_OFFSET_SHIFT 2
-#else
-#define PER_CPU_OFFSET_SHIFT 3
-#endif
-
.macro asm_per_cpu dst sym tmp
lw \tmp, TASK_TI_CPU_NUM(tp)
- slli \tmp, \tmp, PER_CPU_OFFSET_SHIFT
+ slli \tmp, \tmp, RISCV_LGPTR
la \dst, __per_cpu_offset
add \dst, \dst, \tmp
REG_L \tmp, 0(\dst)
diff --git a/arch/riscv/include/asm/cpufeature.h b/arch/riscv/include/asm/cpufeature.h
index fbd0e4306c93..62837fa981e8 100644
--- a/arch/riscv/include/asm/cpufeature.h
+++ b/arch/riscv/include/asm/cpufeature.h
@@ -31,6 +31,8 @@ struct riscv_isainfo {
DECLARE_PER_CPU(struct riscv_cpuinfo, riscv_cpuinfo);
+extern const struct seq_operations cpuinfo_op;
+
/* Per-cpu ISA extensions. */
extern struct riscv_isainfo hart_isa[NR_CPUS];
diff --git a/arch/riscv/include/asm/hwprobe.h b/arch/riscv/include/asm/hwprobe.h
index 948d2b34e94e..58f8dda73259 100644
--- a/arch/riscv/include/asm/hwprobe.h
+++ b/arch/riscv/include/asm/hwprobe.h
@@ -42,4 +42,11 @@ static inline bool riscv_hwprobe_pair_cmp(struct riscv_hwprobe *pair,
return pair->value == other_pair->value;
}
+#ifdef CONFIG_MMU
+void riscv_hwprobe_register_async_probe(void);
+void riscv_hwprobe_complete_async_probe(void);
+#else
+static inline void riscv_hwprobe_register_async_probe(void) {}
+static inline void riscv_hwprobe_complete_async_probe(void) {}
+#endif
#endif
diff --git a/arch/riscv/include/asm/pgtable-64.h b/arch/riscv/include/asm/pgtable-64.h
index 1018d2216901..6e789fa58514 100644
--- a/arch/riscv/include/asm/pgtable-64.h
+++ b/arch/riscv/include/asm/pgtable-64.h
@@ -69,6 +69,8 @@ typedef struct {
#define PTRS_PER_PMD (PAGE_SIZE / sizeof(pmd_t))
+#define MAX_POSSIBLE_PHYSMEM_BITS 56
+
/*
* rv64 PTE format:
* | 63 | 62 61 | 60 54 | 53 10 | 9 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0
diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
index 29e994a9afb6..5a08eb5fe99f 100644
--- a/arch/riscv/include/asm/pgtable.h
+++ b/arch/riscv/include/asm/pgtable.h
@@ -654,6 +654,8 @@ static inline pgprot_t pgprot_writecombine(pgprot_t _prot)
return __pgprot(prot);
}
+#define pgprot_dmacoherent pgprot_writecombine
+
/*
* Both Svade and Svadu control the hardware behavior when the PTE A/D bits need to be set. By
* default the M-mode firmware enables the hardware updating scheme when only Svadu is present in
diff --git a/arch/riscv/include/asm/vdso/arch_data.h b/arch/riscv/include/asm/vdso/arch_data.h
index da57a3786f7a..88b37af55175 100644
--- a/arch/riscv/include/asm/vdso/arch_data.h
+++ b/arch/riscv/include/asm/vdso/arch_data.h
@@ -12,6 +12,12 @@ struct vdso_arch_data {
/* Boolean indicating all CPUs have the same static hwprobe values. */
__u8 homogeneous_cpus;
+
+ /*
+ * A gate to check and see if the hwprobe data is actually ready, as
+ * probing is deferred to avoid boot slowdowns.
