[RFC PATCH v2 2/8] ACPI/IORT: Add support for RMR node parsing
Shameerali Kolothum Thodi
shameerali.kolothum.thodi at huawei.com
Thu Apr 15 11:30:03 BST 2021
Hi Eric,
> -----Original Message-----
> From: Auger Eric [mailto:eric.auger at redhat.com]
> Sent: 15 April 2021 10:39
> To: Shameerali Kolothum Thodi <shameerali.kolothum.thodi at huawei.com>;
> linux-arm-kernel at lists.infradead.org; linux-acpi at vger.kernel.org;
> iommu at lists.linux-foundation.org; devel at acpica.org
> Cc: Linuxarm <linuxarm at huawei.com>; steven.price at arm.com; Guohanjun
> (Hanjun Guo) <guohanjun at huawei.com>; Sami.Mujawar at arm.com;
> robin.murphy at arm.com; wanghuiqiang <wanghuiqiang at huawei.com>
> Subject: Re: [RFC PATCH v2 2/8] ACPI/IORT: Add support for RMR node parsing
>
> Hi Shameer,
> On 11/19/20 1:11 PM, Shameer Kolothum wrote:
> > Add support for parsing RMR node information from ACPI.
> > Find associated stream ids and smmu node info from the
> > RMR node and populate a linked list with RMR memory
> > descriptors.
> >
> > Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi at huawei.com>
> > ---
> > drivers/acpi/arm64/iort.c | 122
> +++++++++++++++++++++++++++++++++++++-
> > 1 file changed, 121 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
> > index 9929ff50c0c0..a9705aa35028 100644
> > --- a/drivers/acpi/arm64/iort.c
> > +++ b/drivers/acpi/arm64/iort.c
> > @@ -40,6 +40,25 @@ struct iort_fwnode {
> > static LIST_HEAD(iort_fwnode_list);
> > static DEFINE_SPINLOCK(iort_fwnode_lock);
> >
> > +struct iort_rmr_id {
> > + u32 sid;
> > + struct acpi_iort_node *smmu;
> > +};
> > +
> > +/*
> > + * One entry for IORT RMR.
> > + */
> > +struct iort_rmr_entry {
> > + struct list_head list;
> > +
> > + unsigned int rmr_ids_num;
> > + struct iort_rmr_id *rmr_ids;
> > +
> > + struct acpi_iort_rmr_desc *rmr_desc;
> > +};
> > +
> > +static LIST_HEAD(iort_rmr_list); /* list of RMR regions from ACPI
> */
> > +
> > /**
> > * iort_set_fwnode() - Create iort_fwnode and use it to register
> > * iommu data in the iort_fwnode_list
> > @@ -393,7 +412,8 @@ static struct acpi_iort_node
> *iort_node_get_id(struct acpi_iort_node *node,
> > if (node->type == ACPI_IORT_NODE_NAMED_COMPONENT ||
> > node->type == ACPI_IORT_NODE_PCI_ROOT_COMPLEX ||
> > node->type == ACPI_IORT_NODE_SMMU_V3 ||
> > - node->type == ACPI_IORT_NODE_PMCG) {
> > + node->type == ACPI_IORT_NODE_PMCG ||
> > + node->type == ACPI_IORT_NODE_RMR) {
> > *id_out = map->output_base;
> > return parent;
> > }
> > @@ -1647,6 +1667,103 @@ static void __init iort_enable_acs(struct
> acpi_iort_node *iort_node)
> > #else
> > static inline void iort_enable_acs(struct acpi_iort_node *iort_node) { }
> > #endif
> > +static int iort_rmr_desc_valid(struct acpi_iort_rmr_desc *desc)
> > +{
> > + struct iort_rmr_entry *e;
> > + u64 end, start = desc->base_address, length = desc->length;
> > +
> > + if (!IS_ALIGNED(start, SZ_64K) || !IS_ALIGNED(length, SZ_64K))
> > + return -EINVAL;
> > +
> > + end = start + length - 1;
> > +
> > + /* Check for address overlap */
> I don't get this check. What is the problem if you attach the same range
> to different stream ids. Shouldn't you check there is no overlap for the
> same sid?
That’s right. The check should be for memory descriptors within an RMR.
I got confused by the wordings in the IORT spec and that is now clarified
with Lorenzo here,
https://op-lists.linaro.org/pipermail/linaro-open-discussions/2021-April/000150.html
I will change this.
