From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Wed, 5 Aug 2015 17:04:01 -0300 Subject: Initial import --- arch/s390/mm/extmem.c | 763 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 763 insertions(+) create mode 100644 arch/s390/mm/extmem.c (limited to 'arch/s390/mm/extmem.c') diff --git a/arch/s390/mm/extmem.c b/arch/s390/mm/extmem.c new file mode 100644 index 000000000..23c496957 --- /dev/null +++ b/arch/s390/mm/extmem.c @@ -0,0 +1,763 @@ +/* + * Author(s)......: Carsten Otte + * Rob M van der Heij + * Steven Shultz + * Bugreports.to..: + * Copyright IBM Corp. 2002, 2004 + */ + +#define KMSG_COMPONENT "extmem" +#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define DCSS_LOADSHR 0x00 +#define DCSS_LOADNSR 0x04 +#define DCSS_PURGESEG 0x08 +#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 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 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_old 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[15]; + unsigned long start_addr; + unsigned long end; + atomic_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, 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) +{ + char *name = kmalloc(8 * sizeof(char), GFP_KERNEL | 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; + } + /* 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 + * 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; + + if (scode_set == 0) { + rc = dcss_set_subcodes(); + if (rc < 0) + return rc; + scode_set = 1; + } + rx = (unsigned long) parameter; + ry = (unsigned long) *func; + + /* 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"); + *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_warning("Querying a DCSS type failed with rc=%ld\n", vmrc); + rc = dcss_diag_translate_rc (vmrc); + goto out_free; + } + + /* 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(*qout_old), GFP_KERNEL | 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); + } + 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; isegcnt; 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 (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) + goto out_free; + + seg->res = kzalloc(sizeof(struct resource), GFP_KERNEL); + if (seg->res == NULL) { + rc = -ENOMEM; + goto out_shared; + } + 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'; + strncat(seg->res_name, " (DCSS)", 7); + 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; + if (request_resource(&iomem_resource, seg->res)) { + rc = -EBUSY; + kfree(seg->res); + goto out_shared; + } + + 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_resource; + } + if (diag_cc > 1) { + pr_warning("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_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); + *addr = seg->start_addr; + *end = seg->end; + if (do_nonshared) + pr_info("DCSS %s of range %p to %p 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 %p to %p 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_resource: + release_resource(seg->res); + kfree(seg->res); + out_shared: + vmem_remove_mapping(seg->start_addr, seg->end - seg->start_addr + 1); + 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 + * -ENOSPC : segment cannot be used (overlaps with storage) + * -EBUSY : segment can temporarily not be used (overlaps with dcss) + * -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) { + atomic_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 (atomic_read (&seg->ref_count) != 1) { + pr_warning("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_warning("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_warning("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 (atomic_dec_return(&seg->ref_count) != 0) + 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; isegcnt; 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 -ENOSPC: + pr_err("DCSS %s overlaps with used storage and cannot " + "be loaded\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); -- cgit v1.2.3-54-g00ecf