[S390] dcssblk: add >2G DCSSs support and stacked contiguous DCSSs support.

The DCSS block device driver is modified to add >2G DCSSs support and
allow a DCSS block device to map to a set of contiguous DCSSs.  The
extmem code is also modified to use new Diagnose x'64' subcodes for
>2G DCSSs.

Signed-off-by: Hongjie Yang <hongjie@us.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 212 insertions, 39 deletions

diff --git a/arch/s390/mm/extmem.c b/arch/s390/mm/extmem.c
index f231f5ec74b6..580fc64cc735 100644
--- a/arch/s390/mm/extmem.c
+++ b/arch/s390/mm/extmem.c
@@ -43,20 +43,40 @@
 #define DCSS_FINDSEG    0x0c
 #define DCSS_LOADNOLY   0x10
 #define DCSS_SEGEXT     0x18
+#define DCSS_LOADSHRX   0x20
+#define DCSS_LOADNSRX   0x24
+#define DCSS_FINDSEGX   0x2c
+#define DCSS_SEGEXTX    0x38
 #define DCSS_FINDSEGA   0x0c
 
 struct qrange {
-        unsigned int  start; // 3byte start address, 1 byte type
-        unsigned int  end;   // 3byte end address, 1 byte reserved
+        unsigned long  start; /* last byte type */
+        unsigned long  end;   /* last byte reserved */
 };
 
 struct qout64 {
+        unsigned long segstart;
+        unsigned long segend;
+        int segcnt;
+        int segrcnt;
+        struct qrange range[6];
+};
+
+#ifdef CONFIG_64BIT
+struct qrange_old {
+        unsigned int start; /* last byte type */
+        unsigned int end;   /* last byte reserved */
+};
+
+/* output area format for the Diag x'64' old subcode x'18' */
+struct qout64_old {
         int segstart;
         int segend;
         int segcnt;
         int segrcnt;
-        struct qrange range[6];
+        struct qrange_old range[6];
 };
+#endif
 
 struct qin64 {
         char qopcode;
@@ -86,6 +106,55 @@ static DEFINE_MUTEX(dcss_lock);
 static LIST_HEAD(dcss_list);
 static char *segtype_string[] = { "SW", "EW", "SR", "ER", "SN", "EN", "SC",
                                         "EW/EN-MIXED" };
+static int loadshr_scode, loadnsr_scode, findseg_scode;
+static int segext_scode, purgeseg_scode;
+static int scode_set;
+
+/* set correct Diag x'64' subcodes. */
+static int
+dcss_set_subcodes(void)
+{
+#ifdef CONFIG_64BIT
+        char *name = kmalloc(8 * sizeof(char), GFP_DMA);
+        unsigned long rx, ry;
+        int rc;
+
+        if (name == NULL)
+                return -ENOMEM;
+
+        rx = (unsigned long) name;
+        ry = DCSS_FINDSEGX;
+
+        strcpy(name, "dummy");
+        asm volatile(
+                "       diag    %0,%1,0x64\n"
+                "0:     ipm     %2\n"
+                "       srl     %2,28\n"
+                "       j       2f\n"
+                "1:     la      %2,3\n"
+                "2:\n"
+                EX_TABLE(0b, 1b)
+                : "+d" (rx), "+d" (ry), "=d" (rc) : : "cc");
+
+        kfree(name);
+        /* Diag x'64' new subcodes are supported, set to new subcodes */
+        if (rc != 3) {
+                loadshr_scode = DCSS_LOADSHRX;
+                loadnsr_scode = DCSS_LOADNSRX;
+                purgeseg_scode = DCSS_PURGESEG;
+                findseg_scode = DCSS_FINDSEGX;
+                segext_scode = DCSS_SEGEXTX;
+                return 0;
+        }
+#endif
+        /* Diag x'64' new subcodes are not supported, set to old subcodes */
+        loadshr_scode = DCSS_LOADNOLY;
+        loadnsr_scode = DCSS_LOADNSR;
+        purgeseg_scode = DCSS_PURGESEG;
+        findseg_scode = DCSS_FINDSEG;
+        segext_scode = DCSS_SEGEXT;
+        return 0;
+}
 
