ia64/pv_op/binarypatch: add helper functions to support binary patching for paravirt_ops.

add helper functions to support binary patching for paravirt_ops.

Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Tony Luck <tony.luck@intel.com>

3 files changed, 594 insertions, 0 deletions

diff --git a/arch/ia64/kernel/paravirt_patch.c b/arch/ia64/kernel/paravirt_patch.c
new file mode 100644
index 000000000000..bfdfef1b1ffd
--- /dev/null
+++ b/arch/ia64/kernel/paravirt_patch.c
@@ -0,0 +1,514 @@
+/******************************************************************************
+ * linux/arch/ia64/xen/paravirt_patch.c
+ *
+ * Copyright (c) 2008 Isaku Yamahata <yamahata at valinux co jp>
+ *                    VA Linux Systems Japan K.K.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ */
+
+#include <linux/init.h>
+#include <asm/intrinsics.h>
+#include <asm/kprobes.h>
+#include <asm/paravirt.h>
+#include <asm/paravirt_patch.h>
+
+typedef union ia64_inst {
+        struct {
+                unsigned long long qp : 6;
+                unsigned long long : 31;
+                unsigned long long opcode : 4;
+                unsigned long long reserved : 23;
+        } generic;
+        unsigned long long l;
+} ia64_inst_t;
+
+/*
+ * flush_icache_range() can't be used here.
+ * we are here before cpu_init() which initializes
+ * ia64_i_cache_stride_shift. flush_icache_range() uses it.
+ */
+void __init_or_module
+paravirt_flush_i_cache_range(const void *instr, unsigned long size)
+{
+        extern void paravirt_fc_i(const void *addr);
+        unsigned long i;
+
+        for (i = 0; i < size; i += sizeof(bundle_t))
+                paravirt_fc_i(instr + i);
+}
+
+bundle_t* __init_or_module
+paravirt_get_bundle(unsigned long tag)
+{
+        return (bundle_t *)(tag & ~3UL);
+}
+
+unsigned long __init_or_module
+paravirt_get_slot(unsigned long tag)
+{
+        return tag & 3UL;
+}
+
+unsigned long __init_or_module
+paravirt_get_num_inst(unsigned long stag, unsigned long etag)
+{
+        bundle_t *sbundle = paravirt_get_bundle(stag);
+        unsigned long sslot = paravirt_get_slot(stag);
+        bundle_t *ebundle = paravirt_get_bundle(etag);
+        unsigned long eslot = paravirt_get_slot(etag);
+
+        return (ebundle - sbundle) * 3 + eslot - sslot + 1;
+}
+
+unsigned long __init_or_module
+paravirt_get_next_tag(unsigned long tag)
+{
+        unsigned long slot = paravirt_get_slot(tag);
+
+        switch (slot) {
+        case 0:
+        case 1:
+                return tag + 1;
+        case 2: {
+                bundle_t *bundle = paravirt_get_bundle(tag);
+                return (unsigned long)(bundle + 1);
+        }
+        default:
+                BUG();
+        }
+        /* NOTREACHED */
+}
+
+ia64_inst_t __init_or_module
+paravirt_read_slot0(const bundle_t *bundle)
+{
+        ia64_inst_t inst;
+        inst.l = bundle->quad0.slot0;
+        return inst;
+}
+
+ia64_inst_t __init_or_module
+paravirt_read_slot1(const bundle_t *bundle)
+{
+        ia64_inst_t inst;
+        inst.l = bundle->quad0.slot1_p0 |
+                ((unsigned long long)bundle->quad1.slot1_p1 << 18UL);
+        return inst;
+}
+
+ia64_inst_t __init_or_module
+paravirt_read_slot2(const bundle_t *bundle)
+{
+        ia64_inst_t inst;
+        inst.l = bundle->quad1.slot2;
+        return inst;
+}
+
+ia64_inst_t __init_or_module
+paravirt_read_inst(unsigned long tag)
+{
+        bundle_t *bundle = paravirt_get_bundle(tag);
+        unsigned long slot = paravirt_get_slot(tag);
+
+        switch (slot) {
+        case 0:
+                return paravirt_read_slot0(bundle);
+        case 1:
+                return paravirt_read_slot1(bundle);
+        case 2:
+                return paravirt_read_slot2(bundle);
+        default:
+                BUG();