+ */
+ __u8 ready;
};
#endif /* __RISCV_ASM_VDSO_ARCH_DATA_H */
diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c
index f6b13e9f5e6c..3dbc8cc557dd 100644
--- a/arch/riscv/kernel/cpu.c
+++ b/arch/riscv/kernel/cpu.c
@@ -62,10 +62,8 @@ int __init riscv_early_of_processor_hartid(struct device_node *node, unsigned lo
return -ENODEV;
}
- if (!of_device_is_available(node)) {
- pr_info("CPU with hartid=%lu is not available\n", *hart);
+ if (!of_device_is_available(node))
return -ENODEV;
- }
if (of_property_read_string(node, "riscv,isa-base", &isa))
goto old_interface;
diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
index 67b59699357d..72ca768f4e91 100644
--- a/arch/riscv/kernel/cpufeature.c
+++ b/arch/riscv/kernel/cpufeature.c
@@ -932,9 +932,9 @@ static int has_thead_homogeneous_vlenb(void)
{
int cpu;
u32 prev_vlenb = 0;
- u32 vlenb;
+ u32 vlenb = 0;
- /* Ignore thead,vlenb property if xtheavector is not enabled in the kernel */
+ /* Ignore thead,vlenb property if xtheadvector is not enabled in the kernel */
if (!IS_ENABLED(CONFIG_RISCV_ISA_XTHEADVECTOR))
return 0;
diff --git a/arch/riscv/kernel/smp.c b/arch/riscv/kernel/smp.c
index e650dec44817..5ed5095320e6 100644
--- a/arch/riscv/kernel/smp.c
+++ b/arch/riscv/kernel/smp.c
@@ -40,6 +40,17 @@ enum ipi_message_type {
IPI_MAX
};
+static const char * const ipi_names[] = {
+ [IPI_RESCHEDULE] = "Rescheduling interrupts",
+ [IPI_CALL_FUNC] = "Function call interrupts",
+ [IPI_CPU_STOP] = "CPU stop interrupts",
+ [IPI_CPU_CRASH_STOP] = "CPU stop (for crash dump) interrupts",
+ [IPI_IRQ_WORK] = "IRQ work interrupts",
+ [IPI_TIMER] = "Timer broadcast interrupts",
+ [IPI_CPU_BACKTRACE] = "CPU backtrace interrupts",
+ [IPI_KGDB_ROUNDUP] = "KGDB roundup interrupts",
+};
+
unsigned long __cpuid_to_hartid_map[NR_CPUS] __ro_after_init = {
[0 ... NR_CPUS-1] = INVALID_HARTID
};
@@ -199,7 +210,7 @@ void riscv_ipi_set_virq_range(int virq, int nr)
/* Request IPIs */
for (i = 0; i < nr_ipi; i++) {
err = request_percpu_irq(ipi_virq_base + i, handle_IPI,
- "IPI", &ipi_dummy_dev);
+ ipi_names[i], &ipi_dummy_dev);
WARN_ON(err);
ipi_desc[i] = irq_to_desc(ipi_virq_base + i);
@@ -210,17 +221,6 @@ void riscv_ipi_set_virq_range(int virq, int nr)
riscv_ipi_enable();
}
-static const char * const ipi_names[] = {
- [IPI_RESCHEDULE] = "Rescheduling interrupts",
- [IPI_CALL_FUNC] = "Function call interrupts",
- [IPI_CPU_STOP] = "CPU stop interrupts",
- [IPI_CPU_CRASH_STOP] = "CPU stop (for crash dump) interrupts",
- [IPI_IRQ_WORK] = "IRQ work interrupts",
- [IPI_TIMER] = "Timer broadcast interrupts",
- [IPI_CPU_BACKTRACE] = "CPU backtrace interrupts",
- [IPI_KGDB_ROUNDUP] = "KGDB roundup interrupts",
-};
-
void show_ipi_stats(struct seq_file *p, int prec)
{
unsigned int cpu, i;
diff --git a/arch/riscv/kernel/sys_hwprobe.c b/arch/riscv/kernel/sys_hwprobe.c
index 000f4451a9d8..199d13f86f31 100644
--- a/arch/riscv/kernel/sys_hwprobe.c
+++ b/arch/riscv/kernel/sys_hwprobe.c
@@ -5,6 +5,9 @@
* more details.
