aboutsummaryrefslogtreecommitdiff
path: root/arch/ia64/kernel/unaligned.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/ia64/kernel/unaligned.c')
-rw-r--r--arch/ia64/kernel/unaligned.c1521
1 files changed, 1521 insertions, 0 deletions
diff --git a/arch/ia64/kernel/unaligned.c b/arch/ia64/kernel/unaligned.c
new file mode 100644
index 000000000000..43b45b65ee5a
--- /dev/null
+++ b/arch/ia64/kernel/unaligned.c
@@ -0,0 +1,1521 @@
+/*
+ * Architecture-specific unaligned trap handling.
+ *
+ * Copyright (C) 1999-2002, 2004 Hewlett-Packard Co
+ * Stephane Eranian <eranian@hpl.hp.com>
+ * David Mosberger-Tang <davidm@hpl.hp.com>
+ *
+ * 2002/12/09 Fix rotating register handling (off-by-1 error, missing fr-rotation). Fix
+ * get_rse_reg() to not leak kernel bits to user-level (reading an out-of-frame
+ * stacked register returns an undefined value; it does NOT trigger a
+ * "rsvd register fault").
+ * 2001/10/11 Fix unaligned access to rotating registers in s/w pipelined loops.
+ * 2001/08/13 Correct size of extended floats (float_fsz) from 16 to 10 bytes.
+ * 2001/01/17 Add support emulation of unaligned kernel accesses.
+ */
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/smp_lock.h>
+#include <linux/tty.h>
+
+#include <asm/intrinsics.h>
+#include <asm/processor.h>
+#include <asm/rse.h>
+#include <asm/uaccess.h>
+#include <asm/unaligned.h>
+
+extern void die_if_kernel(char *str, struct pt_regs *regs, long err) __attribute__ ((noreturn));
+
+#undef DEBUG_UNALIGNED_TRAP
+
+#ifdef DEBUG_UNALIGNED_TRAP
+# define DPRINT(a...) do { printk("%s %u: ", __FUNCTION__, __LINE__); printk (a); } while (0)
+# define DDUMP(str,vp,len) dump(str, vp, len)
+
+static void
+dump (const char *str, void *vp, size_t len)
+{
+ unsigned char *cp = vp;
+ int i;
+
+ printk("%s", str);
+ for (i = 0; i < len; ++i)
+ printk (" %02x", *cp++);
+ printk("\n");
+}
+#else
+# define DPRINT(a...)
+# define DDUMP(str,vp,len)
+#endif
+
+#define IA64_FIRST_STACKED_GR 32
+#define IA64_FIRST_ROTATING_FR 32
+#define SIGN_EXT9 0xffffffffffffff00ul
+
+/*
+ * For M-unit:
+ *
+ * opcode | m | x6 |
+ * --------|------|---------|
+ * [40-37] | [36] | [35:30] |
+ * --------|------|---------|
+ * 4 | 1 | 6 | = 11 bits
+ * --------------------------
+ * However bits [31:30] are not directly useful to distinguish between
+ * load/store so we can use [35:32] instead, which gives the following
+ * mask ([40:32]) using 9 bits. The 'e' comes from the fact that we defer
+ * checking the m-bit until later in the load/store emulation.
+ */
+#define IA64_OPCODE_MASK 0x1ef
+#define IA64_OPCODE_SHIFT 32
+
+/*
+ * Table C-28 Integer Load/Store
+ *
+ * We ignore [35:32]= 0x6, 0x7, 0xE, 0xF
+ *
+ * ld8.fill, st8.fill MUST be aligned because the RNATs are based on
+ * the address (bits [8:3]), so we must failed.
+ */
+#define LD_OP 0x080
+#define LDS_OP 0x081
+#define LDA_OP 0x082
+#define LDSA_OP 0x083
+#define LDBIAS_OP 0x084
+#define LDACQ_OP 0x085
+/* 0x086, 0x087 are not relevant */
+#define LDCCLR_OP 0x088
+#define LDCNC_OP 0x089
+#define LDCCLRACQ_OP 0x08a
+#define ST_OP 0x08c
+#define STREL_OP 0x08d
+/* 0x08e,0x8f are not relevant */
+
+/*
+ * Table C-29 Integer Load +Reg
+ *
+ * we use the ld->m (bit [36:36]) field to determine whether or not we have
+ * a load/store of this form.
+ */
+
+/*
+ * Table C-30 Integer Load/Store +Imm
+ *
+ * We ignore [35:32]= 0x6, 0x7, 0xE, 0xF
+ *
+ * ld8.fill, st8.fill must be aligned because the Nat register are based on
+ * the address, so we must fail and the program must be fixed.
+ */
+#define LD_IMM_OP 0x0a0
+#define LDS_IMM_OP 0x0a1
+#define LDA_IMM_OP 0x0a2
+#define LDSA_IMM_OP 0x0a3
+#define LDBIAS_IMM_OP 0x0a4
+#define LDACQ_IMM_OP 0x0a5
+/* 0x0a6, 0xa7 are not relevant */
+#define LDCCLR_IMM_OP 0x0a8
+#define LDCNC_IMM_OP 0x0a9
+#define LDCCLRACQ_IMM_OP 0x0aa
+#define ST_IMM_OP 0x0ac
+#define STREL_IMM_OP 0x0ad
+/* 0x0ae,0xaf are not relevant */
+
+/*
+ * Table C-32 Floating-point Load/Store
+ */
+#define LDF_OP 0x0c0
+#define LDFS_OP 0x0c1
+#define LDFA_OP 0x0c2
+#define LDFSA_OP 0x0c3
+/* 0x0c6 is irrelevant */
+#define LDFCCLR_OP 0x0c8
+#define LDFCNC_OP 0x0c9
+/* 0x0cb is irrelevant */
+#define STF_OP 0x0cc
+
+/*
+ * Table C-33 Floating-point Load +Reg
+ *
+ * we use the ld->m (bit [36:36]) field to determine whether or not we have
+ * a load/store of this form.
+ */
+
+/*
+ * Table C-34 Floating-point Load/Store +Imm
+ */
+#define LDF_IMM_OP 0x0e0
+#define LDFS_IMM_OP 0x0e1
+#define LDFA_IMM_OP 0x0e2
+#define LDFSA_IMM_OP 0x0e3
+/* 0x0e6 is irrelevant */
+#define LDFCCLR_IMM_OP 0x0e8
+#define LDFCNC_IMM_OP 0x0e9
+#define STF_IMM_OP 0x0ec
+
+typedef struct {
+ unsigned long qp:6; /* [0:5] */
+ unsigned long r1:7; /* [6:12] */
+ unsigned long imm:7; /* [13:19] */
+ unsigned long r3:7; /* [20:26] */
+ unsigned long x:1; /* [27:27] */
+ unsigned long hint:2; /* [28:29] */
+ unsigned long x6_sz:2; /* [30:31] */
+ unsigned long x6_op:4; /* [32:35], x6 = x6_sz|x6_op */
+ unsigned long m:1; /* [36:36] */
+ unsigned long op:4; /* [37:40] */
+ unsigned long pad:23; /* [41:63] */
+} load_store_t;
+
+
+typedef enum {
+ UPD_IMMEDIATE, /* ldXZ r1=[r3],imm(9) */
+ UPD_REG /* ldXZ r1=[r3],r2 */
+} update_t;
+
+/*
+ * We use tables to keep track of the offsets of registers in the saved state.
