On 2/6/2023 2:46 AM, Srivatsa Vaddagiri wrote:
* Elliot Berman <quic_eberman@xxxxxxxxxxx> [2023-01-20 14:46:22]:
+static inline bool gh_vm_io_handler_matches(struct gunyah_vm_io_handler *io_hdlr, u64 addr,
+ u64 len, u64 data)
+{
+ u64 mask = BIT_ULL(io_hdlr->len * BITS_PER_BYTE) - 1;
+
+ if (io_hdlr->addr != addr)
Isn't this test redundant (given that caller would have performed same test)?
Done.
+ return false;
+
+ if (!io_hdlr->datamatch)
+ return true;
+
+ if (io_hdlr->len != len)
+ return false;
+
+ return (data & mask) == (io_hdlr->data & mask);
+}
+
+static struct gunyah_vm_io_handler *gh_vm_mgr_find_io_hdlr(struct gunyah_vm *ghvm, u64 addr,
+ u64 len, u64 data)
+{
+ struct gunyah_vm_io_handler *io_hdlr = NULL;
+ struct rb_node *root = NULL;
+
+ root = ghvm->mmio_handler_root.rb_node;
+ while (root) {
+ io_hdlr = rb_entry(root, struct gunyah_vm_io_handler, node);
+ if (addr < io_hdlr->addr)
+ root = root->rb_left;
+ else if (addr > io_hdlr->addr)
+ root = root->rb_right;
+ else if (gh_vm_io_handler_matches(io_hdlr, addr, len, data))
In case of handler not matching, don't we need to modify root?
Otherwise we can be stuck in infinite loop here AFAICS.
Done.
+ return io_hdlr;
+ }
+ return NULL;
+}
// snip
+int gh_vm_mgr_add_io_handler(struct gunyah_vm *ghvm, struct gunyah_vm_io_handler *io_hdlr)
+{
+ struct rb_node **root, *parent = NULL;
+
+ if (io_hdlr->datamatch &&
+ (!io_hdlr->len || io_hdlr->len > (sizeof(io_hdlr->data) * BITS_PER_BYTE)))
+ return -EINVAL;
+
+ root = &ghvm->mmio_handler_root.rb_node;
+ while (*root) {
+ struct gunyah_vm_io_handler *curr = rb_entry(*root, struct gunyah_vm_io_handler,
+ node);
+
+ parent = *root;
+ if (io_hdlr->addr < curr->addr)
+ root = &((*root)->rb_left);
+ else if (io_hdlr->addr > curr->addr)
+ root = &((*root)->rb_right);
+ else
We should allow two io_handlers on the same addr, but with different data
matches I think.
Done.
+ return -EEXIST;
+ }
+
+ rb_link_node(&io_hdlr->node, parent, root);
+ rb_insert_color(&io_hdlr->node, &ghvm->mmio_handler_root);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(gh_vm_mgr_add_io_handler);
