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Commit dbb43421 authored by Chris Metcalf's avatar Chris Metcalf
Browse files

arch/tile: disable GX prefetcher during cache flush



Otherwise, it's possible to end up with the prefetcher pulling
data into cache that the code believes has been flushed.

Signed-off-by: default avatarChris Metcalf <cmetcalf@tilera.com>
parent 43d9ebba
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+18 −0
Original line number Original line Diff line number Diff line
@@ -15,6 +15,7 @@
#include <asm/page.h>
#include <asm/page.h>
#include <asm/cacheflush.h>
#include <asm/cacheflush.h>
#include <arch/icache.h>
#include <arch/icache.h>
#include <arch/spr_def.h>




void __flush_icache_range(unsigned long start, unsigned long end)
void __flush_icache_range(unsigned long start, unsigned long end)
@@ -39,6 +40,18 @@ void finv_buffer_remote(void *buffer, size_t size, int hfh)
	char *p, *base;
	char *p, *base;
	size_t step_size, load_count;
	size_t step_size, load_count;
	const unsigned long STRIPE_WIDTH = 8192;
	const unsigned long STRIPE_WIDTH = 8192;
#ifdef __tilegx__
	/*
	 * On TILE-Gx, we must disable the dstream prefetcher before doing
	 * a cache flush; otherwise, we could end up with data in the cache
	 * that we don't want there.  Note that normally we'd do an mf
	 * after the SPR write to disabling the prefetcher, but we do one
	 * below, before any further loads, so there's no need to do it
	 * here.
	 */
	uint_reg_t old_dstream_pf = __insn_mfspr(SPR_DSTREAM_PF);
	__insn_mtspr(SPR_DSTREAM_PF, 0);
#endif


	/*
	/*
	 * Flush and invalidate the buffer out of the local L1/L2
	 * Flush and invalidate the buffer out of the local L1/L2
@@ -122,4 +135,9 @@ void finv_buffer_remote(void *buffer, size_t size, int hfh)


	/* Wait for the load+inv's (and thus finvs) to have completed. */
	/* Wait for the load+inv's (and thus finvs) to have completed. */
	__insn_mf();
	__insn_mf();

#ifdef __tilegx__
	/* Reenable the prefetcher. */
	__insn_mtspr(SPR_DSTREAM_PF, old_dstream_pf);
#endif
}
}