+ * This way we save having big switch/case statements.
+ *
+ * We use bit 0 to indicate switch_stack or pt_regs.
+ * The offset is simply shifted by 1 bit.
+ * A 2-byte value should be enough to hold any kind of offset
+ *
+ * In case the calling convention changes (and thus pt_regs/switch_stack)
+ * simply use RSW instead of RPT or vice-versa.
+ */
+
+#define RPO(x) ((size_t) &((struct pt_regs *)0)->x)
+#define RSO(x) ((size_t) &((struct switch_stack *)0)->x)
+
+#define RPT(x) (RPO(x) << 1)
+#define RSW(x) (1| RSO(x)<<1)
+
+#define GR_OFFS(x) (gr_info[x]>>1)
+#define GR_IN_SW(x) (gr_info[x] & 0x1)
+
+#define FR_OFFS(x) (fr_info[x]>>1)
+#define FR_IN_SW(x) (fr_info[x] & 0x1)
+
+static u16 gr_info[32]={
+ 0, /* r0 is read-only : WE SHOULD NEVER GET THIS */
+
+ RPT(r1), RPT(r2), RPT(r3),
+
+ RSW(r4), RSW(r5), RSW(r6), RSW(r7),
+
+ RPT(r8), RPT(r9), RPT(r10), RPT(r11),
+ RPT(r12), RPT(r13), RPT(r14), RPT(r15),
+
+ RPT(r16), RPT(r17), RPT(r18), RPT(r19),
+ RPT(r20), RPT(r21), RPT(r22), RPT(r23),
+ RPT(r24), RPT(r25), RPT(r26), RPT(r27),
+ RPT(r28), RPT(r29), RPT(r30), RPT(r31)
+};
+
+static u16 fr_info[32]={
+ 0, /* constant : WE SHOULD NEVER GET THIS */
+ 0, /* constant : WE SHOULD NEVER GET THIS */
+
+ RSW(f2), RSW(f3), RSW(f4), RSW(f5),
+
+ RPT(f6), RPT(f7), RPT(f8), RPT(f9),
+ RPT(f10), RPT(f11),
+
+ RSW(f12), RSW(f13), RSW(f14),
+ RSW(f15), RSW(f16), RSW(f17), RSW(f18), RSW(f19),
+ RSW(f20), RSW(f21), RSW(f22), RSW(f23), RSW(f24),
+ RSW(f25), RSW(f26), RSW(f27), RSW(f28), RSW(f29),
+ RSW(f30), RSW(f31)
+};
+
+/* Invalidate ALAT entry for integer register REGNO. */
+static void
+invala_gr (int regno)
+{
+# define F(reg) case reg: ia64_invala_gr(reg); break
+
+ switch (regno) {
+ F( 0); F( 1); F( 2); F( 3); F( 4); F( 5); F( 6); F( 7);
+ F( 8); F( 9); F( 10); F( 11); F( 12); F( 13); F( 14); F( 15);
+ F( 16); F( 17); F( 18); F( 19); F( 20); F( 21); F( 22); F( 23);
+ F( 24); F( 25); F( 26); F( 27); F( 28); F( 29); F( 30); F( 31);
+ F( 32); F( 33); F( 34); F( 35); F( 36); F( 37); F( 38); F( 39);
+ F( 40); F( 41); F( 42); F( 43); F( 44); F( 45); F( 46); F( 47);
+ F( 48); F( 49); F( 50); F( 51); F( 52); F( 53); F( 54); F( 55);
+ F( 56); F( 57); F( 58); F( 59); F( 60); F( 61); F( 62); F( 63);
+ F( 64); F( 65); F( 66); F( 67); F( 68); F( 69); F( 70); F( 71);
+ F( 72); F( 73); F( 74); F( 75); F( 76); F( 77); F( 78); F( 79);
+ F( 80); F( 81); F( 82); F( 83); F( 84); F( 85); F( 86); F( 87);
+ F( 88); F( 89); F( 90); F( 91); F( 92); F( 93); F( 94); F( 95);
+ F( 96); F( 97); F( 98); F( 99); F(100); F(101); F(102); F(103);
+ F(104); F(105); F(106); F(107); F(108); F(109); F(110); F(111);
+ F(112); F(113); F(114); F(115); F(116); F(117); F(118); F(119);
+ F(120); F(121); F(122); F(123); F(124); F(125); F(126); F(127);
+ }
+# undef F
+}
+
+/* Invalidate ALAT entry for floating-point register REGNO. */
+static void
+invala_fr (int regno)
+{
+# define F(reg) case reg: ia64_invala_fr(reg); break
+
+ switch (regno) {
+ F( 0); F( 1); F( 2); F( 3); F( 4); F( 5); F( 6); F( 7);
+ F( 8); F( 9); F( 10); F( 11); F( 12); F( 13); F( 14); F( 15);
+ F( 16); F( 17); F( 18); F( 19); F( 20); F( 21); F( 22); F( 23);
+ F( 24); F( 25); F( 26); F( 27); F( 28); F( 29); F( 30); F( 31);
+ F( 32); F( 33); F( 34); F( 35); F( 36); F( 37); F( 38); F( 39);
+ F( 40); F( 41); F( 42); F( 43); F( 44); F( 45); F( 46); F( 47);
+ F( 48); F( 49); F( 50); F( 51); F( 52); F( 53); F( 54); F( 55);
+ F( 56); F( 57); F( 58); F( 59); F( 60); F( 61); F( 62); F( 63);
+ F( 64); F( 65); F( 66); F( 67); F( 68); F( 69); F( 70); F( 71);
+ F( 72); F( 73); F( 74); F( 75); F( 76); F( 77); F( 78); F( 79);
+ F( 80); F( 81); F( 82); F( 83); F( 84); F( 85); F( 86); F( 87);
+ F( 88); F( 89); F( 90); F( 91); F( 92); F( 93); F( 94); F( 95);
+ F( 96); F( 97); F( 98); F( 99); F(100); F(101); F(102); F(103);
+ F(104); F(105); F(106); F(107); F(108); F(109); F(110); F(111);
+ F(112); F(113); F(114); F(115); F(116); F(117); F(118); F(119);
+ F(120); F(121); F(122); F(123); F(124); F(125); F(126); F(127);
+ }
+# undef F
+}
+
+static inline unsigned long
+rotate_reg (unsigned long sor, unsigned long rrb, unsigned long reg)
+{
+ reg += rrb;
+ if (reg >= sor)
+ reg -= sor;
+ return reg;
+}
+
+static void
+set_rse_reg (struct pt_regs *regs, unsigned long r1, unsigned long val, int nat)
+{
+ struct switch_stack *sw = (struct switch_stack *) regs - 1;
+ unsigned long *bsp, *bspstore, *addr, *rnat_addr, *ubs_end;
+ unsigned long *kbs = (void *) current + IA64_RBS_OFFSET;
+ unsigned long rnats, nat_mask;
+ unsigned long on_kbs;
+ long sof = (regs->cr_ifs) & 0x7f;
+ long sor = 8 * ((regs->cr_ifs >> 14) & 0xf);
+ long rrb_gr = (regs->cr_ifs >> 18) & 0x7f;
+ long ridx = r1 - 32;
+
