From: Nathan Lynch <nath...@linux.ibm.com>
Users of rtas_token() supply a string argument that can't be validated
at build time. A typo or misspelling has to be caught by inspection or
by observing wrong behavior at runtime.
Since the core RTAS code now has consolidated the names of all
possible RTAS functions and mapped them to their tokens, token lookup
can be implemented using symbolic constants to index a static array.
So introduce rtas_function_token(), a replacement API which does that,
along with a rtas_service_present()-equivalent helper,
rtas_function_implemented(). Callers supply an opaque predefined
function handle which is used internally to index the function
table. Typos or other inappropriate arguments yield build errors, and
the function handle is a type that can't be easily confused with RTAS
tokens or other integer types.
Signed-off-by: Nathan Lynch <nath...@linux.ibm.com>
---
arch/powerpc/include/asm/rtas.h | 99 +++++++++++++++++++++++++++++++++++++++++
arch/powerpc/kernel/rtas.c | 28 +++++++++++-
2 files changed, 126 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/include/asm/rtas.h b/arch/powerpc/include/asm/rtas.h
index f03891891a2d..3abe15ac79db 100644
--- a/arch/powerpc/include/asm/rtas.h
+++ b/arch/powerpc/include/asm/rtas.h
@@ -101,6 +101,100 @@ enum rtas_function_index {
RTAS_FNIDX__WRITE_PCI_CONFIG,
};
+/*
+ * Opaque handle for client code to refer to RTAS functions. All valid
+ * function handles are build-time constants prefixed with RTAS_FN_.
+ */
+typedef struct {
+ const enum rtas_function_index index;
+} rtas_fn_handle_t;
+
+
+#define rtas_fn_handle(x_) ((const rtas_fn_handle_t) { .index = x_, })
+
+#define RTAS_FN_CHECK_EXCEPTION
rtas_fn_handle(RTAS_FNIDX__CHECK_EXCEPTION)
+#define RTAS_FN_DISPLAY_CHARACTER
rtas_fn_handle(RTAS_FNIDX__DISPLAY_CHARACTER)
+#define RTAS_FN_EVENT_SCAN
rtas_fn_handle(RTAS_FNIDX__EVENT_SCAN)
+#define RTAS_FN_FREEZE_TIME_BASE
rtas_fn_handle(RTAS_FNIDX__FREEZE_TIME_BASE)
+#define RTAS_FN_GET_POWER_LEVEL
rtas_fn_handle(RTAS_FNIDX__GET_POWER_LEVEL)
+#define RTAS_FN_GET_SENSOR_STATE
rtas_fn_handle(RTAS_FNIDX__GET_SENSOR_STATE)
+#define RTAS_FN_GET_TERM_CHAR
rtas_fn_handle(RTAS_FNIDX__GET_TERM_CHAR)
+#define RTAS_FN_GET_TIME_OF_DAY
rtas_fn_handle(RTAS_FNIDX__GET_TIME_OF_DAY)
+#define RTAS_FN_IBM_ACTIVATE_FIRMWARE
rtas_fn_handle(RTAS_FNIDX__IBM_ACTIVATE_FIRMWARE)
+#define RTAS_FN_IBM_CBE_START_PTCAL
rtas_fn_handle(RTAS_FNIDX__IBM_CBE_START_PTCAL)
+#define RTAS_FN_IBM_CBE_STOP_PTCAL
rtas_fn_handle(RTAS_FNIDX__IBM_CBE_STOP_PTCAL)
+#define RTAS_FN_IBM_CHANGE_MSI
rtas_fn_handle(RTAS_FNIDX__IBM_CHANGE_MSI)
+#define RTAS_FN_IBM_CLOSE_ERRINJCT
