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authorLinus Torvalds <torvalds@linux-foundation.org>2019-05-19 09:56:36 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2019-05-19 09:56:36 -0700
commitb0bb1269b9788a35af68587505d8df90498df75f (patch)
treed9cc2ef42c93947c59638f412d479b0fd36f7e9b /arch/riscv/mm
parent72cf0b07418a9c8349aa9137194b1ccba6e54a9d (diff)
parent8fef9900d43feb9d5017c72840966733085e3e82 (diff)
Merge tag 'riscv-for-linus-5.2-mw2' of git://git.kernel.org/pub/scm/linux/kernel/git/palmer/riscv-linux
Pull RISC-V updates from Palmer Dabbelt: "This contains an assortment of RISC-V related patches that I'd like to target for the 5.2 merge window. Most of the patches are cleanups, but there are a handful of user-visible changes: - The nosmp and nr_cpus command-line arguments are now supported, which work like normal. - The SBI console no longer installs itself as a preferred console, we rely on standard mechanisms (/chosen, command-line, hueristics) instead. - sfence_remove_sfence_vma{,_asid} now pass their arguments along to the SBI call. - Modules now support BUG(). - A missing sfence.vma during boot has been added. This bug only manifests during boot. - The arch/riscv support for SiFive's L2 cache controller has been merged, which should un-block the EDAC framework work. I've only tested this on QEMU again, as I didn't have time to get things running on the Unleashed. The latest master from this morning merges in cleanly and passes the tests as well" * tag 'riscv-for-linus-5.2-mw2' of git://git.kernel.org/pub/scm/linux/kernel/git/palmer/riscv-linux: (31 commits) riscv: fix locking violation in page fault handler RISC-V: sifive_l2_cache: Add L2 cache controller driver for SiFive SoCs RISC-V: Add DT documentation for SiFive L2 Cache Controller RISC-V: Avoid using invalid intermediate translations riscv: Support BUG() in kernel module riscv: Add the support for c.ebreak check in is_valid_bugaddr() riscv: support trap-based WARN() riscv: fix sbi_remote_sfence_vma{,_asid}. riscv: move switch_mm to its own file riscv: move flush_icache_{all,mm} to cacheflush.c tty: Don't force RISCV SBI console as preferred console RISC-V: Access CSRs using CSR numbers RISC-V: Add interrupt related SCAUSE defines in asm/csr.h RISC-V: Use tabs to align macro values in asm/csr.h RISC-V: Fix minor checkpatch issues. RISC-V: Support nr_cpus command line option. RISC-V: Implement nosmp commandline option. RISC-V: Add RISC-V specific arch_match_cpu_phys_id riscv: vdso: drop unnecessary cc-ldoption riscv: call pm_power_off from machine_halt / machine_power_off ...
Diffstat (limited to 'arch/riscv/mm')
-rw-r--r--arch/riscv/mm/Makefile2
-rw-r--r--arch/riscv/mm/cacheflush.c61
-rw-r--r--arch/riscv/mm/context.c69
-rw-r--r--arch/riscv/mm/fault.c9
-rw-r--r--arch/riscv/mm/sifive_l2_cache.c175
5 files changed, 310 insertions, 6 deletions
diff --git a/arch/riscv/mm/Makefile b/arch/riscv/mm/Makefile
index b68aac701803..8db569141485 100644
--- a/arch/riscv/mm/Makefile
+++ b/arch/riscv/mm/Makefile
@@ -9,3 +9,5 @@ obj-y += fault.o
obj-y += extable.o
obj-y += ioremap.o
obj-y += cacheflush.o
+obj-y += context.o
+obj-y += sifive_l2_cache.o
diff --git a/arch/riscv/mm/cacheflush.c b/arch/riscv/mm/cacheflush.c
index 498c0a0814fe..497b7d07af0c 100644
--- a/arch/riscv/mm/cacheflush.c
+++ b/arch/riscv/mm/cacheflush.c
@@ -14,6 +14,67 @@
#include <asm/pgtable.h>
#include <asm/cacheflush.h>
+#ifdef CONFIG_SMP
+
+#include <asm/sbi.h>
+
+void flush_icache_all(void)
+{
+ sbi_remote_fence_i(NULL);
+}
+
+/*
+ * Performs an icache flush for the given MM context. RISC-V has no direct
+ * mechanism for instruction cache shoot downs, so instead we send an IPI that
+ * informs the remote harts they need to flush their local instruction caches.
