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Subject[PATCH v3 2/5] I/O Hook: Help functions to manage the hook
Date
Add the following kernel helper functions used to add/delete/query Register
Overrides, and to start/stop the I/O Hook:
iohook_add_ovrd
iohook_query_ovrd
iohook_cleanup_ovrd
iohook_start_ovrd
iohook_stop_ovrd
iohook_get_status

Signed-off-by: Rui Wang <rui.y.wang@intel.com>
---
drivers/misc/iohook/iohook.c | 151 ++++++++++++++++++++++++++++++++++++++++++
1 files changed, 151 insertions(+), 0 deletions(-)

diff --git a/drivers/misc/iohook/iohook.c b/drivers/misc/iohook/iohook.c
index e6a626f..d8c41d0 100644
--- a/drivers/misc/iohook/iohook.c
+++ b/drivers/misc/iohook/iohook.c
@@ -6,6 +6,7 @@
#include "iohook.h"

static DEFINE_RAW_SPINLOCK(io_hook_lock);
+static DEFINE_RAW_SPINLOCK(engine_lock);

LIST_HEAD(ovrd_io_reg_map);
LIST_HEAD(ovrd_mem_reg_map);
@@ -14,6 +15,150 @@ 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 *iohook_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("iohook_query_ovrd() returns %p, idx=%d\n",
+ regentry, idx);
+ return regentry;
+
+}
+
+/* delete all Register Overrides from one space (IO/mem/pciconf) */
+void iohook_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);
+ }
+}
+
+/* for pci config space, address is encoded per PCI_ENCODE_ADDR() */
+void iohook_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("iohook_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("iohook_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);
+
+}
+
+/* to start the hook */
+void iohook_start_ovrd(void)
+{
+ unsigned long lock_flags = 0;
+
+ raw_spin_lock_irqsave(&engine_lock, lock_flags);
+ if (g_ovrd_on)
+ goto done;
+
+ static_key_slow_inc(&ovrdhw_enabled);
+ g_ovrd_on = 1;
+done:
+ raw_spin_unlock_irqrestore(&engine_lock, lock_flags);
+
+}
+
+/* to stop the hook */
+void iohook_stop_ovrd(void)
+{
+ unsigned long lock_flags = 0;
+
+ raw_spin_lock_irqsave(&engine_lock, lock_flags);
+ if (!g_ovrd_on)
+ goto done;
+ g_ovrd_on = 0;
+ static_key_slow_dec(&ovrdhw_enabled);
+done:
+ raw_spin_unlock_irqrestore(&engine_lock, lock_flags);
+
+}
+
+int iohook_get_status(void)
+{
+ return g_ovrd_on;
+}
+
/* len should only be 1, 2, 4, 8 */
static int mem_read(u64 address, int len, void *data)
{
@@ -170,6 +315,9 @@ int read_ovrd_common(int spaceid, u64 address, int len, void *value, void *bus)

ret = -EINVAL;

+ if (!g_ovrd_on)
+ return ret;
+
if (spaceid == OVRD_SPACE_MEM) {
/* in the case of memory, 'address' is virtual */
vaddr = address;
@@ -300,6 +448,9 @@ int write_ovrd_common(int spaceid, u64 address, int len, void *data, void *bus)

ret = -EINVAL;

+ if (!g_ovrd_on)
+ return ret;
+
if (spaceid == OVRD_SPACE_MEM) {
/* in the case of memory, 'address' is virtual */
vaddr = address;
--
1.7.5.4


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