sh: tlb debugfs support.

Export the status of the utlb and itlb entries through debugfs.

Signed-off-by: Matt Fleming <matt@console-pimps.org>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

1 files changed, 179 insertions, 0 deletions

diff --git a/arch/sh/mm/tlb-debugfs.c b/arch/sh/mm/tlb-debugfs.c
new file mode 100644
index 000000000000..229bf75f28df
--- /dev/null
+++ b/arch/sh/mm/tlb-debugfs.c
@@ -0,0 +1,179 @@
+/*
+ * arch/sh/mm/tlb-debugfs.c
+ *
+ * debugfs ops for SH-4 ITLB/UTLBs.
+ *
+ * Copyright (C) 2010  Matt Fleming
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
+#include <asm/processor.h>
+#include <asm/mmu_context.h>
+#include <asm/tlbflush.h>
+
+enum tlb_type {
+        TLB_TYPE_ITLB,
+        TLB_TYPE_UTLB,
+};
+
+static struct {
+        int bits;
+        const char *size;
+} tlb_sizes[] = {
+        { 0x0, "  1KB" },
+        { 0x1, "  4KB" },
+        { 0x2, "  8KB" },
+        { 0x4, " 64KB" },
+        { 0x5, "256KB" },
+        { 0x7, "  1MB" },
+        { 0x8, "  4MB" },
+        { 0xc, " 64MB" },
+};
+
+static int tlb_seq_show(struct seq_file *file, void *iter)
+{
+        unsigned int tlb_type = (unsigned int)file->private;
+        unsigned long addr1, addr2, data1, data2;
+        unsigned long flags;
+        unsigned long mmucr;
+        unsigned int nentries, entry;
+        unsigned int urb;
+
+        mmucr = __raw_readl(MMUCR);
+        if ((mmucr & 0x1) == 0) {
+                seq_printf(file, "address translation disabled\n");
+                return 0;
+        }
+
+        if (tlb_type == TLB_TYPE_ITLB) {
+                addr1 = MMU_ITLB_ADDRESS_ARRAY;
+                addr2 = MMU_ITLB_ADDRESS_ARRAY2;
+                data1 = MMU_ITLB_DATA_ARRAY;
+                data2 = MMU_ITLB_DATA_ARRAY2;
+                nentries = 4;
+        } else {
+                addr1 = MMU_UTLB_ADDRESS_ARRAY;
+                addr2 = MMU_UTLB_ADDRESS_ARRAY2;
+                data1 = MMU_UTLB_DATA_ARRAY;
+                data2 = MMU_UTLB_DATA_ARRAY2;
+                nentries = 64;
+        }
+
+        local_irq_save(flags);
+        jump_to_uncached();
+
+        urb = (mmucr & MMUCR_URB) >> MMUCR_URB_SHIFT;
+
+        /* Make the "entry >= urb" test fail. */
+        if (urb == 0)
+                urb = MMUCR_URB_NENTRIES + 1;
+
+        if (tlb_type == TLB_TYPE_ITLB) {
+                addr1 = MMU_ITLB_ADDRESS_ARRAY;
+                addr2 = MMU_ITLB_ADDRESS_ARRAY2;
+                data1 = MMU_ITLB_DATA_ARRAY;
+                data2 = MMU_ITLB_DATA_ARRAY2;
+                nentries = 4;
+        } else {
+                addr1 = MMU_UTLB_ADDRESS_ARRAY;
+                addr2 = MMU_UTLB_ADDRESS_ARRAY2;
+                data1 = MMU_UTLB_DATA_ARRAY;
+                data2 = MMU_UTLB_DATA_ARRAY2;
+                nentries = 64;
+        }
+
+        seq_printf(file, "entry:     vpn        ppn     asid  size valid wired\n");
+
+        for (entry = 0; entry < nentries; entry++) {
+                unsigned long vpn, ppn, asid, size;
+                unsigned long valid;
+                unsigned long val;
+                const char *sz = "    ?";
+                int i;
+
+                val = __raw_readl(addr1 | (entry << MMU_TLB_ENTRY_SHIFT));
+                ctrl_barrier();
+                vpn = val & 0xfffffc00;
+                valid = val & 0x100;
+
+                val = __raw_readl(addr2 | (entry << MMU_TLB_ENTRY_SHIFT));
+                ctrl_barrier();
+                asid = val & MMU_CONTEXT_ASID_MASK;
+
+                val = __raw_readl(data1 | (entry << MMU_TLB_ENTRY_SHIFT));
+                ctrl_barrier();
+                ppn = (val & 0x0ffffc00) << 4;
+
+                val = __raw_readl(data2 | (entry << MMU_TLB_ENTRY_SHIFT));
+                ctrl_barrier();
+                size = (val & 0xf0) >> 4;
+
+                for (i = 0; i < ARRAY_SIZE(tlb_sizes); i++) {
+                        if (tlb_sizes[i].bits == size)
+                                break;
+                }
+
+                if (i != ARRAY_SIZE(tlb_sizes))
+                        sz = tlb_sizes[i].size;
+
+                seq_printf(file, "%2d:    0x%08lx 0x%08lx %5lu %s   %s     %s\n",
+                           entry, vpn, ppn, asid,
+                           sz, valid ? "V" : "-",
+                           (urb <= entry) ? "W" : "-");
+        }
+
+        back_to_cached();
+        local_irq_restore(flags);
+
+        return 0;
+}
+
+static int tlb_debugfs_open(struct inode *inode, struct file *file)
+{
+        return single_open(file, tlb_seq_show, inode->i_private);
+}
+
+static const struct file_operations tlb_debugfs_fops = {
+        .owner          = THIS_MODULE,
+        .open           = tlb_debugfs_open,
+        .read           = seq_read,
+        .llseek         = seq_lseek,
+        .release        = single_release,
+};
+
+static int __init tlb_debugfs_init(void)
+{
+        struct dentry *itlb, *utlb;
+
+        itlb = debugfs_create_file("itlb", S_IRUSR, sh_debugfs_root,
+                                   (unsigned int *)TLB_TYPE_ITLB,
+                                   &tlb_debugfs_fops);
+        if (unlikely(!itlb))
+                return -ENOMEM;
+        if (IS_ERR(itlb))
+                return PTR_ERR(itlb);
+
+        utlb = debugfs_create_file("utlb", S_IRUSR, sh_debugfs_root,
+                                   (unsigned int *)TLB_TYPE_UTLB,
+                                   &tlb_debugfs_fops);
+        if (unlikely(!utlb)) {
+                debugfs_remove(itlb);
+                return -ENOMEM;
+        }
+
+        if (IS_ERR(utlb)) {
+                debugfs_remove(itlb);
+                return PTR_ERR(utlb);
+        }
+
+        return 0;
+}
+module_init(tlb_debugfs_init);
+
+MODULE_LICENSE("GPL v2");