*/
#include <linux/syscalls.h>
+#include <linux/completion.h>
+#include <linux/atomic.h>
+#include <linux/once.h>
#include <asm/cacheflush.h>
#include <asm/cpufeature.h>
#include <asm/hwprobe.h>
@@ -28,6 +31,11 @@ static void hwprobe_arch_id(struct riscv_hwprobe *pair,
bool first = true;
int cpu;
+ if (pair->key != RISCV_HWPROBE_KEY_MVENDORID &&
+ pair->key != RISCV_HWPROBE_KEY_MIMPID &&
+ pair->key != RISCV_HWPROBE_KEY_MARCHID)
+ goto out;
+
for_each_cpu(cpu, cpus) {
u64 cpu_id;
@@ -58,6 +66,7 @@ static void hwprobe_arch_id(struct riscv_hwprobe *pair,
}
}
+out:
pair->value = id;
}
@@ -454,28 +463,32 @@ static int hwprobe_get_cpus(struct riscv_hwprobe __user *pairs,
return 0;
}
-static int do_riscv_hwprobe(struct riscv_hwprobe __user *pairs,
- size_t pair_count, size_t cpusetsize,
- unsigned long __user *cpus_user,
- unsigned int flags)
-{
- if (flags & RISCV_HWPROBE_WHICH_CPUS)
- return hwprobe_get_cpus(pairs, pair_count, cpusetsize,
- cpus_user, flags);
+#ifdef CONFIG_MMU
- return hwprobe_get_values(pairs, pair_count, cpusetsize,
- cpus_user, flags);
+static DECLARE_COMPLETION(boot_probes_done);
+static atomic_t pending_boot_probes = ATOMIC_INIT(1);
+
+void riscv_hwprobe_register_async_probe(void)
+{
+ atomic_inc(&pending_boot_probes);
}
-#ifdef CONFIG_MMU
+void riscv_hwprobe_complete_async_probe(void)
+{
+ if (atomic_dec_and_test(&pending_boot_probes))
+ complete(&boot_probes_done);
+}
-static int __init init_hwprobe_vdso_data(void)
+static int complete_hwprobe_vdso_data(void)
{
struct vdso_arch_data *avd = vdso_k_arch_data;
u64 id_bitsmash = 0;
struct riscv_hwprobe pair;
int key;
+ if (unlikely(!atomic_dec_and_test(&pending_boot_probes)))
+ wait_for_completion(&boot_probes_done);
+
/*
* Initialize vDSO data with the answers for the "all CPUs" case, to
* save a syscall in the common case.
@@ -503,13 +516,52 @@ static int __init init_hwprobe_vdso_data(void)
* vDSO should defer to the kernel for exotic cpu masks.
*/
avd->homogeneous_cpus = id_bitsmash != 0 && id_bitsmash != -1;
+
+ /*
+ * Make sure all the VDSO values are visible before we look at them.
+ * This pairs with the implicit "no speculativly visible accesses"
+ * barrier in the VDSO hwprobe code.
+ */
+ smp_wmb();
+ avd->ready = true;
+ return 0;
+}
+
+static int __init init_hwprobe_vdso_data(void)
+{
+ struct vdso_arch_data *avd = vdso_k_arch_data;
+
+ /*
+ * Prevent the vDSO cached values from being used, as they're not ready
+ * yet.
