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memory_manager: Fix address range calculation in MemorySlot

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The MCRS method returns a 64-bit memory range descriptor. The
calculation is supposed to be done as follows:

max = min + len - 1

However, every operand is represented not as a QWORD but as combination
of two DWORDs for high and low part. Till now, the calculation was done
this way, please see also inline comments:

max.lo = min.lo + len.lo //this may overflow, need to carry over to high
max.hi = min.hi + len.hi
max.hi = max.hi - 1 // subtraction needs to happen on the low part

This calculation has been corrected the following way:

max.lo = min.lo + len.lo
max.hi = min.hi + len.hi + (max.lo < min.lo) // check for overflow
max.lo = max.lo - 1 // subtract from low part

The relevant part from the generated ASL for the MCRS method:
```
Method (MCRS, 1, Serialized)
{
    Acquire (MLCK, 0xFFFF)
    \_SB.MHPC.MSEL = Arg0
    Name (MR64, ResourceTemplate ()
    {
	QWordMemory (ResourceProducer, PosDecode, MinFixed, MaxFixed, Cacheable, ReadWrite,
	    0x0000000000000000, // Granularity
	    0x0000000000000000, // Range Minimum
	    0xFFFFFFFFFFFFFFFE, // Range Maximum
	    0x0000000000000000, // Translation Offset
	    0xFFFFFFFFFFFFFFFF, // Length
	    ,, _Y00, AddressRangeMemory, TypeStatic)
    })
    CreateQWordField (MR64, \_SB.MHPC.MCRS._Y00._MIN, MINL)  // _MIN: Minimum Base Address
    CreateDWordField (MR64, 0x12, MINH)
    CreateQWordField (MR64, \_SB.MHPC.MCRS._Y00._MAX, MAXL)  // _MAX: Maximum Base Address
    CreateDWordField (MR64, 0x1A, MAXH)
    CreateQWordField (MR64, \_SB.MHPC.MCRS._Y00._LEN, LENL)  // _LEN: Length
    CreateDWordField (MR64, 0x2A, LENH)
    MINL = \_SB.MHPC.MHBL
    MINH = \_SB.MHPC.MHBH
    LENL = \_SB.MHPC.MHLL
    LENH = \_SB.MHPC.MHLH
    MAXL = (MINL + LENL) /* \_SB_.MHPC.MCRS.LENL */
    MAXH = (MINH + LENH) /* \_SB_.MHPC.MCRS.LENH */
    If ((MAXL < MINL))
    {
	MAXH += One /* \_SB_.MHPC.MCRS.MAXH */
    }

    MAXL -= One
    Release (MLCK)
    Return (MR64) /* \_SB_.MHPC.MCRS.MR64 */
}
```

Fixes #1800.

Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
This commit is contained in:
Anatol Belski
2021-04-08 20:05:38 +02:00
committed by Samuel Ortiz
parent 37e2784299
commit e1cc702327
3 changed files with 116 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files

12
vmm/src/memory_manager.rs
View File

@@ -1810,9 +1810,17 @@ impl Aml for MemoryMethods {
&aml::Path::new("MINH"),
&aml::Path::new("LENH"),
),
&aml::If::new(
&aml::LessThan::new(&aml::Path::new("MAXL"), &aml::Path::new("MINL")),
vec![&aml::Add::new(
&aml::Path::new("MAXH"),
&aml::ONE,
&aml::Path::new("MAXH"),
)],
),
&aml::Subtract::new(
&aml::Path::new("MAXH"),
&aml::Path::new("MAXH"),
&aml::Path::new("MAXL"),
&aml::Path::new("MAXL"),
&aml::ONE,
),
// Release lock