Commit a3d9086b authored by Jonas Gorski's avatar Jonas Gorski Committed by Ralf Baechle
Browse files

MIPS: Flush TLB handlers directly after writing them 



When having enabled MIPS_PGD_C0_CONTEXT, trap_init() might call the
generated tlbmiss_handler_setup_pgd before it was committed to memory,
causing boot failures:

  trap_init()
   |- per_cpu_trap_init()
   |   |- TLBMISS_HANDLER_SETUP()
   |       |- tlbmiss_handler_setup_pgd()
   |- flush_tlb_handlers()

To avoid this, move flush_tlb_handlers() into build_tlb_refill_handler()
right after they were generated. We can do this as the cache handling is
initialized just before creating the tlb handlers.

This issue was introduced in 3d8bfdd0
("MIPS: Use C0_KScratch (if present) to hold PGD pointer.").

Signed-off-by: default avatarJonas Gorski <jogo@openwrt.org>
Cc: linux-mips@linux-mips.org
Cc: Steven J. Hill <Steven.Hill@imgtec.com>
Cc: Jayachandran C <jchandra@broadcom.com>
Cc: David Daney <david.daney@cavium.com>
Patchwork: https://patchwork.linux-mips.org/patch/5539/


Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
parent 6a72015d

arch/mips/kernel/traps.c

+0 −2
Original line number Diff line number Diff line
@@ -1627,7 +1627,6 @@ void *set_vi_handler(int n, vi_handler_t addr) 
}



extern void tlb_init(void);

extern void flush_tlb_handlers(void);



/*

 * Timer interrupt
@@ -1956,7 +1955,6 @@ void __init trap_init(void) 
		set_handler(0x080, &except_vec3_generic, 0x80);



	local_flush_icache_range(ebase, ebase + 0x400);

	flush_tlb_handlers();



	sort_extable(__start___dbe_table, __stop___dbe_table);

arch/mips/mm/tlbex.c

+16 −14
Original line number Diff line number Diff line
@@ -2181,6 +2181,20 @@ static void __cpuinit build_r4000_tlb_modify_handler(void) 
	dump_handler("r4000_tlb_modify", handle_tlbm, ARRAY_SIZE(handle_tlbm));

}



static void __cpuinit flush_tlb_handlers(void)

{

	local_flush_icache_range((unsigned long)handle_tlbl,

			   (unsigned long)handle_tlbl + sizeof(handle_tlbl));

	local_flush_icache_range((unsigned long)handle_tlbs,

			   (unsigned long)handle_tlbs + sizeof(handle_tlbs));

	local_flush_icache_range((unsigned long)handle_tlbm,

			   (unsigned long)handle_tlbm + sizeof(handle_tlbm));

#ifdef CONFIG_MIPS_PGD_C0_CONTEXT

	local_flush_icache_range((unsigned long)tlbmiss_handler_setup_pgd_array,

			   (unsigned long)tlbmiss_handler_setup_pgd_array + sizeof(handle_tlbm));

#endif

}



void __cpuinit build_tlb_refill_handler(void)

{

	/*
@@ -2213,6 +2227,7 @@ void __cpuinit build_tlb_refill_handler(void) 
			build_r3000_tlb_load_handler();

			build_r3000_tlb_store_handler();

			build_r3000_tlb_modify_handler();

			flush_tlb_handlers();

			run_once++;

		}

#else
@@ -2240,23 +2255,10 @@ void __cpuinit build_tlb_refill_handler(void) 
			build_r4000_tlb_modify_handler();

			if (!cpu_has_local_ebase)

				build_r4000_tlb_refill_handler();

			flush_tlb_handlers();

			run_once++;

		}

		if (cpu_has_local_ebase)

			build_r4000_tlb_refill_handler();

	}

}
 


void __cpuinit flush_tlb_handlers(void)

{

	local_flush_icache_range((unsigned long)handle_tlbl,

			   (unsigned long)handle_tlbl + sizeof(handle_tlbl));

	local_flush_icache_range((unsigned long)handle_tlbs,

			   (unsigned long)handle_tlbs + sizeof(handle_tlbs));

	local_flush_icache_range((unsigned long)handle_tlbm,

			   (unsigned long)handle_tlbm + sizeof(handle_tlbm));

#ifdef CONFIG_MIPS_PGD_C0_CONTEXT

	local_flush_icache_range((unsigned long)tlbmiss_handler_setup_pgd_array,

			   (unsigned long)tlbmiss_handler_setup_pgd_array + sizeof(handle_tlbm));

#endif

}

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