--- /dev/null
+/*
+ * SN Platform GRU Driver
+ *
+ * KERNEL SERVICES THAT USE THE GRU
+ *
+ * Copyright (c) 2008 Silicon Graphics, Inc. All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/slab.h>
+#include <linux/mm.h>
+#include <linux/smp_lock.h>
+#include <linux/spinlock.h>
+#include <linux/device.h>
+#include <linux/miscdevice.h>
+#include <linux/proc_fs.h>
+#include <linux/interrupt.h>
+#include <linux/uaccess.h>
+#include "gru.h"
+#include "grulib.h"
+#include "grutables.h"
+#include "grukservices.h"
+#include "gru_instructions.h"
+#include <asm/uv/uv_hub.h>
+
+/*
+ * Kernel GRU Usage
+ *
+ * The following is an interim algorithm for management of kernel GRU
+ * resources. This will likely be replaced when we better understand the
+ * kernel/user requirements.
+ *
+ * At boot time, the kernel permanently reserves a fixed number of
+ * CBRs/DSRs for each cpu to use. The resources are all taken from
+ * the GRU chiplet 1 on the blade. This leaves the full set of resources
+ * of chiplet 0 available to be allocated to a single user.
+ */
+
+/* Blade percpu resources PERMANENTLY reserved for kernel use */
+#define GRU_NUM_KERNEL_CBR 1
+#define GRU_NUM_KERNEL_DSR_BYTES 256
+#define KERNEL_CTXNUM 15
+
+/* GRU instruction attributes for all instructions */
+#define IMA IMA_CB_DELAY
+
+/* GRU cacheline size is always 64 bytes - even on arches with 128 byte lines */
+#define __gru_cacheline_aligned__ \
+ __attribute__((__aligned__(GRU_CACHE_LINE_BYTES)))
+
+#define MAGIC 0x1234567887654321UL
+
+/* Default retry count for GRU errors on kernel instructions */
+#define EXCEPTION_RETRY_LIMIT 3
+
+/* Status of message queue sections */
+#define MQS_EMPTY 0
+#define MQS_FULL 1
+#define MQS_NOOP 2
+
+/*----------------- RESOURCE MANAGEMENT -------------------------------------*/
+/* optimized for x86_64 */
+struct message_queue {
+ union gru_mesqhead head __gru_cacheline_aligned__; /* CL 0 */
+ int qlines; /* DW 1 */
+ long hstatus[2];
+ void *next __gru_cacheline_aligned__;/* CL 1 */
+ void *limit;
+ void *start;
+ void *start2;
+ char data ____cacheline_aligned; /* CL 2 */
+};
+
+/* First word in every message - used by mesq interface */
+struct message_header {
+ char present;
+ char present2;
+ char lines;
+ char fill;
+};
+
+#define QLINES(mq) ((mq) + offsetof(struct message_queue, qlines))
+#define HSTATUS(mq, h) ((mq) + offsetof(struct message_queue, hstatus[h]))
+
+static int gru_get_cpu_resources(int dsr_bytes, void **cb, void **dsr)
+{
+ struct gru_blade_state *bs;
+ int lcpu;
+
+ BUG_ON(dsr_bytes > GRU_NUM_KERNEL_DSR_BYTES);
+ preempt_disable();
+ bs = gru_base[uv_numa_blade_id()];
+ lcpu = uv_blade_processor_id();
+ *cb = bs->kernel_cb + lcpu * GRU_HANDLE_STRIDE;
+ *dsr = bs->kernel_dsr + lcpu * GRU_NUM_KERNEL_DSR_BYTES;
+ return 0;
+}
+
+static void gru_free_cpu_resources(void *cb, void *dsr)
+{
+ preempt_enable();
+}
+
+int gru_get_cb_exception_detail(void *cb,
+ struct control_block_extended_exc_detail *excdet)
