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path: root/drivers/irqchip/irq-gic-v3-its.c
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Diffstat (limited to 'drivers/irqchip/irq-gic-v3-its.c')
-rw-r--r--drivers/irqchip/irq-gic-v3-its.c243
1 files changed, 156 insertions, 87 deletions
diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index d7842d312d3e..316a57530f6d 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -23,6 +23,8 @@
#include <linux/dma-iommu.h>
#include <linux/interrupt.h>
#include <linux/irqdomain.h>
+#include <linux/list.h>
+#include <linux/list_sort.h>
#include <linux/log2.h>
#include <linux/mm.h>
#include <linux/msi.h>
@@ -160,7 +162,7 @@ static struct {
} vpe_proxy;
static LIST_HEAD(its_nodes);
-static DEFINE_SPINLOCK(its_lock);
+static DEFINE_RAW_SPINLOCK(its_lock);
static struct rdists *gic_rdists;
static struct irq_domain *its_parent;
@@ -1421,112 +1423,176 @@ static struct irq_chip its_irq_chip = {
.irq_set_vcpu_affinity = its_irq_set_vcpu_affinity,
};
+
/*
* How we allocate LPIs:
*
- * The GIC has id_bits bits for interrupt identifiers. From there, we
- * must subtract 8192 which are reserved for SGIs/PPIs/SPIs. Then, as
- * we allocate LPIs by chunks of 32, we can shift the whole thing by 5
- * bits to the right.
+ * lpi_range_list contains ranges of LPIs that are to available to
+ * allocate from. To allocate LPIs, just pick the first range that
+ * fits the required allocation, and reduce it by the required
+ * amount. Once empty, remove the range from the list.
+ *
+ * To free a range of LPIs, add a free range to the list, sort it and
+ * merge the result if the new range happens to be adjacent to an
+ * already free block.
*
- * This gives us (((1UL << id_bits) - 8192) >> 5) possible allocations.
+ * The consequence of the above is that allocation is cost is low, but
+ * freeing is expensive. We assumes that freeing rarely occurs.
*/
-#define IRQS_PER_CHUNK_SHIFT 5
-#define IRQS_PER_CHUNK (1UL << IRQS_PER_CHUNK_SHIFT)
-#define ITS_MAX_LPI_NRBITS 16 /* 64K LPIs */
-static unsigned long *lpi_bitmap;
-static u32 lpi_chunks;
-static DEFINE_SPINLOCK(lpi_lock);
+static DEFINE_MUTEX(lpi_range_lock);
+static LIST_HEAD(lpi_range_list);
+
+struct lpi_range {
+ struct list_head entry;
+ u32 base_id;
+ u32 span;
+};
-static int its_lpi_to_chunk(int lpi)
+static struct lpi_range *mk_lpi_range(u32 base, u32 span)
{
- return (lpi - 8192) >> IRQS_PER_CHUNK_SHIFT;
+ struct lpi_range *range;
+
+ range = kzalloc(sizeof(*range), GFP_KERNEL);
+ if (range) {
+ INIT_LIST_HEAD(&range->entry);
+ range->base_id = base;