+        }
+        /* NOTREACHED */
+}
+
+void __init_or_module
+paravirt_write_slot0(bundle_t *bundle, ia64_inst_t inst)
+{
+        bundle->quad0.slot0 = inst.l;
+}
+
+void __init_or_module
+paravirt_write_slot1(bundle_t *bundle, ia64_inst_t inst)
+{
+        bundle->quad0.slot1_p0 = inst.l;
+        bundle->quad1.slot1_p1 = inst.l >> 18UL;
+}
+
+void __init_or_module
+paravirt_write_slot2(bundle_t *bundle, ia64_inst_t inst)
+{
+        bundle->quad1.slot2 = inst.l;
+}
+
+void __init_or_module
+paravirt_write_inst(unsigned long tag, ia64_inst_t inst)
+{
+        bundle_t *bundle = paravirt_get_bundle(tag);
+        unsigned long slot = paravirt_get_slot(tag);
+
+        switch (slot) {
+        case 0:
+                paravirt_write_slot0(bundle, inst);
+                break;
+        case 1:
+                paravirt_write_slot1(bundle, inst);
+                break;
+        case 2:
+                paravirt_write_slot2(bundle, inst);
+                break;
+        default:
+                BUG();
+                break;
+        }
+        paravirt_flush_i_cache_range(bundle, sizeof(*bundle));
+}
+
+/* for debug */
+void
+paravirt_print_bundle(const bundle_t *bundle)
+{
+        const unsigned long *quad = (const unsigned long *)bundle;
+        ia64_inst_t slot0 = paravirt_read_slot0(bundle);
+        ia64_inst_t slot1 = paravirt_read_slot1(bundle);
+        ia64_inst_t slot2 = paravirt_read_slot2(bundle);
+
+        printk(KERN_DEBUG
+               "bundle 0x%p 0x%016lx 0x%016lx\n", bundle, quad[0], quad[1]);
+        printk(KERN_DEBUG
+               "bundle template 0x%x\n",
+               bundle->quad0.template);
+        printk(KERN_DEBUG
+               "slot0 0x%lx slot1_p0 0x%lx slot1_p1 0x%lx slot2 0x%lx\n",
+               (unsigned long)bundle->quad0.slot0,
+               (unsigned long)bundle->quad0.slot1_p0,
+               (unsigned long)bundle->quad1.slot1_p1,
+               (unsigned long)bundle->quad1.slot2);
+        printk(KERN_DEBUG
+               "slot0 0x%016llx slot1 0x%016llx slot2 0x%016llx\n",
+               slot0.l, slot1.l, slot2.l);
+}
+
+static int noreplace_paravirt __init_or_module = 0;
+
+static int __init setup_noreplace_paravirt(char *str)
+{
+        noreplace_paravirt = 1;
+        return 1;
+}
+__setup("noreplace-paravirt", setup_noreplace_paravirt);
+
+#ifdef ASM_SUPPORTED
+static void __init_or_module
+fill_nop_bundle(void *sbundle, void *ebundle)
+{
+        extern const char paravirt_nop_bundle[];
+        extern const unsigned long paravirt_nop_bundle_size;
+
+        void *bundle = sbundle;
+
+        BUG_ON((((unsigned long)sbundle) % sizeof(bundle_t)) != 0);
+        BUG_ON((((unsigned long)ebundle) % sizeof(bundle_t)) != 0);
+
+        while (bundle < ebundle) {
+                memcpy(bundle, paravirt_nop_bundle, paravirt_nop_bundle_size);
+
+                bundle += paravirt_nop_bundle_size;
+        }
+}
+
+/* helper function */
+unsigned long __init_or_module
+__paravirt_patch_apply_bundle(void *sbundle, void *ebundle, unsigned long type,
+                              const struct paravirt_patch_bundle_elem *elems,
+                              unsigned long nelems,
+                              const struct paravirt_patch_bundle_elem **found)
+{
+        unsigned long used = 0;
+        unsigned long i;
+
+        BUG_ON((((unsigned long)sbundle) % sizeof(bundle_t)) != 0);
+        BUG_ON((((unsigned long)ebundle) % sizeof(bundle_t)) != 0);
+
+        found = NULL;
+        for (i = 0; i < nelems; i++) {
+                const struct paravirt_patch_bundle_elem *p = &elems[i];
+                if (p->type == type) {
+                        unsigned long need = p->ebundle - p->sbundle;
+                        unsigned long room = ebundle - sbundle;
+