+{
+ struct gru_control_block_extended *cbe;
+
+ cbe = get_cbe(GRUBASE(cb), get_cb_number(cb));
+ excdet->opc = cbe->opccpy;
+ excdet->exopc = cbe->exopccpy;
+ excdet->ecause = cbe->ecause;
+ excdet->exceptdet0 = cbe->idef1upd;
+ excdet->exceptdet1 = cbe->idef3upd;
+ return 0;
+}
+
+char *gru_get_cb_exception_detail_str(int ret, void *cb,
+ char *buf, int size)
+{
+ struct gru_control_block_status *gen = (void *)cb;
+ struct control_block_extended_exc_detail excdet;
+
+ if (ret > 0 && gen->istatus == CBS_EXCEPTION) {
+ gru_get_cb_exception_detail(cb, &excdet);
+ snprintf(buf, size,
+ "GRU exception: cb %p, opc %d, exopc %d, ecause 0x%x,"
+ "excdet0 0x%lx, excdet1 0x%x",
+ gen, excdet.opc, excdet.exopc, excdet.ecause,
+ excdet.exceptdet0, excdet.exceptdet1);
+ } else {
+ snprintf(buf, size, "No exception");
+ }
+ return buf;
+}
+
+static int gru_wait_idle_or_exception(struct gru_control_block_status *gen)
+{
+ while (gen->istatus >= CBS_ACTIVE) {
+ cpu_relax();
+ barrier();
+ }
+ return gen->istatus;
+}
+
+static int gru_retry_exception(void *cb)
+{
+ struct gru_control_block_status *gen = (void *)cb;
+ struct control_block_extended_exc_detail excdet;
+ int retry = EXCEPTION_RETRY_LIMIT;
+
+ while (1) {
+ if (gru_get_cb_message_queue_substatus(cb))
+ break;
+ if (gru_wait_idle_or_exception(gen) == CBS_IDLE)
+ return CBS_IDLE;
+
+ gru_get_cb_exception_detail(cb, &excdet);
+ if (excdet.ecause & ~EXCEPTION_RETRY_BITS)
+ break;
+ if (retry-- == 0)
+ break;
+ gen->icmd = 1;
+ gru_flush_cache(gen);
+ }
+ return CBS_EXCEPTION;
+}
+
+int gru_check_status_proc(void *cb)
+{
+ struct gru_control_block_status *gen = (void *)cb;
+ int ret;
+
+ ret = gen->istatus;
+ if (ret != CBS_EXCEPTION)
+ return ret;
+ return gru_retry_exception(cb);
+
+}
+
+int gru_wait_proc(void *cb)
+{
+ struct gru_control_block_status *gen = (void *)cb;
+ int ret;
+
+ ret = gru_wait_idle_or_exception(gen);
+ if (ret == CBS_EXCEPTION)
+ ret = gru_retry_exception(cb);
+
+ return ret;
+}
+
+void gru_abort(int ret, void *cb, char *str)
+{
+ char buf[GRU_EXC_STR_SIZE];
+
+ panic("GRU FATAL ERROR: %s - %s\n", str,
+ gru_get_cb_exception_detail_str(ret, cb, buf, sizeof(buf)));
+}
+
+void gru_wait_abort_proc(void *cb)
+{
+ int ret;
+
+ ret = gru_wait_proc(cb);
+ if (ret)
+ gru_abort(ret, cb, "gru_wait_abort");
+}
+
+
+/*------------------------------ MESSAGE QUEUES -----------------------------*/
+
+/* Internal status . These are NOT returned to the user. */
+#define MQIE_AGAIN -1 /* try again */
+
+
+/*
+ * Save/restore the "present" flag that is in the second line of 2-line
+ * messages
+ */
+static inline int get_present2(void *p)
+{
+ struct message_header *mhdr = p + GRU_CACHE_LINE_BYTES;
+ return mhdr->present;
+}
+
+static inline void restore_present2(void *p, int val)
+{
+ struct message_header *mhdr = p + GRU_CACHE_LINE_BYTES;
+ mhdr->present = val;
+}
+
+/*
+ * Create a message queue.
+ * qlines - message queue size in cache lines. Includes 2-line header.
