// SPDX-License-Identifier: GPL-2.0 /* * Author(s)......: Carsten Otte <cotte@de.ibm.com> * Rob M van der Heij <rvdheij@nl.ibm.com> * Steven Shultz <shultzss@us.ibm.com> * Bugreports.to..: <Linux390@de.ibm.com> * Copyright IBM Corp. 2002, 2004 */ #define KMSG_COMPONENT "extmem" #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt #include <linux/kernel.h> #include <linux/string.h> #include <linux/spinlock.h> #include <linux/list.h> #include <linux/slab.h> #include <linux/export.h> #include <linux/memblock.h> #include <linux/ctype.h> #include <linux/ioport.h> #include <linux/refcount.h> #include <linux/pgtable.h> #include <asm/diag.h> #include <asm/page.h> #include <asm/ebcdic.h> #include <asm/errno.h> #include <asm/extmem.h> #include <asm/cpcmd.h> #include <asm/setup.h> #define DCSS_PURGESEG 0x08 #define DCSS_LOADSHRX 0x20 #define DCSS_LOADNSRX 0x24 #define DCSS_FINDSEGX 0x2c #define DCSS_SEGEXTX 0x38 #define DCSS_FINDSEGA 0x0c struct qrange { 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]; }; struct qin64 { char qopcode; char rsrv1[3]; char qrcode; char rsrv2[3]; char qname[8]; unsigned int qoutptr; short int qoutlen; }; struct dcss_segment { struct list_head list; char dcss_name[8]; char res_name[16]; unsigned long start_addr; unsigned long end; refcount_t ref_count; int do_nonshared; unsigned int vm_segtype; struct qrange range[6]; int segcnt; struct resource *res; }; 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 = DCSS_LOADSHRX; static int loadnsr_scode = DCSS_LOADNSRX; static int purgeseg_scode = DCSS_PURGESEG; static int segext_scode = DCSS_SEGEXTX; /* * Create the 8 bytes, ebcdic VM segment name from * an ascii name. */ static void dcss_mkname(char *name, char *dcss_name) { int i; for (i = 0; i < 8; i++) { if (name[i] == '\0') break; dcss_name[i] = toupper(name[i]); } for (; i < 8; i++) dcss_name[i] = ' '; ASCEBC(dcss_name, 8); } /* * search all segments in dcss_list, and return the one * namend *name. If not found, return NULL. */ static struct dcss_segment * segment_by_name (char *name) { char dcss_name[9]; struct list_head *l; struct dcss_segment *tmp, *retval = NULL; BUG_ON(!mutex_is_locked(&dcss_lock)); dcss_mkname (name, dcss_name); list_for_each (l, &dcss_list) { tmp = list_entry (l, struct dcss_segment, list); if (memcmp(tmp->dcss_name, dcss_name, 8) == 0) { retval = tmp; break; } } return retval; } /* * Perform a function on a dcss segment. */ static inline int dcss_diag(int *func, void *parameter, unsigned long *ret1, unsigned long *ret2) { unsigned long rx, ry; int rc; rx = (unsigned long) parameter; ry = (unsigned long) *func; diag_stat_inc(DIAG_STAT_X064); asm volatile( " diag %0,%1,0x64\n" " ipm %2\n" " srl %2,28\n" : "+d" (rx), "+d" (ry), "=d" (rc) : : "cc"); *ret1 = rx; *ret2 = ry; return rc; } static inline int dcss_diag_translate_rc (int vm_rc) { if (vm_rc == 44) return -ENOENT; return -EIO; } /* do a diag to get info about a segment. * fills start_address, end and vm_segtype fields */ static int query_segment_type (struct dcss_segment *seg) { unsigned long dummy, vmrc; int diag_cc, rc, i; struct qout64 *qout; struct qin64 *qin; qin = kmalloc(sizeof(*qin), GFP_KERNEL | GFP_DMA); qout = kmalloc(sizeof(*qout), GFP_KERNEL | GFP_DMA); if ((qin == NULL) || (qout == NULL)) { rc = -ENOMEM; goto out_free; } /* initialize diag input parameters */ qin->qopcode = DCSS_FINDSEGA; qin->qoutptr = (unsigned long) qout; qin->qoutlen = sizeof(struct qout64); memcpy (qin->qname, seg->dcss_name, 8); diag_cc = dcss_diag(&segext_scode, qin, &dummy, &vmrc); if (diag_cc < 0) { rc = diag_cc; goto out_free; } if (diag_cc > 1) { pr_warn("Querying a DCSS type failed with rc=%ld\n", vmrc); rc = dcss_diag_translate_rc (vmrc); goto out_free; } if (qout->segcnt > 6) { rc = -EOPNOTSUPP; goto out_free; } if (qout->segcnt == 1) { seg->vm_segtype = qout->range[0].start & 0xff; } else { /* multi-part segment. only one type supported here: - all parts are contiguous - all parts are either EW or EN type - maximum 6 parts allowed */ unsigned long start = qout->segstart >> PAGE_SHIFT; for (i=0; i<qout->segcnt; i++) { if (((qout->range[i].start & 0xff) != SEG_TYPE_EW) && ((qout->range[i].start & 0xff) != SEG_TYPE_EN)) { rc = -EOPNOTSUPP; goto out_free; } if (start != qout->range[i].start >> PAGE_SHIFT) { rc = -EOPNOTSUPP; goto out_free; } start = (qout->range[i].end >> PAGE_SHIFT) + 1; } seg->vm_segtype = SEG_TYPE_EWEN; } /* analyze diag output and update seg */ seg->start_addr = qout->segstart; seg->end = qout->segend; memcpy (seg->range, qout->range, 6*sizeof(struct qrange)); seg->segcnt = qout->segcnt; rc = 0; out_free: kfree(qin); kfree(qout); return rc; } /* * get info about a segment * possible return values: * -ENOSYS : we are not running on VM * -EIO : could not perform query diagnose * -ENOENT : no such segment * -EOPNOTSUPP: multi-part segment cannot be used with linux * -ENOMEM : out of memory * 0 .. 6 : type of segment as defined in include/asm-s390/extmem.h */ int segment_type (char* name) { int rc; struct dcss_segment seg; if (!MACHINE_IS_VM) return -ENOSYS; dcss_mkname(name, seg.dcss_name); rc = query_segment_type (&seg); if (rc < 0) return rc; return seg.vm_segtype; } /* * 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 __segment_load (char *name, int do_nonshared, unsigned long *addr, unsigned long *end) { unsigned long start_addr, end_addr, dummy; struct dcss_segment *seg; int rc, diag_cc; start_addr = end_addr = 0; seg = kmalloc(sizeof(*seg), GFP_KERNEL | GFP_DMA); if (seg == NULL) { rc = -ENOMEM; goto out; } dcss_mkname (name, seg->dcss_name); rc = query_segment_type (seg); if (rc < 0) goto out_free; if (segment_overlaps_others(seg)) { rc = -EBUSY; goto out_free; } seg->res = kzalloc(sizeof(struct resource), GFP_KERNEL); if (seg->res == NULL) { rc = -ENOMEM; goto out_free; } seg->res->flags = IORESOURCE_BUSY | IORESOURCE_MEM; seg->res->start = seg->start_addr; seg->res->end = seg->end; memcpy(&seg->res_name, seg->dcss_name, 8); EBCASC(seg->res_name, 8); seg->res_name[8] = '\0'; strlcat(seg->res_name, " (DCSS)", sizeof(seg->res_name)); seg->res->name = seg->res_name; rc = seg->vm_segtype; if (rc == SEG_TYPE_SC || ((rc == SEG_TYPE_SR || rc == SEG_TYPE_ER) && !do_nonshared)) seg->res->flags |= IORESOURCE_READONLY; /* Check for overlapping resources before adding the mapping. */ if (request_resource(&iomem_resource, seg->res)) { rc = -EBUSY; goto out_free_resource; } rc = vmem_add_mapping(seg->start_addr, seg->end - seg->start_addr + 1); if (rc) goto out_resource; 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) { dcss_diag(&purgeseg_scode, seg->dcss_name, &dummy, &dummy); rc = diag_cc; goto out_mapping; } if (diag_cc > 1) { pr_warn("Loading