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/gem5/src/arch/x86/
H A Dmemhelpers.hhdiff 12384:481add71d2e4 Tue Dec 12 20:54:00 EST 2017 Gabe Black <gabeblack@google.com> x86: Rework how "split" loads/stores are handled.

Explicitly separate the way the data is represented in the underlying
representation from how it's represented in the instruction.

In order to make the ISA parser happy, the Mem operand needs to have
a single, particular type. To handle that with scalar types, we just
used uint64_ts and then worked with values that were smaller than the
maximum we could hold. To work with these new array values, we also
use an underlying uint64_t for each element.

To make accessing the underlying memory system more natural, when we
go to actually read or write values, we translate the access into an
array of the actual, correct underlying type. That way we don't have
non-exact asserts which confuse gcc, or weird endianness conversion
which assumes that the data should be flipped 8 bytes at a time.

Because the functions involved are generally inline, the syntactic
niceness should all boil off, and the final implementation in the
binary should be simple and efficient for the given data types.

Change-Id: I14ce7a2fe0dc2cbaf6ad4a0d19f743c45ee78e26
Reviewed-on: https://gem5-review.googlesource.com/6582
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>
H A Dcpuid.ccdiff 10439:1bd64b294fe4 Fri Jun 13 04:48:00 EDT 2014 Jiuyue Ma <majiuyue@ncic.ac.cn> x86: add LongModeAddressSize function to cpuid

LongModeAddressSize was used by kernel 2.6.28.4 for physical address
validation, if not properly implemented, PCI resource allocation may
failed because of ioremap failed:

- linux-2.6.28.4/arch/x86/mm/ioremap.c:27-30
27 static inline int phys_addr_valid(unsigned long addr)
28 {
29 return addr < (1UL << boot_cpu_data.x86_phys_bits);
30 }

- linux-2.6.28.4/arch/x86/kernel/cpu/common.c:475-482
475 #ifdef CONFIG_X86_64
476 if (c->extended_cpuid_level >= 0x80000008) {
477 u32 eax = cpuid_eax(0x80000008);
478
479 c->x86_virt_bits = (eax >> 8) & 0xff;
480 c->x86_phys_bits = eax & 0xff;
481 }
482 #endif

- linux-2.6.28.4/arch/x86/mm/ioremap.c:209-214
209 if (!phys_addr_valid(phys_addr)) {
210 printk(KERN_WARNING "ioremap: invalid physical address %llx\n",
211 (unsigned long long)phys_addr);
212 WARN_ON_ONCE(1);
213 return NULL;
214 }

This patch return 0x0000ffff for LongModeAddressSize, which guarantee phys_addr_valid never failed.

Committed by: Nilay Vaish <nilay@cs.wisc.edu>
/gem5/src/arch/x86/isa/microops/
H A Dldstop.isadiff 12384:481add71d2e4 Tue Dec 12 20:54:00 EST 2017 Gabe Black <gabeblack@google.com> x86: Rework how "split" loads/stores are handled.

Explicitly separate the way the data is represented in the underlying
representation from how it's represented in the instruction.

In order to make the ISA parser happy, the Mem operand needs to have
a single, particular type. To handle that with scalar types, we just
used uint64_ts and then worked with values that were smaller than the
maximum we could hold. To work with these new array values, we also
use an underlying uint64_t for each element.

To make accessing the underlying memory system more natural, when we
go to actually read or write values, we translate the access into an
array of the actual, correct underlying type. That way we don't have
non-exact asserts which confuse gcc, or weird endianness conversion
which assumes that the data should be flipped 8 bytes at a time.

Because the functions involved are generally inline, the syntactic
niceness should all boil off, and the final implementation in the
binary should be simple and efficient for the given data types.

Change-Id: I14ce7a2fe0dc2cbaf6ad4a0d19f743c45ee78e26
Reviewed-on: https://gem5-review.googlesource.com/6582
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>

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