+ if (ridx >= sof) {
+ /* this should never happen, as the "rsvd register fault" has higher priority */
+ DPRINT("ignoring write to r%lu; only %lu registers are allocated!\n", r1, sof);
+ return;
+ }
+
+ if (ridx < sor)
+ ridx = rotate_reg(sor, rrb_gr, ridx);
+
+ DPRINT("r%lu, sw.bspstore=%lx pt.bspstore=%lx sof=%ld sol=%ld ridx=%ld\n",
+ r1, sw->ar_bspstore, regs->ar_bspstore, sof, (regs->cr_ifs >> 7) & 0x7f, ridx);
+
+ on_kbs = ia64_rse_num_regs(kbs, (unsigned long *) sw->ar_bspstore);
+ addr = ia64_rse_skip_regs((unsigned long *) sw->ar_bspstore, -sof + ridx);
+ if (addr >= kbs) {
+ /* the register is on the kernel backing store: easy... */
+ rnat_addr = ia64_rse_rnat_addr(addr);
+ if ((unsigned long) rnat_addr >= sw->ar_bspstore)
+ rnat_addr = &sw->ar_rnat;
+ nat_mask = 1UL << ia64_rse_slot_num(addr);
+
+ *addr = val;
+ if (nat)
+ *rnat_addr |= nat_mask;
+ else
+ *rnat_addr &= ~nat_mask;
+ return;
+ }
+
+ if (!user_stack(current, regs)) {
+ DPRINT("ignoring kernel write to r%lu; register isn't on the kernel RBS!", r1);
+ return;
+ }
+
+ bspstore = (unsigned long *)regs->ar_bspstore;
+ ubs_end = ia64_rse_skip_regs(bspstore, on_kbs);
+ bsp = ia64_rse_skip_regs(ubs_end, -sof);
+ addr = ia64_rse_skip_regs(bsp, ridx);
+
+ DPRINT("ubs_end=%p bsp=%p addr=%p\n", (void *) ubs_end, (void *) bsp, (void *) addr);
+
+ ia64_poke(current, sw, (unsigned long) ubs_end, (unsigned long) addr, val);
+
+ rnat_addr = ia64_rse_rnat_addr(addr);
+
+ ia64_peek(current, sw, (unsigned long) ubs_end, (unsigned long) rnat_addr, &rnats);
+ DPRINT("rnat @%p = 0x%lx nat=%d old nat=%ld\n",
+ (void *) rnat_addr, rnats, nat, (rnats >> ia64_rse_slot_num(addr)) & 1);
+
+ nat_mask = 1UL << ia64_rse_slot_num(addr);
+ if (nat)
+ rnats |= nat_mask;
+ else
+ rnats &= ~nat_mask;
+ ia64_poke(current, sw, (unsigned long) ubs_end, (unsigned long) rnat_addr, rnats);
+
+ DPRINT("rnat changed to @%p = 0x%lx\n", (void *) rnat_addr, rnats);
+}
+
+
+static void
+get_rse_reg (struct pt_regs *regs, unsigned long r1, unsigned long *val, int *nat)
+{
+ struct switch_stack *sw = (struct switch_stack *) regs - 1;
+ unsigned long *bsp, *addr, *rnat_addr, *ubs_end, *bspstore;
+ unsigned long *kbs = (void *) current + IA64_RBS_OFFSET;
+ unsigned long rnats, nat_mask;
+ unsigned long on_kbs;
+ long sof = (regs->cr_ifs) & 0x7f;
+ long sor = 8 * ((regs->cr_ifs >> 14) & 0xf);
+ long rrb_gr = (regs->cr_ifs >> 18) & 0x7f;
+ long ridx = r1 - 32;
+
+ if (ridx >= sof) {
+ /* read of out-of-frame register returns an undefined value; 0 in our case. */
+ DPRINT("ignoring read from r%lu; only %lu registers are allocated!\n", r1, sof);
+ goto fail;
+ }
+
+ if (ridx < sor)
+ ridx = rotate_reg(sor, rrb_gr, ridx);
+
+ DPRINT("r%lu, sw.bspstore=%lx pt.bspstore=%lx sof=%ld sol=%ld ridx=%ld\n",
+ r1, sw->ar_bspstore, regs->ar_bspstore, sof, (regs->cr_ifs >> 7) & 0x7f, ridx);
+
+ on_kbs = ia64_rse_num_regs(kbs, (unsigned long *) sw->ar_bspstore);
+ addr = ia64_rse_skip_regs((unsigned long *) sw->ar_bspstore, -sof + ridx);
+ if (addr >= kbs) {
+ /* the register is on the kernel backing store: easy... */
+ *val = *addr;
+ if (nat) {
+ rnat_addr = ia64_rse_rnat_addr(addr);
+ if ((unsigned long) rnat_addr >= sw->ar_bspstore)
+ rnat_addr = &sw->ar_rnat;
+ nat_mask = 1UL << ia64_rse_slot_num(addr);
+ *nat = (*rnat_addr & nat_mask) != 0;
+ }
+ return;
+ }
+
+ if (!user_stack(current, regs)) {
+ DPRINT("ignoring kernel read of r%lu; register isn't on the RBS!", r1);
+ goto fail;
+ }
+
+ bspstore = (unsigned long *)regs->ar_bspstore;
+ ubs_end = ia64_rse_skip_regs(bspstore, on_kbs);
+ bsp = ia64_rse_skip_regs(ubs_end, -sof);
+ addr = ia64_rse_skip_regs(bsp, ridx);
+
+ DPRINT("ubs_end=%p bsp=%p addr=%p\n", (void *) ubs_end, (void *) bsp, (void *) addr);
+
+ ia64_peek(current, sw, (unsigned long) ubs_end, (unsigned long) addr, val);
+
+ if (nat) {
+ rnat_addr = ia64_rse_rnat_addr(addr);
+ nat_mask = 1UL << ia64_rse_slot_num(addr);
+
+ DPRINT("rnat @%p = 0x%lx\n", (void *) rnat_addr, rnats);
+
+ ia64_peek(current, sw, (unsigned long) ubs_end, (unsigned long) rnat_addr, &rnats);
+ *nat = (rnats & nat_mask) != 0;
+ }
+ return;
+
+ fail:
+ *val = 0;
+ if (nat)
+ *nat = 0;
+ return;
+}
+
+
+static void
+setreg (unsigned long regnum, unsigned long val, int nat, struct pt_regs *regs)
+{
+ struct switch_stack *sw = (struct switch_stack *) regs - 1;
+ unsigned long addr;
+ unsigned long bitmask;
+ unsigned long *unat;
+
+ /*
+ * First takes care of stacked registers
+ */
+ if (regnum >= IA64_FIRST_STACKED_GR) {
+ set_rse_reg(regs, regnum, val, nat);
+ return;
+ }
+
+ /*
+ * Using r0 as a target raises a General Exception fault which has higher priority
+ * than the Unaligned Reference fault.
