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-rw-r--r--arch/powerpc/sysdev/xive/spapr.c662
1 files changed, 662 insertions, 0 deletions
diff --git a/arch/powerpc/sysdev/xive/spapr.c b/arch/powerpc/sysdev/xive/spapr.c
new file mode 100644
index 000000000000..f24a70bc6855
--- /dev/null
+++ b/arch/powerpc/sysdev/xive/spapr.c
@@ -0,0 +1,662 @@
+/*
+ * Copyright 2016,2017 IBM Corporation.
+ *
+ * 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.
+ */
+
+#define pr_fmt(fmt) "xive: " fmt
+
+#include <linux/types.h>
+#include <linux/irq.h>
+#include <linux/smp.h>
+#include <linux/interrupt.h>
+#include <linux/init.h>
+#include <linux/of.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/cpumask.h>
+#include <linux/mm.h>
+
+#include <asm/prom.h>
+#include <asm/io.h>
+#include <asm/smp.h>
+#include <asm/irq.h>
+#include <asm/errno.h>
+#include <asm/xive.h>
+#include <asm/xive-regs.h>
+#include <asm/hvcall.h>
+
+#include "xive-internal.h"
+
+static u32 xive_queue_shift;
+
+struct xive_irq_bitmap {
+ unsigned long *bitmap;
+ unsigned int base;
+ unsigned int count;
+ spinlock_t lock;
+ struct list_head list;
+};
+
+static LIST_HEAD(xive_irq_bitmaps);
+
+static int xive_irq_bitmap_add(int base, int count)
+{
+ struct xive_irq_bitmap *xibm;
+
+ xibm = kzalloc(sizeof(*xibm), GFP_ATOMIC);
+ if (!xibm)
+ return -ENOMEM;
+
+ spin_lock_init(&xibm->lock);
+ xibm->base = base;
+ xibm->count = count;
+ xibm->bitmap = kzalloc(xibm->count, GFP_KERNEL);
+ list_add(&xibm->list, &xive_irq_bitmaps);
+
+ pr_info("Using IRQ range [%x-%x]", xibm->base,
+ xibm->base + xibm->count - 1);
+ return 0;
+}
+
+static int __xive_irq_bitmap_alloc(struct xive_irq_bitmap *xibm)
+{
+ int irq;
+
+ irq = find_first_zero_bit(xibm->bitmap, xibm->count);
+ if (irq != xibm->count) {
+ set_bit(irq, xibm->bitmap);
+ irq += xibm->base;
+ } else {
+ irq = -ENOMEM;
+ }
+
+ return irq;
+}
+
+static int xive_irq_bitmap_alloc(void)
+{
+ struct xive_irq_bitmap *xibm;
+ unsigned long flags;
+ int irq = -ENOENT;
+
+ list_for_each_entry(xibm, &xive_irq_bitmaps, list) {
+ spin_lock_irqsave(&xibm->lock, flags);
+ irq = __xive_irq_bitmap_alloc(xibm);
+ spin_unlock_irqrestore(&xibm->lock, flags);
+ if (irq >= 0)
+ break;
+ }
+ return irq;
+}
+
+static void xive_irq_bitmap_free(int irq)
+{
+ unsigned long flags;
+ struct xive_irq_bitmap *xibm;
+
+ list_for_each_entry(xibm, &xive_irq_bitmaps, list) {
+ if ((irq >= xibm->base) && (irq < xibm->base + xibm->count)) {
+ spin_lock_irqsave(&xibm->lock, flags);
+ clear_bit(irq - xibm->base, xibm->bitmap);
+ spin_unlock_irqrestore(&xibm->lock, flags);
+ break;
+ }
+ }
+}
+
+static long plpar_int_get_source_info(unsigned long flags,
+ unsigned long lisn,
+ unsigned long *src_flags,
+ unsigned long *eoi_page,
+ unsigned long *trig_page,
+ unsigned long *esb_shift)
+{
+ unsigned long retbuf[PLPAR_HCALL_BUFSIZE];
+ long rc;
+
+ rc = plpar_hcall(H_INT_GET_SOURCE_INFO, retbuf, flags, lisn);
+ if (rc) {
+ pr_err("H_INT_GET_SOURCE_INFO lisn=%ld failed %ld\n", lisn, rc);
+ return rc;
+ }
+
+ *src_flags = retbuf[0];
+ *eoi_page = retbuf[1];
+ *trig_page = retbuf[2];
+ *esb_shift = retbuf[3];
+
+ pr_devel("H_INT_GET_SOURCE_INFO flags=%lx eoi=%lx trig=%lx shift=%lx\n",
