[S390] zfcpdump: remove cross arch dump support

Remove support to be able to dump 31 bit systems with a 64 bit dumper.
This is mostly useless since no distro ships 31 bit kernels together
with a 64 bit dumper.
We also get rid of a bit of hacky code.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

6 files changed, 72 insertions, 205 deletions

diff --git a/arch/s390/include/asm/lowcore.h b/arch/s390/include/asm/lowcore.h
index c25dfac7dd76..8ed3c745cd07 100644
--- a/arch/s390/include/asm/lowcore.h
+++ b/arch/s390/include/asm/lowcore.h
@@ -144,7 +144,9 @@ void pgm_check_handler(void);
 void mcck_int_handler(void);
 void io_int_handler(void);
 
-struct save_area_s390 {
+#ifdef CONFIG_32BIT
+
+struct save_area {
         u32     ext_save;
         u64     timer;
         u64     clk_cmp;
@@ -158,7 +160,11 @@ struct save_area_s390 {
         u32     ctrl_regs[16];
 }  __attribute__((packed));
 
-struct save_area_s390x {
+#define SAVE_AREA_BASE offsetof(struct _lowcore, extended_save_area_addr)
+
+#else /* CONFIG_32BIT */
+
+struct save_area {
         u64     fp_regs[16];
         u64     gp_regs[16];
         u8      psw[16];
@@ -174,21 +180,9 @@ struct save_area_s390x {
         u64     ctrl_regs[16];
 }  __attribute__((packed));
 
-union save_area {
-        struct save_area_s390   s390;
-        struct save_area_s390x  s390x;
-};
-
-#define SAVE_AREA_BASE_S390     0xd4
-#define SAVE_AREA_BASE_S390X    0x1200
+#define SAVE_AREA_BASE offsetof(struct _lowcore, floating_pt_save_area)
 
-#ifndef __s390x__
-#define SAVE_AREA_SIZE sizeof(struct save_area_s390)
-#define SAVE_AREA_BASE SAVE_AREA_BASE_S390
-#else
-#define SAVE_AREA_SIZE sizeof(struct save_area_s390x)
-#define SAVE_AREA_BASE SAVE_AREA_BASE_S390X
-#endif
+#endif /* CONFIG_32BIT */
 
 #ifndef __s390x__
 #define LC_ORDER 0
diff --git a/arch/s390/include/asm/smp.h b/arch/s390/include/asm/smp.h
index 2ab1141eeb50..9d2acb0b4847 100644
--- a/arch/s390/include/asm/smp.h
+++ b/arch/s390/include/asm/smp.h
@@ -29,7 +29,7 @@ extern int smp_cpu_polarization[];
 extern void arch_send_call_function_single_ipi(int cpu);
 extern void arch_send_call_function_ipi_mask(const struct cpumask *mask);
 
-extern union save_area *zfcpdump_save_areas[NR_CPUS + 1];
+extern struct save_area *zfcpdump_save_areas[NR_CPUS + 1];
 