rtas_fn_handle(RTAS_FNIDX__IBM_CLOSE_ERRINJCT)
+#define RTAS_FN_IBM_CONFIGURE_BRIDGE
rtas_fn_handle(RTAS_FNIDX__IBM_CONFIGURE_BRIDGE)
+#define RTAS_FN_IBM_CONFIGURE_CONNECTOR
rtas_fn_handle(RTAS_FNIDX__IBM_CONFIGURE_CONNECTOR)
+#define RTAS_FN_IBM_CONFIGURE_KERNEL_DUMP
rtas_fn_handle(RTAS_FNIDX__IBM_CONFIGURE_KERNEL_DUMP)
+#define RTAS_FN_IBM_CONFIGURE_PE
rtas_fn_handle(RTAS_FNIDX__IBM_CONFIGURE_PE)
+#define RTAS_FN_IBM_CREATE_PE_DMA_WINDOW
rtas_fn_handle(RTAS_FNIDX__IBM_CREATE_PE_DMA_WINDOW)
+#define RTAS_FN_IBM_DISPLAY_MESSAGE
rtas_fn_handle(RTAS_FNIDX__IBM_DISPLAY_MESSAGE)
+#define RTAS_FN_IBM_ERRINJCT
rtas_fn_handle(RTAS_FNIDX__IBM_ERRINJCT)
+#define RTAS_FN_IBM_EXTI2C
rtas_fn_handle(RTAS_FNIDX__IBM_EXTI2C)
+#define RTAS_FN_IBM_GET_CONFIG_ADDR_INFO
rtas_fn_handle(RTAS_FNIDX__IBM_GET_CONFIG_ADDR_INFO)
+#define RTAS_FN_IBM_GET_CONFIG_ADDR_INFO2
rtas_fn_handle(RTAS_FNIDX__IBM_GET_CONFIG_ADDR_INFO2)
+#define RTAS_FN_IBM_GET_DYNAMIC_SENSOR_STATE
rtas_fn_handle(RTAS_FNIDX__IBM_GET_DYNAMIC_SENSOR_STATE)
+#define RTAS_FN_IBM_GET_INDICES
rtas_fn_handle(RTAS_FNIDX__IBM_GET_INDICES)
+#define RTAS_FN_IBM_GET_RIO_TOPOLOGY
rtas_fn_handle(RTAS_FNIDX__IBM_GET_RIO_TOPOLOGY)
+#define RTAS_FN_IBM_GET_SYSTEM_PARAMETER
rtas_fn_handle(RTAS_FNIDX__IBM_GET_SYSTEM_PARAMETER)
+#define RTAS_FN_IBM_GET_VPD
rtas_fn_handle(RTAS_FNIDX__IBM_GET_VPD)
+#define RTAS_FN_IBM_GET_XIVE
rtas_fn_handle(RTAS_FNIDX__IBM_GET_XIVE)
+#define RTAS_FN_IBM_INT_OFF
rtas_fn_handle(RTAS_FNIDX__IBM_INT_OFF)
+#define RTAS_FN_IBM_INT_ON
rtas_fn_handle(RTAS_FNIDX__IBM_INT_ON)
+#define RTAS_FN_IBM_IO_QUIESCE_ACK
rtas_fn_handle(RTAS_FNIDX__IBM_IO_QUIESCE_ACK)
+#define RTAS_FN_IBM_LPAR_PERFTOOLS
rtas_fn_handle(RTAS_FNIDX__IBM_LPAR_PERFTOOLS)
+#define RTAS_FN_IBM_MANAGE_FLASH_IMAGE
rtas_fn_handle(RTAS_FNIDX__IBM_MANAGE_FLASH_IMAGE)
+#define RTAS_FN_IBM_MANAGE_STORAGE_PRESERVATION
rtas_fn_handle(RTAS_FNIDX__IBM_MANAGE_STORAGE_PRESERVATION)
+#define RTAS_FN_IBM_NMI_INTERLOCK
rtas_fn_handle(RTAS_FNIDX__IBM_NMI_INTERLOCK)
+#define RTAS_FN_IBM_NMI_REGISTER
rtas_fn_handle(RTAS_FNIDX__IBM_NMI_REGISTER)
+#define RTAS_FN_IBM_OPEN_ERRINJCT
rtas_fn_handle(RTAS_FNIDX__IBM_OPEN_ERRINJCT)
+#define RTAS_FN_IBM_OPEN_SRIOV_ALLOW_UNFREEZE
rtas_fn_handle(RTAS_FNIDX__IBM_OPEN_SRIOV_ALLOW_UNFREEZE)
+#define RTAS_FN_IBM_OPEN_SRIOV_MAP_PE_NUMBER
rtas_fn_handle(RTAS_FNIDX__IBM_OPEN_SRIOV_MAP_PE_NUMBER)
+#define RTAS_FN_IBM_OS_TERM
rtas_fn_handle(RTAS_FNIDX__IBM_OS_TERM)
+#define RTAS_FN_IBM_PARTNER_CONTROL
rtas_fn_handle(RTAS_FNIDX__IBM_PARTNER_CONTROL)
+#define RTAS_FN_IBM_PHYSICAL_ATTESTATION
rtas_fn_handle(RTAS_FNIDX__IBM_PHYSICAL_ATTESTATION)
+#define RTAS_FN_IBM_PLATFORM_DUMP
