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Date: Fri, 26 Jul 2013 14:51:14 +0800
From: Rui Wang <ruiv.wang@...il.com>
To: bhelgaas@...gle.com
Cc: tony.luck@...el.com, chaohong.guo@...el.com,
gong.chen@...ux.intel.com, rafael.j.wysocki@...el.com,
linux-pci@...r.kernel.org, linux-kernel@...r.kernel.org,
Rui Wang <rui.y.wang@...el.com>
Subject: [RFC 2/3] IO Hook: kernel interface to manage the hook
The following kernel functions are exported:
hook_add_ovrd
hook_query_ovrd
hook_cleanup_ovrd
hook_start_ovrd
hook_stop_ovrd
hook_get_status
Kernel modules can use them to add/delete/query Register Overrides, and
to start/stop the hook engine.
Signed-off-by: Rui Wang <rui.y.wang@...el.com>
---
drivers/pci/access.c | 150 ++++++++++++++++++++++++++++++++++++++++++++++
include/linux/reg_ovrd.h | 9 +++
2 files changed, 159 insertions(+), 0 deletions(-)
diff --git a/drivers/pci/access.c b/drivers/pci/access.c
index fe7b282..81428655 100644
--- a/drivers/pci/access.c
+++ b/drivers/pci/access.c
@@ -27,6 +27,156 @@ LIST_HEAD(ovrd_pci_conf_reg_map);
struct static_key ovrdhw_enabled = STATIC_KEY_INIT_FALSE;
EXPORT_SYMBOL(ovrdhw_enabled);
+int g_ovrd_on;
+/* query a Register Override given spaceid and index */
+struct reg_ovrd *hook_query_ovrd(int spaceid, int idx)
+{
+ struct list_head *reg_ovrd;
+ struct reg_ovrd *ovrdreg, *regentry;
+ unsigned long lock_flags = 0;
+ int n = 0;
+
+ if (spaceid == OVRD_SPACE_MEM)
+ reg_ovrd = &ovrd_mem_reg_map;
+ else if (spaceid == OVRD_SPACE_IO)
+ reg_ovrd = &ovrd_io_reg_map;
+ else
+ reg_ovrd = &ovrd_pci_conf_reg_map;
+
+ regentry = NULL;
+ raw_spin_lock_irqsave(&io_hook_lock, lock_flags);
+ list_for_each_entry(ovrdreg, reg_ovrd, node) {
+ if (n++ >= idx) {
+ regentry = ovrdreg;
+ break;
+ }
+ }
+ raw_spin_unlock_irqrestore(&io_hook_lock, lock_flags);
+
+ pr_info("hook_query_ovrd() returns %p, idx=%d\n",
+ regentry, idx);
+ return regentry;
+
+}
+EXPORT_SYMBOL(hook_query_ovrd);
+
+/* delete all Register Overrides from one space (IO/mem/pciconf) */
+void hook_cleanup_ovrd(int spaceid)
+{
+ struct list_head *tmp, *next, *ovrd_list;
+
+ if (spaceid == OVRD_SPACE_MEM)
+ ovrd_list = &ovrd_mem_reg_map;
+ else if (spaceid == OVRD_SPACE_IO)
+ ovrd_list = &ovrd_io_reg_map;
+ else
+ ovrd_list = &ovrd_pci_conf_reg_map;
+
+ list_for_each_safe(tmp, next, ovrd_list) {
+ struct reg_ovrd *ovrdreg =
+ list_entry(tmp, struct reg_ovrd, node);
+ list_del(tmp);
+ kfree(ovrdreg);
+ }
+}
+EXPORT_SYMBOL(hook_cleanup_ovrd);
+
+/* for pci config space, address is encoded per PCI_ENCODE_ADDR() */
+void hook_add_ovrd(int spaceid, u64 address, u64 value, u64 mask,
+ u32 length, u8 attrib)
+{
+ struct list_head *reg_ovrd;
+ struct reg_ovrd *ovrdreg;
+ unsigned long lock_flags = 0;
+
+ if (spaceid == OVRD_SPACE_MEM)
+ reg_ovrd = &ovrd_mem_reg_map;
+ else if (spaceid == OVRD_SPACE_IO)
+ reg_ovrd = &ovrd_io_reg_map;
+ else