 #endif /* CONFIG_SMP */
 
diff --git a/arch/s390/kernel/head64.S b/arch/s390/kernel/head64.S
index d984a2a380c3..5419aabf8a66 100644
--- a/arch/s390/kernel/head64.S
+++ b/arch/s390/kernel/head64.S
@@ -16,71 +16,9 @@ startup_continue:
         basr    %r13,0                  # get base
 .LPG1:  sll     %r13,1                  # remove high order bit
         srl     %r13,1
-
-#ifdef CONFIG_ZFCPDUMP
-
-        # check if we have been ipled using zfcp dump:
-
-        tm      0xb9,0x01               # test if subchannel is enabled
-        jno     .nodump                 # subchannel disabled
-        l       %r1,0xb8
-        la      %r5,.Lipl_schib-.LPG1(%r13)
-        stsch   0(%r5)                  # get schib of subchannel
-        jne     .nodump                 # schib not available
-        tm      5(%r5),0x01             # devno valid?
-        jno     .nodump
-        tm      4(%r5),0x80             # qdio capable device?
-        jno     .nodump
-        l       %r2,20(%r0)             # address of ipl parameter block
-        lhi     %r3,0
-        ic      %r3,0x148(%r2)          # get opt field
-        chi     %r3,0x20                # load with dump?
-        jne     .nodump
-
-        # store all prefix registers in case of load with dump:
-
-        la      %r7,0                   # base register for 0 page
-        la      %r8,0                   # first cpu
-        l       %r11,.Lpref_arr_ptr-.LPG1(%r13) # address of prefix array
-        ahi     %r11,4                  # skip boot cpu
-        lr      %r12,%r11
-        ahi     %r12,(CONFIG_NR_CPUS*4) # end of prefix array
-        stap    .Lcurrent_cpu+2-.LPG1(%r13)     # store current cpu addr
-1:
-        cl      %r8,.Lcurrent_cpu-.LPG1(%r13)   # is ipl cpu ?
-        je      4f                              # if yes get next cpu
-2:
-        lr      %r9,%r7
-        sigp    %r9,%r8,0x9             # stop & store status of cpu
-        brc     8,3f                    # accepted
-        brc     4,4f                    # status stored: next cpu
-        brc     2,2b                    # busy:          try again
-        brc     1,4f                    # not op:        next cpu
-3:
-        mvc     0(4,%r11),264(%r7)      # copy prefix register to prefix array
-        ahi     %r11,4                  # next element in prefix array
-        clr     %r11,%r12
-        je      5f                      # no more space in prefix array
-4:
-        ahi     %r8,1                   # next cpu (r8 += 1)
-        chi     %r8,MAX_CPU_ADDRESS     # is last possible cpu ?
-        jle     1b                      # jump if not last cpu
-5:
-        lhi     %r1,2                   # mode 2 = esame (dump)
-        j       6f
-        .align 4
-.Lipl_schib:
-        .rept 13
-        .long 0
-        .endr
-.nodump:
-        lhi     %r1,1                   # mode 1 = esame (normal ipl)
-6:
-#else
-        lhi     %r1,1                   # mode 1 = esame (normal ipl)
-#endif /* CONFIG_ZFCPDUMP */
         mvi     __LC_AR_MODE_ID,1       # set esame flag
         slr     %r0,%r0                 # set cpuid to zero
+        lhi     %r1,2                   # mode 2 = esame (dump)
         sigp    %r1,%r0,0x12            # switch to esame mode
         sam64                           # switch to 64 bit mode
         llgfr   %r13,%r13               # clear high-order half of base reg
@@ -130,12 +68,6 @@ startup_continue:
 .Lscan2g:.quad  0x80000000 + 0x20000 - 8        # 2GB + 128K - 8
 .Lnop:  .long   0x07000700
 .Lzero64:.fill  16,4,0x0
-#ifdef CONFIG_ZFCPDUMP
-.Lcurrent_cpu:
-        .long 0x0
-.Lpref_arr_ptr:
-        .long zfcpdump_prefix_array
-#endif /* CONFIG_ZFCPDUMP */
 .Lparmaddr:
         .quad   PARMAREA
         .align  64
diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index 76a6fdd46c45..384a6846a65e 100644
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -248,15 +248,6 @@ EXPORT_SYMBOL(smp_ctl_clear_bit);
 
 #ifdef CONFIG_ZFCPDUMP
 
-/*
- * zfcpdump_prefix_array holds prefix registers for the following scenario:
- * 64 bit zfcpdump kernel and 31 bit kernel which is to be dumped. We have to
- * save its prefix registers, since they get lost, when switching from 31 bit
- * to 64 bit.
- */
-unsigned int zfcpdump_prefix_array[NR_CPUS + 1] \
-        __attribute__((__section__(".data")));
-
 static void __init smp_get_save_area(unsigned int cpu, unsigned int phy_cpu)
 {
         if (ipl_info.type != IPL_TYPE_FCP_DUMP)
@@ -266,21 +257,17 @@ static void __init smp_get_save_area(unsigned int cpu, unsigned int phy_cpu)
                            "the dump\n", cpu, NR_CPUS - 1);
                 return;
         }
-        zfcpdump_save_areas[cpu] = kmalloc(sizeof(union save_area), GFP_KERNEL);
+        zfcpdump_save_areas[cpu] = kmalloc(sizeof(struct save_area), GFP_KERNEL);
         __cpu_logical_map[CPU_INIT_NO] = (__u16) phy_cpu;
         while (signal_processor(CPU_INIT_NO, sigp_stop_and_store_status) ==
                sigp_busy)
                 cpu_relax();
         memcpy(zfcpdump_save_areas[cpu],
                (void *)(unsigned long) store_prefix() + SAVE_AREA_BASE,
-               SAVE_AREA_SIZE);
-#ifdef CONFIG_64BIT
-        /* copy original prefix register */
-        zfcpdump_save_areas[cpu]->s390x.pref_reg = zfcpdump_prefix_array[cpu];
-#endif
+               sizeof(struct save_area));
 }
 
-union save_area *zfcpdump_save_areas[NR_CPUS + 1];
+struct save_area *zfcpdump_save_areas[NR_CPUS + 1];
 EXPORT_SYMBOL_GPL(zfcpdump_save_areas);
 