+ */
+
+ /*
+ * Now look at registers in [0-31] range and init correct UNAT
+ */
+ if (GR_IN_SW(regnum)) {
+ addr = (unsigned long)sw;
+ unat = &sw->ar_unat;
+ } else {
+ addr = (unsigned long)regs;
+ unat = &sw->caller_unat;
+ }
+ DPRINT("tmp_base=%lx switch_stack=%s offset=%d\n",
+ addr, unat==&sw->ar_unat ? "yes":"no", GR_OFFS(regnum));
+ /*
+ * add offset from base of struct
+ * and do it !
+ */
+ addr += GR_OFFS(regnum);
+
+ *(unsigned long *)addr = val;
+
+ /*
+ * We need to clear the corresponding UNAT bit to fully emulate the load
+ * UNAT bit_pos = GR[r3]{8:3} form EAS-2.4
+ */
+ bitmask = 1UL << (addr >> 3 & 0x3f);
+ DPRINT("*0x%lx=0x%lx NaT=%d prev_unat @%p=%lx\n", addr, val, nat, (void *) unat, *unat);
+ if (nat) {
+ *unat |= bitmask;
+ } else {
+ *unat &= ~bitmask;
+ }
+ DPRINT("*0x%lx=0x%lx NaT=%d new unat: %p=%lx\n", addr, val, nat, (void *) unat,*unat);
+}
+
+/*
+ * Return the (rotated) index for floating point register REGNUM (REGNUM must be in the
+ * range from 32-127, result is in the range from 0-95.
+ */
+static inline unsigned long
+fph_index (struct pt_regs *regs, long regnum)
+{
+ unsigned long rrb_fr = (regs->cr_ifs >> 25) & 0x7f;
+ return rotate_reg(96, rrb_fr, (regnum - IA64_FIRST_ROTATING_FR));
+}
+
+static void
+setfpreg (unsigned long regnum, struct ia64_fpreg *fpval, struct pt_regs *regs)
+{
+ struct switch_stack *sw = (struct switch_stack *)regs - 1;
+ unsigned long addr;
+
+ /*
+ * From EAS-2.5: FPDisableFault has higher priority than Unaligned
+ * Fault. Thus, when we get here, we know the partition is enabled.
+ * To update f32-f127, there are three choices:
+ *
+ * (1) save f32-f127 to thread.fph and update the values there
+ * (2) use a gigantic switch statement to directly access the registers
+ * (3) generate code on the fly to update the desired register
+ *
+ * For now, we are using approach (1).
+ */
+ if (regnum >= IA64_FIRST_ROTATING_FR) {
+ ia64_sync_fph(current);
+ current->thread.fph[fph_index(regs, regnum)] = *fpval;
+ } else {
+ /*
+ * pt_regs or switch_stack ?
+ */
+ if (FR_IN_SW(regnum)) {
+ addr = (unsigned long)sw;
+ } else {
+ addr = (unsigned long)regs;
+ }
+
+ DPRINT("tmp_base=%lx offset=%d\n", addr, FR_OFFS(regnum));
+
+ addr += FR_OFFS(regnum);
+ *(struct ia64_fpreg *)addr = *fpval;
+
+ /*
+ * mark the low partition as being used now
+ *
+ * It is highly unlikely that this bit is not already set, but
+ * let's do it for safety.
+ */
+ regs->cr_ipsr |= IA64_PSR_MFL;
+ }
+}
+
+/*
+ * Those 2 inline functions generate the spilled versions of the constant floating point
+ * registers which can be used with stfX
+ */
+static inline void
+float_spill_f0 (struct ia64_fpreg *final)
+{
+ ia64_stf_spill(final, 0);
+}
+
+static inline void
+float_spill_f1 (struct ia64_fpreg *final)
+{
+ ia64_stf_spill(final, 1);
+}
+
+static void
+getfpreg (unsigned long regnum, struct ia64_fpreg *fpval, struct pt_regs *regs)
+{
+ struct switch_stack *sw = (struct switch_stack *) regs - 1;
+ unsigned long addr;
+
+ /*
+ * From EAS-2.5: FPDisableFault has higher priority than
+ * Unaligned Fault. Thus, when we get here, we know the partition is
+ * enabled.
+ *
+ * When regnum > 31, the register is still live and we need to force a save
+ * to current->thread.fph to get access to it. See discussion in setfpreg()
+ * for reasons and other ways of doing this.
+ */
+ if (regnum >= IA64_FIRST_ROTATING_FR) {
+ ia64_flush_fph(current);
+ *fpval = current->thread.fph[fph_index(regs, regnum)];
+ } else {
+ /*
+ * f0 = 0.0, f1= 1.0. Those registers are constant and are thus
+ * not saved, we must generate their spilled form on the fly
+ */
+ switch(regnum) {
+ case 0:
+ float_spill_f0(fpval);
+ break;
+ case 1:
+ float_spill_f1(fpval);
+ break;
+ default:
+ /*
+ * pt_regs or switch_stack ?
+ */
+ addr = FR_IN_SW(regnum) ? (unsigned long)sw
+ : (unsigned long)regs;
+
+ DPRINT("is_sw=%d tmp_base=%lx offset=0x%x\n",
+ FR_IN_SW(regnum), addr, FR_OFFS(regnum));
+
+ addr += FR_OFFS(regnum);
+ *fpval = *(struct ia64_fpreg *)addr;
+ }
+ }
+}
+
+
+static void
+getreg (unsigned long regnum, unsigned long *val, int *nat, struct pt_regs *regs)
+{
+ struct switch_stack *sw = (struct switch_stack *) regs - 1;
+ unsigned long addr, *unat;
+
+ if (regnum >= IA64_FIRST_STACKED_GR) {
+ get_rse_reg(regs, regnum, val, nat);
+ return;
+ }
+
+ /*
+ * take care of r0 (read-only always evaluate to 0)
+ */
+ if (regnum == 0) {
+ *val = 0;
+ if (nat)
+ *nat = 0;
+ return;
+ }
+
+ /*
+ * Now look at registers in [0-31] range and init correct UNAT
+ */
+ if (GR_IN_SW(regnum)) {
+ addr = (unsigned long)sw;
+ unat = &sw->ar_unat;
+ } else {
+ addr = (unsigned long)regs;
+ unat = &sw->caller_unat;
+ }
+
+ DPRINT("addr_base=%lx offset=0x%x\n", addr, GR_OFFS(regnum));
+
+ addr += GR_OFFS(regnum);
+
+ *val = *(unsigned long *)addr;
+
+ /*
+ * do it only when requested
+ */
+ if (nat)
+ *nat = (*unat >> (addr >> 3 & 0x3f)) & 0x1UL;
+}
+
+static void
+emulate_load_updates (update_t type, load_store_t ld, struct pt_regs *regs, unsigned long ifa)
+{
+ /*
+ * IMPORTANT:
+ * Given the way we handle unaligned speculative loads, we should
+ * not get to this point in the code but we keep this sanity check,
+ * just in case.