+ reg_ovrd = &ovrd_pci_conf_reg_map;
+
+ raw_spin_lock_irqsave(&io_hook_lock, lock_flags);
+ list_for_each_entry(ovrdreg, reg_ovrd, node) {
+ if (ovrdreg->address == address &&
+ ovrdreg->attrib == attrib &&
+ ovrdreg->length == length) {
+ /* if already added the address, just change the bits */
+ ovrdreg->bit_mask |= mask;
+ ovrdreg->val |= value;
+ pr_info("hook_add_ovrd(): 0x%llx already added, changed to 0x%llx, mask:0x%llx, attrib:0x%x\n",
+ address, ovrdreg->val, ovrdreg->bit_mask,
+ attrib);
+ goto out;
+ } else if (address >= ovrdreg->address &&
+ address < ovrdreg->address + ovrdreg->length) {
+ pr_info("hook_add_ovrd(): conflicting reg at 0x%llx, length:%llx, mask:0x%llx, attrib:0x%x\n",
+ address, ovrdreg->val, ovrdreg->bit_mask,
+ attrib);
+ goto out;
+ }
+ }
+
+ raw_spin_unlock_irqrestore(&io_hook_lock, lock_flags);
+
+ ovrdreg = kmalloc(sizeof(struct reg_ovrd), GFP_ATOMIC);
+ if (!ovrdreg) {
+ pr_info("failed to alloc Reg Override!\n");
+ return;
+ }
+
+ ovrdreg->address = address;
+ ovrdreg->val = value;
+ ovrdreg->length = length;
+ ovrdreg->bit_mask = mask;
+ ovrdreg->attrib = attrib;
+ raw_spin_lock_irqsave(&io_hook_lock, lock_flags);
+ list_add_tail(&ovrdreg->node, reg_ovrd);
+out:
+ raw_spin_unlock_irqrestore(&io_hook_lock, lock_flags);
+
+}
+EXPORT_SYMBOL(hook_add_ovrd);
+
+/* to start the hook */
+void hook_start_ovrd(void)
+{
+ unsigned long lock_flags = 0;
+
+ raw_spin_lock_irqsave(&io_hook_lock, lock_flags);
+ if (g_ovrd_on)
+ goto done;
+
+ static_key_slow_inc(&ovrdhw_enabled);
+ g_ovrd_on = 1;
+done:
+ raw_spin_unlock_irqrestore(&io_hook_lock, lock_flags);
+
+}
+EXPORT_SYMBOL(hook_start_ovrd);
+
+/* to stop the hook */
+void hook_stop_ovrd(void)
+{
+ unsigned long lock_flags = 0;
+
+ raw_spin_lock_irqsave(&io_hook_lock, lock_flags);
+ if (!g_ovrd_on)
+ goto done;
+ g_ovrd_on = 0;
+ static_key_slow_dec(&ovrdhw_enabled);
+done:
+ raw_spin_unlock_irqrestore(&io_hook_lock, lock_flags);
+
+}
+EXPORT_SYMBOL(hook_stop_ovrd);
+
+int hook_get_status()
+{
+ return g_ovrd_on;
+}
+EXPORT_SYMBOL(hook_get_status);
+
/* len should only be 1, 2, 4, 8 */
static int mem_read(u64 address, int len, void *data)
{
diff --git a/include/linux/reg_ovrd.h b/include/linux/reg_ovrd.h
index 5f851fe..7a81b58 100644
--- a/include/linux/reg_ovrd.h
+++ b/include/linux/reg_ovrd.h
@@ -42,5 +42,14 @@ struct reg_ovrd {
#define PCI_DECODE_BUSN(x) ((u8)(((x) >> 20) & 0xff))
#define PCI_DECODE_DOMAIN(x) ((u32)((x) >> 32))
+#ifdef CONFIG_IO_HOOK
+void hook_add_ovrd(int spaceid, u64 address, u64 value, u64 mask,
+ u32 length, u8 attrib);
+struct reg_ovrd *hook_query_ovrd(int spaceid, int idx);
+void hook_cleanup_ovrd(int spaceid);
+void hook_start_ovrd(void);
+void hook_stop_ovrd(void);
+int hook_get_status(void);
+#endif /* CONFIG_IO_HOOK */
#endif /* __REG_OVRD_H__ */
--
1.7.5.4
--
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