 #else
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index f8bcaefd7d34..70e799eefec9 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -603,45 +603,45 @@ int __kvm_s390_vcpu_store_status(struct kvm_vcpu *vcpu, unsigned long addr)
         } else
                 prefix = 0;
 
-        if (__guestcopy(vcpu, addr + offsetof(struct save_area_s390x, fp_regs),
+        if (__guestcopy(vcpu, addr + offsetof(struct save_area, fp_regs),
                         vcpu->arch.guest_fpregs.fprs, 128, prefix))
                 return -EFAULT;
 
-        if (__guestcopy(vcpu, addr + offsetof(struct save_area_s390x, gp_regs),
+        if (__guestcopy(vcpu, addr + offsetof(struct save_area, gp_regs),
                         vcpu->arch.guest_gprs, 128, prefix))
                 return -EFAULT;
 
-        if (__guestcopy(vcpu, addr + offsetof(struct save_area_s390x, psw),
+        if (__guestcopy(vcpu, addr + offsetof(struct save_area, psw),
                         &vcpu->arch.sie_block->gpsw, 16, prefix))
                 return -EFAULT;
 
-        if (__guestcopy(vcpu, addr + offsetof(struct save_area_s390x, pref_reg),
+        if (__guestcopy(vcpu, addr + offsetof(struct save_area, pref_reg),
                         &vcpu->arch.sie_block->prefix, 4, prefix))
                 return -EFAULT;
 
         if (__guestcopy(vcpu,
-                        addr + offsetof(struct save_area_s390x, fp_ctrl_reg),
+                        addr + offsetof(struct save_area, fp_ctrl_reg),
                         &vcpu->arch.guest_fpregs.fpc, 4, prefix))
                 return -EFAULT;
 
-        if (__guestcopy(vcpu, addr + offsetof(struct save_area_s390x, tod_reg),
+        if (__guestcopy(vcpu, addr + offsetof(struct save_area, tod_reg),
                         &vcpu->arch.sie_block->todpr, 4, prefix))
                 return -EFAULT;
 
-        if (__guestcopy(vcpu, addr + offsetof(struct save_area_s390x, timer),
+        if (__guestcopy(vcpu, addr + offsetof(struct save_area, timer),
                         &vcpu->arch.sie_block->cputm, 8, prefix))
                 return -EFAULT;
 
-        if (__guestcopy(vcpu, addr + offsetof(struct save_area_s390x, clk_cmp),
+        if (__guestcopy(vcpu, addr + offsetof(struct save_area, clk_cmp),
                         &vcpu->arch.sie_block->ckc, 8, prefix))
                 return -EFAULT;
 
-        if (__guestcopy(vcpu, addr + offsetof(struct save_area_s390x, acc_regs),
+        if (__guestcopy(vcpu, addr + offsetof(struct save_area, acc_regs),
                         &vcpu->arch.guest_acrs, 64, prefix))
                 return -EFAULT;
 
         if (__guestcopy(vcpu,
-                        addr + offsetof(struct save_area_s390x, ctrl_regs),
+                        addr + offsetof(struct save_area, ctrl_regs),
                         &vcpu->arch.sie_block->gcr, 128, prefix))
                 return -EFAULT;
         return 0;
diff --git a/drivers/s390/char/zcore.c b/drivers/s390/char/zcore.c
index 82daa3c1dc9c..1d935b2c9bf4 100644
--- a/drivers/s390/char/zcore.c
+++ b/drivers/s390/char/zcore.c
@@ -40,12 +40,12 @@ enum arch_id {
 /* dump system info */
 
 struct sys_info {
-        enum arch_id    arch;
-        unsigned long   sa_base;
-        u32             sa_size;
-        int             cpu_map[NR_CPUS];
-        unsigned long   mem_size;
-        union save_area lc_mask;
+        enum arch_id     arch;
+        unsigned long    sa_base;
+        u32              sa_size;
+        int              cpu_map[NR_CPUS];
+        unsigned long    mem_size;
+        struct save_area lc_mask;
 };
 
 struct ipib_info {
@@ -183,52 +183,9 @@ static int memcpy_real_user(void __user *dest, unsigned long src, size_t count)
         return 0;
 }
 
