/* Copyright 2013-2014 IBM Corp. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or * implied. * See the License for the specific language governing permissions and * limitations under the License. */ #include #include #include #include #include #include #include #include #include #include /* Mask of bits to clear in HMER before an access */ #define HMER_CLR_MASK (~(SPR_HMER_XSCOM_FAIL | \ SPR_HMER_XSCOM_DONE | \ SPR_HMER_XSCOM_STATUS)) DEFINE_LOG_ENTRY(OPAL_RC_XSCOM_RW, OPAL_PLATFORM_ERR_EVT, OPAL_XSCOM, OPAL_CEC_HARDWARE, OPAL_PREDICTIVE_ERR_GENERAL, OPAL_NA); DEFINE_LOG_ENTRY(OPAL_RC_XSCOM_INDIRECT_RW, OPAL_PLATFORM_ERR_EVT, OPAL_XSCOM, OPAL_CEC_HARDWARE, OPAL_PREDICTIVE_ERR_GENERAL, OPAL_NA); DEFINE_LOG_ENTRY(OPAL_RC_XSCOM_RESET, OPAL_PLATFORM_ERR_EVT, OPAL_XSCOM, OPAL_CEC_HARDWARE, OPAL_PREDICTIVE_ERR_GENERAL, OPAL_NA); DEFINE_LOG_ENTRY(OPAL_RC_XSCOM_BUSY, OPAL_PLATFORM_ERR_EVT, OPAL_XSCOM, OPAL_CEC_HARDWARE, OPAL_PREDICTIVE_ERR_GENERAL, OPAL_NA); /* xscom details to trigger xstop */ static struct { uint64_t addr; uint64_t fir_bit; } xstop_xscom; /* * Locking notes: * * We used to have a per-target lock. However due to errata HW822317 * we can have issues on the issuer side if multiple threads try to * send XSCOMs simultaneously (HMER responses get mixed up), so just * use a global lock instead */ static struct lock xscom_lock = LOCK_UNLOCKED; static inline void *xscom_addr(uint32_t gcid, uint32_t pcb_addr) { struct proc_chip *chip = get_chip(gcid); uint64_t addr; assert(chip); addr = chip->xscom_base; if (proc_gen <= proc_gen_p8) { addr |= ((uint64_t)pcb_addr << 4) & ~0xfful; addr |= (pcb_addr << 3) & 0x78; } else addr |= ((uint64_t)pcb_addr << 3); return (void *)addr; } static uint64_t xscom_wait_done(void) { uint64_t hmer; do hmer = mfspr(SPR_HMER); while(!(hmer & SPR_HMER_XSCOM_DONE)); /* * HW822317: We need to read a second time as the actual * status can be delayed by 1 cycle after DONE */ return mfspr(SPR_HMER); } static void xscom_reset(uint32_t gcid) { u64 hmer; /* Clear errors in HMER */ mtspr(SPR_HMER, HMER_CLR_MASK); /* First we need to write 0 to a register on our chip */ out_be64(xscom_addr(this_cpu()->chip_id, 0x202000f), 0); hmer = xscom_wait_done(); if (hmer & SPR_HMER_XSCOM_FAIL) goto fail; /* Then we need to clear those two other registers on the target */ out_be64(xscom_addr(gcid, 0x2020007), 0); hmer = xscom_wait_done(); if (hmer & SPR_HMER_XSCOM_FAIL) goto fail; out_be64(xscom_addr(gcid, 0x2020009), 0); hmer = xscom_wait_done(); if (hmer & SPR_HMER_XSCOM_FAIL) goto fail; return; fail: /* Fatal error resetting XSCOM */ log_simple_error(&e_info(OPAL_RC_XSCOM_RESET), "XSCOM: Fatal error resetting engine after failed access !\n"); /* XXX Generate error log ? attn ? panic ? * If we decide to panic, change the above severity to PANIC */ } static int64_t xscom_handle_error(uint64_t hmer, uint32_t gcid, uint32_t pcb_addr, bool is_write, int64_t retries) { struct timespec ts; unsigned int stat = GETFIELD(SPR_HMER_XSCOM_STATUS, hmer); int64_t rc = OPAL_HARDWARE; /* XXX Figure out error codes from doc and error * recovery procedures */ switch(stat) { case 1: /* * XSCOM engine is blocked, need to retry. Reset XSCOM * engine after crossing retry threshold before * retrying again. */ if (retries && !