From 4337020b950454815204eed4e43a894be0b125ca Mon Sep 17 00:00:00 2001 From: Vladimir Serbinenko Date: Wed, 5 Feb 2014 19:46:45 +0100 Subject: Remove CACHE_ROM. With the recent improvement 3d6ffe76f8a505c2dff5d5c6146da3d63dad6e82, speedup by CACHE_ROM is reduced a lot. On the other hand this makes coreboot run out of MTRRs depending on system configuration, hence screwing up I/O access and cache coherency in worst cases. CACHE_ROM requires the user to sanity check their boot output because the feature is brittle. The working configuration is dependent on I/O hole size, ram size, and chipset. Because of this the current implementation can leave a system configured in an inconsistent state leading to unexpected results such as poor performance and/or inconsistent cache-coherency Remove this as a buggy feature until we figure out how to do it properly if necessary. Change-Id: I858d78a907bf042fcc21fdf7a2bf899e9f6b591d Signed-off-by: Vladimir Serbinenko Reviewed-on: http://review.coreboot.org/5146 Tested-by: build bot (Jenkins) Reviewed-by: Aaron Durbin --- src/cpu/x86/mtrr/mtrr.c | 76 ------------------------------------------------- 1 file changed, 76 deletions(-) (limited to 'src/cpu/x86/mtrr/mtrr.c') diff --git a/src/cpu/x86/mtrr/mtrr.c b/src/cpu/x86/mtrr/mtrr.c index d85a86982c..86e31d0010 100644 --- a/src/cpu/x86/mtrr/mtrr.c +++ b/src/cpu/x86/mtrr/mtrr.c @@ -199,16 +199,6 @@ static struct memranges *get_physical_address_space(void) memranges_add_resources_filter(addr_space, mask, match, MTRR_TYPE_WRCOMB, filter_vga_wrcomb); -#if CONFIG_CACHE_ROM - /* Add a write-protect region covering the ROM size - * when CONFIG_CACHE_ROM is enabled. The ROM is assumed - * to be located at 4GiB - rom size. */ - resource_t rom_base = RANGE_TO_PHYS_ADDR( - RANGE_4GB - PHYS_TO_RANGE_ADDR(CACHE_ROM_SIZE)); - memranges_insert(addr_space, rom_base, CACHE_ROM_SIZE, - MTRR_TYPE_WRPROT); -#endif - /* The address space below 4GiB is special. It needs to be * covered entirly by range entries so that MTRR calculations * can be properly done for the full 32-bit address space. @@ -380,61 +370,6 @@ void x86_setup_fixed_mtrrs(void) enable_fixed_mtrr(); } -/* Keep track of the MTRR that covers the ROM for caching purposes. */ -#if CONFIG_CACHE_ROM -static long rom_cache_mtrr = -1; - -long x86_mtrr_rom_cache_var_index(void) -{ - return rom_cache_mtrr; -} - -void x86_mtrr_enable_rom_caching(void) -{ - msr_t msr_val; - unsigned long index; - - if (rom_cache_mtrr < 0) - return; - - index = rom_cache_mtrr; - disable_cache(); - msr_val = rdmsr(MTRRphysBase_MSR(index)); - msr_val.lo &= ~0xff; - msr_val.lo |= MTRR_TYPE_WRPROT; - wrmsr(MTRRphysBase_MSR(index), msr_val); - enable_cache(); -} - -void x86_mtrr_disable_rom_caching(void) -{ - msr_t msr_val; - unsigned long index; - - if (rom_cache_mtrr < 0) - return; - - index = rom_cache_mtrr; - disable_cache(); - msr_val = rdmsr(MTRRphysBase_MSR(index)); - msr_val.lo &= ~0xff; - wrmsr(MTRRphysBase_MSR(index), msr_val); - enable_cache(); -} - -static void disable_cache_rom(void *unused) -{ - x86_mtrr_disable_rom_caching(); -} - -BOOT_STATE_INIT_ENTRIES(disable_rom_cache_bscb) = { - BOOT_STATE_INIT_ENTRY(BS_OS_RESUME, BS_ON_ENTRY, - disable_cache_rom, NULL), - BOOT_STATE_INIT_ENTRY(BS_PAYLOAD_LOAD, BS_ON_EXIT, - disable_cache_rom, NULL), -}; -#endif - struct var_mtrr_state { struct memranges *addr_space; int above4gb; @@ -482,17 +417,6 @@ static void write_var_mtrr(struct var_mtrr_state *var_state, mask = (1ULL << var_state->address_bits) - 1; rsize = rsize & mask; -#if CONFIG_CACHE_ROM - /* CONFIG_CACHE_ROM allocates an MTRR specifically for allowing - * one to turn on caching for faster ROM access. However, it is - * left to the MTRR callers to enable it. */ - if (mtrr_type == MTRR_TYPE_WRPROT) { - mtrr_type = MTRR_TYPE_UNCACHEABLE; - if (rom_cache_mtrr < 0) - rom_cache_mtrr = var_state->mtrr_index; - } -#endif - printk(BIOS_DEBUG, "MTRR: %d base 0x%016llx mask 0x%016llx type %d\n", var_state->mtrr_index, rbase, rsize, mtrr_type); -- cgit v1.2.3