From e2ce7255e84db656853e91536e6023f92ff89f97 Mon Sep 17 00:00:00 2001 From: Doug Thompson Date: Mon, 27 Apr 2009 15:57:12 +0200 Subject: [PATCH] amd64_edac: add functionality to compute the DRAM hole Borislav: - cleanup/fix comments, add BKDG refs - cleanup debug calls Reviewed-by: Mauro Carvalho Chehab Signed-off-by: Doug Thompson Signed-off-by: Borislav Petkov --- drivers/edac/amd64_edac.c | 166 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 166 insertions(+) diff --git a/drivers/edac/amd64_edac.c b/drivers/edac/amd64_edac.c index a774f34d508b..4716fb561e6e 100644 --- a/drivers/edac/amd64_edac.c +++ b/drivers/edac/amd64_edac.c @@ -269,3 +269,169 @@ err_no_match: return NULL; } + +/* + * Extract the DRAM CS base address from selected csrow register. + */ +static u64 base_from_dct_base(struct amd64_pvt *pvt, int csrow) +{ + return ((u64) (amd64_get_dct_base(pvt, 0, csrow) & pvt->dcsb_base)) << + pvt->dcs_shift; +} + +/* + * Extract the mask from the dcsb0[csrow] entry in a CPU revision-specific way. + */ +static u64 mask_from_dct_mask(struct amd64_pvt *pvt, int csrow) +{ + u64 dcsm_bits, other_bits; + u64 mask; + + /* Extract bits from DRAM CS Mask. */ + dcsm_bits = amd64_get_dct_mask(pvt, 0, csrow) & pvt->dcsm_mask; + + other_bits = pvt->dcsm_mask; + other_bits = ~(other_bits << pvt->dcs_shift); + + /* + * The extracted bits from DCSM belong in the spaces represented by + * the cleared bits in other_bits. + */ + mask = (dcsm_bits << pvt->dcs_shift) | other_bits; + + return mask; +} + +/* + * @input_addr is an InputAddr associated with the node given by mci. Return the + * csrow that input_addr maps to, or -1 on failure (no csrow claims input_addr). + */ +static int input_addr_to_csrow(struct mem_ctl_info *mci, u64 input_addr) +{ + struct amd64_pvt *pvt; + int csrow; + u64 base, mask; + + pvt = mci->pvt_info; + + /* + * Here we use the DRAM CS Base and DRAM CS Mask registers. For each CS + * base/mask register pair, test the condition shown near the start of + * section 3.5.4 (p. 84, BKDG #26094, K8, revA-E). + */ + for (csrow = 0; csrow < CHIPSELECT_COUNT; csrow++) { + + /* This DRAM chip select is disabled on this node */ + if ((pvt->dcsb0[csrow] & K8_DCSB_CS_ENABLE) == 0) + continue; + + base = base_from_dct_base(pvt, csrow); + mask = ~mask_from_dct_mask(pvt, csrow); + + if ((input_addr & mask) == (base & mask)) { + debugf2("InputAddr 0x%lx matches csrow %d (node %d)\n", + (unsigned long)input_addr, csrow, + pvt->mc_node_id); + + return csrow; + } + } + + debugf2("no matching csrow for InputAddr 0x%lx (MC node %d)\n", + (unsigned long)input_addr, pvt->mc_node_id); + + return -1; +} + +/* + * Return the base value defined by the DRAM Base register for the node + * represented by mci. This function returns the full 40-bit value despite the + * fact that the register only stores bits 39-24 of the value. See section + * 3.4.4.1 (BKDG #26094, K8, revA-E) + */ +static inline u64 get_dram_base(struct mem_ctl_info *mci) +{ + struct amd64_pvt *pvt = mci->pvt_info; + + return pvt->dram_base[pvt->mc_node_id]; +} + +/* + * Obtain info from the DRAM Hole Address Register (section 3.4.8, pub #26094) + * for the node represented by mci. Info is passed back in *hole_base, + * *hole_offset, and *hole_size. Function returns 0 if info is valid or 1 if + * info is invalid. Info may be invalid for either of the following reasons: + * + * - The revision of the node is not E or greater. In this case, the DRAM Hole + * Address Register does not exist. + * + * - The DramHoleValid bit is cleared in the DRAM Hole Address Register, + * indicating that its contents are not valid. + * + * The values passed back in *hole_base, *hole_offset, and *hole_size are + * complete 32-bit values despite the fact that the bitfields in the DHAR + * only represent bits 31-24 of the base and offset values. + */ +int amd64_get_dram_hole_info(struct mem_ctl_info *mci, u64 *hole_base, + u64 *hole_offset, u64 *hole_size) +{ + struct amd64_pvt *pvt = mci->pvt_info; + u64 base; + + /* only revE and later have the DRAM Hole Address Register */ + if (boot_cpu_data.x86 == 0xf && pvt->ext_model < OPTERON_CPU_REV_E) { + debugf1(" revision %d for node %d does not support DHAR\n", + pvt->ext_model, pvt->mc_node_id); + return 1; + } + + /* only valid for Fam10h */ + if (boot_cpu_data.x86 == 0x10 && + (pvt->dhar & F10_DRAM_MEM_HOIST_VALID) == 0) { + debugf1(" Dram Memory Hoisting is DISABLED on this system\n"); + return 1; + } + + if ((pvt->dhar & DHAR_VALID) == 0) { + debugf1(" Dram Memory Hoisting is DISABLED on this node %d\n", + pvt->mc_node_id); + return 1; + } + + /* This node has Memory Hoisting */ + + /* +------------------+--------------------+--------------------+----- + * | memory | DRAM hole | relocated | + * | [0, (x - 1)] | [x, 0xffffffff] | addresses from | + * | | | DRAM hole | + * | | | [0x100000000, | + * | | | (0x100000000+ | + * | | | (0xffffffff-x))] | + * +------------------+--------------------+--------------------+----- + * + * Above is a diagram of physical memory showing the DRAM hole and the + * relocated addresses from the DRAM hole. As shown, the DRAM hole + * starts at address x (the base address) and extends through address + * 0xffffffff. The DRAM Hole Address Register (DHAR) relocates the + * addresses in the hole so that they start at 0x100000000. + */ + + base = dhar_base(pvt->dhar); + + *hole_base = base; + *hole_size = (0x1ull << 32) - base; + + if (boot_cpu_data.x86 > 0xf) + *hole_offset = f10_dhar_offset(pvt->dhar); + else + *hole_offset = k8_dhar_offset(pvt->dhar); + + debugf1(" DHAR info for node %d base 0x%lx offset 0x%lx size 0x%lx\n", + pvt->mc_node_id, (unsigned long)*hole_base, + (unsigned long)*hole_offset, (unsigned long)*hole_size); + + return 0; +} +EXPORT_SYMBOL_GPL(amd64_get_dram_hole_info); + +