Merge changes from topic "bk/warnings" into integration

* changes:
  docs: describe the new warning levels
  build: add -Wunused-const-variable=2 to W=2
  build: include -Wextra in generic builds
  docs(porting-guide): update a reference
  fix(st-usb): replace redundant checks with asserts
  fix(brcm): add braces around bodies of conditionals
  fix(renesas): align incompatible function pointers
  fix(zynqmp): remove redundant api_version check
  fix: remove old-style declarations
  fix: unify fallthrough annotations
diff --git a/Makefile b/Makefile
index c4350dc..f4d623e 100644
--- a/Makefile
+++ b/Makefile
@@ -350,27 +350,53 @@
 # General warnings
 WARNINGS		:=	-Wall -Wmissing-include-dirs -Wunused	\
 				-Wdisabled-optimization -Wvla -Wshadow	\
-				-Wno-unused-parameter -Wredundant-decls
+				-Wredundant-decls
+# stricter warnings
+WARNINGS		+=	-Wextra -Wno-trigraphs
+# too verbose for generic build
+WARNINGS		+=	-Wno-missing-field-initializers \
+				-Wno-type-limits -Wno-sign-compare \
+# on clang this flag gets reset if -Wextra is set after it. No difference on gcc
+WARNINGS		+=	-Wno-unused-parameter
 
 # Additional warnings
-# Level 1
-WARNING1 := -Wextra
-WARNING1 += -Wmissing-format-attribute
-WARNING1 += -Wmissing-prototypes
-WARNING1 += -Wold-style-definition
+# Level 1 - infrequent warnings we should have none of
+# full -Wextra
+WARNING1 += -Wsign-compare
+WARNING1 += -Wtype-limits
+WARNING1 += -Wmissing-field-initializers
 
-# Level 2
-WARNING2 := -Waggregate-return
-WARNING2 += -Wcast-align
-WARNING2 += -Wnested-externs
+# Level 2 - problematic warnings that we want
+# zlib, compiler-rt, coreboot, and mbdedtls blow up with these
+# TODO: disable just for them and move into default build
+WARNING2 += -Wold-style-definition
+WARNING2 += -Wmissing-prototypes
+WARNING2 += -Wmissing-format-attribute
+# TF-A aims to comply with this eventually. Effort too large at present
+WARNING2 += -Wundef
+# currently very involved and many platforms set this off
+WARNING2 += -Wunused-const-variable=2
 
+# Level 3 - very pedantic, frequently ignored
 WARNING3 := -Wbad-function-cast
+WARNING3 += -Waggregate-return
+WARNING3 += -Wnested-externs
+WARNING3 += -Wcast-align
 WARNING3 += -Wcast-qual
 WARNING3 += -Wconversion
 WARNING3 += -Wpacked
 WARNING3 += -Wpointer-arith
 WARNING3 += -Wswitch-default
 
+# Setting W is quite verbose and most warnings will be pre-existing issues
+# outside of the contributor's control. Don't fail the build on them so warnings
+# can be seen and hopefully addressed
+ifdef W
+ifneq (${W},0)
+E	 ?= 0
+endif
+endif
+
 ifeq (${W},1)
 WARNINGS += $(WARNING1)
 else ifeq (${W},2)
diff --git a/docs/getting_started/build-options.rst b/docs/getting_started/build-options.rst
index e54ff41..d5ded5e 100644
--- a/docs/getting_started/build-options.rst
+++ b/docs/getting_started/build-options.rst
@@ -213,6 +213,12 @@
 
 -  ``E``: Boolean option to make warnings into errors. Default is 1.
 
+   When specifying higher warnings levels (``W=1`` and higher), this option
+   defaults to 0. This is done to encourage contributors to use them, as they
+   are expected to produce warnings that would otherwise fail the build. New
+   contributions are still expected to build with ``W=0`` and ``E=1`` (the
+   default).
+
 -  ``EL3_PAYLOAD_BASE``: This option enables booting an EL3 payload instead of
    the normal boot flow. It must specify the entry point address of the EL3
    payload. Please refer to the "Booting an EL3 payload" section for more
@@ -954,6 +960,43 @@
    regrouped and put in the root Makefile. This flag can take the values 0 to 3,
    each level enabling more warning options. Default is 0.
 