rtas_fn_handle(RTAS_FNIDX__IBM_PLATFORM_DUMP)
+#define RTAS_FN_IBM_POWER_OFF_UPS
rtas_fn_handle(RTAS_FNIDX__IBM_POWER_OFF_UPS)
+#define RTAS_FN_IBM_QUERY_INTERRUPT_SOURCE_NUMBER
rtas_fn_handle(RTAS_FNIDX__IBM_QUERY_INTERRUPT_SOURCE_NUMBER)
+#define RTAS_FN_IBM_QUERY_PE_DMA_WINDOW
rtas_fn_handle(RTAS_FNIDX__IBM_QUERY_PE_DMA_WINDOW)
+#define RTAS_FN_IBM_READ_PCI_CONFIG
rtas_fn_handle(RTAS_FNIDX__IBM_READ_PCI_CONFIG)
+#define RTAS_FN_IBM_READ_SLOT_RESET_STATE
rtas_fn_handle(RTAS_FNIDX__IBM_READ_SLOT_RESET_STATE)
+#define RTAS_FN_IBM_READ_SLOT_RESET_STATE2
rtas_fn_handle(RTAS_FNIDX__IBM_READ_SLOT_RESET_STATE2)
+#define RTAS_FN_IBM_REMOVE_PE_DMA_WINDOW
rtas_fn_handle(RTAS_FNIDX__IBM_REMOVE_PE_DMA_WINDOW)
+#define RTAS_FN_IBM_RESET_PE_DMA_WINDOWS
rtas_fn_handle(RTAS_FNIDX__IBM_RESET_PE_DMA_WINDOWS)
+#define RTAS_FN_IBM_SCAN_LOG_DUMP
rtas_fn_handle(RTAS_FNIDX__IBM_SCAN_LOG_DUMP)
+#define RTAS_FN_IBM_SET_DYNAMIC_INDICATOR
rtas_fn_handle(RTAS_FNIDX__IBM_SET_DYNAMIC_INDICATOR)
+#define RTAS_FN_IBM_SET_EEH_OPTION
rtas_fn_handle(RTAS_FNIDX__IBM_SET_EEH_OPTION)
+#define RTAS_FN_IBM_SET_SLOT_RESET
rtas_fn_handle(RTAS_FNIDX__IBM_SET_SLOT_RESET)
+#define RTAS_FN_IBM_SET_SYSTEM_PARAMETER
rtas_fn_handle(RTAS_FNIDX__IBM_SET_SYSTEM_PARAMETER)
+#define RTAS_FN_IBM_SET_XIVE
rtas_fn_handle(RTAS_FNIDX__IBM_SET_XIVE)
+#define RTAS_FN_IBM_SLOT_ERROR_DETAIL
rtas_fn_handle(RTAS_FNIDX__IBM_SLOT_ERROR_DETAIL)
+#define RTAS_FN_IBM_SUSPEND_ME
rtas_fn_handle(RTAS_FNIDX__IBM_SUSPEND_ME)
+#define RTAS_FN_IBM_TUNE_DMA_PARMS
rtas_fn_handle(RTAS_FNIDX__IBM_TUNE_DMA_PARMS)
+#define RTAS_FN_IBM_UPDATE_FLASH_64_AND_REBOOT
rtas_fn_handle(RTAS_FNIDX__IBM_UPDATE_FLASH_64_AND_REBOOT)
+#define RTAS_FN_IBM_UPDATE_NODES
rtas_fn_handle(RTAS_FNIDX__IBM_UPDATE_NODES)
+#define RTAS_FN_IBM_UPDATE_PROPERTIES
rtas_fn_handle(RTAS_FNIDX__IBM_UPDATE_PROPERTIES)
+#define RTAS_FN_IBM_VALIDATE_FLASH_IMAGE
rtas_fn_handle(RTAS_FNIDX__IBM_VALIDATE_FLASH_IMAGE)
+#define RTAS_FN_IBM_WRITE_PCI_CONFIG
rtas_fn_handle(RTAS_FNIDX__IBM_WRITE_PCI_CONFIG)
+#define RTAS_FN_NVRAM_FETCH
rtas_fn_handle(RTAS_FNIDX__NVRAM_FETCH)
+#define RTAS_FN_NVRAM_STORE
rtas_fn_handle(RTAS_FNIDX__NVRAM_STORE)
+#define RTAS_FN_POWER_OFF
rtas_fn_handle(RTAS_FNIDX__POWER_OFF)
+#define RTAS_FN_PUT_TERM_CHAR
rtas_fn_handle(RTAS_FNIDX__PUT_TERM_CHAR)
+#define RTAS_FN_QUERY_CPU_STOPPED_STATE
rtas_fn_handle(RTAS_FNIDX__QUERY_CPU_STOPPED_STATE)
+#define RTAS_FN_READ_PCI_CONFIG
rtas_fn_handle(RTAS_FNIDX__READ_PCI_CONFIG)
+#define RTAS_FN_RTAS_LAST_ERROR
rtas_fn_handle(RTAS_FNIDX__RTAS_LAST_ERROR)
+#define RTAS_FN_SET_INDICATOR
rtas_fn_handle(RTAS_FNIDX__SET_INDICATOR)
+#define RTAS_FN_SET_POWER_LEVEL
