[PATCH 02/18] arm64: versal2: Decouple multiboot register access from firmware

[Michal Simek]

versal2_multi_boot() in board code selected between the firmware call
zynqmp_pm_get_pmc_multi_boot_reg() and a direct readl() based on an
IS_ENABLED(CONFIG_ZYNQMP_FIRMWARE) check. Generic board code should not
carry firmware-specific ifdefs, and this becomes harder to maintain once
SCMI introduces yet another access method.

Introduce an overridable accessor versal2_pmc_multi_boot(). The weak
default lives in arch/arm/mach-versal2 and performs the plain MMIO read
(used at EL3 and when no firmware is present). When CONFIG_ZYNQMP_FIRMWARE
is enabled, firmware-zynqmp.c provides a strong definition that issues the
firmware call, falling back to the direct read at EL3 where the SMC path
to firmware is unavailable. The shared MMIO read is factored into
versal2_multi_boot_reg() so the firmware override does not duplicate it.

versal2_multi_boot() keeps the generic JTAG/QEMU workaround and simply
calls the accessor, so board code no longer references the firmware
interface and the now unused zynqmp_firmware.h include is dropped. The
firmware-vs-MMIO decision is selected at link time, and adding SCMI later
only requires a third strong definition with no board-code changes.

Signed-off-by: Michal Simek <michal.simek at amd.com>
---

 arch/arm/mach-versal2/cpu.c                    | 10 ++++++++++
 arch/arm/mach-versal2/include/mach/sys_proto.h |  5 +++++
 board/amd/versal2/board.c                      |  9 +--------
 drivers/firmware/firmware-zynqmp.c             | 13 +++++++++++++
 4 files changed, 29 insertions(+), 8 deletions(-)

diff --git a/arch/arm/mach-versal2/cpu.c b/arch/arm/mach-versal2/cpu.c
index e264ef0f2924..0c7a5040cffb 100644
--- a/arch/arm/mach-versal2/cpu.c
+++ b/arch/arm/mach-versal2/cpu.c
@@ -128,6 +128,16 @@ u64 get_page_table_size(void)
 }
 #endif
 
+u32 versal2_multi_boot_reg(void)
+{
+	return readl(PMC_MULTI_BOOT_REG) & PMC_MULTI_BOOT_MASK;
+}
+
+u32 __weak versal2_pmc_multi_boot(void)
+{
+	return versal2_multi_boot_reg();
+}
+
 U_BOOT_DRVINFO(soc_amd_versal2) = {
 	.name = "soc_amd_versal2",
 };
diff --git a/arch/arm/mach-versal2/include/mach/sys_proto.h b/arch/arm/mach-versal2/include/mach/sys_proto.h
index 3ed0b25be802..e0576754836a 100644
--- a/arch/arm/mach-versal2/include/mach/sys_proto.h
+++ b/arch/arm/mach-versal2/include/mach/sys_proto.h
@@ -13,4 +13,9 @@
 void mem_map_fill(struct mm_region *bank_info, u32 num_banks);
 void fill_bd_mem_info(void);
 
+/* Overridable PMC multiboot accessor: weak MMIO default, firmware override */
+u32 versal2_pmc_multi_boot(void);
+/* Direct MMIO read of the multiboot register (EL3 / no-firmware path) */
+u32 versal2_multi_boot_reg(void);
+
 #endif /* _ASM_ARCH_SYS_PROTO_H */
diff --git a/board/amd/versal2/board.c b/board/amd/versal2/board.c
index 6e4f0c6e9b8f..06d144db4f02 100644
--- a/board/amd/versal2/board.c
+++ b/board/amd/versal2/board.c
@@ -29,7 +29,6 @@
 #include <dm/device.h>
 #include <dm/uclass.h>
 #include <versalpl.h>
-#include <zynqmp_firmware.h>
 #include "../../xilinx/common/board.h"
 
 #include <linux/bitfield.h>
@@ -195,18 +194,12 @@ static u8 versal2_get_bootmode(void)
 static u32 versal2_multi_boot(void)
 {
 	u8 bootmode = versal2_get_bootmode();
-	u32 reg = 0;
 
 	/* Mostly workaround for QEMU CI pipeline */
 	if (bootmode == JTAG_MODE)
 		return 0;
 
-	if (IS_ENABLED(CONFIG_ZYNQMP_FIRMWARE) && current_el() != 3)
-		reg = zynqmp_pm_get_pmc_multi_boot_reg();
-	else
-		reg = readl(PMC_MULTI_BOOT_REG);
-
-	return reg & PMC_MULTI_BOOT_MASK;
+	return versal2_pmc_multi_boot();
 }
 
 static int boot_targets_setup(void)
diff --git a/drivers/firmware/firmware-zynqmp.c b/drivers/firmware/firmware-zynqmp.c
index ea14ed4ef950..70d205ff3ef9 100644
--- a/drivers/firmware/firmware-zynqmp.c
+++ b/drivers/firmware/firmware-zynqmp.c
@@ -7,6 +7,7 @@
  */
 
 #include <asm/arch/hardware.h>
+#include <asm/arch/sys_proto.h>
 #include <asm/io.h>
 #include <cpu_func.h>
 #include <dm.h>
@@ -16,6 +17,7 @@
 #include <zynqmp_firmware.h>
 #include <asm/cache.h>
 #include <asm/ptrace.h>
+#include <asm/system.h>
 #include <linux/bitfield.h>
 
 #if defined(CONFIG_ZYNQMP_IPI)
@@ -326,6 +328,17 @@ u32 zynqmp_pm_get_pmc_multi_boot_reg(void)
 }
 #endif
 
+#if defined(CONFIG_ARCH_VERSAL2)
+u32 versal2_pmc_multi_boot(void)
+{
+	/* At EL3 the SMC path to firmware is unavailable, read directly */
+	if (current_el() == 3)
+		return versal2_multi_boot_reg();
+
+	return zynqmp_pm_get_pmc_multi_boot_reg() & PMC_MULTI_BOOT_MASK;
+}
+#endif
+
 int zynqmp_pm_feature(const u32 api_id)
 {
 	int ret;
-- 
2.43.0