+   This option is closely related to the ``E`` option, which enables
+   ``-Werror``.
+
+   - ``W=0`` (default)
+
+     Enables a wide assortment of warnings, most notably ``-Wall`` and
+     ``-Wextra``, as well as various bad practices and things that are likely to
+     result in errors. Includes some compiler specific flags. No warnings are
+     expected at this level for any build.
+
+   - ``W=1``
+
+     Enables warnings we want the generic build to include but are too time
+     consuming to fix at the moment. It re-enables warnings taken out for
+     ``W=0`` builds (a few of the ``-Wextra`` additions). This level is expected
+     to eventually be merged into ``W=0``. Some warnings are expected on some
+     builds, but new contributions should not introduce new ones.
+
+   - ``W=2`` (recommended)
+
+    Enables warnings we want the generic build to include but cannot be enabled
+    due to external libraries. This level is expected to eventually be merged
+    into ``W=0``. Lots of warnings are expected, primarily from external
+    libraries like zlib and compiler-rt, but new controbutions should not
+    introduce new ones.
+
+   - ``W=3``
+
+     Enables warnings that are informative but not necessary and generally too
+     verbose and frequently ignored. A very large number of warnings are
+     expected.
+
+   The exact set of warning flags depends on the compiler and TF-A warning
+   level, however they are all succinctly set in the top-level Makefile. Please
+   refer to the `GCC`_ or `Clang`_ documentation for more information on the
+   individual flags.
+
 -  ``WARMBOOT_ENABLE_DCACHE_EARLY`` : Boolean option to enable D-cache early on
    the CPU after warm boot. This is applicable for platforms which do not
    require interconnect programming to enable cache coherency (eg: single
@@ -1161,3 +1204,5 @@
 .. _DEN0115: https://developer.arm.com/docs/den0115/latest
 .. _PSA FW update specification: https://developer.arm.com/documentation/den0118/a/
 .. _PSA DRTM specification: https://developer.arm.com/documentation/den0113/a
+.. _GCC: https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html
+.. _Clang: https://clang.llvm.org/docs/DiagnosticsReference.html
diff --git a/docs/getting_started/porting-guide.rst b/docs/getting_started/porting-guide.rst
index d57345d..80b72e5 100644
--- a/docs/getting_started/porting-guide.rst
+++ b/docs/getting_started/porting-guide.rst
@@ -2135,7 +2135,7 @@
 
 #. Providing runtime firmware services. Currently, BL31 only implements a
    subset of the Power State Coordination Interface (PSCI) API as a runtime
-   service. See Section 3.3 below for details of porting the PSCI
+   service. See :ref:`psci_in_bl31` below for details of porting the PSCI
    implementation.
 
 #. Optionally passing control to the BL32 image, pre-loaded at a platform-
@@ -2544,6 +2544,8 @@
 This function writes entropy into storage provided by the caller. If no entropy
 is available, it must return false and the storage must not be written.
 
+.. _psci_in_bl31:
+
 Power State Coordination Interface (in BL31)
 --------------------------------------------
 
diff --git a/docs/process/security-hardening.rst b/docs/process/security-hardening.rst
index 507046f..f9618db 100644
--- a/docs/process/security-hardening.rst
+++ b/docs/process/security-hardening.rst
@@ -131,38 +131,9 @@
   overflows.
 
 - The ``W`` build flag can be used to enable a number of compiler warning
-  options to detect potentially incorrect code.
-
-  - W=0 (default value)
-
-    The ``Wunused`` with ``Wno-unused-parameter``, ``Wdisabled-optimization``
-    and ``Wvla`` flags are enabled.
-
-    The ``Wunused-but-set-variable``, ``Wmaybe-uninitialized`` and
-    ``Wpacked-bitfield-compat`` are GCC specific flags that are also enabled.
-
-  - W=1
-
-    Adds ``Wextra``, ``Wmissing-format-attribute``, ``Wmissing-prototypes``,
-    ``Wold-style-definition`` and ``Wunused-const-variable``.
-
-  - W=2
-
-    Adds ``Waggregate-return``, ``Wcast-align``, ``Wnested-externs``,
-    ``Wshadow``, ``Wlogical-op``.
-
-  - W=3
-
-    Adds ``Wbad-function-cast``, ``Wcast-qual``, ``Wconversion``, ``Wpacked``,
-    ``Wpointer-arith``, ``Wredundant-decls`` and
-    ``Wswitch-default``.
-
-  Refer to the GCC or Clang documentation for more information on the individual
-  options: https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html and
-  https://clang.llvm.org/docs/DiagnosticsReference.html.
-
-  NB: The ``Werror`` flag is enabled by default in TF-A and can be disabled by
-  setting the ``E`` build flag to 0.
+  options to detect potentially incorrect code. TF-A is tested with ``W=0`` but
+  it is recommended to develop against ``W=2`` (which will eventually become the
+  default).
 