+ */
+ if (ld.x6_op == 1 || ld.x6_op == 3) {
+ printk(KERN_ERR "%s: register update on speculative load, error\n", __FUNCTION__);
+ die_if_kernel("unaligned reference on speculative load with register update\n",
+ regs, 30);
+ }
+
+
+ /*
+ * at this point, we know that the base register to update is valid i.e.,
+ * it's not r0
+ */
+ if (type == UPD_IMMEDIATE) {
+ unsigned long imm;
+
+ /*
+ * Load +Imm: ldXZ r1=[r3],imm(9)
+ *
+ *
+ * form imm9: [13:19] contain the first 7 bits
+ */
+ imm = ld.x << 7 | ld.imm;
+
+ /*
+ * sign extend (1+8bits) if m set
+ */
+ if (ld.m) imm |= SIGN_EXT9;
+
+ /*
+ * ifa == r3 and we know that the NaT bit on r3 was clear so
+ * we can directly use ifa.
+ */
+ ifa += imm;
+
+ setreg(ld.r3, ifa, 0, regs);
+
+ DPRINT("ld.x=%d ld.m=%d imm=%ld r3=0x%lx\n", ld.x, ld.m, imm, ifa);
+
+ } else if (ld.m) {
+ unsigned long r2;
+ int nat_r2;
+
+ /*
+ * Load +Reg Opcode: ldXZ r1=[r3],r2
+ *
+ * Note: that we update r3 even in the case of ldfX.a
+ * (where the load does not happen)
+ *
+ * The way the load algorithm works, we know that r3 does not
+ * have its NaT bit set (would have gotten NaT consumption
+ * before getting the unaligned fault). So we can use ifa
+ * which equals r3 at this point.
+ *
+ * IMPORTANT:
+ * The above statement holds ONLY because we know that we
+ * never reach this code when trying to do a ldX.s.
+ * If we ever make it to here on an ldfX.s then
+ */
+ getreg(ld.imm, &r2, &nat_r2, regs);
+
+ ifa += r2;
+
+ /*
+ * propagate Nat r2 -> r3
+ */
+ setreg(ld.r3, ifa, nat_r2, regs);
+
+ DPRINT("imm=%d r2=%ld r3=0x%lx nat_r2=%d\n",ld.imm, r2, ifa, nat_r2);
+ }
+}
+
+
+static int
+emulate_load_int (unsigned long ifa, load_store_t ld, struct pt_regs *regs)
+{
+ unsigned int len = 1 << ld.x6_sz;
+ unsigned long val = 0;
+
+ /*
+ * r0, as target, doesn't need to be checked because Illegal Instruction
+ * faults have higher priority than unaligned faults.
+ *
+ * r0 cannot be found as the base as it would never generate an
+ * unaligned reference.
+ */
+
+ /*
+ * ldX.a we will emulate load and also invalidate the ALAT entry.
+ * See comment below for explanation on how we handle ldX.a
+ */
+
+ if (len != 2 && len != 4 && len != 8) {
+ DPRINT("unknown size: x6=%d\n", ld.x6_sz);
+ return -1;
+ }
+ /* this assumes little-endian byte-order: */
+ if (copy_from_user(&val, (void __user *) ifa, len))
+ return -1;
+ setreg(ld.r1, val, 0, regs);
+
+ /*
+ * check for updates on any kind of loads
+ */
+ if (ld.op == 0x5 || ld.m)
+ emulate_load_updates(ld.op == 0x5 ? UPD_IMMEDIATE: UPD_REG, ld, regs, ifa);
+
+ /*
+ * handling of various loads (based on EAS2.4):
+ *
+ * ldX.acq (ordered load):
+ * - acquire semantics would have been used, so force fence instead.
+ *
+ * ldX.c.clr (check load and clear):
+ * - if we get to this handler, it's because the entry was not in the ALAT.
+ * Therefore the operation reverts to a normal load
+ *
+ * ldX.c.nc (check load no clear):
+ * - same as previous one
+ *
+ * ldX.c.clr.acq (ordered check load and clear):
+ * - same as above for c.clr part. The load needs to have acquire semantics. So
+ * we use the fence semantics which is stronger and thus ensures correctness.
+ *
+ * ldX.a (advanced load):
+ * - suppose ldX.a r1=[r3]. If we get to the unaligned trap it's because the
+ * address doesn't match requested size alignment. This means that we would
+ * possibly need more than one load to get the result.
+ *
+ * The load part can be handled just like a normal load, however the difficult
+ * part is to get the right thing into the ALAT. The critical piece of information
+ * in the base address of the load & size. To do that, a ld.a must be executed,
+ * clearly any address can be pushed into the table by using ld1.a r1=[r3]. Now
+ * if we use the same target register, we will be okay for the check.a instruction.
+ * If we look at the store, basically a stX [r3]=r1 checks the ALAT for any entry
+ * which would overlap within [r3,r3+X] (the size of the load was store in the
+ * ALAT). If such an entry is found the entry is invalidated. But this is not good
+ * enough, take the following example:
+ * r3=3
+ * ld4.a r1=[r3]
+ *
+ * Could be emulated by doing:
+ * ld1.a r1=[r3],1
+ * store to temporary;
+ * ld1.a r1=[r3],1
+ * store & shift to temporary;
+ * ld1.a r1=[r3],1
+ * store & shift to temporary;
+ * ld1.a r1=[r3]
+ * store & shift to temporary;
+ * r1=temporary
+ *
+ * So in this case, you would get the right value is r1 but the wrong info in
+ * the ALAT. Notice that you could do it in reverse to finish with address 3
+ * but you would still get the size wrong. To get the size right, one needs to
+ * execute exactly the same kind of load. You could do it from a aligned
+ * temporary location, but you would get the address wrong.
+ *
+ * So no matter what, it is not possible to emulate an advanced load
+ * correctly. But is that really critical ?
+ *
+ * We will always convert ld.a into a normal load with ALAT invalidated. This
+ * will enable compiler to do optimization where certain code path after ld.a
+ * is not required to have ld.c/chk.a, e.g., code path with no intervening stores.
+ *
+ * If there is a store after the advanced load, one must either do a ld.c.* or
+ * chk.a.* to reuse the value stored in the ALAT. Both can "fail" (meaning no
+ * entry found in ALAT), and that's perfectly ok because:
+ *
+ * - ld.c.*, if the entry is not present a normal load is executed
+ * - chk.a.*, if the entry is not present, execution jumps to recovery code
+ *
+ * In either case, the load can be potentially retried in another form.
+ *
+ * ALAT must be invalidated for the register (so that chk.a or ld.c don't pick
+ * up a stale entry later). The register base update MUST also be performed.
+ */
+
+ /*
+ * when the load has the .acq completer then
+ * use ordering fence.
+ */
+ if (ld.x6_op == 0x5 || ld.x6_op == 0xa)
+ mb();
+
+ /*
+ * invalidate ALAT entry in case of advanced load
+ */
+ if (ld.x6_op == 0x2)
+ invala_gr(ld.r1);
+
+ return 0;
+}
+
+static int
+emulate_store_int (unsigned long ifa, load_store_t ld, struct pt_regs *regs)
+{
+ unsigned long r2;
+ unsigned int len = 1 << ld.x6_sz;
+
+ /*
+ * if we get to this handler, Nat bits on both r3 and r2 have already
+ * been checked. so we don't need to do it
+ *
+ * extract the value to be stored
+ */
+ getreg(ld.imm, &r2, NULL, regs);
+
+ /*
+ * we rely on the macros in unaligned.h for now i.e.,
+ * we let the compiler figure out how to read memory gracefully.