-#ifdef __s390x__
-/*
- * Convert s390x (64 bit) cpu info to s390 (32 bit) cpu info
- */
-static void __init s390x_to_s390_regs(union save_area *out, union save_area *in,
-                                      int cpu)
-{
-        int i;
-
-        for (i = 0; i < 16; i++) {
-                out->s390.gp_regs[i] = in->s390x.gp_regs[i] & 0x00000000ffffffff;
-                out->s390.acc_regs[i] = in->s390x.acc_regs[i];
-                out->s390.ctrl_regs[i] =
-                        in->s390x.ctrl_regs[i] & 0x00000000ffffffff;
-        }
-        /* locore for 31 bit has only space for fpregs 0,2,4,6 */
-        out->s390.fp_regs[0] = in->s390x.fp_regs[0];
-        out->s390.fp_regs[1] = in->s390x.fp_regs[2];
-        out->s390.fp_regs[2] = in->s390x.fp_regs[4];
-        out->s390.fp_regs[3] = in->s390x.fp_regs[6];
-        memcpy(&(out->s390.psw[0]), &(in->s390x.psw[0]), 4);
-        out->s390.psw[1] |= 0x8; /* set bit 12 */
-        memcpy(&(out->s390.psw[4]),&(in->s390x.psw[12]), 4);
-        out->s390.psw[4] |= 0x80; /* set (31bit) addressing bit */
-        out->s390.pref_reg = in->s390x.pref_reg;
-        out->s390.timer = in->s390x.timer;
-        out->s390.clk_cmp = in->s390x.clk_cmp;
-}
-
-static void __init s390x_to_s390_save_areas(void)
-{
-        int i = 1;
-        static union save_area tmp;
-
-        while (zfcpdump_save_areas[i]) {
-                s390x_to_s390_regs(&tmp, zfcpdump_save_areas[i], i);
-                memcpy(zfcpdump_save_areas[i], &tmp, sizeof(tmp));
-                i++;
-        }
-}
-
-#endif /* __s390x__ */
-
 static int __init init_cpu_info(enum arch_id arch)
 {
-        union save_area *sa;
+        struct save_area *sa;
 
         /* get info for boot cpu from lowcore, stored in the HSA */
 
@@ -241,14 +198,6 @@ static int __init init_cpu_info(enum arch_id arch)
                 return -EIO;
         }
         zfcpdump_save_areas[0] = sa;
-
-#ifdef __s390x__
-        /* convert s390x regs to s390, if we are dumping an s390 Linux */
-
-        if (arch == ARCH_S390)
-                s390x_to_s390_save_areas();
-#endif
-
         return 0;
 }
 
@@ -289,7 +238,7 @@ static struct zcore_header zcore_header = {
         .dump_level     = 0,
         .page_size      = PAGE_SIZE,
         .mem_start      = 0,
-#ifdef __s390x__
+#ifdef CONFIG_64BIT
         .build_arch     = DUMP_ARCH_S390X,
 #else
         .build_arch     = DUMP_ARCH_S390,
@@ -340,11 +289,7 @@ static int zcore_add_lc(char __user *buf, unsigned long start, size_t count)
                 unsigned long prefix;
                 unsigned long sa_off, len, buf_off;
 
-                if (sys_info.arch == ARCH_S390)
-                        prefix = zfcpdump_save_areas[i]->s390.pref_reg;
-                else
-                        prefix = zfcpdump_save_areas[i]->s390x.pref_reg;
-
+                prefix = zfcpdump_save_areas[i]->pref_reg;
                 sa_start = prefix + sys_info.sa_base;
                 sa_end = prefix + sys_info.sa_base + sys_info.sa_size;
 
@@ -561,34 +506,39 @@ static const struct file_operations zcore_reipl_fops = {
         .release        = zcore_reipl_release,
 };
 
+#ifdef CONFIG_32BIT
 
-static void __init set_s390_lc_mask(union save_area *map)
+static void __init set_lc_mask(struct save_area *map)
 {
-        memset(&map->s390.ext_save, 0xff, sizeof(map->s390.ext_save));
-        memset(&map->s390.timer, 0xff, sizeof(map->s390.timer));
-        memset(&map->s390.clk_cmp, 0xff, sizeof(map->s390.clk_cmp));
-        memset(&map->s390.psw, 0xff, sizeof(map->s390.psw));
-        memset(&map->s390.pref_reg, 0xff, sizeof(map->s390.pref_reg));
-        memset(&map->s390.acc_regs, 0xff, sizeof(map->s390.acc_regs));
-        memset(&map->s390.fp_regs, 0xff, sizeof(map->s390.fp_regs));
-        memset(&map->s390.gp_regs, 0xff, sizeof(map->s390.gp_regs));
-        memset(&map->s390.ctrl_regs, 0xff, sizeof(map->s390.ctrl_regs));
+        memset(&map->ext_save, 0xff, sizeof(map->ext_save));
+        memset(&map->timer, 0xff, sizeof(map->timer));
+        memset(&map->clk_cmp, 0xff, sizeof(map->clk_cmp));
+        memset(&map->psw, 0xff, sizeof(map->psw));
+        memset(&map->pref_reg, 0xff, sizeof(map->pref_reg));
+        memset(&map->acc_regs, 0xff, sizeof(map->acc_regs));
+        memset(&map->fp_regs, 0xff, sizeof(map->fp_regs));
+        memset(&map->gp_regs, 0xff, sizeof(map->gp_regs));
+        memset(&map->ctrl_regs, 0xff, sizeof(map->ctrl_regs));
 }
 