 .. rubric:: References
 
diff --git a/drivers/brcm/emmc/emmc_csl_sdcard.c b/drivers/brcm/emmc/emmc_csl_sdcard.c
index 9e2c618..40bc4a0 100644
--- a/drivers/brcm/emmc/emmc_csl_sdcard.c
+++ b/drivers/brcm/emmc/emmc_csl_sdcard.c
@@ -479,10 +479,11 @@
 			handle->device->cfg.blockSize = 512;
 		}
 
-		if (handle->device->ctrl.ocr & SD_CARD_HIGH_CAPACITY)
+		if (handle->device->ctrl.ocr & SD_CARD_HIGH_CAPACITY) {
 			EMMC_TRACE("Sector addressing\n");
-		else
+		} else {
 			EMMC_TRACE("Byte addressing\n");
+		}
 
 		EMMC_TRACE("Ext_CSD_storage[162]: 0x%02X  Ext_CSD_storage[179]: 0x%02X\n",
 			   emmc_global_buf_ptr->u.Ext_CSD_storage[162],
diff --git a/drivers/brcm/emmc/emmc_pboot_hal_memory_drv.c b/drivers/brcm/emmc/emmc_pboot_hal_memory_drv.c
index 68f93e7..fcd499f 100644
--- a/drivers/brcm/emmc/emmc_pboot_hal_memory_drv.c
+++ b/drivers/brcm/emmc/emmc_pboot_hal_memory_drv.c
@@ -278,8 +278,9 @@
 
 	SDIO_base = EMMC_CTRL_REGS_BASE_ADDR;
 
-	if (SDIO_base == SDIO0_EMMCSDXC_SYSADDR)
+	if (SDIO_base == SDIO0_EMMCSDXC_SYSADDR) {
 		EMMC_TRACE(" ---> for SDIO 0 Controller\n\n");
+	}
 
 	memset(p_sdhandle, 0, sizeof(struct sd_handle));
 
@@ -290,8 +291,9 @@
 	memset(p_sdhandle->card, 0, sizeof(struct sd_card_info));
 
 	if (chal_sd_start((CHAL_HANDLE *) p_sdhandle->device,
-			  SD_PIO_MODE, SDIO_base, SDIO_base) != SD_OK)
+			  SD_PIO_MODE, SDIO_base, SDIO_base) != SD_OK) {
 		return NULL;
+	}
 
 	set_config(p_sdhandle, SD_NORMAL_SPEED, MAX_CMD_RETRY, SD_DMA_OFF,
 		   SD_DMA_BOUNDARY_4K, EMMC_BLOCK_SIZE, EMMC_WFE_RETRY);
@@ -330,14 +332,16 @@
 	VERBOSE("EMMC READ: dst=0x%lx, src=0x%lx, size=0x%lx\n",
 			storage_addr, mem_addr, bytes_to_read);
 
-	if (storage_size < bytes_to_read)
+	if (storage_size < bytes_to_read) {
 		/* Don't have sufficient storage to complete the operation */
 		return 0;
+	}
 
 	/* Range check non high capacity memory */
 	if ((p_sdhandle->device->ctrl.ocr & SD_CARD_HIGH_CAPACITY) == 0) {
-		if (mem_addr > 0x80000000)
+		if (mem_addr > 0x80000000) {
 			return 0;
+		}
 	}
 
 	/* High capacity card use block address mode */
@@ -384,10 +388,11 @@
 			/* Update Physical address */
 			outputBuf += manual_copy_size;
 
-			if (p_sdhandle->device->ctrl.ocr & SD_CARD_HIGH_CAPACITY)
+			if (p_sdhandle->device->ctrl.ocr & SD_CARD_HIGH_CAPACITY) {
 				blockAddr++;
-			else
+			} else {
 				blockAddr += blockSize;
+			}
 		} else {
 			return 0;
 		}
@@ -395,10 +400,11 @@
 
 	while (remSize >= blockSize) {
 
-		if (remSize >= SD_MAX_BLK_TRANSFER_LENGTH)
+		if (remSize >= SD_MAX_BLK_TRANSFER_LENGTH) {
 			readLen = SD_MAX_BLK_TRANSFER_LENGTH;
-		else
+		} else {
 			readLen = (remSize / blockSize) * blockSize;
+		}
 