+ retbuf[0], retbuf[1], retbuf[2], retbuf[3]);
+
+ return 0;
+}
+
+#define XIVE_SRC_SET_EISN (1ull << (63 - 62))
+#define XIVE_SRC_MASK (1ull << (63 - 63)) /* unused */
+
+static long plpar_int_set_source_config(unsigned long flags,
+ unsigned long lisn,
+ unsigned long target,
+ unsigned long prio,
+ unsigned long sw_irq)
+{
+ long rc;
+
+
+ pr_devel("H_INT_SET_SOURCE_CONFIG flags=%lx lisn=%lx target=%lx prio=%lx sw_irq=%lx\n",
+ flags, lisn, target, prio, sw_irq);
+
+
+ rc = plpar_hcall_norets(H_INT_SET_SOURCE_CONFIG, flags, lisn,
+ target, prio, sw_irq);
+ if (rc) {
+ pr_err("H_INT_SET_SOURCE_CONFIG lisn=%ld target=%lx prio=%lx failed %ld\n",
+ lisn, target, prio, rc);
+ return rc;
+ }
+
+ return 0;
+}
+
+static long plpar_int_get_queue_info(unsigned long flags,
+ unsigned long target,
+ unsigned long priority,
+ unsigned long *esn_page,
+ unsigned long *esn_size)
+{
+ unsigned long retbuf[PLPAR_HCALL_BUFSIZE];
+ long rc;
+
+ rc = plpar_hcall(H_INT_GET_QUEUE_INFO, retbuf, flags, target, priority);
+ if (rc) {
+ pr_err("H_INT_GET_QUEUE_INFO cpu=%ld prio=%ld failed %ld\n",
+ target, priority, rc);
+ return rc;
+ }
+
+ *esn_page = retbuf[0];
+ *esn_size = retbuf[1];
+
+ pr_devel("H_INT_GET_QUEUE_INFO page=%lx size=%lx\n",
+ retbuf[0], retbuf[1]);
+
+ return 0;
+}
+
+#define XIVE_EQ_ALWAYS_NOTIFY (1ull << (63 - 63))
+
+static long plpar_int_set_queue_config(unsigned long flags,
+ unsigned long target,
+ unsigned long priority,
+ unsigned long qpage,
+ unsigned long qsize)
+{
+ long rc;
+
+ pr_devel("H_INT_SET_QUEUE_CONFIG flags=%lx target=%lx priority=%lx qpage=%lx qsize=%lx\n",
+ flags, target, priority, qpage, qsize);
+
+ rc = plpar_hcall_norets(H_INT_SET_QUEUE_CONFIG, flags, target,
+ priority, qpage, qsize);
+ if (rc) {
+ pr_err("H_INT_SET_QUEUE_CONFIG cpu=%ld prio=%ld qpage=%lx returned %ld\n",
+ target, priority, qpage, rc);
+ return rc;
+ }
+
+ return 0;
+}
+
+static long plpar_int_sync(unsigned long flags, unsigned long lisn)
+{
+ long rc;
+
+ rc = plpar_hcall_norets(H_INT_SYNC, flags, lisn);
+ if (rc) {
+ pr_err("H_INT_SYNC lisn=%ld returned %ld\n", lisn, rc);
+ return rc;
+ }
+
+ return 0;
+}
+
+#define XIVE_ESB_FLAG_STORE (1ull << (63 - 63))
+
+static long plpar_int_esb(unsigned long flags,
+ unsigned long lisn,
+ unsigned long offset,
+ unsigned long in_data,
+ unsigned long *out_data)
+{
+ unsigned long retbuf[PLPAR_HCALL_BUFSIZE];
+ long rc;
+
+ pr_devel("H_INT_ESB flags=%lx lisn=%lx offset=%lx in=%lx\n",
+ flags, lisn, offset, in_data);
+
+ rc = plpar_hcall(H_INT_ESB, retbuf, flags, lisn, offset, in_data);
+ if (rc) {
+ pr_err("H_INT_ESB lisn=%ld offset=%ld returned %ld\n",
+ lisn, offset, rc);
+ return rc;
+ }
+
+ *out_data = retbuf[0];
+
+ return 0;
+}
+
+static u64 xive_spapr_esb_rw(u32 lisn, u32 offset, u64 data, bool write)
+{
+ unsigned long read_data;
+ long rc;
+
+ rc = plpar_int_esb(write ? XIVE_ESB_FLAG_STORE : 0,
+ lisn, offset, data, &read_data);
+ if (rc)
+ return -1;
+
+ return write ? 0 : read_data;
+}
+
+#define XIVE_SRC_H_INT_ESB (1ull << (63 - 60))
+#define XIVE_SRC_LSI (1ull << (63 - 61))
+#define XIVE_SRC_TRIGGER (1ull << (63 - 62))
+#define XIVE_SRC_STORE_EOI (1ull << (63 - 63))