-static void __init set_s390x_lc_mask(union save_area *map)
+#else /* CONFIG_32BIT */
+
+static void __init set_lc_mask(struct save_area *map)
 {
-        memset(&map->s390x.fp_regs, 0xff, sizeof(map->s390x.fp_regs));
-        memset(&map->s390x.gp_regs, 0xff, sizeof(map->s390x.gp_regs));
-        memset(&map->s390x.psw, 0xff, sizeof(map->s390x.psw));
-        memset(&map->s390x.pref_reg, 0xff, sizeof(map->s390x.pref_reg));
-        memset(&map->s390x.fp_ctrl_reg, 0xff, sizeof(map->s390x.fp_ctrl_reg));
-        memset(&map->s390x.tod_reg, 0xff, sizeof(map->s390x.tod_reg));
-        memset(&map->s390x.timer, 0xff, sizeof(map->s390x.timer));
-        memset(&map->s390x.clk_cmp, 0xff, sizeof(map->s390x.clk_cmp));
-        memset(&map->s390x.acc_regs, 0xff, sizeof(map->s390x.acc_regs));
-        memset(&map->s390x.ctrl_regs, 0xff, sizeof(map->s390x.ctrl_regs));
+        memset(&map->fp_regs, 0xff, sizeof(map->fp_regs));
+        memset(&map->gp_regs, 0xff, sizeof(map->gp_regs));
+        memset(&map->psw, 0xff, sizeof(map->psw));
+        memset(&map->pref_reg, 0xff, sizeof(map->pref_reg));
+        memset(&map->fp_ctrl_reg, 0xff, sizeof(map->fp_ctrl_reg));
+        memset(&map->tod_reg, 0xff, sizeof(map->tod_reg));
+        memset(&map->timer, 0xff, sizeof(map->timer));
+        memset(&map->clk_cmp, 0xff, sizeof(map->clk_cmp));
+        memset(&map->acc_regs, 0xff, sizeof(map->acc_regs));
+        memset(&map->ctrl_regs, 0xff, sizeof(map->ctrl_regs));
 }
 
+#endif /* CONFIG_32BIT */
+
 /*
  * Initialize dump globals for a given architecture
  */
@@ -599,21 +549,18 @@ static int __init sys_info_init(enum arch_id arch)
         switch (arch) {
         case ARCH_S390X:
                 pr_alert("DETECTED 'S390X (64 bit) OS'\n");
-                sys_info.sa_base = SAVE_AREA_BASE_S390X;
-                sys_info.sa_size = sizeof(struct save_area_s390x);
-                set_s390x_lc_mask(&sys_info.lc_mask);
                 break;
         case ARCH_S390:
                 pr_alert("DETECTED 'S390 (32 bit) OS'\n");
-                sys_info.sa_base = SAVE_AREA_BASE_S390;
-                sys_info.sa_size = sizeof(struct save_area_s390);
-                set_s390_lc_mask(&sys_info.lc_mask);
                 break;
         default:
                 pr_alert("0x%x is an unknown architecture.\n",arch);
                 return -EINVAL;
         }
+        sys_info.sa_base = SAVE_AREA_BASE;
+        sys_info.sa_size = sizeof(struct save_area);
         sys_info.arch = arch;
+        set_lc_mask(&sys_info.lc_mask);
         rc = init_cpu_info(arch);
         if (rc)
                 return rc;
@@ -741,14 +688,21 @@ static int __init zcore_init(void)
         if (rc)
                 goto fail;
 
-#ifndef __s390x__
+#ifdef CONFIG_64BIT
+        if (arch == ARCH_S390) {
+                pr_alert("The 64-bit dump tool cannot be used for a "
+                         "32-bit system\n");
+                rc = -EINVAL;
+                goto fail;
+        }
+#else /* CONFIG_64BIT */
         if (arch == ARCH_S390X) {
                 pr_alert("The 32-bit dump tool cannot be used for a "
                          "64-bit system\n");
                 rc = -EINVAL;
                 goto fail;
         }
-#endif
+#endif /* CONFIG_64BIT */
 
         rc = sys_info_init(arch);
         if (rc)