 		/* Check for overflow */
 		if ((rdCount + readLen) > storage_size ||
@@ -409,10 +415,11 @@
 		}
 
 		if (!read_block(p_sdhandle, outputBuf, blockAddr, readLen)) {
-			if (p_sdhandle->device->ctrl.ocr & SD_CARD_HIGH_CAPACITY)
+			if (p_sdhandle->device->ctrl.ocr & SD_CARD_HIGH_CAPACITY) {
 				blockAddr += (readLen / blockSize);
-			else
+			} else {
 				blockAddr += readLen;
+			}
 
 			remSize -= readLen;
 			rdCount += readLen;
@@ -463,8 +470,9 @@
 
 	/* range check non high capacity memory */
 	if ((p_sdhandle->device->ctrl.ocr & SD_CARD_HIGH_CAPACITY) == 0) {
-		if (mem_addr > 0x80000000)
+		if (mem_addr > 0x80000000) {
 			return 0;
+		}
 	}
 
 	/* the high capacity card use block address mode */
@@ -491,11 +499,12 @@
 				blockAddr, p_sdhandle->device->cfg.blockSize)) {
 
 			if (remSize <
-			    (p_sdhandle->device->cfg.blockSize - offset))
+			    (p_sdhandle->device->cfg.blockSize - offset)) {
 				manual_copy_size = remSize;
-			else
+			} else {
 				manual_copy_size =
 				    p_sdhandle->device->cfg.blockSize - offset;
+			}
 
 			memcpy((void *)((uintptr_t)
 				(emmc_global_buf_ptr->u.tempbuf + offset)),
@@ -530,11 +539,12 @@
 				inputBuf += manual_copy_size;
 
 				if (p_sdhandle->device->ctrl.ocr &
-				    SD_CARD_HIGH_CAPACITY)
+				    SD_CARD_HIGH_CAPACITY) {
 					blockAddr++;
-				else
+				} else {
 					blockAddr +=
 					    p_sdhandle->device->cfg.blockSize;
+				}
 			} else
 				return 0;
 		} else {
diff --git a/drivers/imx/usdhc/imx_usdhc.c b/drivers/imx/usdhc/imx_usdhc.c
index 07f55b7..49dfc07 100644
--- a/drivers/imx/usdhc/imx_usdhc.c
+++ b/drivers/imx/usdhc/imx_usdhc.c
@@ -136,7 +136,8 @@
 		break;
 	case MMC_CMD(18):
 		multiple = 1;
-		/* fall thru for read op */
+		/* for read op */
+		/* fallthrough */
 	case MMC_CMD(17):
 	case MMC_CMD(8):
 		mixctl |= MIXCTRL_DTDSEL;
@@ -144,7 +145,8 @@
 		break;
 	case MMC_CMD(25):
 		multiple = 1;
-		/* fall thru for data op flag */
+		/* for data op flag */
+		/* fallthrough */
 	case MMC_CMD(24):
 		data = 1;
 		break;
diff --git a/drivers/nxp/ddr/nxp-ddr/ddr.c b/drivers/nxp/ddr/nxp-ddr/ddr.c
index c051b3b..faf20e9 100644
--- a/drivers/nxp/ddr/nxp-ddr/ddr.c
+++ b/drivers/nxp/ddr/nxp-ddr/ddr.c
@@ -269,7 +269,7 @@
 	unsigned int i;
 	const struct dynamic_odt *pdodt = NULL;
 
-	const static struct dynamic_odt *table[2][5] = {
+	static const struct dynamic_odt *table[2][5] = {
 		{single_S, single_D, NULL, NULL},
 		{dual_SS, dual_DD, NULL, NULL},
 	};
diff --git a/drivers/nxp/ddr/phy-gen2/messages.h b/drivers/nxp/ddr/phy-gen2/messages.h
index 7dec7df..a2310f2 100644
--- a/drivers/nxp/ddr/phy-gen2/messages.h
+++ b/drivers/nxp/ddr/phy-gen2/messages.h
@@ -13,7 +13,7 @@
 	const char *msg;
 };
 
-const static struct phy_msg messages_1d[] = {
+static const struct phy_msg messages_1d[] = {
 	{0x00000001,
 	 "PMU1:prbsGenCtl:%x\n"
 	},
@@ -1239,7 +1239,7 @@
 	},
 };
 
