projects / mirror_edk2.git / blame
| Commit | Line | Data |
|---|---|---|
| 3cbfba02 DW |
1 | /*++\r |
| 2 | \r | |
| 3 | Copyright (c) 1999 - 2014, Intel Corporation. All rights reserved\r | |
| 4 | \r\r | |
| 9dc8036d MK |
5 | SPDX-License-Identifier: BSD-2-Clause-Patent\r |
| 6 | \r | |
| 3cbfba02 DW |
7 | \r\r |
| 8 | \r | |
| 9 | \r | |
| 10 | Module Name:\r | |
| 11 | \r | |
| 12 | SmmIo.c\r | |
| 13 | \r | |
| 14 | Abstract:\r | |
| 15 | \r | |
| 16 | SMM I/O access utility implementation file, for Ia32\r | |
| 17 | \r | |
| 18 | --*/\r | |
| 19 | \r | |
| 20 | //\r | |
| 21 | // Include files\r | |
| 22 | //\r | |
| 23 | #include "Library/StallSmmLib.h"\r | |
| 24 | #include "Pi/PiSmmCis.h"\r | |
| 25 | #include "PiDxe.h"\r | |
| 26 | #include <Library/IoLib.h>\r | |
| 27 | #include <Library/PcdLib.h>\r | |
| 28 | #include "PchAccess.h"\r | |
| 29 | \r | |
| 30 | /**\r | |
| 31 | Delay for at least the request number of microseconds.\r | |
| 32 | Timer used is ACPI time counter, which has 1us granularity.\r | |
| 33 | \r | |
| 34 | @param Microseconds Number of microseconds to delay.\r | |
| 35 | \r | |
| 36 | @retval None\r | |
| 37 | \r | |
| 38 | **/\r | |
| 39 | VOID\r | |
| 40 | SmmStall (\r | |
| 41 | IN UINTN Microseconds\r | |
| 42 | )\r | |
| 43 | {\r | |
| 44 | UINTN Ticks;\r | |
| 45 | UINTN Counts;\r | |
| 46 | UINTN CurrentTick;\r | |
| 47 | UINTN OriginalTick;\r | |
| 48 | UINTN RemainingTick;\r | |
| 49 | UINT16 AcpiBaseAddr;\r | |
| 50 | \r | |
| 51 | if (Microseconds == 0) {\r | |
| 52 | return;\r | |
| 53 | }\r | |
| 54 | \r | |
| 55 | AcpiBaseAddr = PchLpcPciCfg16 (R_PCH_LPC_ACPI_BASE) & B_PCH_LPC_ACPI_BASE_BAR;\r | |
| 56 | \r | |
| 57 | OriginalTick = IoRead32 (AcpiBaseAddr + R_PCH_ACPI_PM1_TMR);\r | |
| 58 | CurrentTick = OriginalTick;\r | |
| 59 | \r | |
| 60 | //\r | |
| 61 | // The timer frequency is 3.579545 MHz, so 1 ms corresponds 3.58 clocks\r | |
| 62 | //\r | |
| 63 | Ticks = Microseconds * 358 / 100 + OriginalTick + 1;\r | |
| 64 | \r | |
| 65 | //\r | |
| 66 | // The loops needed by timer overflow\r | |
| 67 | //\r | |
| 68 | Counts = Ticks / V_PCH_ACPI_PM1_TMR_MAX_VAL;\r | |
| 69 | \r | |
| 70 | //\r | |
| 71 | // Remaining clocks within one loop\r | |
| 72 | //\r | |
| 73 | RemainingTick = Ticks % V_PCH_ACPI_PM1_TMR_MAX_VAL;\r | |
| 74 | \r | |
| 75 | //\r | |
| 76 | // not intend to use TMROF_STS bit of register PM1_STS, because this adds extra\r | |
| 77 | // one I/O operation, and maybe generate SMI\r | |
| 78 | //\r | |
| 79 | while ((Counts != 0) || (RemainingTick > CurrentTick)) {\r | |
| 80 | CurrentTick = IoRead32 (AcpiBaseAddr + R_PCH_ACPI_PM1_TMR);\r | |
| 81 | //\r | |
| 82 | // Check if timer overflow\r | |
| 83 | //\r | |
| 84 | if (CurrentTick < OriginalTick) {\r | |
| 85 | Counts--;\r | |
| 86 | }\r | |
| 87 | OriginalTick = CurrentTick;\r | |
| 88 | }\r | |
| 89 | }\r |