[PATCH 4.1 051/123] irqchip/gicv3-its: Fix mapping of LPIs to collections

From: Greg Kroah-Hartman
Date: Sat Aug 08 2015 - 18:15:41 EST


4.1-stable review patch. If anyone has any objections, please let me know.

------------------

From: Marc Zyngier <marc.zyngier@xxxxxxx>

commit 591e5bec13f15feb13fc445b6c9c59954711c4ac upstream.

The GICv3 ITS architecture allows a given [DevID, EventID] pair to be
translated to a [LPI, Collection] pair, where DevID is the device writing
the MSI, EventID is the payload being written, LPI is the actual
interrupt number, and Collection is roughly equivalent to a target CPU.

Each LPI can be mapped to a separate collection, but the ITS driver
insists on maintaining the collection on a device basis, instead of doing
it on a per interrupt basis.

This is obviously flawed, and this patch fixes it by adding a per interrupt
index that indicates which collection number is in use.

Reported-by: Ian Campbell <ian.campbell@xxxxxxxxxx>
Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
Cc: <linux-arm-kernel@xxxxxxxxxxxxxxxxxxx>
Cc: Jason Cooper <jason@xxxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/1437126402-11677-1-git-send-email-marc.zyngier@xxxxxxx
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/irqchip/irq-gic-v3-its.c | 111 ++++++++++++++++++++++++++-------------
1 file changed, 75 insertions(+), 36 deletions(-)

--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -75,6 +75,13 @@ struct its_node {

#define ITS_ITT_ALIGN SZ_256

+struct event_lpi_map {
+ unsigned long *lpi_map;
+ u16 *col_map;
+ irq_hw_number_t lpi_base;
+ int nr_lpis;
+};
+
/*
* The ITS view of a device - belongs to an ITS, a collection, owns an
* interrupt translation table, and a list of interrupts.
@@ -82,11 +89,8 @@ struct its_node {
struct its_device {
struct list_head entry;
struct its_node *its;
- struct its_collection *collection;
+ struct event_lpi_map event_map;
void *itt;
- unsigned long *lpi_map;
- irq_hw_number_t lpi_base;
- int nr_lpis;
u32 nr_ites;
u32 device_id;
};
@@ -99,6 +103,14 @@ static struct rdists *gic_rdists;
#define gic_data_rdist() (raw_cpu_ptr(gic_rdists->rdist))
#define gic_data_rdist_rd_base() (gic_data_rdist()->rd_base)

+static struct its_collection *dev_event_to_col(struct its_device *its_dev,
+ u32 event)
+{
+ struct its_node *its = its_dev->its;
+
+ return its->collections + its_dev->event_map.col_map[event];
+}
+
/*
* ITS command descriptors - parameters to be encoded in a command
* block.
@@ -134,7 +146,7 @@ struct its_cmd_desc {
struct {
struct its_device *dev;
struct its_collection *col;
- u32 id;
+ u32 event_id;
} its_movi_cmd;

struct {
@@ -241,7 +253,7 @@ static struct its_collection *its_build_

its_fixup_cmd(cmd);

- return desc->its_mapd_cmd.dev->collection;
+ return NULL;
}

static struct its_collection *its_build_mapc_cmd(struct its_cmd_block *cmd,
@@ -260,52 +272,72 @@ static struct its_collection *its_build_
static struct its_collection *its_build_mapvi_cmd(struct its_cmd_block *cmd,
struct its_cmd_desc *desc)
{
+ struct its_collection *col;
+
+ col = dev_event_to_col(desc->its_mapvi_cmd.dev,
+ desc->its_mapvi_cmd.event_id);
+
its_encode_cmd(cmd, GITS_CMD_MAPVI);
its_encode_devid(cmd, desc->its_mapvi_cmd.dev->device_id);
its_encode_event_id(cmd, desc->its_mapvi_cmd.event_id);
its_encode_phys_id(cmd, desc->its_mapvi_cmd.phys_id);
- its_encode_collection(cmd, desc->its_mapvi_cmd.dev->collection->col_id);
+ its_encode_collection(cmd, col->col_id);

its_fixup_cmd(cmd);