-const static struct phy_msg messages_2d[] = {
+static const struct phy_msg messages_2d[] = {
 	{0x00000001,
 	 "PMU0: Converting %d into an MR\n"
 	},
diff --git a/drivers/renesas/common/emmc/emmc_cmd.c b/drivers/renesas/common/emmc/emmc_cmd.c
index d255bff..02fc26b 100644
--- a/drivers/renesas/common/emmc/emmc_cmd.c
+++ b/drivers/renesas/common/emmc/emmc_cmd.c
@@ -254,8 +254,7 @@
 				(SD_INFO2_ALL_ERR | SD_INFO2_CLEAR));
 
 			state = ESTATE_ISSUE_CMD;
-			/* through */
-
+			/* fallthrough */
 		case ESTATE_ISSUE_CMD:
 			/* ARG */
 			SETR_32(SD_ARG, mmc_drv_obj.cmd_info.arg);
@@ -454,8 +453,8 @@
 				SETR_32(SD_STOP, 0x00000000U);
 				mmc_drv_obj.during_dma_transfer = FALSE;
 			}
-			/* through */
 
+			/* fallthrough */
 		case ESTATE_ERROR:
 			if (err_not_care_flag == TRUE) {
 				mmc_drv_obj.during_cmd_processing = FALSE;
diff --git a/drivers/renesas/common/rom/rom_api.c b/drivers/renesas/common/rom/rom_api.c
index fda2815..4eede17 100644
--- a/drivers/renesas/common/rom/rom_api.c
+++ b/drivers/renesas/common/rom/rom_api.c
@@ -11,7 +11,7 @@
 #include "rcar_def.h"
 #include "rom_api.h"
 
-typedef uint32_t(*rom_secure_boot_api_f) (uint32_t *key, uint32_t *cert,
+typedef uint32_t(*rom_secure_boot_api_f) (uint32_t key, uint32_t cert,
 					  rom_read_flash_f pFuncReadFlash);
 
 typedef uint32_t(*rom_get_lcs_api_f) (uint32_t *lcs);
@@ -68,7 +68,7 @@
 	return index;
 }
 
-uint32_t rcar_rom_secure_boot_api(uint32_t *key, uint32_t *cert,
+uint32_t rcar_rom_secure_boot_api(uint32_t key, uint32_t cert,
 			     rom_read_flash_f read_flash)
 {
 	static const uintptr_t rom_api_table[API_TABLE_MAX] = {
diff --git a/drivers/renesas/common/rom/rom_api.h b/drivers/renesas/common/rom/rom_api.h
index 1d5b03d..4b10080 100644
--- a/drivers/renesas/common/rom/rom_api.h
+++ b/drivers/renesas/common/rom/rom_api.h
@@ -24,7 +24,7 @@
 #define LCS_FA					(0x7U)
 
 typedef uint32_t(*rom_read_flash_f) (uint64_t src, uint8_t *dst, uint32_t len);
-uint32_t rcar_rom_secure_boot_api(uint32_t *key, uint32_t *cert,
+uint32_t rcar_rom_secure_boot_api(uint32_t key, uint32_t cert,
 				  rom_read_flash_f f);
 uint32_t rcar_rom_get_lcs(uint32_t *lcs);
 
diff --git a/drivers/st/usb/stm32mp1_usb.c b/drivers/st/usb/stm32mp1_usb.c
index 9a49690..78890f5 100644
--- a/drivers/st/usb/stm32mp1_usb.c
+++ b/drivers/st/usb/stm32mp1_usb.c
@@ -4,6 +4,7 @@
  * SPDX-License-Identifier: BSD-3-Clause
  */
 
+#include <assert.h>
 #include <stdint.h>
 
 #include <arch_helpers.h>
@@ -794,7 +795,7 @@
 	uint32_t epint;
 	uint32_t epnum;
 	uint32_t temp;
-	enum usb_status ret;
+	enum usb_status __unused ret;
 
 	if (usb_dwc2_get_mode(handle) != USB_OTG_MODE_DEVICE) {
 		return USB_NOTHING;
@@ -947,9 +948,7 @@
 
 		/* Setup EP0 to receive SETUP packets */
 		ret = usb_dwc2_ep0_out_start(handle);
-		if (ret != USBD_OK) {
-			return ret;
-		}
+		assert(ret == USBD_OK);
 
 		mmio_write_32(usb_base_addr + OTG_GINTSTS, OTG_GINTSTS_USBRST);
 
