3 A PEIM with the following responsibilities:
5 - verify & configure the Q35 TSEG in the entry point,
6 - provide SMRAM access by producing PEI_SMM_ACCESS_PPI,
7 - set aside the SMM_S3_RESUME_STATE object at the bottom of TSEG, and expose
8 it via the gEfiAcpiVariableGuid GUID HOB.
10 This PEIM runs from RAM, so we can write to variables with static storage
13 Copyright (C) 2013, 2015, Red Hat, Inc.<BR>
14 Copyright (c) 2010, Intel Corporation. All rights reserved.<BR>
16 This program and the accompanying materials are licensed and made available
17 under the terms and conditions of the BSD License which accompanies this
18 distribution. The full text of the license may be found at
19 http://opensource.org/licenses/bsd-license.php
21 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, WITHOUT
22 WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
26 #include <Guid/AcpiS3Context.h>
27 #include <Library/BaseLib.h>
28 #include <Library/BaseMemoryLib.h>
29 #include <Library/DebugLib.h>
30 #include <Library/HobLib.h>
31 #include <Library/IoLib.h>
32 #include <Library/PcdLib.h>
33 #include <Library/PciLib.h>
34 #include <Library/PeiServicesLib.h>
35 #include <Ppi/SmmAccess.h>
37 #include <OvmfPlatforms.h>
39 #include "SmramInternal.h"
42 // PEI_SMM_ACCESS_PPI implementation.
46 Opens the SMRAM area to be accessible by a PEIM driver.
48 This function "opens" SMRAM so that it is visible while not inside of SMM.
49 The function should return EFI_UNSUPPORTED if the hardware does not support
50 hiding of SMRAM. The function should return EFI_DEVICE_ERROR if the SMRAM
51 configuration is locked.
53 @param PeiServices General purpose services available to every
55 @param This The pointer to the SMM Access Interface.
56 @param DescriptorIndex The region of SMRAM to Open.
58 @retval EFI_SUCCESS The region was successfully opened.
59 @retval EFI_DEVICE_ERROR The region could not be opened because locked
61 @retval EFI_INVALID_PARAMETER The descriptor index was out of bounds.
68 IN EFI_PEI_SERVICES
**PeiServices
,
69 IN PEI_SMM_ACCESS_PPI
*This
,
70 IN UINTN DescriptorIndex
73 if (DescriptorIndex
>= DescIdxCount
) {
74 return EFI_INVALID_PARAMETER
;
78 // According to current practice, DescriptorIndex is not considered at all,
79 // beyond validating it.
81 return SmramAccessOpen (&This
->LockState
, &This
->OpenState
);
85 Inhibits access to the SMRAM.
87 This function "closes" SMRAM so that it is not visible while outside of SMM.
88 The function should return EFI_UNSUPPORTED if the hardware does not support
91 @param PeiServices General purpose services available to every
93 @param This The pointer to the SMM Access Interface.
94 @param DescriptorIndex The region of SMRAM to Close.
96 @retval EFI_SUCCESS The region was successfully closed.
97 @retval EFI_DEVICE_ERROR The region could not be closed because
99 @retval EFI_INVALID_PARAMETER The descriptor index was out of bounds.
106 IN EFI_PEI_SERVICES
**PeiServices
,
107 IN PEI_SMM_ACCESS_PPI
*This
,
108 IN UINTN DescriptorIndex
111 if (DescriptorIndex
>= DescIdxCount
) {
112 return EFI_INVALID_PARAMETER
;
116 // According to current practice, DescriptorIndex is not considered at all,
117 // beyond validating it.
119 return SmramAccessClose (&This
->LockState
, &This
->OpenState
);
123 Inhibits access to the SMRAM.
125 This function prohibits access to the SMRAM region. This function is usually
126 implemented such that it is a write-once operation.
128 @param PeiServices General purpose services available to every
130 @param This The pointer to the SMM Access Interface.
131 @param DescriptorIndex The region of SMRAM to Close.
133 @retval EFI_SUCCESS The region was successfully locked.
134 @retval EFI_DEVICE_ERROR The region could not be locked because at
135 least one range is still open.
136 @retval EFI_INVALID_PARAMETER The descriptor index was out of bounds.
143 IN EFI_PEI_SERVICES
**PeiServices
,
144 IN PEI_SMM_ACCESS_PPI
*This
,
145 IN UINTN DescriptorIndex
148 if (DescriptorIndex
>= DescIdxCount
) {
149 return EFI_INVALID_PARAMETER
;
153 // According to current practice, DescriptorIndex is not considered at all,
154 // beyond validating it.