(retries % XSCOM_BUSY_RESET_THRESHOLD)) { prlog(PR_NOTICE, "XSCOM: Busy even after %d retries, " "resetting XSCOM now. Total retries = %lld\n", XSCOM_BUSY_RESET_THRESHOLD, retries); xscom_reset(gcid); /* * Its observed that sometimes immediate retry of * XSCOM operation returns wrong data. Adding a * delay for XSCOM reset to be effective. Delay of * 10 ms is found to be working fine experimentally. * FIXME: Replace 10ms delay by exact delay needed * or other alternate method to confirm XSCOM reset * completion, after checking from HW folks. */ ts.tv_sec = 0; ts.tv_nsec = 10 * 1000; nanosleep_nopoll(&ts, NULL); } /* Log error if we have retried enough and its still busy */ if (retries == XSCOM_BUSY_MAX_RETRIES) log_simple_error(&e_info(OPAL_RC_XSCOM_BUSY), "XSCOM: %s-busy error gcid=0x%x pcb_addr=0x%x " "stat=0x%x\n", is_write ? "write" : "read", gcid, pcb_addr, stat); return OPAL_XSCOM_BUSY; case 2: /* CPU is asleep, reset XSCOM engine and return */ xscom_reset(gcid); return OPAL_XSCOM_CHIPLET_OFF; case 3: /* Partial good */ rc = OPAL_XSCOM_PARTIAL_GOOD; break; case 4: /* Invalid address / address error */ rc = OPAL_XSCOM_ADDR_ERROR; break; case 5: /* Clock error */ rc = OPAL_XSCOM_CLOCK_ERROR; break; case 6: /* Parity error */ rc = OPAL_XSCOM_PARITY_ERROR; break; case 7: /* Time out */ rc = OPAL_XSCOM_TIMEOUT; break; } /* XXX: Create error log entry ? */ log_simple_error(&e_info(OPAL_RC_XSCOM_RW), "XSCOM: %s error gcid=0x%x pcb_addr=0x%x stat=0x%x\n", is_write ? "write" : "read", gcid, pcb_addr, stat); /* We need to reset the XSCOM or we'll hang on the next access */ xscom_reset(gcid); /* Non recovered ... just fail */ return rc; } static void xscom_handle_ind_error(uint64_t data, uint32_t gcid, uint64_t pcb_addr, bool is_write) { unsigned int stat = GETFIELD(XSCOM_DATA_IND_ERR, data); bool timeout = !(data & XSCOM_DATA_IND_COMPLETE); /* XXX: Create error log entry ? */ if (timeout) log_simple_error(&e_info(OPAL_RC_XSCOM_INDIRECT_RW), "XSCOM: indirect %s timeout, gcid=0x%x pcb_addr=0x%llx" " stat=0x%x\n", is_write ? "write" : "read", gcid, pcb_addr, stat); else log_simple_error(&e_info(OPAL_RC_XSCOM_INDIRECT_RW), "XSCOM: indirect %s error, gcid=0x%x pcb_addr=0x%llx" " stat=0x%x\n", is_write ? "write" : "read", gcid, pcb_addr, stat); } static bool xscom_gcid_ok(uint32_t gcid) { return get_chip(gcid) != NULL; } /* * Low level XSCOM access functions, perform a single direct xscom * access via MMIO */ static int __xscom_read(uint32_t gcid, uint32_t pcb_addr, uint64_t *val) { uint64_t hmer; int64_t ret, retries; if (!xscom_gcid_ok(gcid)) { prerror("%s: invalid XSCOM gcid 0x%x\n", __func__, gcid); return OPAL_PARAMETER; } for (retries = 0; retries <= XSCOM_BUSY_MAX_RETRIES; retries++) { /* Clear status bits in HMER (HMER is special * writing to it *ands* bits */ mtspr(SPR_HMER, HMER_CLR_MASK); /* Read value from SCOM */ *val = in_be64(xscom_addr(gcid, pcb_addr)); /* Wait for done bit */ hmer = xscom_wait_done(); /* Check for error */ if (!