+ */
+ avd->ready = false;
return 0;
}
arch_initcall_sync(init_hwprobe_vdso_data);
+#else
+
+static int complete_hwprobe_vdso_data(void) { return 0; }
+
#endif /* CONFIG_MMU */
+static int do_riscv_hwprobe(struct riscv_hwprobe __user *pairs,
+ size_t pair_count, size_t cpusetsize,
+ unsigned long __user *cpus_user,
+ unsigned int flags)
+{
+ DO_ONCE_SLEEPABLE(complete_hwprobe_vdso_data);
+
+ if (flags & RISCV_HWPROBE_WHICH_CPUS)
+ return hwprobe_get_cpus(pairs, pair_count, cpusetsize,
+ cpus_user, flags);
+
+ return hwprobe_get_values(pairs, pair_count, cpusetsize,
+ cpus_user, flags);
+}
+
SYSCALL_DEFINE5(riscv_hwprobe, struct riscv_hwprobe __user *, pairs,
size_t, pair_count, size_t, cpusetsize, unsigned long __user *,
cpus, unsigned int, flags)
diff --git a/arch/riscv/kernel/unaligned_access_speed.c b/arch/riscv/kernel/unaligned_access_speed.c
index ae2068425fbc..70b5e6927620 100644
--- a/arch/riscv/kernel/unaligned_access_speed.c
+++ b/arch/riscv/kernel/unaligned_access_speed.c
@@ -379,6 +379,7 @@ free:
static int __init vec_check_unaligned_access_speed_all_cpus(void *unused __always_unused)
{
schedule_on_each_cpu(check_vector_unaligned_access);
+ riscv_hwprobe_complete_async_probe();
return 0;
}
@@ -473,8 +474,12 @@ static int __init check_unaligned_access_all_cpus(void)
per_cpu(vector_misaligned_access, cpu) = unaligned_vector_speed_param;
} else if (!check_vector_unaligned_access_emulated_all_cpus() &&
IS_ENABLED(CONFIG_RISCV_PROBE_VECTOR_UNALIGNED_ACCESS)) {
- kthread_run(vec_check_unaligned_access_speed_all_cpus,
- NULL, "vec_check_unaligned_access_speed_all_cpus");
+ riscv_hwprobe_register_async_probe();
+ if (IS_ERR(kthread_run(vec_check_unaligned_access_speed_all_cpus,
+ NULL, "vec_check_unaligned_access_speed_all_cpus"))) {
+ pr_warn("Failed to create vec_unalign_check kthread\n");
+ riscv_hwprobe_complete_async_probe();
+ }
}
/*
diff --git a/arch/riscv/kernel/vdso/hwprobe.c b/arch/riscv/kernel/vdso/hwprobe.c
index 2ddeba6c68dd..8f45500d0a6e 100644
--- a/arch/riscv/kernel/vdso/hwprobe.c
+++ b/arch/riscv/kernel/vdso/hwprobe.c
@@ -27,7 +27,7 @@ static int riscv_vdso_get_values(struct riscv_hwprobe *pairs, size_t pair_count,
* homogeneous, then this function can handle requests for arbitrary
* masks.
*/
- if ((flags != 0) || (!all_cpus && !avd->homogeneous_cpus))
+ if (flags != 0 || (!all_cpus && !avd->homogeneous_cpus) || unlikely(!avd->ready))
return riscv_hwprobe(pairs, pair_count, cpusetsize, cpus, flags);
/* This is something we can handle, fill out the pairs. */
diff --git a/drivers/acpi/riscv/rimt.c b/drivers/acpi/riscv/rimt.c
index 683fcfe35c31..7f423405e5ef 100644
--- a/drivers/acpi/riscv/rimt.c
+++ b/drivers/acpi/riscv/rimt.c
@@ -61,30 +61,6 @@ static int rimt_set_fwnode(struct acpi_rimt_node *rimt_node,
return 0;
}
-/**
- * rimt_get_fwnode() - Retrieve fwnode associated with an RIMT node
- *
- * @node: RIMT table node to be looked-up
- *
- * Returns: fwnode_handle pointer on success, NULL on failure
- */
-static struct fwnode_handle *rimt_get_fwnode(struct acpi_rimt_node *node)
-{
- struct fwnode_handle *fwnode = NULL;
- struct rimt_fwnode *curr;
-
- spin_lock(&rimt_fwnode_lock);
- list_for_each_entry(curr, &rimt_fwnode_list, list) {
- if (curr->rimt_node == node) {
- fwnode = curr->fwnode;
- break;
- }
- }
- spin_unlock(&rimt_fwnode_lock);
-
- return fwnode;
-}
-
static acpi_status rimt_match_node_callback(struct acpi_rimt_node *node,
void *context)
{
@@ -202,6 +178,67 @@ static struct acpi_rimt_node *rimt_scan_node(enum acpi_rimt_node_type type,
return NULL;
}
+/*
+ * RISC-V supports IOMMU as a PCI device or a platform device.