+                        if (found != NULL)
+                                *found = p;
+
+                        if (room < need) {
+                                /* no room to replace. skip it */
+                                printk(KERN_DEBUG
+                                       "the space is too small to put "
+                                       "bundles. type %ld need %ld room %ld\n",
+                                       type, need, room);
+                                break;
+                        }
+
+                        used = need;
+                        memcpy(sbundle, p->sbundle, used);
+                        break;
+                }
+        }
+
+        return used;
+}
+
+void __init_or_module
+paravirt_patch_apply_bundle(const struct paravirt_patch_site_bundle *start,
+                            const struct paravirt_patch_site_bundle *end)
+{
+        const struct paravirt_patch_site_bundle *p;
+
+        if (noreplace_paravirt)
+                return;
+        if (pv_init_ops.patch_bundle == NULL)
+                return;
+
+        for (p = start; p < end; p++) {
+                unsigned long used;
+
+                used = (*pv_init_ops.patch_bundle)(p->sbundle, p->ebundle,
+                                                   p->type);
+                if (used == 0)
+                        continue;
+
+                fill_nop_bundle(p->sbundle + used, p->ebundle);
+                paravirt_flush_i_cache_range(p->sbundle,
+                                             p->ebundle - p->sbundle);
+        }
+        ia64_sync_i();
+        ia64_srlz_i();
+}
+
+/*
+ * nop.i, nop.m, nop.f instruction are same format.
+ * but nop.b has differennt format.
+ * This doesn't support nop.b for now.
+ */
+static void __init_or_module
+fill_nop_inst(unsigned long stag, unsigned long etag)
+{
+        extern const bundle_t paravirt_nop_mfi_inst_bundle[];
+        unsigned long tag;
+        const ia64_inst_t nop_inst =
+                paravirt_read_slot0(paravirt_nop_mfi_inst_bundle);
+
+        for (tag = stag; tag < etag; tag = paravirt_get_next_tag(tag))
+                paravirt_write_inst(tag, nop_inst);
+}
+
+void __init_or_module
+paravirt_patch_apply_inst(const struct paravirt_patch_site_inst *start,
+                          const struct paravirt_patch_site_inst *end)
+{
+        const struct paravirt_patch_site_inst *p;
+
+        if (noreplace_paravirt)
+                return;
+        if (pv_init_ops.patch_inst == NULL)
+                return;
+
+        for (p = start; p < end; p++) {
+                unsigned long tag;
+                bundle_t *sbundle;
+                bundle_t *ebundle;
+
+                tag = (*pv_init_ops.patch_inst)(p->stag, p->etag, p->type);
+                if (tag == p->stag)
+                        continue;
+
+                fill_nop_inst(tag, p->etag);
+                sbundle = paravirt_get_bundle(p->stag);
+                ebundle = paravirt_get_bundle(p->etag) + 1;
+                paravirt_flush_i_cache_range(sbundle, (ebundle - sbundle) *
+                                             sizeof(bundle_t));
+        }
+        ia64_sync_i();
+        ia64_srlz_i();
+}
+#endif /* ASM_SUPPOTED */
+
+/* brl.cond.sptk.many <target64> X3 */
+typedef union inst_x3_op {
+        ia64_inst_t inst;
+        struct {
+                unsigned long qp: 6;
+                unsigned long btyp: 3;
+                unsigned long unused: 3;
+                unsigned long p: 1;
+                unsigned long imm20b: 20;
+                unsigned long wh: 2;
+                unsigned long d: 1;
+                unsigned long i: 1;
+                unsigned long opcode: 4;
+        };
+        unsigned long l;
+} inst_x3_op_t;
+
+typedef union inst_x3_imm {
+        ia64_inst_t inst;