+ *
+ * We need this switch/case because the way the inline function
+ * works. The code is optimized by the compiler and looks like
+ * a single switch/case.
+ */
+ DPRINT("st%d [%lx]=%lx\n", len, ifa, r2);
+
+ if (len != 2 && len != 4 && len != 8) {
+ DPRINT("unknown size: x6=%d\n", ld.x6_sz);
+ return -1;
+ }
+
+ /* this assumes little-endian byte-order: */
+ if (copy_to_user((void __user *) ifa, &r2, len))
+ return -1;
+
+ /*
+ * stX [r3]=r2,imm(9)
+ *
+ * NOTE:
+ * ld.r3 can never be r0, because r0 would not generate an
+ * unaligned access.
+ */
+ if (ld.op == 0x5) {
+ unsigned long imm;
+
+ /*
+ * form imm9: [12:6] contain first 7bits
+ */
+ imm = ld.x << 7 | ld.r1;
+ /*
+ * sign extend (8bits) if m set
+ */
+ if (ld.m) imm |= SIGN_EXT9;
+ /*
+ * ifa == r3 (NaT is necessarily cleared)
+ */
+ ifa += imm;
+
+ DPRINT("imm=%lx r3=%lx\n", imm, ifa);
+
+ setreg(ld.r3, ifa, 0, regs);
+ }
+ /*
+ * we don't have alat_invalidate_multiple() so we need
+ * to do the complete flush :-<<
+ */
+ ia64_invala();
+
+ /*
+ * stX.rel: use fence instead of release
+ */
+ if (ld.x6_op == 0xd)
+ mb();
+
+ return 0;
+}
+
+/*
+ * floating point operations sizes in bytes
+ */
+static const unsigned char float_fsz[4]={
+ 10, /* extended precision (e) */
+ 8, /* integer (8) */
+ 4, /* single precision (s) */
+ 8 /* double precision (d) */
+};
+
+static inline void
+mem2float_extended (struct ia64_fpreg *init, struct ia64_fpreg *final)
+{
+ ia64_ldfe(6, init);
+ ia64_stop();
+ ia64_stf_spill(final, 6);
+}
+
+static inline void
+mem2float_integer (struct ia64_fpreg *init, struct ia64_fpreg *final)
+{
+ ia64_ldf8(6, init);
+ ia64_stop();
+ ia64_stf_spill(final, 6);
+}
+
+static inline void
+mem2float_single (struct ia64_fpreg *init, struct ia64_fpreg *final)
+{
+ ia64_ldfs(6, init);
+ ia64_stop();
+ ia64_stf_spill(final, 6);
+}
+
+static inline void
+mem2float_double (struct ia64_fpreg *init, struct ia64_fpreg *final)
+{
+ ia64_ldfd(6, init);
+ ia64_stop();
+ ia64_stf_spill(final, 6);
+}
+
+static inline void
+float2mem_extended (struct ia64_fpreg *init, struct ia64_fpreg *final)
+{
+ ia64_ldf_fill(6, init);
+ ia64_stop();
+ ia64_stfe(final, 6);
+}
+
+static inline void
+float2mem_integer (struct ia64_fpreg *init, struct ia64_fpreg *final)
+{
+ ia64_ldf_fill(6, init);
+ ia64_stop();
+ ia64_stf8(final, 6);
+}
+
+static inline void
+float2mem_single (struct ia64_fpreg *init, struct ia64_fpreg *final)
+{
+ ia64_ldf_fill(6, init);
+ ia64_stop();
+ ia64_stfs(final, 6);
+}
+
+static inline void
+float2mem_double (struct ia64_fpreg *init, struct ia64_fpreg *final)
+{
+ ia64_ldf_fill(6, init);
+ ia64_stop();
+ ia64_stfd(final, 6);
+}
+
+static int
+emulate_load_floatpair (unsigned long ifa, load_store_t ld, struct pt_regs *regs)
+{
+ struct ia64_fpreg fpr_init[2];
+ struct ia64_fpreg fpr_final[2];
+ unsigned long len = float_fsz[ld.x6_sz];
+
+ /*
+ * fr0 & fr1 don't need to be checked because Illegal Instruction faults have
+ * higher priority than unaligned faults.
+ *
+ * r0 cannot be found as the base as it would never generate an unaligned
+ * reference.
+ */
+
+ /*
+ * make sure we get clean buffers
+ */
+ memset(&fpr_init, 0, sizeof(fpr_init));
+ memset(&fpr_final, 0, sizeof(fpr_final));
+
+ /*
+ * ldfpX.a: we don't try to emulate anything but we must
+ * invalidate the ALAT entry and execute updates, if any.
+ */
+ if (ld.x6_op != 0x2) {
+ /*
+ * This assumes little-endian byte-order. Note that there is no "ldfpe"
+ * instruction:
+ */
+ if (copy_from_user(&fpr_init[0], (void __user *) ifa, len)
+ || copy_from_user(&fpr_init[1], (void __user *) (ifa + len), len))
+ return -1;
+
+ DPRINT("ld.r1=%d ld.imm=%d x6_sz=%d\n", ld.r1, ld.imm, ld.x6_sz);
+ DDUMP("frp_init =", &fpr_init, 2*len);
+ /*
+ * XXX fixme
+ * Could optimize inlines by using ldfpX & 2 spills
+ */
+ switch( ld.x6_sz ) {
+ case 0:
+ mem2float_extended(&fpr_init[0], &fpr_final[0]);
+ mem2float_extended(&fpr_init[1], &fpr_final[1]);
+ break;
+ case 1:
+ mem2float_integer(&fpr_init[0], &fpr_final[0]);
+ mem2float_integer(&fpr_init[1], &fpr_final[1]);
+ break;
+ case 2:
+ mem2float_single(&fpr_init[0], &fpr_final[0]);
+ mem2float_single(&fpr_init[1], &fpr_final[1]);
+ break;
+ case 3:
+ mem2float_double(&fpr_init[0], &fpr_final[0]);
+ mem2float_double(&fpr_init[1], &fpr_final[1]);
+ break;
+ }
+ DDUMP("fpr_final =", &fpr_final, 2*len);
+ /*
+ * XXX fixme
+ *
+ * A possible optimization would be to drop fpr_final and directly
+ * use the storage from the saved context i.e., the actual final
+ * destination (pt_regs, switch_stack or thread structure).
+ */
+ setfpreg(ld.r1, &fpr_final[0], regs);
+ setfpreg(ld.imm, &fpr_final[1], regs);
+ }
+
+ /*
+ * Check for updates: only immediate updates are available for this
+ * instruction.
+ */
+ if (ld.m) {
+ /*
+ * the immediate is implicit given the ldsz of the operation:
+ * single: 8 (2x4) and for all others it's 16 (2x8)
+ */
+ ifa += len<<1;
+
+ /*
+ * IMPORTANT:
+ * the fact that we force the NaT of r3 to zero is ONLY valid
+ * as long as we don't come here with a ldfpX.s.
+ * For this reason we keep this sanity check
+ */
+ if (ld.x6_op == 1 || ld.x6_op == 3)
+ printk(KERN_ERR "%s: register update on speculative load pair, error\n",
+ __FUNCTION__);
+
+ setreg(ld.r3, ifa, 0, regs);
+ }
+
+ /*
+ * Invalidate ALAT entries, if any, for both registers.