(hmer & SPR_HMER_XSCOM_FAIL)) return OPAL_SUCCESS; /* Handle error and possibly eventually retry */ ret = xscom_handle_error(hmer, gcid, pcb_addr, false, retries); if (ret != OPAL_BUSY) break; } prerror("XSCOM: Read failed, ret = %lld\n", ret); return ret; } static int __xscom_write(uint32_t gcid, uint32_t pcb_addr, uint64_t val) { uint64_t hmer; int64_t ret, retries = 0; if (!xscom_gcid_ok(gcid)) { prerror("%s: invalid XSCOM gcid 0x%x\n", __func__, gcid); return OPAL_PARAMETER; } for (retries = 0; retries <= XSCOM_BUSY_MAX_RETRIES; retries++) { /* Clear status bits in HMER (HMER is special * writing to it *ands* bits */ mtspr(SPR_HMER, HMER_CLR_MASK); /* Write value to SCOM */ out_be64(xscom_addr(gcid, pcb_addr), val); /* Wait for done bit */ hmer = xscom_wait_done(); /* Check for error */ if (!(hmer & SPR_HMER_XSCOM_FAIL)) return OPAL_SUCCESS; /* Handle error and possibly eventually retry */ ret = xscom_handle_error(hmer, gcid, pcb_addr, true, retries); if (ret != OPAL_BUSY) break; } prerror("XSCOM: Write failed, ret = %lld\n", ret); return ret; } /* * Indirect XSCOM access functions */ static int xscom_indirect_read(uint32_t gcid, uint64_t pcb_addr, uint64_t *val) { uint32_t addr; uint64_t data; int rc, retries; if (proc_gen < proc_gen_p8) { *val = (uint64_t)-1; return OPAL_UNSUPPORTED; } /* Write indirect address */ addr = pcb_addr & 0x7fffffff; data = XSCOM_DATA_IND_READ | (pcb_addr & XSCOM_ADDR_IND_ADDR); rc = __xscom_write(gcid, addr, data); if (rc) goto bail; /* Wait for completion */ for (retries = 0; retries < XSCOM_IND_MAX_RETRIES; retries++) { rc = __xscom_read(gcid, addr, &data); if (rc) goto bail; if ((data & XSCOM_DATA_IND_COMPLETE) && ((data & XSCOM_DATA_IND_ERR) == 0)) { *val = data & XSCOM_DATA_IND_DATA; break; } if ((data & XSCOM_DATA_IND_COMPLETE) || (retries >= XSCOM_IND_MAX_RETRIES)) { xscom_handle_ind_error(data, gcid, pcb_addr, false); rc = OPAL_HARDWARE; goto bail; } } bail: if (rc) *val = (uint64_t)-1; return rc; } static int xscom_indirect_write(uint32_t gcid, uint64_t pcb_addr, uint64_t val) { uint32_t addr; uint64_t data; int rc, retries; if (proc_gen < proc_gen_p8) return OPAL_UNSUPPORTED; /* Write indirect address & data */ addr = pcb_addr & 0x7fffffff; data = pcb_addr & XSCOM_ADDR_IND_ADDR; data |= val & XSCOM_ADDR_IND_DATA; rc = __xscom_write(gcid, addr, data); if (rc) goto bail; /* Wait for completion */ for (retries = 0; retries < XSCOM_IND_MAX_RETRIES; retries++) { rc = __xscom_read(gcid, addr, &data); if (rc) goto bail; if ((data & XSCOM_DATA_IND_COMPLETE) && ((data & XSCOM_DATA_IND_ERR) == 0)) break; if ((data & XSCOM_DATA_IND_COMPLETE) || (retries >= XSCOM_IND_MAX_RETRIES)) { xscom_handle_ind_error(data, gcid, pcb_addr, true); rc = OPAL_HARDWARE; goto bail; } } bail: return rc; } static uint32_t xscom_decode_chiplet(uint32_t partid, uint64_t *pcb_addr) { uint32_t gcid = (partid & 0x0fffffff) >> 4; uint32_t core = partid & 0xf; if (proc_gen == proc_gen_p9) { /* XXX Not supported */ *pcb_addr = 0; } else { *pcb_addr |= P8_EX_PCB_SLAVE_BASE; *pcb_addr |= core << 24; } return gcid; } void _xscom_lock(void) { lock(&xscom_lock); } void _xscom_unlock(void) { unlock(&xscom_lock); } /* * External API */ int _xscom_read(uint32_t partid, uint64_t pcb_addr, uint64_t *val, bool take_lock) { uint32_t gcid; int rc; if (!opal_addr_valid(val)) return OPAL_PARAMETER; /* Due to a bug in some versions of the PRD wrapper app, errors * might not be properly forwarded to PRD, in which case the data * set here will be used. Rather than a random value let's thus * initialize the data to a known clean state. */ *val = 0xdeadbeefdeadbeefull; /* Handle part ID decoding */ switch(partid >> 28) { case 0: /* Normal processor chip */ gcid = partid; break; case 8: /* Centaur */ return centaur_xscom_read(partid, pcb_addr, val); case 4: /* EX chiplet */ gcid = xscom_decode_chiplet(partid, &pcb_addr); if (pcb_addr == 0) return OPAL_UNSUPPORTED; break; default: /** * @fwts-label XSCOMReadInvalidPartID * @fwts-advice xscom_read was called with an invalid partid. * There's likely a bug somewhere in the stack that's causing * someone to try an xscom_read on something that isn't a * processor, Centaur or EX chiplet. */ prerror("%s: invalid XSCOM partid 0x%x\n", __func__, partid); return OPAL_PARAMETER; } /* HW822317 requires us to do global locking */ if (take_lock) lock(&xscom_lock); /* Direct vs indirect access */ if (pcb_addr & XSCOM_ADDR_IND_FLAG) rc = xscom_indirect_read(gcid, pcb_addr, val); else rc = __xscom_read(gcid, pcb_addr & 0x7fffffff, val); /* Unlock it */ if (take_lock) unlock(&xscom_lock); return rc; } opal_call(OPAL_XSCOM_READ, xscom_read, 3); int _xscom_write(uint32_t partid, uint64_t pcb_addr, uint64_t val, bool take_lock) { uint32_t gcid; int rc; /* Handle part ID decoding */ switch(partid >> 28) { case 0: /* Normal processor chip */ gcid = partid; break; case 8: /* Centaur */ return centaur_xscom_write(partid, pcb_addr, val); case 4: /* EX chiplet */ gcid = xscom_decode_chiplet(partid, &pcb_addr); break; default: /** * @fwts-label XSCOMWriteInvalidPartID * @fwts-advice xscom_write was called with an invalid partid. * There's likely a bug somewhere in the stack that's causing * someone to try an xscom_write on something that isn't a * processor, Centaur or EX chiplet. */ prerror("%s: invalid XSCOM partid 0x%x\n", __func__, partid); return OPAL_PARAMETER; } /* HW822317 requires us to do global locking */ if (take_lock) lock(&xscom_lock); /* Direct vs indirect access */ if (pcb_addr & XSCOM_ADDR_IND_FLAG) rc = xscom_indirect_write(gcid, pcb_addr, val); else rc = __xscom_write(gcid, pcb_addr & 0x7fffffff, val); /* Unlock it */ if (take_lock) unlock(&xscom_lock); return rc; } opal_call(OPAL_XSCOM_WRITE, xscom_write, 3); int xscom_readme(uint64_t pcb_addr, uint64_t *val) { return xscom_read(this_cpu()->chip_id, pcb_addr, val); } int xscom_writeme(uint64_t pcb_addr, uint64_t val) { return xscom_write(this_cpu()->chip_id, pcb_addr, val); } int64_t xscom_read_cfam_chipid(uint32_t partid, uint32_t *chip_id) { uint64_t val; int64_t rc = OPAL_SUCCESS; /* Mambo chip model lacks the f000f register, just make * something up */ if (chip_quirk(QUIRK_NO_F000F)) { if (proc_gen == proc_gen_p9) val = 0x100D104980000000UL; /* P9 Nimbus DD1.0 */ else val = 