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@xxxxxxxxx> --- 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 -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html