- return desc->its_mapvi_cmd.dev->collection;
+ return col;
}

static struct its_collection *its_build_movi_cmd(struct its_cmd_block *cmd,
struct its_cmd_desc *desc)
{
+ struct its_collection *col;
+
+ col = dev_event_to_col(desc->its_movi_cmd.dev,
+ desc->its_movi_cmd.event_id);
+
its_encode_cmd(cmd, GITS_CMD_MOVI);
its_encode_devid(cmd, desc->its_movi_cmd.dev->device_id);
- its_encode_event_id(cmd, desc->its_movi_cmd.id);
+ its_encode_event_id(cmd, desc->its_movi_cmd.event_id);
its_encode_collection(cmd, desc->its_movi_cmd.col->col_id);

its_fixup_cmd(cmd);

- return desc->its_movi_cmd.dev->collection;
+ return col;
}

static struct its_collection *its_build_discard_cmd(struct its_cmd_block *cmd,
struct its_cmd_desc *desc)
{
+ struct its_collection *col;
+
+ col = dev_event_to_col(desc->its_discard_cmd.dev,
+ desc->its_discard_cmd.event_id);
+
its_encode_cmd(cmd, GITS_CMD_DISCARD);
its_encode_devid(cmd, desc->its_discard_cmd.dev->device_id);
its_encode_event_id(cmd, desc->its_discard_cmd.event_id);

its_fixup_cmd(cmd);

- return desc->its_discard_cmd.dev->collection;
+ return col;
}

static struct its_collection *its_build_inv_cmd(struct its_cmd_block *cmd,
struct its_cmd_desc *desc)
{
+ struct its_collection *col;
+
+ col = dev_event_to_col(desc->its_inv_cmd.dev,
+ desc->its_inv_cmd.event_id);
+
its_encode_cmd(cmd, GITS_CMD_INV);
its_encode_devid(cmd, desc->its_inv_cmd.dev->device_id);
its_encode_event_id(cmd, desc->its_inv_cmd.event_id);

its_fixup_cmd(cmd);

- return desc->its_inv_cmd.dev->collection;
+ return col;
}

static struct its_collection *its_build_invall_cmd(struct its_cmd_block *cmd,
@@ -497,7 +529,7 @@ static void its_send_movi(struct its_dev

desc.its_movi_cmd.dev = dev;
desc.its_movi_cmd.col = col;
- desc.its_movi_cmd.id = id;
+ desc.its_movi_cmd.event_id = id;

its_send_single_command(dev->its, its_build_movi_cmd, &desc);
}
@@ -528,7 +560,7 @@ static void its_send_invall(struct its_n
static inline u32 its_get_event_id(struct irq_data *d)
{
struct its_device *its_dev = irq_data_get_irq_chip_data(d);
- return d->hwirq - its_dev->lpi_base;
+ return d->hwirq - its_dev->event_map.lpi_base;
}

static void lpi_set_config(struct irq_data *d, bool enable)
@@ -583,7 +615,7 @@ static int its_set_affinity(struct irq_d

target_col = &its_dev->its->collections[cpu];
its_send_movi(its_dev, target_col, id);
- its_dev->collection = target_col;
+ its_dev->event_map.col_map[id] = cpu;

return IRQ_SET_MASK_OK_DONE;
}
@@ -713,8 +745,10 @@ out:
return bitmap;
}

-static void its_lpi_free(unsigned long *bitmap, int base, int nr_ids)
+static void its_lpi_free(struct event_lpi_map *map)
{
+ int base = map->lpi_base;
+ int nr_ids = map->nr_lpis;
int lpi;

spin_lock(&lpi_lock);
@@ -731,7 +765,8 @@ static void its_lpi_free(unsigned long *

spin_unlock(&lpi_lock);

- kfree(bitmap);
+ kfree(map->lpi_map);
+ kfree(map->col_map);
}

/*
@@ -1099,11 +1134,11 @@ static struct its_device *its_create_dev
struct its_device *dev;
unsigned long *lpi_map;
unsigned long flags;
+ u16 *col_map = NULL;
void *itt;
int lpi_base;
int nr_lpis;
int nr_ites;
- int cpu;
int sz;

dev = kzalloc(sizeof(*dev), GFP_KERNEL);
@@ -1117,20 +1152,24 @@ static struct its_device *its_create_dev
sz = max(sz, ITS_ITT_ALIGN) + ITS_ITT_ALIGN - 1;
itt = kzalloc(sz, GFP_KERNEL);
lpi_map = its_lpi_alloc_chunks(nvecs, &lpi_base, &nr_lpis);
+ if (lpi_map)
+ col_map = kzalloc(sizeof(*col_map) * nr_lpis, GFP_KERNEL);