+        struct {
+                unsigned long unused: 2;
+                unsigned long imm39: 39;
+        };
+        unsigned long l;
+} inst_x3_imm_t;
+
+void __init_or_module
+paravirt_patch_reloc_brl(unsigned long tag, const void *target)
+{
+        unsigned long tag_op = paravirt_get_next_tag(tag);
+        unsigned long tag_imm = tag;
+        bundle_t *bundle = paravirt_get_bundle(tag);
+
+        ia64_inst_t inst_op = paravirt_read_inst(tag_op);
+        ia64_inst_t inst_imm = paravirt_read_inst(tag_imm);
+
+        inst_x3_op_t inst_x3_op = { .l = inst_op.l };
+        inst_x3_imm_t inst_x3_imm = { .l = inst_imm.l };
+
+        unsigned long imm60 =
+                ((unsigned long)target - (unsigned long)bundle) >> 4;
+
+        BUG_ON(paravirt_get_slot(tag) != 1); /* MLX */
+        BUG_ON(((unsigned long)target & (sizeof(bundle_t) - 1)) != 0);
+
+        /* imm60[59] 1bit */
+        inst_x3_op.i = (imm60 >> 59) & 1;
+        /* imm60[19:0] 20bit */
+        inst_x3_op.imm20b = imm60 & ((1UL << 20) - 1);
+        /* imm60[58:20] 39bit */
+        inst_x3_imm.imm39 = (imm60 >> 20) & ((1UL << 39) - 1);
+
+        inst_op.l = inst_x3_op.l;
+        inst_imm.l = inst_x3_imm.l;
+
+        paravirt_write_inst(tag_op, inst_op);
+        paravirt_write_inst(tag_imm, inst_imm);
+}
+
+/* br.cond.sptk.many <target25> B1 */
+typedef union inst_b1 {
+        ia64_inst_t inst;
+        struct {
+                unsigned long qp: 6;
+                unsigned long btype: 3;
+                unsigned long unused: 3;
+                unsigned long p: 1;
+                unsigned long imm20b: 20;
+                unsigned long wh: 2;
+                unsigned long d: 1;
+                unsigned long s: 1;
+                unsigned long opcode: 4;
+        };
+        unsigned long l;
+} inst_b1_t;
+
+void __init
+paravirt_patch_reloc_br(unsigned long tag, const void *target)
+{
+        bundle_t *bundle = paravirt_get_bundle(tag);
+        ia64_inst_t inst = paravirt_read_inst(tag);
+        unsigned long target25 = (unsigned long)target - (unsigned long)bundle;
+        inst_b1_t inst_b1;
+
+        BUG_ON(((unsigned long)target & (sizeof(bundle_t) - 1)) != 0);
+
+        inst_b1.l = inst.l;
+        if (target25 & (1UL << 63))
+                inst_b1.s = 1;
+        else
+                inst_b1.s = 0;
+
+        inst_b1.imm20b = target25 >> 4;
+        inst.l = inst_b1.l;
+
+        paravirt_write_inst(tag, inst);
+}
+
+void __init
+__paravirt_patch_apply_branch(
+        unsigned long tag, unsigned long type,
+        const struct paravirt_patch_branch_target *entries,
+        unsigned int nr_entries)
+{
+        unsigned int i;
+        for (i = 0; i < nr_entries; i++) {
+                if (entries[i].type == type) {
+                        paravirt_patch_reloc_br(tag, entries[i].entry);
+                        break;
+                }
+        }
+}
+
+static void __init
+paravirt_patch_apply_branch(const struct paravirt_patch_site_branch *start,
+                            const struct paravirt_patch_site_branch *end)
+{
+        const struct paravirt_patch_site_branch *p;
+
+        if (noreplace_paravirt)
+                return;
+        if (pv_init_ops.patch_branch == NULL)
+                return;
+
+        for (p = start; p < end; p++)
+                (*pv_init_ops.patch_branch)(p->tag, p->type);
+
+        ia64_sync_i();
+        ia64_srlz_i();
+}
+
+void __init
+paravirt_patch_apply(void)
+{
+        extern const char __start_paravirt_bundles[];
+        extern const char __stop_paravirt_bundles[];
+        extern const char __start_paravirt_insts[];
+        extern const char __stop_paravirt_insts[];
+        extern const char __start_paravirt_branches[];
+        extern const char __stop_paravirt_branches[];