+ range->span = span;
+ }
+
+ return range;
}
-static int its_chunk_to_lpi(int chunk)
+static int lpi_range_cmp(void *priv, struct list_head *a, struct list_head *b)
{
- return (chunk << IRQS_PER_CHUNK_SHIFT) + 8192;
+ struct lpi_range *ra, *rb;
+
+ ra = container_of(a, struct lpi_range, entry);
+ rb = container_of(b, struct lpi_range, entry);
+
+ return rb->base_id - ra->base_id;
}
-static int __init its_lpi_init(u32 id_bits)
+static void merge_lpi_ranges(void)
{
- lpi_chunks = its_lpi_to_chunk(1UL << id_bits);
+ struct lpi_range *range, *tmp;
- lpi_bitmap = kcalloc(BITS_TO_LONGS(lpi_chunks), sizeof(long),
- GFP_KERNEL);
- if (!lpi_bitmap) {
- lpi_chunks = 0;
- return -ENOMEM;
+ list_for_each_entry_safe(range, tmp, &lpi_range_list, entry) {
+ if (!list_is_last(&range->entry, &lpi_range_list) &&
+ (tmp->base_id == (range->base_id + range->span))) {
+ tmp->base_id = range->base_id;
+ tmp->span += range->span;
+ list_del(&range->entry);
+ kfree(range);
+ }
}
+}
- pr_info("ITS: Allocated %d chunks for LPIs\n", (int)lpi_chunks);
- return 0;
+static int alloc_lpi_range(u32 nr_lpis, u32 *base)
+{
+ struct lpi_range *range, *tmp;
+ int err = -ENOSPC;
+
+ mutex_lock(&lpi_range_lock);
+
+ list_for_each_entry_safe(range, tmp, &lpi_range_list, entry) {
+ if (range->span >= nr_lpis) {
+ *base = range->base_id;
+ range->base_id += nr_lpis;
+ range->span -= nr_lpis;
+
+ if (range->span == 0) {
+ list_del(&range->entry);
+ kfree(range);
+ }
+
+ err = 0;
+ break;
+ }
+ }
+
+ mutex_unlock(&lpi_range_lock);
+
+ pr_debug("ITS: alloc %u:%u\n", *base, nr_lpis);
+ return err;
}
-static unsigned long *its_lpi_alloc_chunks(int nr_irqs, int *base, int *nr_ids)
+static int free_lpi_range(u32 base, u32 nr_lpis)
{
- unsigned long *bitmap = NULL;
- int chunk_id;
- int nr_chunks;
- int i;
+ struct lpi_range *new;
+ int err = 0;
+
+ mutex_lock(&lpi_range_lock);
+
+ new = mk_lpi_range(base, nr_lpis);
+ if (!new) {
+ err = -ENOMEM;
+ goto out;
+ }
+
+ list_add(&new->entry, &lpi_range_list);
+ list_sort(NULL, &lpi_range_list, lpi_range_cmp);
+ merge_lpi_ranges();
+out:
+ mutex_unlock(&lpi_range_lock);
+ return err;
+}
+
+static int __init its_lpi_init(u32 id_bits)
+{
+ u32 lpis = (1UL << id_bits) - 8192;
+ u32 numlpis;
+ int err;
+
+ numlpis = 1UL << GICD_TYPER_NUM_LPIS(gic_rdists->gicd_typer);
+
+ if (numlpis > 2 && !WARN_ON(numlpis > lpis)) {
+ lpis = numlpis;
+ pr_info("ITS: Using hypervisor restricted LPI range [%u]\n",
+ lpis);
+ }
- nr_chunks = DIV_ROUND_UP(nr_irqs, IRQS_PER_CHUNK);
+ /*
+ * Initializing the allocator is just the same as freeing the
+ * full range of LPIs.