+ * To avoid pathologically slow behavior in a common case (a bunch of
+ * single-hart processes on a many-hart machine, ie 'make -j') we avoid the
+ * IPIs for harts that are not currently executing a MM context and instead
+ * schedule a deferred local instruction cache flush to be performed before
+ * execution resumes on each hart.
+ */
+void flush_icache_mm(struct mm_struct *mm, bool local)
+{
+ unsigned int cpu;
+ cpumask_t others, hmask, *mask;
+
+ preempt_disable();
+
+ /* Mark every hart's icache as needing a flush for this MM. */
+ mask = &mm->context.icache_stale_mask;
+ cpumask_setall(mask);
+ /* Flush this hart's I$ now, and mark it as flushed. */
+ cpu = smp_processor_id();
+ cpumask_clear_cpu(cpu, mask);
+ local_flush_icache_all();
+
+ /*
+ * Flush the I$ of other harts concurrently executing, and mark them as
+ * flushed.
+ */
+ cpumask_andnot(&others, mm_cpumask(mm), cpumask_of(cpu));
+ local |= cpumask_empty(&others);
+ if (mm != current->active_mm || !local) {
+ cpumask_clear(&hmask);
+ riscv_cpuid_to_hartid_mask(&others, &hmask);
+ sbi_remote_fence_i(hmask.bits);
+ } else {
+ /*
+ * It's assumed that at least one strongly ordered operation is
+ * performed on this hart between setting a hart's cpumask bit
+ * and scheduling this MM context on that hart. Sending an SBI
+ * remote message will do this, but in the case where no
+ * messages are sent we still need to order this hart's writes
+ * with flush_icache_deferred().
+ */
+ smp_mb();
+ }
+
+ preempt_enable();
+}
+
+#endif /* CONFIG_SMP */
+
void flush_icache_pte(pte_t pte)
{
struct page *page = pte_page(pte);
diff --git a/arch/riscv/mm/context.c b/arch/riscv/mm/context.c
new file mode 100644
index 000000000000..89ceb3cbe218
--- /dev/null
+++ b/arch/riscv/mm/context.c
@@ -0,0 +1,69 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2012 Regents of the University of California
+ * Copyright (C) 2017 SiFive
+ */
+
+#include <linux/mm.h>
+#include <asm/tlbflush.h>
+#include <asm/cacheflush.h>
+
+/*
+ * When necessary, performs a deferred icache flush for the given MM context,
+ * on the local CPU. RISC-V has no direct mechanism for instruction cache
+ * shoot downs, so instead we send an IPI that informs the remote harts they
+ * need to flush their local instruction caches. To avoid pathologically slow
+ * behavior in a common case (a bunch of single-hart processes on a many-hart
+ * machine, ie 'make -j') we avoid the IPIs for harts that are not currently
+ * executing a MM context and instead schedule a deferred local instruction
+ * cache flush to be performed before execution resumes on each hart. This
+ * actually performs that local instruction cache flush, which implicitly only
+ * refers to the current hart.
+ */
+static inline void flush_icache_deferred(struct mm_struct *mm)
+{
+#ifdef CONFIG_SMP
+ unsigned int cpu = smp_processor_id();
+ cpumask_t *mask = &mm->context.icache_stale_mask;
+
+ if (cpumask_test_cpu(cpu, mask)) {
+ cpumask_clear_cpu(cpu, mask);
+ /*
+ * Ensure the remote hart's writes are visible to this hart.
+ * This pairs with a barrier in flush_icache_mm.
+ */
+ smp_mb();
+ local_flush_icache_all();
+ }
+
+#endif
+}
+
+void switch_mm(struct mm_struct *prev, struct mm_struct *next,
+ struct task_struct *task)
+{
+ unsigned int cpu;
+
+ if (unlikely(prev == next))
+ return;
+
+ /*
+ * Mark the current MM context as inactive, and the next as
+ * active. This is at least used by the icache flushing
+ * routines in order to determine who should be flushed.
+ */
+ cpu = smp_processor_id();
+
+ cpumask_clear_cpu(cpu, mm_cpumask(prev));
+ cpumask_set_cpu(cpu, mm_cpumask(next));
+
+ /*
+ * Use the old spbtr name instead of using the current satp
+ * name to support binutils 2.29 which doesn't know about the
+ * privileged ISA 1.10 yet.
