northbridge/amd/amdht: Get maximum HT link frequency from NVRAM

This patch allows the user to set a maximum HT link frequency in
NVRAM, paralleling a similar option available in the proprietary
BIOS on some mainboards.

Change-Id: Iba3789262eefa52421e76533cbf14d9da2ef1de8
Signed-off-by: Timothy Pearson <tpearson@raptorengineeringinc.com>
Reviewed-on: http://review.coreboot.org/8462
Tested-by: build bot (Jenkins)
Reviewed-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
This commit is contained in:
Timothy Pearson 2015-02-15 17:11:14 -06:00 committed by Alexandru Gagniuc
parent 033bb4bc8d
commit 03259a8794
1 changed files with 29 additions and 0 deletions

View File

@ -52,6 +52,29 @@
#define APIC_Base_BSP 8
#define APIC_Base 0x1b
#define NVRAM_LIMIT_HT_SPEED_200 0xf
#define NVRAM_LIMIT_HT_SPEED_300 0xe
#define NVRAM_LIMIT_HT_SPEED_400 0xd
#define NVRAM_LIMIT_HT_SPEED_500 0xc
#define NVRAM_LIMIT_HT_SPEED_600 0xb
#define NVRAM_LIMIT_HT_SPEED_800 0xa
#define NVRAM_LIMIT_HT_SPEED_1000 0x9
#define NVRAM_LIMIT_HT_SPEED_1200 0x8
#define NVRAM_LIMIT_HT_SPEED_1400 0x7
#define NVRAM_LIMIT_HT_SPEED_1600 0x6
#define NVRAM_LIMIT_HT_SPEED_1800 0x5
#define NVRAM_LIMIT_HT_SPEED_2000 0x4
#define NVRAM_LIMIT_HT_SPEED_2200 0x3
#define NVRAM_LIMIT_HT_SPEED_2400 0x2
#define NVRAM_LIMIT_HT_SPEED_2600 0x1
#define NVRAM_LIMIT_HT_SPEED_AUTO 0x0
static const uint16_t ht_speed_limit[16] =
{0xFFFF, 0x7FFF, 0x3FFF, 0x1FFF,
0x0FFF, 0x07FF, 0x03FF, 0x01FF,
0x00FF, 0x007F, 0x003F, 0x001F,
0x000F, 0x0007, 0x0003, 0x0001};
/*----------------------------------------------------------------------------
* TYPEDEFS AND STRUCTURES
*
@ -1326,15 +1349,21 @@ static void selectOptimalWidthAndFrequency(sMainData *pDat)
u8 i, j;
u32 temp;
u16 cbPCBFreqLimit;
u16 cbPCBFreqLimit_NVRAM;
u8 cbPCBABDownstreamWidth;
u8 cbPCBBAUpstreamWidth;
cbPCBFreqLimit_NVRAM = 0xFFFF;
if (get_option(&temp, "hypertransport_speed_limit") == CB_SUCCESS)
cbPCBFreqLimit_NVRAM = ht_speed_limit[temp & 0xf];
for (i = 0; i < pDat->TotalLinks*2; i += 2)
{
/* FIXME
* Mainboards need to be able to set cbPCBFreqLimit
*/
cbPCBFreqLimit = 0xFFFF; // Maximum allowed by autoconfiguration
cbPCBFreqLimit = min(cbPCBFreqLimit, cbPCBFreqLimit_NVRAM);
#if CONFIG_EXPERT && CONFIG_LIMIT_HT_DOWN_WIDTH_8
cbPCBABDownstreamWidth = 8;