+ */
+int gru_create_message_queue(void *p, unsigned int bytes)
+{
+ struct message_queue *mq = p;
+ unsigned int qlines;
+
+ qlines = bytes / GRU_CACHE_LINE_BYTES - 2;
+ memset(mq, 0, bytes);
+ mq->start = &mq->data;
+ mq->start2 = &mq->data + (qlines / 2 - 1) * GRU_CACHE_LINE_BYTES;
+ mq->next = &mq->data;
+ mq->limit = &mq->data + (qlines - 2) * GRU_CACHE_LINE_BYTES;
+ mq->qlines = qlines;
+ mq->hstatus[0] = 0;
+ mq->hstatus[1] = 1;
+ mq->head = gru_mesq_head(2, qlines / 2 + 1);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(gru_create_message_queue);
+
+/*
+ * Send a NOOP message to a message queue
+ * Returns:
+ * 0 - if queue is full after the send. This is the normal case
+ * but various races can change this.
+ * -1 - if mesq sent successfully but queue not full
+ * >0 - unexpected error. MQE_xxx returned
+ */
+static int send_noop_message(void *cb,
+ unsigned long mq, void *mesg)
+{
+ const struct message_header noop_header = {
+ .present = MQS_NOOP, .lines = 1};
+ unsigned long m;
+ int substatus, ret;
+ struct message_header save_mhdr, *mhdr = mesg;
+
+ STAT(mesq_noop);
+ save_mhdr = *mhdr;
+ *mhdr = noop_header;
+ gru_mesq(cb, mq, gru_get_tri(mhdr), 1, IMA);
+ ret = gru_wait(cb);
+
+ if (ret) {
+ substatus = gru_get_cb_message_queue_substatus(cb);
+ switch (substatus) {
+ case CBSS_NO_ERROR:
+ STAT(mesq_noop_unexpected_error);
+ ret = MQE_UNEXPECTED_CB_ERR;
+ break;
+ case CBSS_LB_OVERFLOWED:
+ STAT(mesq_noop_lb_overflow);
+ ret = MQE_CONGESTION;
+ break;
+ case CBSS_QLIMIT_REACHED:
+ STAT(mesq_noop_qlimit_reached);
+ ret = 0;
+ break;
+ case CBSS_AMO_NACKED:
+ STAT(mesq_noop_amo_nacked);
+ ret = MQE_CONGESTION;
+ break;
+ case CBSS_PUT_NACKED:
+ STAT(mesq_noop_put_nacked);
+ m = mq + (gru_get_amo_value_head(cb) << 6);
+ gru_vstore(cb, m, gru_get_tri(mesg), XTYPE_CL, 1, 1,
+ IMA);
+ if (gru_wait(cb) == CBS_IDLE)
+ ret = MQIE_AGAIN;
+ else
+ ret = MQE_UNEXPECTED_CB_ERR;
+ break;
+ case CBSS_PAGE_OVERFLOW:
+ default:
+ BUG();
+ }
+ }
+ *mhdr = save_mhdr;
+ return ret;
+}
+
+/*
+ * Handle a gru_mesq full.
+ */
+static int send_message_queue_full(void *cb,
+ unsigned long mq, void *mesg, int lines)
+{
+ union gru_mesqhead mqh;
+ unsigned int limit, head;
+ unsigned long avalue;
+ int half, qlines, save;
+
+ /* Determine if switching to first/second half of q */
+ avalue = gru_get_amo_value(cb);
+ head = gru_get_amo_value_head(cb);
+ limit = gru_get_amo_value_limit(cb);
+
+ /*
+ * Fetch "qlines" from the queue header. Since the queue may be
+ * in memory that can't be accessed using socket addresses, use
+ * the GRU to access the data. Use DSR space from the message.