 /*
  * Create the 8 bytes, ebcdic VM segment name from
@@ -135,25 +204,45 @@ segment_by_name (char *name)
  * Perform a function on a dcss segment.
  */
 static inline int
-dcss_diag (__u8 func, void *parameter,
+dcss_diag(int *func, void *parameter,
            unsigned long *ret1, unsigned long *ret2)
 {
         unsigned long rx, ry;
         int rc;
 
+        if (scode_set == 0) {
+                rc = dcss_set_subcodes();
+                if (rc < 0)
+                        return rc;
+                scode_set = 1;
+        }
         rx = (unsigned long) parameter;
-        ry = (unsigned long) func;
-        asm volatile(
+        ry = (unsigned long) *func;
+
 #ifdef CONFIG_64BIT
-                "       sam31\n"
-                "       diag    %0,%1,0x64\n"
-                "       sam64\n"
+        /* 64-bit Diag x'64' new subcode, keep in 64-bit addressing mode */
+        if (*func > DCSS_SEGEXT)
+                asm volatile(
+                        "       diag    %0,%1,0x64\n"
+                        "       ipm     %2\n"
+                        "       srl     %2,28\n"
+                        : "+d" (rx), "+d" (ry), "=d" (rc) : : "cc");
+        /* 31-bit Diag x'64' old subcode, switch to 31-bit addressing mode */
+        else
+                asm volatile(
+                        "       sam31\n"
+                        "       diag    %0,%1,0x64\n"
+                        "       sam64\n"
+                        "       ipm     %2\n"
+                        "       srl     %2,28\n"
+                        : "+d" (rx), "+d" (ry), "=d" (rc) : : "cc");
 #else
+        asm volatile(
                 "       diag    %0,%1,0x64\n"
-#endif
                 "       ipm     %2\n"
                 "       srl     %2,28\n"
                 : "+d" (rx), "+d" (ry), "=d" (rc) : : "cc");
+#endif
         *ret1 = rx;
         *ret2 = ry;
         return rc;
@@ -190,14 +279,45 @@ query_segment_type (struct dcss_segment *seg)
         qin->qoutlen = sizeof(struct qout64);
         memcpy (qin->qname, seg->dcss_name, 8);
 
-        diag_cc = dcss_diag (DCSS_SEGEXT, qin, &dummy, &vmrc);
+        diag_cc = dcss_diag(&segext_scode, qin, &dummy, &vmrc);
 
+        if (diag_cc < 0) {
+                rc = diag_cc;
+                goto out_free;
+        }
         if (diag_cc > 1) {
                 PRINT_WARN ("segment_type: diag returned error %ld\n", vmrc);
                 rc = dcss_diag_translate_rc (vmrc);
                 goto out_free;
         }
 
+#ifdef CONFIG_64BIT
+        /* Only old format of output area of Diagnose x'64' is supported,
+           copy data for the new format. */
+        if (segext_scode == DCSS_SEGEXT) {
+                struct qout64_old *qout_old;
+                qout_old = kzalloc(sizeof(struct qout64_old), GFP_DMA);
+                if (qout_old == NULL) {
+                        rc = -ENOMEM;
+                        goto out_free;
+                }
+                memcpy(qout_old, qout, sizeof(struct qout64_old));
+                qout->segstart = (unsigned long) qout_old->segstart;
+                qout->segend = (unsigned long) qout_old->segend;
+                qout->segcnt = qout_old->segcnt;
+                qout->segrcnt = qout_old->segrcnt;
+
+                if (qout->segcnt > 6)
+                        qout->segrcnt = 6;
+                for (i = 0; i < qout->segrcnt; i++) {
+                        qout->range[i].start =
+                                (unsigned long) qout_old->range[i].start;
+                        qout->range[i].end =
+                                (unsigned long) qout_old->range[i].end;
+                }
+                kfree(qout_old);
+        }
+#endif
         if (qout->segcnt > 6) {
                 rc = -ENOTSUPP;
                 goto out_free;
@@ -269,6 +389,30 @@ segment_type (char* name)
 }
 