+
+static int xive_spapr_populate_irq_data(u32 hw_irq, struct xive_irq_data *data)
+{
+ long rc;
+ unsigned long flags;
+ unsigned long eoi_page;
+ unsigned long trig_page;
+ unsigned long esb_shift;
+
+ memset(data, 0, sizeof(*data));
+
+ rc = plpar_int_get_source_info(0, hw_irq, &flags, &eoi_page, &trig_page,
+ &esb_shift);
+ if (rc)
+ return -EINVAL;
+
+ if (flags & XIVE_SRC_H_INT_ESB)
+ data->flags |= XIVE_IRQ_FLAG_H_INT_ESB;
+ if (flags & XIVE_SRC_STORE_EOI)
+ data->flags |= XIVE_IRQ_FLAG_STORE_EOI;
+ if (flags & XIVE_SRC_LSI)
+ data->flags |= XIVE_IRQ_FLAG_LSI;
+ data->eoi_page = eoi_page;
+ data->esb_shift = esb_shift;
+ data->trig_page = trig_page;
+
+ /*
+ * No chip-id for the sPAPR backend. This has an impact how we
+ * pick a target. See xive_pick_irq_target().
+ */
+ data->src_chip = XIVE_INVALID_CHIP_ID;
+
+ data->eoi_mmio = ioremap(data->eoi_page, 1u << data->esb_shift);
+ if (!data->eoi_mmio) {
+ pr_err("Failed to map EOI page for irq 0x%x\n", hw_irq);
+ return -ENOMEM;
+ }
+
+ data->hw_irq = hw_irq;
+
+ /* Full function page supports trigger */
+ if (flags & XIVE_SRC_TRIGGER) {
+ data->trig_mmio = data->eoi_mmio;
+ return 0;
+ }
+
+ data->trig_mmio = ioremap(data->trig_page, 1u << data->esb_shift);
+ if (!data->trig_mmio) {
+ pr_err("Failed to map trigger page for irq 0x%x\n", hw_irq);
+ return -ENOMEM;
+ }
+ return 0;
+}
+
+static int xive_spapr_configure_irq(u32 hw_irq, u32 target, u8 prio, u32 sw_irq)
+{
+ long rc;
+
+ rc = plpar_int_set_source_config(XIVE_SRC_SET_EISN, hw_irq, target,
+ prio, sw_irq);
+
+ return rc == 0 ? 0 : -ENXIO;
+}
+
+/* This can be called multiple time to change a queue configuration */
+static int xive_spapr_configure_queue(u32 target, struct xive_q *q, u8 prio,
+ __be32 *qpage, u32 order)
+{
+ s64 rc = 0;
+ unsigned long esn_page;
+ unsigned long esn_size;
+ u64 flags, qpage_phys;
+
+ /* If there's an actual queue page, clean it */
+ if (order) {
+ if (WARN_ON(!qpage))
+ return -EINVAL;
+ qpage_phys = __pa(qpage);
+ } else {
+ qpage_phys = 0;
+ }
+
+ /* Initialize the rest of the fields */
+ q->msk = order ? ((1u << (order - 2)) - 1) : 0;
+ q->idx = 0;
+ q->toggle = 0;
+
+ rc = plpar_int_get_queue_info(0, target, prio, &esn_page, &esn_size);
+ if (rc) {
+ pr_err("Error %lld getting queue info prio %d\n", rc, prio);
+ rc = -EIO;
+ goto fail;
+ }
+
+ /* TODO: add support for the notification page */
+ q->eoi_phys = esn_page;
+
+ /* Default is to always notify */
+ flags = XIVE_EQ_ALWAYS_NOTIFY;
+
+ /* Configure and enable the queue in HW */
+ rc = plpar_int_set_queue_config(flags, target, prio, qpage_phys, order);
+ if (rc) {
+ pr_err("Error %lld setting queue for prio %d\n", rc, prio);
+ rc = -EIO;
+ } else {
+ q->qpage = qpage;
+ }
+fail:
+ return rc;
+}
+
+static int xive_spapr_setup_queue(unsigned int cpu, struct xive_cpu *xc,
+ u8 prio)
+{
+ struct xive_q *q = &xc->queue[prio];
+ __be32 *qpage;
+
+ qpage = xive_queue_page_alloc(cpu, xive_queue_shift);
+ if (IS_ERR(qpage))
+ return PTR_ERR(qpage);
+
+ return xive_spapr_configure_queue(cpu, q, prio, qpage,
+ xive_queue_shift);
+}
+
+static void xive_spapr_cleanup_queue(unsigned int cpu, struct xive_cpu *xc,
+ u8 prio)
+{