+ */
+ save = *(int *)mesg;
+ gru_vload(cb, QLINES(mq), gru_get_tri(mesg), XTYPE_W, 1, 1, IMA);
+ if (gru_wait(cb) != CBS_IDLE)
+ goto cberr;
+ qlines = *(int *)mesg;
+ *(int *)mesg = save;
+ half = (limit != qlines);
+
+ if (half)
+ mqh = gru_mesq_head(qlines / 2 + 1, qlines);
+ else
+ mqh = gru_mesq_head(2, qlines / 2 + 1);
+
+ /* Try to get lock for switching head pointer */
+ gru_gamir(cb, EOP_IR_CLR, HSTATUS(mq, half), XTYPE_DW, IMA);
+ if (gru_wait(cb) != CBS_IDLE)
+ goto cberr;
+ if (!gru_get_amo_value(cb)) {
+ STAT(mesq_qf_locked);
+ return MQE_QUEUE_FULL;
+ }
+
+ /* Got the lock. Send optional NOP if queue not full, */
+ if (head != limit) {
+ if (send_noop_message(cb, mq, mesg)) {
+ gru_gamir(cb, EOP_IR_INC, HSTATUS(mq, half),
+ XTYPE_DW, IMA);
+ if (gru_wait(cb) != CBS_IDLE)
+ goto cberr;
+ STAT(mesq_qf_noop_not_full);
+ return MQIE_AGAIN;
+ }
+ avalue++;
+ }
+
+ /* Then flip queuehead to other half of queue. */
+ gru_gamer(cb, EOP_ERR_CSWAP, mq, XTYPE_DW, mqh.val, avalue, IMA);
+ if (gru_wait(cb) != CBS_IDLE)
+ goto cberr;
+
+ /* If not successfully in swapping queue head, clear the hstatus lock */
+ if (gru_get_amo_value(cb) != avalue) {
+ STAT(mesq_qf_switch_head_failed);
+ gru_gamir(cb, EOP_IR_INC, HSTATUS(mq, half), XTYPE_DW, IMA);
+ if (gru_wait(cb) != CBS_IDLE)
+ goto cberr;
+ }
+ return MQIE_AGAIN;
+cberr:
+ STAT(mesq_qf_unexpected_error);
+ return MQE_UNEXPECTED_CB_ERR;
+}
+
+
+/*
+ * Handle a gru_mesq failure. Some of these failures are software recoverable
+ * or retryable.
+ */
+static int send_message_failure(void *cb,
+ unsigned long mq,
+ void *mesg,
+ int lines)
+{
+ int substatus, ret = 0;
+ unsigned long m;
+
+ substatus = gru_get_cb_message_queue_substatus(cb);
+ switch (substatus) {
+ case CBSS_NO_ERROR:
+ STAT(mesq_send_unexpected_error);
+ ret = MQE_UNEXPECTED_CB_ERR;
+ break;
+ case CBSS_LB_OVERFLOWED:
+ STAT(mesq_send_lb_overflow);
+ ret = MQE_CONGESTION;
+ break;
+ case CBSS_QLIMIT_REACHED:
+ STAT(mesq_send_qlimit_reached);
+ ret = send_message_queue_full(cb, mq, mesg, lines);
+ break;
+ case CBSS_AMO_NACKED:
+ STAT(mesq_send_amo_nacked);
+ ret = MQE_CONGESTION;
+ break;
+ case CBSS_PUT_NACKED:
+ STAT(mesq_send_put_nacked);
+ m =mq + (gru_get_amo_value_head(cb) << 6);
+ gru_vstore(cb, m, gru_get_tri(mesg), XTYPE_CL, lines, 1, IMA);
+ if (gru_wait(cb) == CBS_IDLE)
+ ret = MQE_OK;
+ else
+ ret = MQE_UNEXPECTED_CB_ERR;
+ break;
+ default:
+ BUG();
+ }
+ return ret;
+}
+
+/*
+ * Send a message to a message queue
+ * cb GRU control block to use to send message
+ * mq message queue
+ * mesg message. ust be vaddr within a GSEG
+ * bytes message size (<= 2 CL)
+ */
+int gru_send_message_gpa(unsigned long mq, void *mesg, unsigned int bytes)
+{
+ struct message_header *mhdr;
+ void *cb;
+ void *dsr;
+ int istatus, clines, ret;
+
+ STAT(mesq_send);
+ BUG_ON(bytes < sizeof(int) || bytes > 2 * GRU_CACHE_LINE_BYTES);
+
+ clines = (bytes + GRU_CACHE_LINE_BYTES - 1) / GRU_CACHE_LINE_BYTES;
+ if (gru_get_cpu_resources(bytes, &cb, &dsr))
+ return MQE_BUG_NO_RESOURCES;
+ memcpy(dsr, mesg, bytes);
+ mhdr = dsr;
+ mhdr->present = MQS_FULL;
+ mhdr->lines = clines;
+ if (clines == 2) {
+ mhdr->present2 = get_present2(mhdr);
+ restore_present2(mhdr, MQS_FULL);
+ }
+
+ do {
+ ret = MQE_OK;
+ gru_mesq(cb, mq, gru_get_tri(mhdr), clines, IMA);
+ istatus = gru_wait(cb);
+ if (istatus != CBS_IDLE)
+ ret = send_message_failure(cb, mq, dsr, clines);
+ } while (ret == MQIE_AGAIN);
+ gru_free_cpu_resources(cb, dsr);
+
+ if (ret)
+ STAT(mesq_send_failed);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(gru_send_message_gpa);
+
+/*
+ * Advance the receive pointer for the queue to the next message.