+ */
+ err = free_lpi_range(8192, lpis);
+ pr_debug("ITS: Allocator initialized for %u LPIs\n", lpis);
+ return err;
+}
- spin_lock(&lpi_lock);
+static unsigned long *its_lpi_alloc(int nr_irqs, u32 *base, int *nr_ids)
+{
+ unsigned long *bitmap = NULL;
+ int err = 0;
do {
- chunk_id = bitmap_find_next_zero_area(lpi_bitmap, lpi_chunks,
- 0, nr_chunks, 0);
- if (chunk_id < lpi_chunks)
+ err = alloc_lpi_range(nr_irqs, base);
+ if (!err)
break;
- nr_chunks--;
- } while (nr_chunks > 0);
+ nr_irqs /= 2;
+ } while (nr_irqs > 0);
- if (!nr_chunks)
+ if (err)
goto out;
- bitmap = kcalloc(BITS_TO_LONGS(nr_chunks * IRQS_PER_CHUNK),
- sizeof(long),
- GFP_ATOMIC);
+ bitmap = kcalloc(BITS_TO_LONGS(nr_irqs), sizeof (long), GFP_ATOMIC);
if (!bitmap)
goto out;
- for (i = 0; i < nr_chunks; i++)
- set_bit(chunk_id + i, lpi_bitmap);
-
- *base = its_chunk_to_lpi(chunk_id);
- *nr_ids = nr_chunks * IRQS_PER_CHUNK;
+ *nr_ids = nr_irqs;
out:
- spin_unlock(&lpi_lock);
-
if (!bitmap)
*base = *nr_ids = 0;
return bitmap;
}
-static void its_lpi_free_chunks(unsigned long *bitmap, int base, int nr_ids)
+static void its_lpi_free(unsigned long *bitmap, u32 base, u32 nr_ids)
{
- int lpi;
-
- spin_lock(&lpi_lock);
-
- for (lpi = base; lpi < (base + nr_ids); lpi += IRQS_PER_CHUNK) {
- int chunk = its_lpi_to_chunk(lpi);
-
- BUG_ON(chunk > lpi_chunks);
- if (test_bit(chunk, lpi_bitmap)) {
- clear_bit(chunk, lpi_bitmap);
- } else {
- pr_err("Bad LPI chunk %d\n", chunk);
- }
- }
-
- spin_unlock(&lpi_lock);
-
+ WARN_ON(free_lpi_range(base, nr_ids));
kfree(bitmap);
}
@@ -1559,7 +1625,7 @@ static int __init its_alloc_lpi_tables(void)
{
phys_addr_t paddr;
- lpi_id_bits = min_t(u32, gic_rdists->id_bits, ITS_MAX_LPI_NRBITS);
+ lpi_id_bits = GICD_TYPER_ID_BITS(gic_rdists->gicd_typer);
gic_rdists->prop_page = its_allocate_prop_table(GFP_NOWAIT);
if (!gic_rdists->prop_page) {
pr_err("Failed to allocate PROPBASE\n");
@@ -1997,12 +2063,12 @@ static void its_cpu_init_collections(void)
{
struct its_node *its;
- spin_lock(&its_lock);
+ raw_spin_lock(&its_lock);
list_for_each_entry(its, &its_nodes, entry)
its_cpu_init_collection(its);
- spin_unlock(&its_lock);
+ raw_spin_unlock(&its_lock);
}
static struct its_device *its_find_device(struct its_node *its, u32 dev_id)
@@ -2134,17 +2200,20 @@ static struct its_device *its_create_device(struct its_node *its, u32 dev_id,
if (!its_alloc_device_table(its, dev_id))
return NULL;
+ if (WARN_ON(!is_power_of_2(nvecs)))
+ nvecs = roundup_pow_of_two(nvecs);
+
dev = kzalloc(sizeof(*dev), GFP_KERNEL);
/*
- * We allocate at least one chunk worth of LPIs bet device,
- * and thus that many ITEs. The device may require less though.
+ * Even if the device wants a single LPI, the ITT must be
+ * sized as a power of two (and you need at least one bit...).