 /*
+ * check if segment collides with other segments that are currently loaded
+ * returns 1 if this is the case, 0 if no collision was found
+ */
+static int
+segment_overlaps_others (struct dcss_segment *seg)
+{
+        struct list_head *l;
+        struct dcss_segment *tmp;
+
+        BUG_ON(!mutex_is_locked(&dcss_lock));
+        list_for_each(l, &dcss_list) {
+                tmp = list_entry(l, struct dcss_segment, list);
+                if ((tmp->start_addr >> 20) > (seg->end >> 20))
+                        continue;
+                if ((tmp->end >> 20) < (seg->start_addr >> 20))
+                        continue;
+                if (seg == tmp)
+                        continue;
+                return 1;
+        }
+        return 0;
+}
+
+/*
  * real segment loading function, called from segment_load
  */
 static int
@@ -276,7 +420,8 @@ __segment_load (char *name, int do_nonshared, unsigned long *addr, unsigned long
 {
         struct dcss_segment *seg = kmalloc(sizeof(struct dcss_segment),
                         GFP_DMA);
-        int dcss_command, rc, diag_cc;
+        int rc, diag_cc;
+        unsigned long start_addr, end_addr, dummy;
 
         if (seg == NULL) {
                 rc = -ENOMEM;
@@ -287,6 +432,13 @@ __segment_load (char *name, int do_nonshared, unsigned long *addr, unsigned long
         if (rc < 0)
                 goto out_free;
 
+        if (loadshr_scode == DCSS_LOADSHRX) {
+                if (segment_overlaps_others(seg)) {
+                        rc = -EBUSY;
+                        goto out_free;
+                }
+        }
+
         rc = vmem_add_mapping(seg->start_addr, seg->end - seg->start_addr + 1);
 
         if (rc)
@@ -316,20 +468,28 @@ __segment_load (char *name, int do_nonshared, unsigned long *addr, unsigned long
         }
 
         if (do_nonshared)
-                dcss_command = DCSS_LOADNSR;
+                diag_cc = dcss_diag(&loadnsr_scode, seg->dcss_name,
+                                &start_addr, &end_addr);
         else
-                dcss_command = DCSS_LOADNOLY;
-
-        diag_cc = dcss_diag(dcss_command, seg->dcss_name,
-                        &seg->start_addr, &seg->end);
+                diag_cc = dcss_diag(&loadshr_scode, seg->dcss_name,
+                                &start_addr, &end_addr);
+        if (diag_cc < 0) {
+                dcss_diag(&purgeseg_scode, seg->dcss_name,
+                                &dummy, &dummy);
+                rc = diag_cc;
+                goto out_resource;
+        }
         if (diag_cc > 1) {
                 PRINT_WARN ("segment_load: could not load segment %s - "
-                                "diag returned error (%ld)\n",name,seg->end);
-                rc = dcss_diag_translate_rc (seg->end);
-                dcss_diag(DCSS_PURGESEG, seg->dcss_name,
-                                &seg->start_addr, &seg->end);
+                                "diag returned error (%ld)\n",
+                                name, end_addr);
+                rc = dcss_diag_translate_rc(end_addr);
+                dcss_diag(&purgeseg_scode, seg->dcss_name,
+                                &dummy, &dummy);
                 goto out_resource;
         }
+        seg->start_addr = start_addr;
+        seg->end = end_addr;
         seg->do_nonshared = do_nonshared;
         atomic_set(&seg->ref_count, 1);
         list_add(&seg->list, &dcss_list);
@@ -423,8 +583,8 @@ int
 segment_modify_shared (char *name, int do_nonshared)
 {
         struct dcss_segment *seg;
-        unsigned long dummy;
-        int dcss_command, rc, diag_cc;
+        unsigned long start_addr, end_addr, dummy;
+        int rc, diag_cc;
 
