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	Exposing set/way cache maintenance to a virtual machine is unsafe, not least because the instructions are not permission-checked but also because they are not broadcast between CPUs. Consequently, KVM traps and emulates such maintenance in the host kernel using by-VA operations and looping over the stage-2 page-tables. However, when running under protected KVM, these instructions are not able to be emulated and will instead result in an exception being delivered to the guest. Introduce CONFIG_CMO_BY_VA_ONLY so that virtual platforms can select this option and perform by-VA cache maintenance instead of using the set/way instructions. Signed-off-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Will Deacon <willdeacon@google.com> Signed-off-by: Pierre-Clément Tosi <ptosi@google.com> [ Paul: pick from the Android tree. Fixup Pierre's commit. And fix some checkpatch warnings. Rebased to upstream. ] Signed-off-by: Ying-Chun Liu (PaulLiu) <paul.liu@linaro.org> Cc: Tom Rini <trini@konsulko.com> Link:db5507f47fLink:2baf54e743
		
			
				
	
	
		
			98 lines
		
	
	
		
			2.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			98 lines
		
	
	
		
			2.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| // SPDX-License-Identifier: GPL-2.0+
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| /*
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|  * (C) Copyright 2008 Texas Insturments
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|  *
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|  * (C) Copyright 2002
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|  * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
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|  * Marius Groeger <mgroeger@sysgo.de>
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|  *
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|  * (C) Copyright 2002
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|  * Gary Jennejohn, DENX Software Engineering, <garyj@denx.de>
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|  */
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| 
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| #include <common.h>
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| #include <command.h>
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| #include <cpu_func.h>
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| #include <irq_func.h>
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| #include <asm/cache.h>
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| #include <asm/system.h>
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| #include <asm/secure.h>
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| #include <linux/compiler.h>
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| 
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| /*
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|  * sdelay() - simple spin loop.
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|  *
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|  * Will delay execution by roughly (@loops * 2) cycles.
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|  * This is necessary to be used before timers are accessible.
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|  *
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|  * A value of "0" will results in 2^64 loops.
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|  */
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| void sdelay(unsigned long loops)
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| {
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| 	__asm__ volatile ("1:\n" "subs %0, %0, #1\n"
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| 			  "b.ne 1b" : "=r" (loops) : "0"(loops) : "cc");
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| }
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| 
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| void __weak board_cleanup_before_linux(void){}
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| 
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| int cleanup_before_linux(void)
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| {
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| 	/*
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| 	 * this function is called just before we call linux
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| 	 * it prepares the processor for linux
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| 	 *
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| 	 * disable interrupt and turn off caches etc ...
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| 	 */
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| 
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| 	board_cleanup_before_linux();
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| 
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| 	disable_interrupts();
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| 
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| 	if (IS_ENABLED(CONFIG_CMO_BY_VA_ONLY)) {
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| 		/*
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| 		 * Disable D-cache.
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| 		 */
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| 		dcache_disable();
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| 	} else {
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| 		/*
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| 		 * Turn off I-cache and invalidate it
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| 		 */
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| 		icache_disable();
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| 		invalidate_icache_all();
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| 
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| 		/*
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| 		 * turn off D-cache
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| 		 * dcache_disable() in turn flushes the d-cache and disables
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| 		 * MMU
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| 		 */
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| 		dcache_disable();
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| 		invalidate_dcache_all();
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| 	}
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| 
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| 	return 0;
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| }
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| 
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| #ifdef CONFIG_ARMV8_PSCI
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| static void relocate_secure_section(void)
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| {
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| #ifdef CONFIG_ARMV8_SECURE_BASE
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| 	size_t sz = __secure_end - __secure_start;
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| 
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| 	memcpy((void *)CONFIG_ARMV8_SECURE_BASE, __secure_start, sz);
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| 	flush_dcache_range(CONFIG_ARMV8_SECURE_BASE,
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| 			   CONFIG_ARMV8_SECURE_BASE + sz + 1);
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| 	invalidate_icache_all();
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| #endif
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| }
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| 
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| void armv8_setup_psci(void)
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| {
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| 	if (current_el() != 3)
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| 		return;
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| 
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| 	relocate_secure_section();
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| 	secure_ram_addr(psci_setup_vectors)();
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| 	secure_ram_addr(psci_arch_init)();
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| }
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| #endif
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