- if (!dev || !itt || !lpi_map) {
+ if (!dev || !itt || !lpi_map || !col_map) {
kfree(dev);
kfree(itt);
kfree(lpi_map);
+ kfree(col_map);
return NULL;
}

dev->its = its;
dev->itt = itt;
dev->nr_ites = nr_ites;
- dev->lpi_map = lpi_map;
- dev->lpi_base = lpi_base;
- dev->nr_lpis = nr_lpis;
+ dev->event_map.lpi_map = lpi_map;
+ dev->event_map.col_map = col_map;
+ dev->event_map.lpi_base = lpi_base;
+ dev->event_map.nr_lpis = nr_lpis;
dev->device_id = dev_id;
INIT_LIST_HEAD(&dev->entry);

@@ -1138,10 +1177,6 @@ static struct its_device *its_create_dev
list_add(&dev->entry, &its->its_device_list);
raw_spin_unlock_irqrestore(&its->lock, flags);

- /* Bind the device to the first possible CPU */
- cpu = cpumask_first(cpu_online_mask);
- dev->collection = &its->collections[cpu];
-
/* Map device to its ITT */
its_send_mapd(dev, 1);

@@ -1163,12 +1198,13 @@ static int its_alloc_device_irq(struct i
{
int idx;

- idx = find_first_zero_bit(dev->lpi_map, dev->nr_lpis);
- if (idx == dev->nr_lpis)
+ idx = find_first_zero_bit(dev->event_map.lpi_map,
+ dev->event_map.nr_lpis);
+ if (idx == dev->event_map.nr_lpis)
return -ENOSPC;

- *hwirq = dev->lpi_base + idx;
- set_bit(idx, dev->lpi_map);
+ *hwirq = dev->event_map.lpi_base + idx;
+ set_bit(idx, dev->event_map.lpi_map);

return 0;
}
@@ -1288,7 +1324,8 @@ static int its_irq_domain_alloc(struct i
irq_domain_set_hwirq_and_chip(domain, virq + i,
hwirq, &its_irq_chip, its_dev);
dev_dbg(info->scratchpad[1].ptr, "ID:%d pID:%d vID:%d\n",
- (int)(hwirq - its_dev->lpi_base), (int)hwirq, virq + i);
+ (int)(hwirq - its_dev->event_map.lpi_base),
+ (int)hwirq, virq + i);
}

return 0;
@@ -1300,6 +1337,9 @@ static void its_irq_domain_activate(stru
struct its_device *its_dev = irq_data_get_irq_chip_data(d);
u32 event = its_get_event_id(d);

+ /* Bind the LPI to the first possible CPU */
+ its_dev->event_map.col_map[event] = cpumask_first(cpu_online_mask);
+
/* Map the GIC IRQ and event to the device */
its_send_mapvi(its_dev, d->hwirq, event);
}
@@ -1327,17 +1367,16 @@ static void its_irq_domain_free(struct i
u32 event = its_get_event_id(data);

/* Mark interrupt index as unused */
- clear_bit(event, its_dev->lpi_map);
+ clear_bit(event, its_dev->event_map.lpi_map);

/* Nuke the entry in the domain */
irq_domain_reset_irq_data(data);
}

/* If all interrupts have been freed, start mopping the floor */
- if (bitmap_empty(its_dev->lpi_map, its_dev->nr_lpis)) {
- its_lpi_free(its_dev->lpi_map,
- its_dev->lpi_base,
- its_dev->nr_lpis);
+ if (bitmap_empty(its_dev->event_map.lpi_map,
+ its_dev->event_map.nr_lpis)) {
+ its_lpi_free(&its_dev->event_map);

/* Unmap device/itt */
its_send_mapd(its_dev, 0);


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