)\r
{\r
EFI_PHYSICAL_ADDRESS GuardPage;\r
+ UINT64 GuardBitmap;\r
\r
if (NumberOfPages == 0) {\r
return;\r
//\r
// Head Guard must be one page before, if any.\r
//\r
+ // MSB-> 1 0 <-LSB\r
+ // -------------------\r
+ // Head Guard -> 0 1 -> Don't free Head Guard (shared Guard)\r
+ // Head Guard -> 0 0 -> Free Head Guard either (not shared Guard)\r
+ // 1 X -> Don't free first page (need a new Guard)\r
+ // (it'll be turned into a Guard page later)\r
+ // -------------------\r
+ // Start -> -1 -2\r
+ //\r
GuardPage = Memory - EFI_PAGES_TO_SIZE (1);\r
- if (IsHeadGuard (GuardPage)) {\r
- if (!IsMemoryGuarded (GuardPage - EFI_PAGES_TO_SIZE (1))) {\r
+ GuardBitmap = GetGuardedMemoryBits (Memory - EFI_PAGES_TO_SIZE (2), 2);\r
+ if ((GuardBitmap & BIT1) == 0) {\r
+ //\r
+ // Head Guard exists.\r
+ //\r
+ if ((GuardBitmap & BIT0) == 0) {\r
//\r
// If the head Guard is not a tail Guard of adjacent memory block,\r
// unset it.\r
//\r
UnsetGuardPage (GuardPage);\r
}\r
- } else if (IsMemoryGuarded (GuardPage)) {\r
+ } else {\r
//\r
// Pages before memory to free are still in Guard. It's a partial free\r
// case. Turn first page of memory block to free into a new Guard.\r
//\r
// Tail Guard must be the page after this memory block to free, if any.\r
//\r
+ // MSB-> 1 0 <-LSB\r
+ // --------------------\r
+ // 1 0 <- Tail Guard -> Don't free Tail Guard (shared Guard)\r
+ // 0 0 <- Tail Guard -> Free Tail Guard either (not shared Guard)\r
+ // X 1 -> Don't free last page (need a new Guard)\r
+ // (it'll be turned into a Guard page later)\r
+ // --------------------\r
+ // +1 +0 <- End\r
+ //\r
GuardPage = Memory + EFI_PAGES_TO_SIZE (NumberOfPages);\r
- if (IsTailGuard (GuardPage)) {\r
- if (!IsMemoryGuarded (GuardPage + EFI_PAGES_TO_SIZE (1))) {\r
+ GuardBitmap = GetGuardedMemoryBits (GuardPage, 2);\r
+ if ((GuardBitmap & BIT0) == 0) {\r
+ //\r
+ // Tail Guard exists.\r
+ //\r
+ if ((GuardBitmap & BIT1) == 0) {\r
//\r
// If the tail Guard is not a head Guard of adjacent memory block,\r
// free it; otherwise, keep it.\r
//\r
UnsetGuardPage (GuardPage);\r
}\r
- } else if (IsMemoryGuarded (GuardPage)) {\r
+ } else {\r
//\r
// Pages after memory to free are still in Guard. It's a partial free\r
// case. We need to keep one page to be a head Guard.\r
EFI_PHYSICAL_ADDRESS Start;\r
EFI_PHYSICAL_ADDRESS MemoryToTest;\r
UINTN PagesToFree;\r
+ UINT64 GuardBitmap;\r
\r
if (Memory == NULL || NumberOfPages == NULL || *NumberOfPages == 0) {\r
return;\r
//\r
// Head Guard must be one page before, if any.\r
//\r
- MemoryToTest = Start - EFI_PAGES_TO_SIZE (1);\r
- if (IsHeadGuard (MemoryToTest)) {\r
- if (!IsMemoryGuarded (MemoryToTest - EFI_PAGES_TO_SIZE (1))) {\r
+ // MSB-> 1 0 <-LSB\r
+ // -------------------\r
+ // Head Guard -> 0 1 -> Don't free Head Guard (shared Guard)\r
+ // Head Guard -> 0 0 -> Free Head Guard either (not shared Guard)\r
+ // 1 X -> Don't free first page (need a new Guard)\r
+ // (it'll be turned into a Guard page later)\r
+ // -------------------\r
+ // Start -> -1 -2\r
+ //\r
+ MemoryToTest = Start - EFI_PAGES_TO_SIZE (2);\r
+ GuardBitmap = GetGuardedMemoryBits (MemoryToTest, 2);\r
+ if ((GuardBitmap & BIT1) == 0) {\r
+ //\r
+ // Head Guard exists.\r
+ //\r
+ if ((GuardBitmap & BIT0) == 0) {\r
//\r
// If the head Guard is not a tail Guard of adjacent memory block,\r
// free it; otherwise, keep it.\r
Start -= EFI_PAGES_TO_SIZE (1);\r
PagesToFree += 1;\r
}\r
- } else if (IsMemoryGuarded (MemoryToTest)) {\r
+ } else {\r
//\r
- // Pages before memory to free are still in Guard. It's a partial free\r
- // case. We need to keep one page to be a tail Guard.\r
+ // No Head Guard, and pages before memory to free are still in Guard. It's a\r
+ // partial free case. We need to keep one page to be a tail Guard.\r
//\r
Start += EFI_PAGES_TO_SIZE (1);\r
PagesToFree -= 1;\r
//\r
// Tail Guard must be the page after this memory block to free, if any.\r
//\r
+ // MSB-> 1 0 <-LSB\r
+ // --------------------\r
+ // 1 0 <- Tail Guard -> Don't free Tail Guard (shared Guard)\r
+ // 0 0 <- Tail Guard -> Free Tail Guard either (not shared Guard)\r
+ // X 1 -> Don't free last page (need a new Guard)\r
+ // (it'll be turned into a Guard page later)\r
+ // --------------------\r
+ // +1 +0 <- End\r
+ //\r
MemoryToTest = Start + EFI_PAGES_TO_SIZE (PagesToFree);\r
- if (IsTailGuard (MemoryToTest)) {\r
- if (!IsMemoryGuarded (MemoryToTest + EFI_PAGES_TO_SIZE (1))) {\r
+ GuardBitmap = GetGuardedMemoryBits (MemoryToTest, 2);\r
+ if ((GuardBitmap & BIT0) == 0) {\r
+ //\r
+ // Tail Guard exists.\r
+ //\r
+ if ((GuardBitmap & BIT1) == 0) {\r
//\r
// If the tail Guard is not a head Guard of adjacent memory block,\r
// free it; otherwise, keep it.\r
//\r
PagesToFree += 1;\r
}\r
- } else if (IsMemoryGuarded (MemoryToTest)) {\r
+ } else if (PagesToFree > 0) {\r
//\r
- // Pages after memory to free are still in Guard. It's a partial free\r
- // case. We need to keep one page to be a head Guard.\r
+ // No Tail Guard, and pages after memory to free are still in Guard. It's a\r
+ // partial free case. We need to keep one page to be a head Guard.\r
//\r
PagesToFree -= 1;\r
}\r
{\r
if (NewType == EfiConventionalMemory) {\r
AdjustMemoryF (&Start, &NumberOfPages);\r
+ if (NumberOfPages == 0) {\r
+ return EFI_SUCCESS;\r
+ }\r
} else {\r
AdjustMemoryA (&Start, &NumberOfPages);\r
}\r
\r
- return CoreConvertPages(Start, NumberOfPages, NewType);\r
+ return CoreConvertPages (Start, NumberOfPages, NewType);\r
}\r
\r
/**\r
projects / mirror_edk2.git / blobdiff