+ */
+ if (ld.x6_op == 0x2) {
+ invala_fr(ld.r1);
+ invala_fr(ld.imm);
+ }
+ return 0;
+}
+
+
+static int
+emulate_load_float (unsigned long ifa, load_store_t ld, struct pt_regs *regs)
+{
+ struct ia64_fpreg fpr_init;
+ struct ia64_fpreg fpr_final;
+ unsigned long len = float_fsz[ld.x6_sz];
+
+ /*
+ * fr0 & fr1 don't need to be checked because Illegal Instruction
+ * faults have higher priority than unaligned faults.
+ *
+ * r0 cannot be found as the base as it would never generate an
+ * unaligned reference.
+ */
+
+ /*
+ * make sure we get clean buffers
+ */
+ memset(&fpr_init,0, sizeof(fpr_init));
+ memset(&fpr_final,0, sizeof(fpr_final));
+
+ /*
+ * ldfX.a we don't try to emulate anything but we must
+ * invalidate the ALAT entry.
+ * See comments in ldX for descriptions on how the various loads are handled.
+ */
+ if (ld.x6_op != 0x2) {
+ if (copy_from_user(&fpr_init, (void __user *) ifa, len))
+ return -1;
+
+ DPRINT("ld.r1=%d x6_sz=%d\n", ld.r1, ld.x6_sz);
+ DDUMP("fpr_init =", &fpr_init, len);
+ /*
+ * we only do something for x6_op={0,8,9}
+ */
+ switch( ld.x6_sz ) {
+ case 0:
+ mem2float_extended(&fpr_init, &fpr_final);
+ break;
+ case 1:
+ mem2float_integer(&fpr_init, &fpr_final);
+ break;
+ case 2:
+ mem2float_single(&fpr_init, &fpr_final);
+ break;
+ case 3:
+ mem2float_double(&fpr_init, &fpr_final);
+ break;
+ }
+ DDUMP("fpr_final =", &fpr_final, len);
+ /*
+ * XXX fixme
+ *
+ * A possible optimization would be to drop fpr_final and directly
+ * use the storage from the saved context i.e., the actual final
+ * destination (pt_regs, switch_stack or thread structure).
+ */
+ setfpreg(ld.r1, &fpr_final, regs);
+ }
+
+ /*
+ * check for updates on any loads
+ */
+ if (ld.op == 0x7 || ld.m)
+ emulate_load_updates(ld.op == 0x7 ? UPD_IMMEDIATE: UPD_REG, ld, regs, ifa);
+
+ /*
+ * invalidate ALAT entry in case of advanced floating point loads
+ */
+ if (ld.x6_op == 0x2)
+ invala_fr(ld.r1);
+
+ return 0;
+}
+
+
+static int
+emulate_store_float (unsigned long ifa, load_store_t ld, struct pt_regs *regs)
+{
+ struct ia64_fpreg fpr_init;
+ struct ia64_fpreg fpr_final;
+ unsigned long len = float_fsz[ld.x6_sz];
+
+ /*
+ * make sure we get clean buffers
+ */
+ memset(&fpr_init,0, sizeof(fpr_init));
+ memset(&fpr_final,0, sizeof(fpr_final));
+
+ /*
+ * if we get to this handler, Nat bits on both r3 and r2 have already
+ * been checked. so we don't need to do it
+ *
+ * extract the value to be stored
+ */
+ getfpreg(ld.imm, &fpr_init, regs);
+ /*
+ * during this step, we extract the spilled registers from the saved
+ * context i.e., we refill. Then we store (no spill) to temporary
+ * aligned location
+ */
+ switch( ld.x6_sz ) {
+ case 0:
+ float2mem_extended(&fpr_init, &fpr_final);
+ break;
+ case 1:
+ float2mem_integer(&fpr_init, &fpr_final);
+ break;
+ case 2:
+ float2mem_single(&fpr_init, &fpr_final);
+ break;
+ case 3:
+ float2mem_double(&fpr_init, &fpr_final);
+ break;
+ }
+ DPRINT("ld.r1=%d x6_sz=%d\n", ld.r1, ld.x6_sz);
+ DDUMP("fpr_init =", &fpr_init, len);
+ DDUMP("fpr_final =", &fpr_final, len);
+
+ if (copy_to_user((void __user *) ifa, &fpr_final, len))
+ return -1;
+
+ /*
+ * stfX [r3]=r2,imm(9)
+ *
+ * NOTE:
+ * ld.r3 can never be r0, because r0 would not generate an
+ * unaligned access.
+ */
+ if (ld.op == 0x7) {
+ unsigned long imm;
+
+ /*
+ * form imm9: [12:6] contain first 7bits
+ */
+ imm = ld.x << 7 | ld.r1;
+ /*
+ * sign extend (8bits) if m set
+ */
+ if (ld.m)
+ imm |= SIGN_EXT9;
+ /*
+ * ifa == r3 (NaT is necessarily cleared)
+ */
+ ifa += imm;
+
+ DPRINT("imm=%lx r3=%lx\n", imm, ifa);
+
+ setreg(ld.r3, ifa, 0, regs);
+ }
+ /*
+ * we don't have alat_invalidate_multiple() so we need
+ * to do the complete flush :-<<
+ */
+ ia64_invala();
+
+ return 0;
+}
+
+/*
+ * Make sure we log the unaligned access, so that user/sysadmin can notice it and
+ * eventually fix the program. However, we don't want to do that for every access so we
+ * pace it with jiffies. This isn't really MP-safe, but it doesn't really have to be
+ * either...
+ */
+static int
+within_logging_rate_limit (void)
+{
+ static unsigned long count, last_time;
+
+ if (jiffies - last_time > 5*HZ)
+ count = 0;
+ if (++count < 5) {
+ last_time = jiffies;
+ return 1;
+ }
+ return 0;
+
+}
+
+void
+ia64_handle_unaligned (unsigned long ifa, struct pt_regs *regs)
+{
+ struct ia64_psr *ipsr = ia64_psr(regs);
+ mm_segment_t old_fs = get_fs();
+ unsigned long bundle[2];
+ unsigned long opcode;
+ struct siginfo si;
+ const struct exception_table_entry *eh = NULL;
+ union {
+ unsigned long l;
+ load_store_t insn;
+ } u;
+ int ret = -1;
+
+ if (ia64_psr(regs)->be) {
+ /* we don't support big-endian accesses */
+ die_if_kernel("big-endian unaligned accesses are not supported", regs, 0);
+ goto force_sigbus;
+ }
+
+ /*
+ * Treat kernel accesses for which there is an exception handler entry the same as
+ * user-level unaligned accesses. Otherwise, a clever program could trick this
+ * handler into reading an arbitrary kernel addresses...