+ * When it is a platform device, there should be a namespace device as
+ * well along with RIMT. To create the link between RIMT information and
+ * the platform device, the IOMMU driver should register itself with the
+ * RIMT module. This is true for PCI based IOMMU as well.
+ */
+int rimt_iommu_register(struct device *dev)
+{
+ struct fwnode_handle *rimt_fwnode;
+ struct acpi_rimt_node *node;
+
+ node = rimt_scan_node(ACPI_RIMT_NODE_TYPE_IOMMU, dev);
+ if (!node) {
+ pr_err("Could not find IOMMU node in RIMT\n");
+ return -ENODEV;
+ }
+
+ if (dev_is_pci(dev)) {
+ rimt_fwnode = acpi_alloc_fwnode_static();
+ if (!rimt_fwnode)
+ return -ENOMEM;
+
+ rimt_fwnode->dev = dev;
+ if (!dev->fwnode)
+ dev->fwnode = rimt_fwnode;
+
+ rimt_set_fwnode(node, rimt_fwnode);
+ } else {
+ rimt_set_fwnode(node, dev->fwnode);
+ }
+
+ return 0;
+}
+
+#ifdef CONFIG_IOMMU_API
+
+/**
+ * rimt_get_fwnode() - Retrieve fwnode associated with an RIMT node
+ *
+ * @node: RIMT table node to be looked-up
+ *
+ * Returns: fwnode_handle pointer on success, NULL on failure
+ */
+static struct fwnode_handle *rimt_get_fwnode(struct acpi_rimt_node *node)
+{
+ struct fwnode_handle *fwnode = NULL;
+ struct rimt_fwnode *curr;
+
+ spin_lock(&rimt_fwnode_lock);
+ list_for_each_entry(curr, &rimt_fwnode_list, list) {
+ if (curr->rimt_node == node) {
+ fwnode = curr->fwnode;
+ break;
+ }
+ }
+ spin_unlock(&rimt_fwnode_lock);
+
+ return fwnode;
+}
+
static bool rimt_pcie_rc_supports_ats(struct acpi_rimt_node *node)
{
struct acpi_rimt_pcie_rc *pci_rc;
@@ -290,43 +327,6 @@ static struct acpi_rimt_node *rimt_node_get_id(struct acpi_rimt_node *node,
return NULL;
}
-/*
- * RISC-V supports IOMMU as a PCI device or a platform device.
- * When it is a platform device, there should be a namespace device as
- * well along with RIMT. To create the link between RIMT information and
- * the platform device, the IOMMU driver should register itself with the
- * RIMT module. This is true for PCI based IOMMU as well.
- */
-int rimt_iommu_register(struct device *dev)
-{
- struct fwnode_handle *rimt_fwnode;
- struct acpi_rimt_node *node;
-
- node = rimt_scan_node(ACPI_RIMT_NODE_TYPE_IOMMU, dev);
- if (!node) {
- pr_err("Could not find IOMMU node in RIMT\n");
- return -ENODEV;
- }
-
- if (dev_is_pci(dev)) {
- rimt_fwnode = acpi_alloc_fwnode_static();
- if (!rimt_fwnode)
- return -ENOMEM;
-
- rimt_fwnode->dev = dev;
- if (!dev->fwnode)
- dev->fwnode = rimt_fwnode;
-
- rimt_set_fwnode(node, rimt_fwnode);
- } else {
- rimt_set_fwnode(node, dev->fwnode);
- }
-
- return 0;
-}
-
-#ifdef CONFIG_IOMMU_API
-
static struct acpi_rimt_node *rimt_node_map_id(struct acpi_rimt_node *node,
u32 id_in, u32 *id_out,
u8 type_mask)