+ */
+ csr_write(sptbr, virt_to_pfn(next->pgd) | SATP_MODE);
+ local_flush_tlb_all();
+
+ flush_icache_deferred(next);
+}
diff --git a/arch/riscv/mm/fault.c b/arch/riscv/mm/fault.c
index 88401d5125bc..cec8be9e2d6a 100644
--- a/arch/riscv/mm/fault.c
+++ b/arch/riscv/mm/fault.c
@@ -229,8 +229,9 @@ vmalloc_fault:
pte_t *pte_k;
int index;
+ /* User mode accesses just cause a SIGSEGV */
if (user_mode(regs))
- goto bad_area;
+ return do_trap(regs, SIGSEGV, code, addr, tsk);
/*
* Synchronize this task's top level page-table
@@ -239,13 +240,9 @@ vmalloc_fault:
* Do _not_ use "tsk->active_mm->pgd" here.
* We might be inside an interrupt in the middle
* of a task switch.
- *
- * Note: Use the old spbtr name instead of using the current
- * satp name to support binutils 2.29 which doesn't know about
- * the privileged ISA 1.10 yet.
*/
index = pgd_index(addr);
- pgd = (pgd_t *)pfn_to_virt(csr_read(sptbr)) + index;
+ pgd = (pgd_t *)pfn_to_virt(csr_read(CSR_SATP)) + index;
pgd_k = init_mm.pgd + index;
if (!pgd_present(*pgd_k))
diff --git a/arch/riscv/mm/sifive_l2_cache.c b/arch/riscv/mm/sifive_l2_cache.c
new file mode 100644
index 000000000000..4eb64619b3f4
--- /dev/null
+++ b/arch/riscv/mm/sifive_l2_cache.c
@@ -0,0 +1,175 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * SiFive L2 cache controller Driver
+ *
+ * Copyright (C) 2018-2019 SiFive, Inc.
+ *
+ */
+#include <linux/debugfs.h>
+#include <linux/interrupt.h>
+#include <linux/of_irq.h>
+#include <linux/of_address.h>
+#include <asm/sifive_l2_cache.h>
+
+#define SIFIVE_L2_DIRECCFIX_LOW 0x100
+#define SIFIVE_L2_DIRECCFIX_HIGH 0x104
+#define SIFIVE_L2_DIRECCFIX_COUNT 0x108
+
+#define SIFIVE_L2_DATECCFIX_LOW 0x140
+#define SIFIVE_L2_DATECCFIX_HIGH 0x144
+#define SIFIVE_L2_DATECCFIX_COUNT 0x148
+
+#define SIFIVE_L2_DATECCFAIL_LOW 0x160
+#define SIFIVE_L2_DATECCFAIL_HIGH 0x164
+#define SIFIVE_L2_DATECCFAIL_COUNT 0x168
+
+#define SIFIVE_L2_CONFIG 0x00
+#define SIFIVE_L2_WAYENABLE 0x08
+#define SIFIVE_L2_ECCINJECTERR 0x40
+
+#define SIFIVE_L2_MAX_ECCINTR 3
+
+static void __iomem *l2_base;
+static int g_irq[SIFIVE_L2_MAX_ECCINTR];
+
+enum {
+ DIR_CORR = 0,
+ DATA_CORR,
+ DATA_UNCORR,
+};
+
+#ifdef CONFIG_DEBUG_FS
+static struct dentry *sifive_test;
+
+static ssize_t l2_write(struct file *file, const char __user *data,
+ size_t count, loff_t *ppos)
+{
+ unsigned int val;
+
+ if (kstrtouint_from_user(data, count, 0, &val))
+ return -EINVAL;
+ if ((val >= 0 && val < 0xFF) || (val >= 0x10000 && val < 0x100FF))
+ writel(val, l2_base + SIFIVE_L2_ECCINJECTERR);
+ else
+ return -EINVAL;
+ return count;
+}
+
+static const struct file_operations l2_fops = {
+ .owner = THIS_MODULE,
+ .open = simple_open,
+ .write = l2_write
+};
+
+static void setup_sifive_debug(void)
+{
+ sifive_test = debugfs_create_dir("sifive_l2_cache", NULL);
+
+ debugfs_create_file("sifive_debug_inject_error", 0200,
+ sifive_test, NULL, &l2_fops);
+}
+#endif
+
+static void l2_config_read(void)
+{
+ u32 regval, val;
+