+ */
+ if (!user_mode(regs))
+ eh = search_exception_tables(regs->cr_iip + ia64_psr(regs)->ri);
+ if (user_mode(regs) || eh) {
+ if ((current->thread.flags & IA64_THREAD_UAC_SIGBUS) != 0)
+ goto force_sigbus;
+
+ if (!(current->thread.flags & IA64_THREAD_UAC_NOPRINT)
+ && within_logging_rate_limit())
+ {
+ char buf[200]; /* comm[] is at most 16 bytes... */
+ size_t len;
+
+ len = sprintf(buf, "%s(%d): unaligned access to 0x%016lx, "
+ "ip=0x%016lx\n\r", current->comm, current->pid,
+ ifa, regs->cr_iip + ipsr->ri);
+ /*
+ * Don't call tty_write_message() if we're in the kernel; we might
+ * be holding locks...
+ */
+ if (user_mode(regs))
+ tty_write_message(current->signal->tty, buf);
+ buf[len-1] = '\0'; /* drop '\r' */
+ printk(KERN_WARNING "%s", buf); /* watch for command names containing %s */
+ }
+ } else {
+ if (within_logging_rate_limit())
+ printk(KERN_WARNING "kernel unaligned access to 0x%016lx, ip=0x%016lx\n",
+ ifa, regs->cr_iip + ipsr->ri);
+ set_fs(KERNEL_DS);
+ }
+
+ DPRINT("iip=%lx ifa=%lx isr=%lx (ei=%d, sp=%d)\n",
+ regs->cr_iip, ifa, regs->cr_ipsr, ipsr->ri, ipsr->it);
+
+ if (__copy_from_user(bundle, (void __user *) regs->cr_iip, 16))
+ goto failure;
+
+ /*
+ * extract the instruction from the bundle given the slot number
+ */
+ switch (ipsr->ri) {
+ case 0: u.l = (bundle[0] >> 5); break;
+ case 1: u.l = (bundle[0] >> 46) | (bundle[1] << 18); break;
+ case 2: u.l = (bundle[1] >> 23); break;
+ }
+ opcode = (u.l >> IA64_OPCODE_SHIFT) & IA64_OPCODE_MASK;
+
+ DPRINT("opcode=%lx ld.qp=%d ld.r1=%d ld.imm=%d ld.r3=%d ld.x=%d ld.hint=%d "
+ "ld.x6=0x%x ld.m=%d ld.op=%d\n", opcode, u.insn.qp, u.insn.r1, u.insn.imm,
+ u.insn.r3, u.insn.x, u.insn.hint, u.insn.x6_sz, u.insn.m, u.insn.op);
+
+ /*
+ * IMPORTANT:
+ * Notice that the switch statement DOES not cover all possible instructions
+ * that DO generate unaligned references. This is made on purpose because for some
+ * instructions it DOES NOT make sense to try and emulate the access. Sometimes it
+ * is WRONG to try and emulate. Here is a list of instruction we don't emulate i.e.,
+ * the program will get a signal and die:
+ *
+ * load/store:
+ * - ldX.spill
+ * - stX.spill
+ * Reason: RNATs are based on addresses
+ * - ld16
+ * - st16
+ * Reason: ld16 and st16 are supposed to occur in a single
+ * memory op
+ *
+ * synchronization:
+ * - cmpxchg
+ * - fetchadd
+ * - xchg
+ * Reason: ATOMIC operations cannot be emulated properly using multiple
+ * instructions.
+ *
+ * speculative loads:
+ * - ldX.sZ
+ * Reason: side effects, code must be ready to deal with failure so simpler
+ * to let the load fail.
+ * ---------------------------------------------------------------------------------
+ * XXX fixme
+ *
+ * I would like to get rid of this switch case and do something
+ * more elegant.
+ */
+ switch (opcode) {
+ case LDS_OP:
+ case LDSA_OP:
+ if (u.insn.x)
+ /* oops, really a semaphore op (cmpxchg, etc) */
+ goto failure;
+ /* no break */
+ case LDS_IMM_OP:
+ case LDSA_IMM_OP:
+ case LDFS_OP:
+ case LDFSA_OP:
+ case LDFS_IMM_OP:
+ /*
+ * The instruction will be retried with deferred exceptions turned on, and
+ * we should get Nat bit installed
+ *
+ * IMPORTANT: When PSR_ED is set, the register & immediate update forms
+ * are actually executed even though the operation failed. So we don't
+ * need to take care of this.
+ */
+ DPRINT("forcing PSR_ED\n");
+ regs->cr_ipsr |= IA64_PSR_ED;
+ goto done;
+
+ case LD_OP:
+ case LDA_OP:
+ case LDBIAS_OP:
+ case LDACQ_OP:
+ case LDCCLR_OP:
+ case LDCNC_OP:
+ case LDCCLRACQ_OP:
+ if (u.insn.x)
+ /* oops, really a semaphore op (cmpxchg, etc) */
+ goto failure;
+ /* no break */
+ case LD_IMM_OP:
+ case LDA_IMM_OP:
+ case LDBIAS_IMM_OP:
+ case LDACQ_IMM_OP:
+ case LDCCLR_IMM_OP:
+ case LDCNC_IMM_OP:
+ case LDCCLRACQ_IMM_OP:
+ ret = emulate_load_int(ifa, u.insn, regs);
+ break;
+
+ case ST_OP:
+ case STREL_OP:
+ if (u.insn.x)
+ /* oops, really a semaphore op (cmpxchg, etc) */
+ goto failure;
+ /* no break */
+ case ST_IMM_OP:
+ case STREL_IMM_OP:
+ ret = emulate_store_int(ifa, u.insn, regs);
+ break;
+
+ case LDF_OP:
+ case LDFA_OP:
+ case LDFCCLR_OP:
+ case LDFCNC_OP:
+ case LDF_IMM_OP:
+ case LDFA_IMM_OP:
+ case LDFCCLR_IMM_OP:
+ case LDFCNC_IMM_OP:
+ if (u.insn.x)
+ ret = emulate_load_floatpair(ifa, u.insn, regs);
+ else
+ ret = emulate_load_float(ifa, u.insn, regs);
+ break;
+
+ case STF_OP:
+ case STF_IMM_OP:
+ ret = emulate_store_float(ifa, u.insn, regs);
+ break;
+
+ default:
+ goto failure;
+ }
+ DPRINT("ret=%d\n", ret);
+ if (ret)
+ goto failure;
+
+ if (ipsr->ri == 2)
+ /*
+ * given today's architecture this case is not likely to happen because a
+ * memory access instruction (M) can never be in the last slot of a
+ * bundle. But let's keep it for now.
+ */
+ regs->cr_iip += 16;
+ ipsr->ri = (ipsr->ri + 1) & 0x3;
+
+ DPRINT("ipsr->ri=%d iip=%lx\n", ipsr->ri, regs->cr_iip);
+ done:
+ set_fs(old_fs); /* restore original address limit */
+ return;
+
+ failure:
+ /* something went wrong... */
+ if (!user_mode(regs)) {
+ if (eh) {
+ ia64_handle_exception(regs, eh);
+ goto done;
+ }
+ die_if_kernel("error during unaligned kernel access\n", regs, ret);
+ /* NOT_REACHED */
+ }
+ force_sigbus:
+ si.si_signo = SIGBUS;
+ si.si_errno = 0;
+ si.si_code = BUS_ADRALN;
+ si.si_addr = (void __user *) ifa;
+ si.si_flags = 0;
+ si.si_isr = 0;
+ si.si_imm = 0;
+ force_sig_info(SIGBUS, &si, current);
+ goto done;
+}