rtas_fn_handle(RTAS_FNIDX__SET_POWER_LEVEL)
+#define RTAS_FN_SET_TIME_FOR_POWER_ON
rtas_fn_handle(RTAS_FNIDX__SET_TIME_FOR_POWER_ON)
+#define RTAS_FN_SET_TIME_OF_DAY
rtas_fn_handle(RTAS_FNIDX__SET_TIME_OF_DAY)
+#define RTAS_FN_START_CPU
rtas_fn_handle(RTAS_FNIDX__START_CPU)
+#define RTAS_FN_STOP_SELF
rtas_fn_handle(RTAS_FNIDX__STOP_SELF)
+#define RTAS_FN_SYSTEM_REBOOT
rtas_fn_handle(RTAS_FNIDX__SYSTEM_REBOOT)
+#define RTAS_FN_THAW_TIME_BASE
rtas_fn_handle(RTAS_FNIDX__THAW_TIME_BASE)
+#define RTAS_FN_WRITE_PCI_CONFIG
rtas_fn_handle(RTAS_FNIDX__WRITE_PCI_CONFIG)
+
#define RTAS_UNKNOWN_SERVICE (-1)
#define RTAS_INSTANTIATE_MAX (1ULL<<30) /* Don't instantiate rtas at/above
this value */
@@ -307,6 +401,11 @@ extern void (*rtas_flash_term_hook)(int);
extern struct rtas_t rtas;
+s32 rtas_function_token(const rtas_fn_handle_t handle);
+static inline bool rtas_function_implemented(const rtas_fn_handle_t handle)
+{
+ return rtas_function_token(handle) != RTAS_UNKNOWN_SERVICE;
+}
extern int rtas_token(const char *service);
extern int rtas_service_present(const char *service);
extern int rtas_call(int token, int, int, int *, ...);
diff --git a/arch/powerpc/kernel/rtas.c b/arch/powerpc/kernel/rtas.c
index 1f80f0b8a9ad..bb6f5370c279 100644
--- a/arch/powerpc/kernel/rtas.c
+++ b/arch/powerpc/kernel/rtas.c
@@ -453,6 +453,32 @@ static struct rtas_function rtas_function_table[]
__ro_after_init = {
},
};
+/**
+ * rtas_function_token() - RTAS function token lookup.
+ * @handle: Function handle, e.g. RTAS_FN_EVENT_SCAN.
+ *
+ * Context: Any context.
+ * Return: the token value for the function if implemented by this platform,
+ * otherwise RTAS_UNKNOWN_SERVICE.
+ */
+s32 rtas_function_token(const rtas_fn_handle_t handle)
+{
+ const size_t index = handle.index;
+ const bool out_of_bounds = index >= ARRAY_SIZE(rtas_function_table);
+
+ if (WARN_ONCE(out_of_bounds, "invalid function index %zu", index))
+ return RTAS_UNKNOWN_SERVICE;
+ /*
+ * Various drivers attempt token lookups on non-RTAS
+ * platforms.
+ */
+ if (!rtas.dev)
+ return RTAS_UNKNOWN_SERVICE;
+
+ return rtas_function_table[index].token;
+}
+EXPORT_SYMBOL_GPL(rtas_function_token);
+
static int rtas_function_cmp(const void *a, const void *b)
{
const struct rtas_function *f1 = a;
@@ -1011,7 +1037,7 @@ static int ibm_errinjct_token;
* @....: List of @nargs input parameters.
*
* Invokes the RTAS function indicated by @token, which the caller
- * should obtain via rtas_token().
+ * should obtain via rtas_function_token().
*
* The @nargs and @nret arguments must match the number of input and
* output parameters specified for the RTAS function.
--
2.39.1