+ regval = readl(l2_base + SIFIVE_L2_CONFIG);
+ val = regval & 0xFF;
+ pr_info("L2CACHE: No. of Banks in the cache: %d\n", val);
+ val = (regval & 0xFF00) >> 8;
+ pr_info("L2CACHE: No. of ways per bank: %d\n", val);
+ val = (regval & 0xFF0000) >> 16;
+ pr_info("L2CACHE: Sets per bank: %llu\n", (uint64_t)1 << val);
+ val = (regval & 0xFF000000) >> 24;
+ pr_info("L2CACHE: Bytes per cache block: %llu\n", (uint64_t)1 << val);
+
+ regval = readl(l2_base + SIFIVE_L2_WAYENABLE);
+ pr_info("L2CACHE: Index of the largest way enabled: %d\n", regval);
+}
+
+static const struct of_device_id sifive_l2_ids[] = {
+ { .compatible = "sifive,fu540-c000-ccache" },
+ { /* end of table */ },
+};
+
+static ATOMIC_NOTIFIER_HEAD(l2_err_chain);
+
+int register_sifive_l2_error_notifier(struct notifier_block *nb)
+{
+ return atomic_notifier_chain_register(&l2_err_chain, nb);
+}
+EXPORT_SYMBOL_GPL(register_sifive_l2_error_notifier);
+
+int unregister_sifive_l2_error_notifier(struct notifier_block *nb)
+{
+ return atomic_notifier_chain_unregister(&l2_err_chain, nb);
+}
+EXPORT_SYMBOL_GPL(unregister_sifive_l2_error_notifier);
+
+static irqreturn_t l2_int_handler(int irq, void *device)
+{
+ unsigned int regval, add_h, add_l;
+
+ if (irq == g_irq[DIR_CORR]) {
+ add_h = readl(l2_base + SIFIVE_L2_DIRECCFIX_HIGH);
+ add_l = readl(l2_base + SIFIVE_L2_DIRECCFIX_LOW);
+ pr_err("L2CACHE: DirError @ 0x%08X.%08X\n", add_h, add_l);
+ regval = readl(l2_base + SIFIVE_L2_DIRECCFIX_COUNT);
+ atomic_notifier_call_chain(&l2_err_chain, SIFIVE_L2_ERR_TYPE_CE,
+ "DirECCFix");
+ }
+ if (irq == g_irq[DATA_CORR]) {
+ add_h = readl(l2_base + SIFIVE_L2_DATECCFIX_HIGH);
+ add_l = readl(l2_base + SIFIVE_L2_DATECCFIX_LOW);
+ pr_err("L2CACHE: DataError @ 0x%08X.%08X\n", add_h, add_l);
+ regval = readl(l2_base + SIFIVE_L2_DATECCFIX_COUNT);
+ atomic_notifier_call_chain(&l2_err_chain, SIFIVE_L2_ERR_TYPE_CE,
+ "DatECCFix");
+ }
+ if (irq == g_irq[DATA_UNCORR]) {
+ add_h = readl(l2_base + SIFIVE_L2_DATECCFAIL_HIGH);
+ add_l = readl(l2_base + SIFIVE_L2_DATECCFAIL_LOW);
+ pr_err("L2CACHE: DataFail @ 0x%08X.%08X\n", add_h, add_l);
+ regval = readl(l2_base + SIFIVE_L2_DATECCFAIL_COUNT);
+ atomic_notifier_call_chain(&l2_err_chain, SIFIVE_L2_ERR_TYPE_UE,
+ "DatECCFail");
+ }
+
+ return IRQ_HANDLED;
+}
+
+int __init sifive_l2_init(void)
+{
+ struct device_node *np;
+ struct resource res;
+ int i, rc;
+
+ np = of_find_matching_node(NULL, sifive_l2_ids);
+ if (!np)
+ return -ENODEV;
+
+ if (of_address_to_resource(np, 0, &res))
+ return -ENODEV;
+
+ l2_base = ioremap(res.start, resource_size(&res));
+ if (!l2_base)
+ return -ENOMEM;
+
+ for (i = 0; i < SIFIVE_L2_MAX_ECCINTR; i++) {
+ g_irq[i] = irq_of_parse_and_map(np, i);
+ rc = request_irq(g_irq[i], l2_int_handler, 0, "l2_ecc", NULL);
+ if (rc) {
+ pr_err("L2CACHE: Could not request IRQ %d\n", g_irq[i]);
+ return rc;
+ }
+ }
+
+ l2_config_read();
+
+#ifdef CONFIG_DEBUG_FS
+ setup_sifive_debug();
+#endif
+ return 0;
+}
+device_initcall(sifive_l2_init);