         mutex_lock(&dcss_lock);
         seg = segment_by_name (name);
@@ -445,38 +605,51 @@ segment_modify_shared (char *name, int do_nonshared)
                 goto out_unlock;
         }
         release_resource(seg->res);
-        if (do_nonshared) {
-                dcss_command = DCSS_LOADNSR;
+        if (do_nonshared)
                 seg->res->flags &= ~IORESOURCE_READONLY;
-        } else {
-                dcss_command = DCSS_LOADNOLY;
+        else
                 if (seg->vm_segtype == SEG_TYPE_SR ||
                     seg->vm_segtype == SEG_TYPE_ER)
                         seg->res->flags |= IORESOURCE_READONLY;
-        }
+
         if (request_resource(&iomem_resource, seg->res)) {
                 PRINT_WARN("segment_modify_shared: could not reload segment %s"
                            " - overlapping resources\n", name);
                 rc = -EBUSY;
                 kfree(seg->res);
-                goto out_del;
+                goto out_del_mem;
+        }
+
+        dcss_diag(&purgeseg_scode, seg->dcss_name, &dummy, &dummy);
+        if (do_nonshared)
+                diag_cc = dcss_diag(&loadnsr_scode, seg->dcss_name,
+                                &start_addr, &end_addr);
+        else
+                diag_cc = dcss_diag(&loadshr_scode, seg->dcss_name,
+                                &start_addr, &end_addr);
+        if (diag_cc < 0) {
+                rc = diag_cc;
+                goto out_del_res;
         }
-        dcss_diag(DCSS_PURGESEG, seg->dcss_name, &dummy, &dummy);
-        diag_cc = dcss_diag(dcss_command, seg->dcss_name,
-                        &seg->start_addr, &seg->end);
         if (diag_cc > 1) {
                 PRINT_WARN ("segment_modify_shared: could not reload segment %s"
-                                " - diag returned error (%ld)\n",name,seg->end);
-                rc = dcss_diag_translate_rc (seg->end);
-                goto out_del;
+                                " - diag returned error (%ld)\n",
+                                name, end_addr);
+                rc = dcss_diag_translate_rc(end_addr);
+                goto out_del_res;
         }
+        seg->start_addr = start_addr;
+        seg->end = end_addr;
         seg->do_nonshared = do_nonshared;
         rc = 0;
         goto out_unlock;
- out_del:
+ out_del_res:
+        release_resource(seg->res);
+        kfree(seg->res);
+ out_del_mem:
         vmem_remove_mapping(seg->start_addr, seg->end - seg->start_addr + 1);
         list_del(&seg->list);
-        dcss_diag(DCSS_PURGESEG, seg->dcss_name, &dummy, &dummy);
+        dcss_diag(&purgeseg_scode, seg->dcss_name, &dummy, &dummy);
         kfree(seg);
  out_unlock:
         mutex_unlock(&dcss_lock);
@@ -510,7 +683,7 @@ segment_unload(char *name)
         kfree(seg->res);
         vmem_remove_mapping(seg->start_addr, seg->end - seg->start_addr + 1);
         list_del(&seg->list);
-        dcss_diag(DCSS_PURGESEG, seg->dcss_name, &dummy, &dummy);
+        dcss_diag(&purgeseg_scode, seg->dcss_name, &dummy, &dummy);
         kfree(seg);
 out_unlock:
         mutex_unlock(&dcss_lock);
@@ -545,7 +718,7 @@ segment_save(char *name)
         endpfn = (seg->end) >> PAGE_SHIFT;
         sprintf(cmd1, "DEFSEG %s", name);
         for (i=0; i<seg->segcnt; i++) {
-                sprintf(cmd1+strlen(cmd1), " %X-%X %s",
+                sprintf(cmd1+strlen(cmd1), " %lX-%lX %s",
                         seg->range[i].start >> PAGE_SHIFT,
                         seg->range[i].end >> PAGE_SHIFT,
                         segtype_string[seg->range[i].start & 0xff]);