+ */
+void gru_free_message(void *rmq, void *mesg)
+{
+ struct message_queue *mq = rmq;
+ struct message_header *mhdr = mq->next;
+ void *next, *pnext;
+ int half = -1;
+ int lines = mhdr->lines;
+
+ if (lines == 2)
+ restore_present2(mhdr, MQS_EMPTY);
+ mhdr->present = MQS_EMPTY;
+
+ pnext = mq->next;
+ next = pnext + GRU_CACHE_LINE_BYTES * lines;
+ if (next == mq->limit) {
+ next = mq->start;
+ half = 1;
+ } else if (pnext < mq->start2 && next >= mq->start2) {
+ half = 0;
+ }
+
+ if (half >= 0)
+ mq->hstatus[half] = 1;
+ mq->next = next;
+}
+EXPORT_SYMBOL_GPL(gru_free_message);
+
+/*
+ * Get next message from message queue. Return NULL if no message
+ * present. User must call next_message() to move to next message.
+ * rmq message queue
+ */
+void *gru_get_next_message(void *rmq)
+{
+ struct message_queue *mq = rmq;
+ struct message_header *mhdr = mq->next;
+ int present = mhdr->present;
+
+ /* skip NOOP messages */
+ STAT(mesq_receive);
+ while (present == MQS_NOOP) {
+ gru_free_message(rmq, mhdr);
+ mhdr = mq->next;
+ present = mhdr->present;
+ }
+
+ /* Wait for both halves of 2 line messages */
+ if (present == MQS_FULL && mhdr->lines == 2 &&
+ get_present2(mhdr) == MQS_EMPTY)
+ present = MQS_EMPTY;
+
+ if (!present) {
+ STAT(mesq_receive_none);
+ return NULL;
+ }
+
+ if (mhdr->lines == 2)
+ restore_present2(mhdr, mhdr->present2);
+
+ return mhdr;
+}
+EXPORT_SYMBOL_GPL(gru_get_next_message);
+
+/* ---------------------- GRU DATA COPY FUNCTIONS ---------------------------*/
+
+/*
+ * Copy a block of data using the GRU resources
+ */
+int gru_copy_gpa(unsigned long dest_gpa, unsigned long src_gpa,
+ unsigned int bytes)
+{
+ void *cb;
+ void *dsr;
+ int ret;
+
+ STAT(copy_gpa);
+ if (gru_get_cpu_resources(GRU_NUM_KERNEL_DSR_BYTES, &cb, &dsr))
+ return MQE_BUG_NO_RESOURCES;
+ gru_bcopy(cb, src_gpa, dest_gpa, gru_get_tri(dsr),
+ XTYPE_B, bytes, GRU_NUM_KERNEL_DSR_BYTES, IMA);
+ ret = gru_wait(cb);
+ gru_free_cpu_resources(cb, dsr);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(gru_copy_gpa);
+
+/* ------------------- KERNEL QUICKTESTS RUN AT STARTUP ----------------*/
+/* Temp - will delete after we gain confidence in the GRU */
+static __cacheline_aligned unsigned long word0;
+static __cacheline_aligned unsigned long word1;
+
+static int quicktest(struct gru_state *gru)
+{
+ void *cb;