+ struct xive_q *q = &xc->queue[prio];
+ unsigned int alloc_order;
+ long rc;
+
+ rc = plpar_int_set_queue_config(0, cpu, prio, 0, 0);
+ if (rc)
+ pr_err("Error %ld setting queue for prio %d\n", rc, prio);
+
+ alloc_order = xive_alloc_order(xive_queue_shift);
+ free_pages((unsigned long)q->qpage, alloc_order);
+ q->qpage = NULL;
+}
+
+static bool xive_spapr_match(struct device_node *node)
+{
+ /* Ignore cascaded controllers for the moment */
+ return 1;
+}
+
+#ifdef CONFIG_SMP
+static int xive_spapr_get_ipi(unsigned int cpu, struct xive_cpu *xc)
+{
+ int irq = xive_irq_bitmap_alloc();
+
+ if (irq < 0) {
+ pr_err("Failed to allocate IPI on CPU %d\n", cpu);
+ return -ENXIO;
+ }
+
+ xc->hw_ipi = irq;
+ return 0;
+}
+
+static void xive_spapr_put_ipi(unsigned int cpu, struct xive_cpu *xc)
+{
+ xive_irq_bitmap_free(xc->hw_ipi);
+}
+#endif /* CONFIG_SMP */
+
+static void xive_spapr_shutdown(void)
+{
+ long rc;
+
+ rc = plpar_hcall_norets(H_INT_RESET, 0);
+ if (rc)
+ pr_err("H_INT_RESET failed %ld\n", rc);
+}
+
+/*
+ * Perform an "ack" cycle on the current thread. Grab the pending
+ * active priorities and update the CPPR to the most favored one.
+ */
+static void xive_spapr_update_pending(struct xive_cpu *xc)
+{
+ u8 nsr, cppr;
+ u16 ack;
+
+ /*
+ * Perform the "Acknowledge O/S to Register" cycle.
+ *
+ * Let's speedup the access to the TIMA using the raw I/O
+ * accessor as we don't need the synchronisation routine of
+ * the higher level ones
+ */
+ ack = be16_to_cpu(__raw_readw(xive_tima + TM_SPC_ACK_OS_REG));
+
+ /* Synchronize subsequent queue accesses */
+ mb();
+
+ /*
+ * Grab the CPPR and the "NSR" field which indicates the source
+ * of the interrupt (if any)
+ */
+ cppr = ack & 0xff;
+ nsr = ack >> 8;
+
+ if (nsr & TM_QW1_NSR_EO) {
+ if (cppr == 0xff)
+ return;
+ /* Mark the priority pending */
+ xc->pending_prio |= 1 << cppr;
+
+ /*
+ * A new interrupt should never have a CPPR less favored
+ * than our current one.
+ */
+ if (cppr >= xc->cppr)
+ pr_err("CPU %d odd ack CPPR, got %d at %d\n",
+ smp_processor_id(), cppr, xc->cppr);
+
+ /* Update our idea of what the CPPR is */
+ xc->cppr = cppr;
+ }
+}
+
+static void xive_spapr_eoi(u32 hw_irq)
+{
+ /* Not used */;
+}
+
+static void xive_spapr_setup_cpu(unsigned int cpu, struct xive_cpu *xc)
+{
+ /* Only some debug on the TIMA settings */
+ pr_debug("(HW value: %08x %08x %08x)\n",
+ in_be32(xive_tima + TM_QW1_OS + TM_WORD0),
+ in_be32(xive_tima + TM_QW1_OS + TM_WORD1),
+ in_be32(xive_tima + TM_QW1_OS + TM_WORD2));
+}
+
+static void xive_spapr_teardown_cpu(unsigned int cpu, struct xive_cpu *xc)
+{
+ /* Nothing to do */;
+}
+
+static void xive_spapr_sync_source(u32 hw_irq)
+{
+ /* Specs are unclear on what this is doing */
+ plpar_int_sync(0, hw_irq);
+}
+
+static const struct xive_ops xive_spapr_ops = {
+ .populate_irq_data = xive_spapr_populate_irq_data,
+ .configure_irq = xive_spapr_configure_irq,
+ .setup_queue = xive_spapr_setup_queue,
+ .cleanup_queue = xive_spapr_cleanup_queue,
+ .match = xive_spapr_match,
+ .shutdown = xive_spapr_shutdown,
+ .update_pending = xive_spapr_update_pending,
+ .eoi = xive_spapr_eoi,
+ .setup_cpu = xive_spapr_setup_cpu,
+ .teardown_cpu = xive_spapr_teardown_cpu,
