We are not checking whether the requested device identifier fits into the device table memory or not. The function its_create_device() assumes that enough memory has been allocated for whole DevID space (reported by ITS_TYPER.Devbits) during the ITS probe() and continues to initialize ITS hardware.
This assumption is not perfect, sometimes we reduce memory size either because of its size crossing MAX_ORDER-1 or BASERn max size limit. The MAPD command fails if 'Device ID' is outside of device table range. Add a simple validation check to avoid MAPD failures since we are not handling ITS command errors. This change also helps to return an error -ENOMEM instead of success to caller. Signed-off-by: Shanker Donthineni <[email protected]> --- [v3]->[v4] Cleanup code based on Marc's comments, remove the variable 'device_table' and extend validation check to cover case ITS HW with on-chip device table memory. [v2]->[v3] Fix typo. [v1]->[v2] Rebase to v4.5-rc6, edit commit text and simplify code changes. drivers/irqchip/irq-gic-v3-its.c | 42 ++++++++++++++++++++++++++++++++++++---- 1 file changed, 38 insertions(+), 4 deletions(-) diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c index 43dfd15..d50d837 100644 --- a/drivers/irqchip/irq-gic-v3-its.c +++ b/drivers/irqchip/irq-gic-v3-its.c @@ -55,6 +55,16 @@ struct its_collection { }; /* + * The ITS_BASER structure - contains memory information and cached + * value of BASER register configuration. + */ +struct its_baser { + void *base; + u64 val; + u32 order; +}; + +/* * The ITS structure - contains most of the infrastructure, with the * top-level MSI domain, the command queue, the collections, and the * list of devices writing to it. @@ -66,14 +76,12 @@ struct its_node { unsigned long phys_base; struct its_cmd_block *cmd_base; struct its_cmd_block *cmd_write; - struct { - void *base; - u32 order; - } tables[GITS_BASER_NR_REGS]; + struct its_baser tables[GITS_BASER_NR_REGS]; struct its_collection *collections; struct list_head its_device_list; u64 flags; u32 ite_size; + u32 device_ids; }; #define ITS_ITT_ALIGN SZ_256 @@ -839,6 +847,8 @@ static int its_alloc_tables(const char *node_name, struct its_node *its) ids = GITS_TYPER_DEVBITS(typer); } + its->device_ids = ids; + for (i = 0; i < GITS_BASER_NR_REGS; i++) { u64 val = readq_relaxed(its->base + GITS_BASER + i * 8); u64 type = GITS_BASER_TYPE(val); @@ -914,6 +924,7 @@ retry_baser: } val |= alloc_pages - 1; + its->tables[i].val = val; writeq_relaxed(val, its->base + GITS_BASER + i * 8); tmp = readq_relaxed(its->base + GITS_BASER + i * 8); @@ -1139,9 +1150,22 @@ static struct its_device *its_find_device(struct its_node *its, u32 dev_id) return its_dev; } +static struct its_baser *its_get_baser(struct its_node *its, u32 type) +{ + int i; + + for (i = 0; i < GITS_BASER_NR_REGS; i++) { + if (GITS_BASER_TYPE(its->tables[i].val) == type) + return &its->tables[i]; + } + + return NULL; +} + static struct its_device *its_create_device(struct its_node *its, u32 dev_id, int nvecs) { + struct its_baser *baser; struct its_device *dev; unsigned long *lpi_map; unsigned long flags; @@ -1152,6 +1176,16 @@ static struct its_device *its_create_device(struct its_node *its, u32 dev_id, int nr_ites; int sz; + baser = its_get_baser(its, GITS_BASER_TYPE_DEVICE); + + /* Don't allow 'dev_id' that exceeds single, flat table limit */ + if (baser) { + if (dev_id >= (PAGE_ORDER_TO_SIZE(baser->order) / + GITS_BASER_ENTRY_SIZE(baser->val))) + return NULL; + } else if (ilog2(dev_id) >= its->device_ids) + return NULL; + dev = kzalloc(sizeof(*dev), GFP_KERNEL); /* * At least one bit of EventID is being used, hence a minimum -- Qualcomm Technologies, Inc. on behalf of Qualcomm Innovation Center, Inc. Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project