+ void *ds;
+ unsigned long *p;
+
+ cb = get_gseg_base_address_cb(gru->gs_gru_base_vaddr, KERNEL_CTXNUM, 0);
+ ds = get_gseg_base_address_ds(gru->gs_gru_base_vaddr, KERNEL_CTXNUM, 0);
+ p = ds;
+ word0 = MAGIC;
+
+ gru_vload(cb, uv_gpa(&word0), 0, XTYPE_DW, 1, 1, IMA);
+ if (gru_wait(cb) != CBS_IDLE)
+ BUG();
+
+ if (*(unsigned long *)ds != MAGIC)
+ BUG();
+ gru_vstore(cb, uv_gpa(&word1), 0, XTYPE_DW, 1, 1, IMA);
+ if (gru_wait(cb) != CBS_IDLE)
+ BUG();
+
+ if (word0 != word1 || word0 != MAGIC) {
+ printk
+ ("GRU quicktest err: gru %d, found 0x%lx, expected 0x%lx\n",
+ gru->gs_gid, word1, MAGIC);
+ BUG(); /* ZZZ should not be fatal */
+ }
+
+ return 0;
+}
+
+
+int gru_kservices_init(struct gru_state *gru)
+{
+ struct gru_blade_state *bs;
+ struct gru_context_configuration_handle *cch;
+ unsigned long cbr_map, dsr_map;
+ int err, num, cpus_possible;
+
+ /*
+ * Currently, resources are reserved ONLY on the second chiplet
+ * on each blade. This leaves ALL resources on chiplet 0 available
+ * for user code.
+ */
+ bs = gru->gs_blade;
+ if (gru != &bs->bs_grus[1])
+ return 0;
+
+ cpus_possible = uv_blade_nr_possible_cpus(gru->gs_blade_id);
+
+ num = GRU_NUM_KERNEL_CBR * cpus_possible;
+ cbr_map = reserve_gru_cb_resources(gru, GRU_CB_COUNT_TO_AU(num), NULL);
+ gru->gs_reserved_cbrs += num;
+
+ num = GRU_NUM_KERNEL_DSR_BYTES * cpus_possible;
+ dsr_map = reserve_gru_ds_resources(gru, GRU_DS_BYTES_TO_AU(num), NULL);
+ gru->gs_reserved_dsr_bytes += num;
+
+ gru->gs_active_contexts++;
+ __set_bit(KERNEL_CTXNUM, &gru->gs_context_map);
+ cch = get_cch(gru->gs_gru_base_vaddr, KERNEL_CTXNUM);
+
+ bs->kernel_cb = get_gseg_base_address_cb(gru->gs_gru_base_vaddr,
+ KERNEL_CTXNUM, 0);
+ bs->kernel_dsr = get_gseg_base_address_ds(gru->gs_gru_base_vaddr,
+ KERNEL_CTXNUM, 0);
+
+ lock_cch_handle(cch);
+ cch->tfm_fault_bit_enable = 0;
+ cch->tlb_int_enable = 0;
+ cch->tfm_done_bit_enable = 0;
+ cch->unmap_enable = 1;
+ err = cch_allocate(cch, 0, cbr_map, dsr_map);
+ if (err) {
+ gru_dbg(grudev,
+ "Unable to allocate kernel CCH: gru %d, err %d\n",
+ gru->gs_gid, err);
+ BUG();
+ }
+ if (cch_start(cch)) {
+ gru_dbg(grudev, "Unable to start kernel CCH: gru %d, err %d\n",
+ gru->gs_gid, err);
+ BUG();
+ }
+ unlock_cch_handle(cch);
+
+ if (options & GRU_QUICKLOOK)
+ quicktest(gru);
+ return 0;
+}
projects / linux-2.6 / commitdiff