+
+        paravirt_patch_apply_bundle((const struct paravirt_patch_site_bundle *)
+                                    __start_paravirt_bundles,
+                                    (const struct paravirt_patch_site_bundle *)
+                                    __stop_paravirt_bundles);
+        paravirt_patch_apply_inst((const struct paravirt_patch_site_inst *)
+                                  __start_paravirt_insts,
+                                  (const struct paravirt_patch_site_inst *)
+                                  __stop_paravirt_insts);
+        paravirt_patch_apply_branch((const struct paravirt_patch_site_branch *)
+                                    __start_paravirt_branches,
+                                    (const struct paravirt_patch_site_branch *)
+                                    __stop_paravirt_branches);
+}
+
+/*
+ * Local variables:
+ * mode: C
+ * c-set-style: "linux"
+ * c-basic-offset: 8
+ * tab-width: 8
+ * indent-tabs-mode: t
+ * End:
+ */
diff --git a/arch/ia64/kernel/paravirtentry.S b/arch/ia64/kernel/paravirtentry.S
index 2f42fcb9776a..80c0d365cbc0 100644
--- a/arch/ia64/kernel/paravirtentry.S
+++ b/arch/ia64/kernel/paravirtentry.S
@@ -58,3 +58,59 @@ BRANCH_PROC(switch_to, r22, b7)
 BRANCH_PROC_UNWINFO(leave_syscall, r22, b7)
 BRANCH_PROC(work_processed_syscall, r2, b7)
 BRANCH_PROC_UNWINFO(leave_kernel, r22, b7)
+
+
+#ifdef CONFIG_MODULES
+#define __INIT_OR_MODULE        .text
+#define __INITDATA_OR_MODULE    .data
+#else
+#define __INIT_OR_MODULE        __INIT
+#define __INITDATA_OR_MODULE    __INITDATA
+#endif /* CONFIG_MODULES */
+
+        __INIT_OR_MODULE
+        GLOBAL_ENTRY(paravirt_fc_i)
+        fc.i r32
+        br.ret.sptk.many rp
+        END(paravirt_fc_i)
+        __FINIT
+
+        __INIT_OR_MODULE
+        .align 32
+        GLOBAL_ENTRY(paravirt_nop_b_inst_bundle)
+        {
+                nop.b 0
+                nop.b 0
+                nop.b 0
+        }
+        END(paravirt_nop_b_inst_bundle)
+        __FINIT
+
+        /* NOTE: nop.[mfi] has same format */
+        __INIT_OR_MODULE
+        GLOBAL_ENTRY(paravirt_nop_mfi_inst_bundle)
+        {
+                nop.m 0
+                nop.f 0
+                nop.i 0
+        }
+        END(paravirt_nop_mfi_inst_bundle)
+        __FINIT
+
+        __INIT_OR_MODULE
+        GLOBAL_ENTRY(paravirt_nop_bundle)
+paravirt_nop_bundle_start:
+        {
+                nop 0
+                nop 0
+                nop 0
+        }
+paravirt_nop_bundle_end:
+        END(paravirt_nop_bundle)
+        __FINIT
+
+        __INITDATA_OR_MODULE
+        .align 8
+        .global paravirt_nop_bundle_size
+paravirt_nop_bundle_size:
+        data8   paravirt_nop_bundle_end - paravirt_nop_bundle_start
diff --git a/arch/ia64/kernel/vmlinux.lds.S b/arch/ia64/kernel/vmlinux.lds.S
index 92ae7e8f0142..794d168bc8a4 100644
--- a/arch/ia64/kernel/vmlinux.lds.S
+++ b/arch/ia64/kernel/vmlinux.lds.S
@@ -169,6 +169,30 @@ SECTIONS
           __end___mckinley_e9_bundles = .;
         }
 
+#if defined(CONFIG_PARAVIRT)
+  . = ALIGN(16);
+  .paravirt_bundles : AT(ADDR(.paravirt_bundles) - LOAD_OFFSET)
+        {
+          __start_paravirt_bundles = .;
+          *(.paravirt_bundles)
+          __stop_paravirt_bundles = .;
+        }
+  . = ALIGN(16);
+  .paravirt_insts : AT(ADDR(.paravirt_insts) - LOAD_OFFSET)
+        {
+          __start_paravirt_insts = .;
+          *(.paravirt_insts)
+          __stop_paravirt_insts = .;
+        }
+  . = ALIGN(16);
+  .paravirt_branches : AT(ADDR(.paravirt_branches) - LOAD_OFFSET)
+        {
+          __start_paravirt_branches = .;
+          *(.paravirt_branches)
+          __stop_paravirt_branches = .;
+        }
+#endif
+
 #if defined(CONFIG_IA64_GENERIC)
   /* Machine Vector */
   . = ALIGN(16);