>
>
> > + list_for_each_entry(e, &iort_rmr_list, list) {
> > + u64 e_start = e->rmr_desc->base_address;
> > + u64 e_end = e_start + e->rmr_desc->length - 1;
> > +
> > + if (start <= e_end && end >= e_start)
> > + return -EINVAL;
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +static int __init iort_parse_rmr(struct acpi_iort_node *iort_node)
> > +{
> > + struct iort_rmr_id *rmr_ids, *ids;
> > + struct iort_rmr_entry *e;
> > + struct acpi_iort_rmr *rmr;
> > + struct acpi_iort_rmr_desc *rmr_desc;
> > + u32 map_count = iort_node->mapping_count;
> > + int i, ret = 0, desc_count = 0;
> > +
> > + if (iort_node->type != ACPI_IORT_NODE_RMR)
> > + return 0;
> > +
> > + if (!iort_node->mapping_offset || !map_count) {
> > + pr_err(FW_BUG "Invalid ID mapping, skipping RMR node %p\n",
> > + iort_node);
> > + return -EINVAL;
> > + }
> > +
> > + rmr_ids = kmalloc(sizeof(*rmr_ids) * map_count, GFP_KERNEL);
> > + if (!rmr_ids)
> > + return -ENOMEM;
> > +
> > + /* Retrieve associated smmu and stream id */
> > + ids = rmr_ids;
> nit: do you need both rmr_ids and ids?
Not really as the spec says it is M:1 mapping. So we only will have one
single id here(also map_count for the node must be set to 1 as well).
> > + for (i = 0; i < map_count; i++, ids++) {
> > + ids->smmu = iort_node_get_id(iort_node, &ids->sid, i);
> > + if (!ids->smmu) {
> > + pr_err(FW_BUG "Invalid SMMU reference, skipping RMR
> node %p\n",
> > + iort_node);
> > + ret = -EINVAL;
> > + goto out;
> > + }
> > + }
> > +
> > + /* Retrieve RMR data */
> > + rmr = (struct acpi_iort_rmr *)iort_node->node_data;
> > + if (!rmr->rmr_offset || !rmr->rmr_count) {
> > + pr_err(FW_BUG "Invalid RMR descriptor array, skipping RMR
> node %p\n",
> > + iort_node);
> > + ret = -EINVAL;
> > + goto out;
> > + }
> > +
> > + rmr_desc = ACPI_ADD_PTR(struct acpi_iort_rmr_desc, iort_node,
> > + rmr->rmr_offset);
> > +
> > + for (i = 0; i < rmr->rmr_count; i++, rmr_desc++) {
> > + ret = iort_rmr_desc_valid(rmr_desc);
> > + if (ret) {
> > + pr_err(FW_BUG "Invalid RMR descriptor[%d] for node %p,
> skipping...\n",
> > + i, iort_node);
> > + goto out;
> so I understand you skip the whole node and not just that rmr desc,
> otherwise you would continue. so in that case don't you need to free
> both rmr_ids and already allocated 'e'?
Agree. This needs to be changed.
> > + }
> > +
> > + e = kmalloc(sizeof(*e), GFP_KERNEL);
> > + if (!e) {
> > + ret = -ENOMEM;
> > + goto out;
> > + }
> > +
> > + e->rmr_ids_num = map_count;
> > + e->rmr_ids = rmr_ids;
> > + e->rmr_desc = rmr_desc;
> > +
> > + list_add_tail(&e->list, &iort_rmr_list);
> > + desc_count++;
> > + }
> > +
> > + return 0;
> > +
> > +out:
> > + if (!desc_count)
> don't you want to test ret instead? see comment above. + free allocated ''e'
Right. I will change it next revision.
Thanks for taking a look.
Regards,
Shameer
> > + kfree(rmr_ids);
> > + return ret;
> > +}
> >
> > static void __init iort_init_platform_devices(void)
> > {
> > @@ -1676,6 +1793,9 @@ static void __init iort_init_platform_devices(void)
> >
> > iort_enable_acs(iort_node);
> >
> > + if (iort_table->revision == 1)
> > + iort_parse_rmr(iort_node);
> > +
> > ops = iort_get_dev_cfg(iort_node);
> > if (ops) {
> > fwnode = acpi_alloc_fwnode_static();
> >
> Thanks
>
> Eric
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