156 return SmramAccessLock (&This
->LockState
, &This
->OpenState
);
160 Queries the memory controller for the possible regions that will support
163 @param PeiServices General purpose services available to every
165 @param This The pointer to the SmmAccessPpi Interface.
166 @param SmramMapSize The pointer to the variable containing size of
167 the buffer to contain the description
169 @param SmramMap The buffer containing the data describing the
170 Smram region descriptors.
172 @retval EFI_BUFFER_TOO_SMALL The user did not provide a sufficient buffer.
173 @retval EFI_SUCCESS The user provided a sufficiently-sized buffer.
179 SmmAccessPeiGetCapabilities (
180 IN EFI_PEI_SERVICES
**PeiServices
,
181 IN PEI_SMM_ACCESS_PPI
*This
,
182 IN OUT UINTN
*SmramMapSize
,
183 IN OUT EFI_SMRAM_DESCRIPTOR
*SmramMap
186 return SmramAccessGetCapabilities (This
->LockState
, This
->OpenState
,
187 SmramMapSize
, SmramMap
);
191 // LockState and OpenState will be filled in by the entry point.
193 STATIC PEI_SMM_ACCESS_PPI mAccess
= {
197 &SmmAccessPeiGetCapabilities
201 STATIC EFI_PEI_PPI_DESCRIPTOR mPpiList
[] = {
203 EFI_PEI_PPI_DESCRIPTOR_PPI
| EFI_PEI_PPI_DESCRIPTOR_TERMINATE_LIST
,
204 &gPeiSmmAccessPpiGuid
, &mAccess
210 // Utility functions.
218 IoWrite8 (0x70, Index
);
219 return IoRead8 (0x71);
224 GetSystemMemorySizeBelow4gb (
231 Cmos0x34
= CmosRead8 (0x34);
232 Cmos0x35
= CmosRead8 (0x35);
234 return ((Cmos0x35
<< 8 | Cmos0x34
) << 16) + SIZE_16MB
;
239 // Entry point of this driver.
243 SmmAccessPeiEntryPoint (
244 IN EFI_PEI_FILE_HANDLE FileHandle
,
245 IN CONST EFI_PEI_SERVICES
**PeiServices
248 UINT16 HostBridgeDevId
;
251 UINT32 TopOfLowRam
, TopOfLowRamMb
;
254 EFI_SMRAM_DESCRIPTOR SmramMap
[DescIdxCount
];
258 // This module should only be included if SMRAM support is required.
260 ASSERT (FeaturePcdGet (PcdSmmSmramRequire
));
263 // Verify if we're running on a Q35 machine type.
265 HostBridgeDevId
= PciRead16 (OVMF_HOSTBRIDGE_DID
);
266 if (HostBridgeDevId
!= INTEL_Q35_MCH_DEVICE_ID
) {
267 DEBUG ((EFI_D_ERROR
, "%a: no SMRAM with host bridge DID=0x%04x; only "
268 "DID=0x%04x (Q35) is supported\n", __FUNCTION__
, HostBridgeDevId
,
269 INTEL_Q35_MCH_DEVICE_ID
));
274 // Confirm if QEMU supports SMRAM.
276 // With no support for it, the ESMRAMC (Extended System Management RAM
277 // Control) register reads as zero. If there is support, the cache-enable
278 // bits are hard-coded as 1 by QEMU.
280 EsmramcVal
= PciRead8 (DRAMC_REGISTER_Q35 (MCH_ESMRAMC
));
281 RegMask8
= MCH_ESMRAMC_SM_CACHE
| MCH_ESMRAMC_SM_L1
| MCH_ESMRAMC_SM_L2
;
282 if ((EsmramcVal
& RegMask8
) != RegMask8
) {
283 DEBUG ((EFI_D_ERROR
, "%a: this Q35 implementation lacks SMRAM\n",
288 TopOfLowRam
= GetSystemMemorySizeBelow4gb ();
289 ASSERT ((TopOfLowRam
& (SIZE_1MB
- 1)) == 0);
290 TopOfLowRamMb
= TopOfLowRam
>> 20;
293 // Some of the following registers are no-ops for QEMU at the moment, but it
294 // is recommended to set them correctly, since the ESMRAMC that we ultimately
295 // care about is in the same set of registers.
297 // First, we disable the integrated VGA, and set both the GTT Graphics Memory
298 // Size and the Graphics Mode Select memory pre-allocation fields to zero.
299 // This takes just one write to the Graphics Control Register.
