u-boot/arch/arm/include/asm/global_data.h

/*
 * (C) Copyright 2002-2010
 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
 *
 * SPDX-License-Identifier:	GPL-2.0+
 */

#ifndef	__ASM_GBL_DATA_H
#define __ASM_GBL_DATA_H

/* Architecture-specific global data */
struct arch_global_data {
#if defined(CONFIG_FSL_ESDHC)
	u32 sdhc_clk;
#endif

#if defined(CONFIG_U_QE)
	u32 qe_clk;
	u32 brg_clk;
	uint mp_alloc_base;
	uint mp_alloc_top;
#endif /* CONFIG_U_QE */

#ifdef CONFIG_AT91FAMILY
	/* "static data" needed by at91's clock.c */
	unsigned long	cpu_clk_rate_hz;
	unsigned long	main_clk_rate_hz;
	unsigned long	mck_rate_hz;
	unsigned long	plla_rate_hz;
	unsigned long	pllb_rate_hz;
	unsigned long	at91_pllb_usb_init;
#endif
	/* "static data" needed by most of timer.c on ARM platforms */
	unsigned long timer_rate_hz;
	unsigned int tbu;
	unsigned int tbl;
	unsigned long lastinc;
	unsigned long long timer_reset_value;
#if !(defined(CONFIG_SYS_ICACHE_OFF) && defined(CONFIG_SYS_DCACHE_OFF))
	unsigned long tlb_addr;
	unsigned long tlb_size;
#if defined(CONFIG_ARM64)
	unsigned long tlb_fillptr;
	unsigned long tlb_emerg;
#endif
#endif
#ifdef CONFIG_SYS_MEM_RESERVE_SECURE
#define MEM_RESERVE_SECURE_SECURED	0x1
#define MEM_RESERVE_SECURE_MAINTAINED	0x2
#define MEM_RESERVE_SECURE_ADDR_MASK	(~0x3)
	/*
	 * Secure memory addr
	 * This variable needs maintenance if the RAM base is not zero,
	 * or if RAM splits into non-consecutive banks. It also has a
	 * flag indicating the secure memory is marked as secure by MMU.
	 * Flags used: 0x1 secured
	 *             0x2 maintained
	 */
	phys_addr_t secure_ram;
	unsigned long tlb_allocated;
#endif
#ifdef CONFIG_RESV_RAM
	/*
	 * Reserved RAM for memory resident, eg. Management Complex (MC)
	 * driver which continues to run after U-Boot exits.
	 */
	phys_addr_t resv_ram;
#endif

#ifdef CONFIG_ARCH_OMAP2PLUS
	u32 omap_boot_device;
	u32 omap_boot_mode;
	u8 omap_ch_flags;
#endif
#if defined(CONFIG_FSL_LSCH3) && defined(CONFIG_SYS_FSL_HAS_DP_DDR)
	unsigned long mem2_clk;
#endif
};

#include <asm-generic/global_data.h>

#ifdef __clang__

#define DECLARE_GLOBAL_DATA_PTR
#define gd	get_gd()

static inline gd_t *get_gd(void)
{
	gd_t *gd_ptr;

#ifdef CONFIG_ARM64
	/*
	 * Make will already error that reserving x18 is not supported at the
	 * time of writing, clang: error: unknown argument: '-ffixed-x18'
	 */
	__asm__ volatile("mov %0, x18\n" : "=r" (gd_ptr));
#else
	__asm__ volatile("mov %0, r9\n" : "=r" (gd_ptr));
#endif

	return gd_ptr;
}

#else

#ifdef CONFIG_ARM64
#define DECLARE_GLOBAL_DATA_PTR		register volatile gd_t *gd asm ("x18")
#else
#define DECLARE_GLOBAL_DATA_PTR		register volatile gd_t *gd asm ("r9")
#endif
#endif

#endif /* __ASM_GBL_DATA_H */