@@ -959,9 +958,7 @@
 	/* Handle enumeration done interrupt */
 	if ((usb_dwc2_read_int(handle) & OTG_GINTSTS_ENUMDNE) != 0U) {
 		ret = usb_dwc2_activate_setup(handle);
-		if (ret != USBD_OK) {
-			return ret;
-		}
+		assert(ret == USBD_OK);
 
 		mmio_clrbits_32(usb_base_addr + OTG_GUSBCFG, OTG_GUSBCFG_TRDT);
 
diff --git a/lib/libc/snprintf.c b/lib/libc/snprintf.c
index 6a2f0ba..0e3256c 100644
--- a/lib/libc/snprintf.c
+++ b/lib/libc/snprintf.c
@@ -209,6 +209,7 @@
 				break;
 			case 'X':
 				capitalise = true;
+				/* fallthrough */
 			case 'x':
 				unum = get_unum_va_args(args, l_count);
 				unsigned_num_print(&s, n, &chars_printed,
diff --git a/plat/imx/common/imx_sip_handler.c b/plat/imx/common/imx_sip_handler.c
index d4b3425..ec8631a 100644
--- a/plat/imx/common/imx_sip_handler.c
+++ b/plat/imx/common/imx_sip_handler.c
@@ -20,7 +20,7 @@
 #if defined(PLAT_imx8qm) || defined(PLAT_imx8qx)
 
 #ifdef PLAT_imx8qm
-const static int ap_cluster_index[PLATFORM_CLUSTER_COUNT] = {
+static const int ap_cluster_index[PLATFORM_CLUSTER_COUNT] = {
 	SC_R_A53, SC_R_A72,
 };
 #endif
diff --git a/plat/imx/imx8qm/imx8qm_bl31_setup.c b/plat/imx/imx8qm/imx8qm_bl31_setup.c
index 68eb534..bd7896a 100644
--- a/plat/imx/imx8qm/imx8qm_bl31_setup.c
+++ b/plat/imx/imx8qm/imx8qm_bl31_setup.c
@@ -62,7 +62,7 @@
 #error "Provide proper UART number in IMX_DEBUG_UART"
 #endif
 
-const static int imx8qm_cci_map[] = {
+static const int imx8qm_cci_map[] = {
 	CLUSTER0_CCI_SLVAE_IFACE,
 	CLUSTER1_CCI_SLVAE_IFACE
 };
diff --git a/plat/imx/imx8qm/imx8qm_psci.c b/plat/imx/imx8qm/imx8qm_psci.c
index bdba37c..dcc502f 100644
--- a/plat/imx/imx8qm/imx8qm_psci.c
+++ b/plat/imx/imx8qm/imx8qm_psci.c
@@ -26,7 +26,7 @@
 #define SYSTEM_PWR_STATE(state) \
 	((state)->pwr_domain_state[PLAT_MAX_PWR_LVL])
 
-const static int ap_core_index[PLATFORM_CORE_COUNT] = {
+static const int ap_core_index[PLATFORM_CORE_COUNT] = {
 	SC_R_A53_0, SC_R_A53_1, SC_R_A53_2,
 	SC_R_A53_3, SC_R_A72_0, SC_R_A72_1,
 };
diff --git a/plat/imx/imx8qx/imx8qx_psci.c b/plat/imx/imx8qx/imx8qx_psci.c
index aab3a2d..5f05566 100644
--- a/plat/imx/imx8qx/imx8qx_psci.c
+++ b/plat/imx/imx8qx/imx8qx_psci.c
@@ -18,7 +18,7 @@
 
 #include "../../common/sci/imx8_mu.h"
 
-const static int ap_core_index[PLATFORM_CORE_COUNT] = {
+static const int ap_core_index[PLATFORM_CORE_COUNT] = {
 	SC_R_A35_0, SC_R_A35_1, SC_R_A35_2, SC_R_A35_3
 };
 