301 PciWrite16 (DRAMC_REGISTER_Q35 (MCH_GGC
), MCH_GGC_IVD
);
304 // Set Top of Low Usable DRAM.
306 PciWrite16 (DRAMC_REGISTER_Q35 (MCH_TOLUD
),
307 (UINT16
)(TopOfLowRamMb
<< MCH_TOLUD_MB_SHIFT
));
310 // Given the zero graphics memory sizes configured above, set the
311 // graphics-related stolen memory bases to the same as TOLUD.
313 PciWrite32 (DRAMC_REGISTER_Q35 (MCH_GBSM
),
314 TopOfLowRamMb
<< MCH_GBSM_MB_SHIFT
);
315 PciWrite32 (DRAMC_REGISTER_Q35 (MCH_BGSM
),
316 TopOfLowRamMb
<< MCH_BGSM_MB_SHIFT
);
319 // Set TSEG Memory Base.
321 PciWrite32 (DRAMC_REGISTER_Q35 (MCH_TSEGMB
),
322 (TopOfLowRamMb
- FixedPcdGet8 (PcdQ35TsegMbytes
)) << MCH_TSEGMB_MB_SHIFT
);
325 // Set TSEG size, and disable TSEG visibility outside of SMM. Note that the
326 // T_EN bit has inverse meaning; when T_EN is set, then TSEG visibility is
327 // *restricted* to SMM.
329 EsmramcVal
&= ~(UINT32
)MCH_ESMRAMC_TSEG_MASK
;
330 EsmramcVal
|= FixedPcdGet8 (PcdQ35TsegMbytes
) == 8 ? MCH_ESMRAMC_TSEG_8MB
:
331 FixedPcdGet8 (PcdQ35TsegMbytes
) == 2 ? MCH_ESMRAMC_TSEG_2MB
:
332 MCH_ESMRAMC_TSEG_1MB
;
333 EsmramcVal
|= MCH_ESMRAMC_T_EN
;
334 PciWrite8 (DRAMC_REGISTER_Q35 (MCH_ESMRAMC
), EsmramcVal
);
337 // TSEG should be closed (see above), but unlocked, initially. Set G_SMRAME
338 // (Global SMRAM Enable) too, as both D_LCK and T_EN depend on it.
340 PciAndThenOr8 (DRAMC_REGISTER_Q35 (MCH_SMRAM
),
341 (UINT8
)((~(UINT32
)MCH_SMRAM_D_LCK
) & 0xff), MCH_SMRAM_G_SMRAME
);
344 // Create the GUID HOB and point it to the first SMRAM range.
346 GetStates (&mAccess
.LockState
, &mAccess
.OpenState
);
347 SmramMapSize
= sizeof SmramMap
;
348 Status
= SmramAccessGetCapabilities (mAccess
.LockState
, mAccess
.OpenState
,
349 &SmramMapSize
, SmramMap
);
350 ASSERT_EFI_ERROR (Status
);
357 Count
= SmramMapSize
/ sizeof SmramMap
[0];
358 DEBUG ((EFI_D_VERBOSE
, "%a: SMRAM map follows, %d entries\n", __FUNCTION__
,
360 DEBUG ((EFI_D_VERBOSE
, "% 20a % 20a % 20a % 20a\n", "PhysicalStart(0x)",
361 "PhysicalSize(0x)", "CpuStart(0x)", "RegionState(0x)"));
362 for (Idx
= 0; Idx
< Count
; ++Idx
) {
363 DEBUG ((EFI_D_VERBOSE
, "% 20Lx % 20Lx % 20Lx % 20Lx\n",
364 SmramMap
[Idx
].PhysicalStart
, SmramMap
[Idx
].PhysicalSize
,
365 SmramMap
[Idx
].CpuStart
, SmramMap
[Idx
].RegionState
));
370 GuidHob
= BuildGuidHob (&gEfiAcpiVariableGuid
,
371 sizeof SmramMap
[DescIdxSmmS3ResumeState
]);
372 if (GuidHob
== NULL
) {
373 return EFI_OUT_OF_RESOURCES
;
376 CopyMem (GuidHob
, &SmramMap
[DescIdxSmmS3ResumeState
],
377 sizeof SmramMap
[DescIdxSmmS3ResumeState
]);
380 // We're done. The next step should succeed, but even if it fails, we can't
381 // roll back the above BuildGuidHob() allocation, because PEI doesn't support
384 return PeiServicesInstallPpi (mPpiList
);
388 // We really don't want to continue in this case.
392 return EFI_UNSUPPORTED
;