DCSS %s failed with rc=%ld\n", name, end_addr); rc = dcss_diag_translate_rc(end_addr); dcss_diag(&purgeseg_scode, seg->dcss_name, &dummy, &dummy); goto out_mapping; } seg->start_addr = start_addr; seg->end = end_addr; seg->do_nonshared = do_nonshared; refcount_set(&seg->ref_count, 1); list_add(&seg->list, &dcss_list); *addr = seg->start_addr; *end = seg->end; if (do_nonshared) pr_info("DCSS %s of range %px to %px and type %s loaded as " "exclusive-writable\n", name, (void*) seg->start_addr, (void*) seg->end, segtype_string[seg->vm_segtype]); else { pr_info("DCSS %s of range %px to %px and type %s loaded in " "shared access mode\n", name, (void*) seg->start_addr, (void*) seg->end, segtype_string[seg->vm_segtype]); } goto out; out_mapping: vmem_remove_mapping(seg->start_addr, seg->end - seg->start_addr + 1); out_resource: release_resource(seg->res); out_free_resource: kfree(seg->res); out_free: kfree(seg); out: return rc; } /* * this function loads a DCSS segment * name : name of the DCSS * do_nonshared : 0 indicates that the dcss should be shared with other linux images * 1 indicates that the dcss should be exclusive for this linux image * addr : will be filled with start address of the segment * end : will be filled with end address of the segment * return values: * -ENOSYS : we are not running on VM * -EIO : could not perform query or load diagnose * -ENOENT : no such segment * -EOPNOTSUPP: multi-part segment cannot be used with linux * -EBUSY : segment cannot be used (overlaps with dcss or storage) * -ERANGE : segment cannot be used (exceeds kernel mapping range) * -EPERM : segment is currently loaded with incompatible permissions * -ENOMEM : out of memory * 0 .. 6 : type of segment as defined in include/asm-s390/extmem.h */ int segment_load (char *name, int do_nonshared, unsigned long *addr, unsigned long *end) { struct dcss_segment *seg; int rc; if (!MACHINE_IS_VM) return -ENOSYS; mutex_lock(&dcss_lock); seg = segment_by_name (name); if (seg == NULL) rc = __segment_load (name, do_nonshared, addr, end); else { if (do_nonshared == seg->do_nonshared) { refcount_inc(&seg->ref_count); *addr = seg->start_addr; *end = seg->end; rc = seg->vm_segtype; } else { *addr = *end = 0; rc = -EPERM; } } mutex_unlock(&dcss_lock); return rc; } /* * this function modifies the shared state of a DCSS segment. note that * name : name of the DCSS * do_nonshared : 0 indicates that the dcss should be shared with other linux images * 1 indicates that the dcss should be exclusive for this linux image * return values: * -EIO : could not perform load diagnose (segment gone!) * -ENOENT : no such segment (segment gone!) * -EAGAIN : segment is in use by other exploiters, try later * -EINVAL : no segment with the given name is currently loaded - name invalid * -EBUSY : segment can temporarily not be used (overlaps with dcss) * 0 : operation succeeded */ int segment_modify_shared (char *name, int do_nonshared) { struct dcss_segment *seg; unsigned long start_addr, end_addr, dummy; int rc, diag_cc; start_addr = end_addr = 0; mutex_lock(&dcss_lock); seg = segment_by_name (name); if (seg == NULL) { rc = -EINVAL; goto out_unlock; } if (do_nonshared == seg->do_nonshared) { pr_info("DCSS %s is already in the requested access " "mode\n", name); rc = 0; goto out_unlock; } if (refcount_read(&seg->ref_count) != 1) { pr_warn("DCSS %s is in use and cannot be reloaded\n", name); rc = -EAGAIN; goto out_unlock; } release_resource(seg->res); if (do_nonshared) seg->res->flags &= ~IORESOURCE_READONLY; 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)) { pr_warn("DCSS %s overlaps with used memory resources and cannot be reloaded\n", name); rc = -EBUSY; kfree(seg->res); 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; } if (diag_cc > 1) { pr_warn("Reloading DCSS %s failed with rc=%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_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(&purgeseg_scode, seg->dcss_name, &dummy, &dummy); kfree(seg); out_unlock: mutex_unlock(&dcss_lock); return rc; } /* * Decrease the use count of a DCSS segment and remove * it from the address space if nobody is using it * any longer. */ void segment_unload(char *name) { unsigned long dummy; struct dcss_segment *seg; if (!MACHINE_IS_VM) return; mutex_lock(&dcss_lock); seg = segment_by_name (name); if (seg == NULL) { pr_err("Unloading unknown DCSS %s failed\n", name); goto out_unlock; } if (!refcount_dec_and_test(&seg->ref_count)) goto out_unlock; release_resource(seg->res); kfree(seg->res); vmem_remove_mapping(seg->start_addr, seg->end - seg->start_addr + 1); list_del(&seg->list); dcss_diag(&purgeseg_scode, seg->dcss_name, &dummy, &dummy); kfree(seg); out_unlock: mutex_unlock(&dcss_lock); } /* * save segment content permanently */ void segment_save(char *name) { struct dcss_segment *seg; char cmd1[160]; char cmd2[80]; int i, response; if (!MACHINE_IS_VM) return; mutex_lock(&dcss_lock); seg = segment_by_name (name); if (seg == NULL) { pr_err("Saving unknown DCSS %s failed\n", name); goto out; } sprintf(cmd1, "DEFSEG %s", name); for (i=0; i<seg->segcnt; i++) { 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]); } sprintf(cmd2, "SAVESEG %s", name); response = 0; cpcmd(cmd1, NULL, 0, &response); if (response) { pr_err("Saving a DCSS failed with DEFSEG response code " "%i\n", response); goto out; } cpcmd(cmd2, NULL, 0, &response); if (response) { pr_err("Saving a DCSS failed with SAVESEG response code " "%i\n", response); goto out; } out: mutex_unlock(&dcss_lock); } /* * print appropriate error message for segment_load()/segment_type() * return code */ void segment_warning(int rc, char *seg_name) { switch (rc) { case -ENOENT: pr_err("DCSS %s cannot be loaded or queried\n", seg_name); break; case -ENOSYS: pr_err("DCSS %s cannot be loaded or queried without " "z/VM\n", seg_name); break; case -EIO: pr_err("Loading or querying DCSS %s resulted in a " "hardware error\n", seg_name); break; case -EOPNOTSUPP: pr_err("DCSS %s has multiple page ranges and cannot be " "loaded or queried\n", seg_name); break; case -EBUSY: pr_err("%s needs used memory resources and cannot be " "loaded or queried\n", seg_name); break; case -EPERM: pr_err("DCSS %s is already loaded in a different access " "mode\n", seg_name); break; case -ENOMEM: pr_err("There is not enough memory to load or query " "DCSS %s\n", seg_name); break; case -ERANGE: pr_err("DCSS %s exceeds the kernel mapping range (%lu) " "and cannot be loaded\n", seg_name, VMEM_MAX_PHYS); break; default: break; } } EXPORT_SYMBOL(segment_load); EXPORT_SYMBOL(segment_unload); EXPORT_SYMBOL(segment_save); EXPORT_SYMBOL(segment_type); EXPORT_SYMBOL(segment_modify_shared); EXPORT_SYMBOL(segment_warning);