diff --git a/plat/mediatek/common/mtk_smc_handlers.c b/plat/mediatek/common/mtk_smc_handlers.c
index 51a960f..92b3873 100644
--- a/plat/mediatek/common/mtk_smc_handlers.c
+++ b/plat/mediatek/common/mtk_smc_handlers.c
@@ -51,6 +51,7 @@
 		x3 = x3 & MASK_32_BIT; \
 		x4 = x4 & MASK_32_BIT; \
 	} \
+	/* fallthrough */ \
 	case _smc_id##_AARCH64: \
 	{ \
 		if (_smc_id##_descriptor_index < 0) { \
diff --git a/plat/nvidia/tegra/soc/t186/plat_memctrl.c b/plat/nvidia/tegra/soc/t186/plat_memctrl.c
index 81de674..2533013 100644
--- a/plat/nvidia/tegra/soc/t186/plat_memctrl.c
+++ b/plat/nvidia/tegra/soc/t186/plat_memctrl.c
@@ -20,7 +20,7 @@
 /*******************************************************************************
  * Array to hold stream_id override config register offsets
  ******************************************************************************/
-const static uint32_t tegra186_streamid_override_regs[] = {
+static const uint32_t tegra186_streamid_override_regs[] = {
 	MC_STREAMID_OVERRIDE_CFG_SDMMCRA,
 	MC_STREAMID_OVERRIDE_CFG_SDMMCRAA,
 	MC_STREAMID_OVERRIDE_CFG_SDMMCR,
@@ -34,7 +34,7 @@
 /*******************************************************************************
  * Array to hold the security configs for stream IDs
  ******************************************************************************/
-const static mc_streamid_security_cfg_t tegra186_streamid_sec_cfgs[] = {
+static const mc_streamid_security_cfg_t tegra186_streamid_sec_cfgs[] = {
 	mc_make_sec_cfg(SCEW, NON_SECURE, NO_OVERRIDE, DISABLE),
 	mc_make_sec_cfg(AFIR, NON_SECURE, OVERRIDE, DISABLE),
 	mc_make_sec_cfg(AFIW, NON_SECURE, OVERRIDE, DISABLE),
@@ -112,7 +112,7 @@
 /*******************************************************************************
  * Array to hold the transaction override configs
  ******************************************************************************/
-const static mc_txn_override_cfg_t tegra186_txn_override_cfgs[] = {
+static const mc_txn_override_cfg_t tegra186_txn_override_cfgs[] = {
 	mc_make_txn_override_cfg(BPMPW, CGID_TAG_ADR),
 	mc_make_txn_override_cfg(EQOSW, CGID_TAG_ADR),
 	mc_make_txn_override_cfg(NVJPGSWR, CGID_TAG_ADR),
diff --git a/plat/nxp/common/psci/plat_psci.c b/plat/nxp/common/psci/plat_psci.c
index 9281e97..f6dd7b3 100644
--- a/plat/nxp/common/psci/plat_psci.c
+++ b/plat/nxp/common/psci/plat_psci.c
@@ -350,7 +350,7 @@
 		else if (SOC_SYSTEM_STANDBY)
 			state->pwr_domain_state[PLAT_MAX_LVL] =
 				PLAT_MAX_RET_STATE;
-		 /* intentional fall-thru condition */
+		 /* fallthrough */
 	case PWR_STATE_LVL_SYS:
 		if (pwrdn && SOC_SYSTEM_PWR_DWN)
 			state->pwr_domain_state[PLAT_SYS_LVL] =
@@ -358,7 +358,7 @@
 		else if (SOC_SYSTEM_STANDBY)
 			state->pwr_domain_state[PLAT_SYS_LVL] =
 				PLAT_MAX_RET_STATE;
-		 /* intentional fall-thru condition */
+		 /* fallthrough */
 	case PWR_STATE_LVL_CLSTR:
 		if (pwrdn && SOC_CLUSTER_PWR_DWN)
 			state->pwr_domain_state[PLAT_CLSTR_LVL] =
@@ -366,7 +366,7 @@
 		else if (SOC_CLUSTER_STANDBY)
 			state->pwr_domain_state[PLAT_CLSTR_LVL] =
 				PLAT_MAX_RET_STATE;
-		 /* intentional fall-thru condition */
+		 /* fallthrough */
 	case PWR_STATE_LVL_CORE:
 		stat = PSCI_E_SUCCESS;
 
diff --git a/plat/xilinx/common/ipi.c b/plat/xilinx/common/ipi.c
index 6438896..8fa7bc5 100644
--- a/plat/xilinx/common/ipi.c
+++ b/plat/xilinx/common/ipi.c
@@ -39,7 +39,7 @@
 #define IPI_BIT_MASK(I) (ipi_table[(I)].ipi_bit_mask)
 