+ .sync_source = xive_spapr_sync_source,
+ .esb_rw = xive_spapr_esb_rw,
+#ifdef CONFIG_SMP
+ .get_ipi = xive_spapr_get_ipi,
+ .put_ipi = xive_spapr_put_ipi,
+#endif /* CONFIG_SMP */
+ .name = "spapr",
+};
+
+/*
+ * get max priority from "/ibm,plat-res-int-priorities"
+ */
+static bool xive_get_max_prio(u8 *max_prio)
+{
+ struct device_node *rootdn;
+ const __be32 *reg;
+ u32 len;
+ int prio, found;
+
+ rootdn = of_find_node_by_path("/");
+ if (!rootdn) {
+ pr_err("not root node found !\n");
+ return false;
+ }
+
+ reg = of_get_property(rootdn, "ibm,plat-res-int-priorities", &len);
+ if (!reg) {
+ pr_err("Failed to read 'ibm,plat-res-int-priorities' property\n");
+ return false;
+ }
+
+ if (len % (2 * sizeof(u32)) != 0) {
+ pr_err("invalid 'ibm,plat-res-int-priorities' property\n");
+ return false;
+ }
+
+ /* HW supports priorities in the range [0-7] and 0xFF is a
+ * wildcard priority used to mask. We scan the ranges reserved
+ * by the hypervisor to find the lowest priority we can use.
+ */
+ found = 0xFF;
+ for (prio = 0; prio < 8; prio++) {
+ int reserved = 0;
+ int i;
+
+ for (i = 0; i < len / (2 * sizeof(u32)); i++) {
+ int base = be32_to_cpu(reg[2 * i]);
+ int range = be32_to_cpu(reg[2 * i + 1]);
+
+ if (prio >= base && prio < base + range)
+ reserved++;
+ }
+
+ if (!reserved)
+ found = prio;
+ }
+
+ if (found == 0xFF) {
+ pr_err("no valid priority found in 'ibm,plat-res-int-priorities'\n");
+ return false;
+ }
+
+ *max_prio = found;
+ return true;
+}
+
+bool __init xive_spapr_init(void)
+{
+ struct device_node *np;
+ struct resource r;
+ void __iomem *tima;
+ struct property *prop;
+ u8 max_prio;
+ u32 val;
+ u32 len;
+ const __be32 *reg;
+ int i;
+
+ if (xive_cmdline_disabled)
+ return false;
+
+ pr_devel("%s()\n", __func__);
+ np = of_find_compatible_node(NULL, NULL, "ibm,power-ivpe");
+ if (!np) {
+ pr_devel("not found !\n");
+ return false;
+ }
+ pr_devel("Found %s\n", np->full_name);
+
+ /* Resource 1 is the OS ring TIMA */
+ if (of_address_to_resource(np, 1, &r)) {
+ pr_err("Failed to get thread mgmnt area resource\n");
+ return false;
+ }
+ tima = ioremap(r.start, resource_size(&r));
+ if (!tima) {
+ pr_err("Failed to map thread mgmnt area\n");
+ return false;
+ }
+
+ if (!xive_get_max_prio(&max_prio))
+ return false;
+
+ /* Feed the IRQ number allocator with the ranges given in the DT */
+ reg = of_get_property(np, "ibm,xive-lisn-ranges", &len);
+ if (!reg) {
+ pr_err("Failed to read 'ibm,xive-lisn-ranges' property\n");
+ return false;
+ }
+
+ if (len % (2 * sizeof(u32)) != 0) {
+ pr_err("invalid 'ibm,xive-lisn-ranges' property\n");
+ return false;
+ }
+
+ for (i = 0; i < len / (2 * sizeof(u32)); i++, reg += 2)
+ xive_irq_bitmap_add(be32_to_cpu(reg[0]),
+ be32_to_cpu(reg[1]));
+
+ /* Iterate the EQ sizes and pick one */
+ of_property_for_each_u32(np, "ibm,xive-eq-sizes", prop, reg, val) {
+ xive_queue_shift = val;
+ if (val == PAGE_SHIFT)
+ break;
+ }
+
+ /* Initialize XIVE core with our backend */
+ if (!xive_core_init(&xive_spapr_ops, tima, TM_QW1_OS, max_prio))
+ return false;
+
+ pr_info("Using %dkB queues\n", 1 << (xive_queue_shift - 10));
+ return true;
+}
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.