*/
- nr_ites = max(IRQS_PER_CHUNK, roundup_pow_of_two(nvecs));
+ nr_ites = max(2, nvecs);
sz = nr_ites * its->ite_size;
sz = max(sz, ITS_ITT_ALIGN) + ITS_ITT_ALIGN - 1;
itt = kzalloc(sz, GFP_KERNEL);
if (alloc_lpis) {
- lpi_map = its_lpi_alloc_chunks(nvecs, &lpi_base, &nr_lpis);
+ lpi_map = its_lpi_alloc(nvecs, &lpi_base, &nr_lpis);
if (lpi_map)
col_map = kcalloc(nr_lpis, sizeof(*col_map),
GFP_KERNEL);
@@ -2379,9 +2448,9 @@ static void its_irq_domain_free(struct irq_domain *domain, unsigned int virq,
/* If all interrupts have been freed, start mopping the floor */
if (bitmap_empty(its_dev->event_map.lpi_map,
its_dev->event_map.nr_lpis)) {
- its_lpi_free_chunks(its_dev->event_map.lpi_map,
- its_dev->event_map.lpi_base,
- its_dev->event_map.nr_lpis);
+ its_lpi_free(its_dev->event_map.lpi_map,
+ its_dev->event_map.lpi_base,
+ its_dev->event_map.nr_lpis);
kfree(its_dev->event_map.col_map);
/* Unmap device/itt */
@@ -2780,7 +2849,7 @@ static void its_vpe_irq_domain_free(struct irq_domain *domain,
}
if (bitmap_empty(vm->db_bitmap, vm->nr_db_lpis)) {
- its_lpi_free_chunks(vm->db_bitmap, vm->db_lpi_base, vm->nr_db_lpis);
+ its_lpi_free(vm->db_bitmap, vm->db_lpi_base, vm->nr_db_lpis);
its_free_prop_table(vm->vprop_page);
}
}
@@ -2795,18 +2864,18 @@ static int its_vpe_irq_domain_alloc(struct irq_domain *domain, unsigned int virq
BUG_ON(!vm);
- bitmap = its_lpi_alloc_chunks(nr_irqs, &base, &nr_ids);
+ bitmap = its_lpi_alloc(roundup_pow_of_two(nr_irqs), &base, &nr_ids);
if (!bitmap)
return -ENOMEM;
if (nr_ids < nr_irqs) {
- its_lpi_free_chunks(bitmap, base, nr_ids);
+ its_lpi_free(bitmap, base, nr_ids);
return -ENOMEM;
}
vprop_page = its_allocate_prop_table(GFP_KERNEL);
if (!vprop_page) {
- its_lpi_free_chunks(bitmap, base, nr_ids);
+ its_lpi_free(bitmap, base, nr_ids);
return -ENOMEM;
}
@@ -2833,7 +2902,7 @@ static int its_vpe_irq_domain_alloc(struct irq_domain *domain, unsigned int virq
if (i > 0)
its_vpe_irq_domain_free(domain, virq, i - 1);
- its_lpi_free_chunks(bitmap, base, nr_ids);
+ its_lpi_free(bitmap, base, nr_ids);
its_free_prop_table(vprop_page);
}
@@ -3070,7 +3139,7 @@ static int its_save_disable(void)
struct its_node *its;
int err = 0;
- spin_lock(&its_lock);
+ raw_spin_lock(&its_lock);
list_for_each_entry(its, &its_nodes, entry) {
void __iomem *base;
@@ -3102,7 +3171,7 @@ err:
writel_relaxed(its->ctlr_save, base + GITS_CTLR);
}
}
- spin_unlock(&its_lock);
+ raw_spin_unlock(&its_lock);
return err;
}
@@ -3112,7 +3181,7 @@ static void its_restore_enable(void)
struct its_node *its;
int ret;
- spin_lock(&its_lock);
+ raw_spin_lock(&its_lock);
list_for_each_entry(its, &its_nodes, entry) {
void __iomem *base;
int i;
@@ -3164,7 +3233,7 @@ static void its_restore_enable(void)
GITS_TYPER_HCC(gic_read_typer(base + GITS_TYPER)))
its_cpu_init_collection(its);
}
- spin_unlock(&its_lock);
+ raw_spin_unlock(&its_lock);
}
static struct syscore_ops its_syscore_ops = {
@@ -3398,9 +3467,9 @@ static int __init its_probe_one(struct resource *res,
if (err)
goto out_free_tables;
- spin_lock(&its_lock);
+ raw_spin_lock(&its_lock);
list_add(&its->entry, &its_nodes);
- spin_unlock(&its_lock);
+ raw_spin_unlock(&its_lock);
return 0;