 /* IPI configuration table */
-const static struct ipi_config *ipi_table;
+static const struct ipi_config *ipi_table;
 
 /* Total number of IPI */
 static uint32_t ipi_total;
diff --git a/plat/xilinx/versal/versal_ipi.c b/plat/xilinx/versal/versal_ipi.c
index f99af82..d821929 100644
--- a/plat/xilinx/versal/versal_ipi.c
+++ b/plat/xilinx/versal/versal_ipi.c
@@ -19,7 +19,7 @@
 #include <lib/mmio.h>
 
 /* versal ipi configuration table */
-const static struct ipi_config versal_ipi_table[] = {
+static const struct ipi_config versal_ipi_table[] = {
 	/* A72 IPI */
 	[IPI_ID_APU] = {
 		.ipi_bit_mask = IPI0_TRIG_BIT,
diff --git a/plat/xilinx/zynqmp/pm_service/pm_svc_main.c b/plat/xilinx/zynqmp/pm_service/pm_svc_main.c
index 4adbef3..a3f0278 100644
--- a/plat/xilinx/zynqmp/pm_service/pm_svc_main.c
+++ b/plat/xilinx/zynqmp/pm_service/pm_svc_main.c
@@ -334,22 +334,18 @@
 		SMC_RET1(handle, (uint64_t)ret);
 
 	case PM_GET_API_VERSION:
-		/* Check is PM API version already verified */
-		if (pm_ctx.api_version >= PM_VERSION) {
-			if (ipi_irq_flag == 0U) {
-				/*
-				 * Enable IPI IRQ
-				 * assume the rich OS is OK to handle callback IRQs now.
-				 * Even if we were wrong, it would not enable the IRQ in
-				 * the GIC.
-				 */
-				pm_ipi_irq_enable(primary_proc);
-				ipi_irq_flag = 1U;
-			}
-			SMC_RET1(handle, (uint64_t)PM_RET_SUCCESS |
-				 ((uint64_t)pm_ctx.api_version << 32));
+		if (ipi_irq_flag == 0U) {
+			/*
+			 * Enable IPI IRQ
+			 * assume the rich OS is OK to handle callback IRQs now.
+			 * Even if we were wrong, it would not enable the IRQ in
+			 * the GIC.
+			 */
+			pm_ipi_irq_enable(primary_proc);
+			ipi_irq_flag = 1U;
 		}
-
+		SMC_RET1(handle, (uint64_t)PM_RET_SUCCESS |
+			 ((uint64_t)pm_ctx.api_version << 32));
 	case PM_FPGA_LOAD:
 		ret = pm_fpga_load(pm_arg[0], pm_arg[1], pm_arg[2], pm_arg[3]);
 		SMC_RET1(handle, (uint64_t)ret);
diff --git a/plat/xilinx/zynqmp/zynqmp_ipi.c b/plat/xilinx/zynqmp/zynqmp_ipi.c
index 4ea3c6a..acd31df 100644
--- a/plat/xilinx/zynqmp/zynqmp_ipi.c
+++ b/plat/xilinx/zynqmp/zynqmp_ipi.c
@@ -21,7 +21,7 @@
 #include <plat_private.h>
 
 /* Zynqmp ipi configuration table */
-const static struct ipi_config zynqmp_ipi_table[] = {
+static const struct ipi_config zynqmp_ipi_table[] = {
 	/* APU IPI */
 	{
 		.ipi_bit_mask = 0x1,
diff --git a/services/std_svc/spmd/spmd_main.c b/services/std_svc/spmd/spmd_main.c
index 7e6c89d..afd0f2e 100644
--- a/services/std_svc/spmd/spmd_main.c
+++ b/services/std_svc/spmd/spmd_main.c
@@ -868,7 +868,8 @@
 						     FFA_ERROR_NOT_SUPPORTED);
 		}
 
-		/* Fall through to forward the call to the other world */
+		/* Forward the call to the other world */
+		/* fallthrough */
 	case FFA_MSG_SEND:
 	case FFA_MSG_SEND_DIRECT_RESP_SMC64:
 	case FFA_MEM_DONATE_SMC32:
@@ -908,7 +909,8 @@
 			spmd_spm_core_sync_exit(0ULL);
 		}
 
-		/* Fall through to forward the call to the other world */
+		/* Forward the call to the other world */
+		/* fallthrough */
 	case FFA_INTERRUPT:
 	case FFA_MSG_YIELD:
 		/* This interface must be invoked only by the Secure world */