0x221EF04980000000UL; /* P8 Murano DD2.1 */ } else rc = xscom_read(partid, 0xf000f, &val); /* Extract CFAM id */ if (rc == OPAL_SUCCESS) *chip_id = (uint32_t)(val >> 44); return rc; } static void xscom_init_chip_info(struct proc_chip *chip) { uint32_t val; int64_t rc; rc = xscom_read_cfam_chipid(chip->id, &val); if (rc) { prerror("XSCOM: Error %lld reading 0xf000f register\n", rc); /* We leave chip type to UNKNOWN */ return; } /* Identify chip */ switch(val & 0xff) { case 0xf9: chip->type = PROC_CHIP_P7; assert(proc_gen == proc_gen_p7); break; case 0xe8: chip->type = PROC_CHIP_P7P; assert(proc_gen == proc_gen_p7); break; case 0xef: chip->type = PROC_CHIP_P8_MURANO; assert(proc_gen == proc_gen_p8); break; case 0xea: chip->type = PROC_CHIP_P8_VENICE; assert(proc_gen == proc_gen_p8); break; case 0xd3: chip->type = PROC_CHIP_P8_NAPLES; assert(proc_gen == proc_gen_p8); break; case 0xd1: chip->type = PROC_CHIP_P9_NIMBUS; assert(proc_gen == proc_gen_p9); break; case 0xd4: chip->type = PROC_CHIP_P9_CUMULUS; assert(proc_gen == proc_gen_p9); break; default: printf("CHIP: Unknown chip type 0x%02x !!!\n", (unsigned char)(val & 0xff)); } /* Get EC level from CFAM ID */ chip->ec_level = ((val >> 16) & 0xf) << 4; chip->ec_level |= (val >> 8) & 0xf; } /* * This function triggers xstop by writing to XSCOM. * Machine would enter xstop state post completion of this. */ int64_t xscom_trigger_xstop(void) { int rc = OPAL_UNSUPPORTED; if (xstop_xscom.addr) rc = xscom_writeme(xstop_xscom.addr, PPC_BIT(xstop_xscom.fir_bit)); return rc; } void xscom_init(void) { struct dt_node *xn; const struct dt_property *p; dt_for_each_compatible(dt_root, xn, "ibm,xscom") { uint32_t gcid = dt_get_chip_id(xn); const struct dt_property *reg; struct proc_chip *chip; const char *chip_name; static const char *chip_names[] = { "UNKNOWN", "P7", "P7+", "P8E", "P8", "P8NVL", "P9N", "P9C" }; chip = get_chip(gcid); assert(chip); /* XXX We need a proper address parsing. For now, we just * "know" that we are looking at a u64 */ reg = dt_find_property(xn, "reg"); assert(reg); chip->xscom_base = dt_translate_address(xn, 0, NULL); /* Grab processor type and EC level */ xscom_init_chip_info(chip); if (chip->type >= ARRAY_SIZE(chip_names)) chip_name = "INVALID"; else chip_name = chip_names[chip->type]; printf("XSCOM: chip 0x%x at 0x%llx [%s DD%x.%x]\n", gcid, chip->xscom_base, chip_name, chip->ec_level >> 4, chip->ec_level & 0xf); } /* Collect details to trigger xstop via XSCOM write */ p = dt_find_property(dt_root, "ibm,sw-checkstop-fir"); if (p) { xstop_xscom.addr = dt_property_get_cell(p, 0); xstop_xscom.fir_bit = dt_property_get_cell(p, 1); prlog(PR_INFO, "XSTOP: XSCOM addr = 0x%llx, FIR bit = %lld\n", xstop_xscom.addr, xstop_xscom.fir_bit); } else prlog(PR_INFO, "XSTOP: ibm,sw-checkstop-fir prop not found\n"); } void xscom_used_by_console(void) { xscom_lock.in_con_path = true; /* * Some other processor might hold it without having * disabled the console locally so let's make sure that * is over by taking/releasing the lock ourselves */ lock(&xscom_lock); unlock(&xscom_lock); } bool xscom_ok(void) { return !lock_held_by_me(&xscom_lock); }