diff options
Diffstat (limited to 'Documentation/arm64')
| -rw-r--r-- | Documentation/arm64/elf_hwcaps.txt | 12 | ||||
| -rw-r--r-- | Documentation/arm64/hugetlbpage.txt | 38 | ||||
| -rw-r--r-- | Documentation/arm64/silicon-errata.txt | 1 | ||||
| -rw-r--r-- | Documentation/arm64/sve.txt | 4 |
4 files changed, 49 insertions, 6 deletions
diff --git a/Documentation/arm64/elf_hwcaps.txt b/Documentation/arm64/elf_hwcaps.txt index d6aff2c5e9e2..ea819ae024dd 100644 --- a/Documentation/arm64/elf_hwcaps.txt +++ b/Documentation/arm64/elf_hwcaps.txt @@ -78,11 +78,11 @@ HWCAP_EVTSTRM HWCAP_AES - Functionality implied by ID_AA64ISAR1_EL1.AES == 0b0001. + Functionality implied by ID_AA64ISAR0_EL1.AES == 0b0001. HWCAP_PMULL - Functionality implied by ID_AA64ISAR1_EL1.AES == 0b0010. + Functionality implied by ID_AA64ISAR0_EL1.AES == 0b0010. HWCAP_SHA1 @@ -153,7 +153,7 @@ HWCAP_ASIMDDP HWCAP_SHA512 - Functionality implied by ID_AA64ISAR0_EL1.SHA2 == 0b0002. + Functionality implied by ID_AA64ISAR0_EL1.SHA2 == 0b0010. HWCAP_SVE @@ -173,8 +173,12 @@ HWCAP_USCAT HWCAP_ILRCPC - Functionality implied by ID_AA64ISR1_EL1.LRCPC == 0b0002. + Functionality implied by ID_AA64ISAR1_EL1.LRCPC == 0b0010. HWCAP_FLAGM Functionality implied by ID_AA64ISAR0_EL1.TS == 0b0001. + +HWCAP_SSBS + + Functionality implied by ID_AA64PFR1_EL1.SSBS == 0b0010. diff --git a/Documentation/arm64/hugetlbpage.txt b/Documentation/arm64/hugetlbpage.txt new file mode 100644 index 000000000000..cfae87dc653b --- /dev/null +++ b/Documentation/arm64/hugetlbpage.txt @@ -0,0 +1,38 @@ +HugeTLBpage on ARM64 +==================== + +Hugepage relies on making efficient use of TLBs to improve performance of +address translations. The benefit depends on both - + + - the size of hugepages + - size of entries supported by the TLBs + +The ARM64 port supports two flavours of hugepages. + +1) Block mappings at the pud/pmd level +-------------------------------------- + +These are regular hugepages where a pmd or a pud page table entry points to a +block of memory. Regardless of the supported size of entries in TLB, block +mappings reduce the depth of page table walk needed to translate hugepage +addresses. + +2) Using the Contiguous bit +--------------------------- + +The architecture provides a contiguous bit in the translation table entries +(D4.5.3, ARM DDI 0487C.a) that hints to the MMU to indicate that it is one of a +contiguous set of entries that can be cached in a single TLB entry. + +The contiguous bit is used in Linux to increase the mapping size at the pmd and +pte (last) level. The number of supported contiguous entries varies by page size +and level of the page table. + + +The following hugepage sizes are supported - + + CONT PTE PMD CONT PMD PUD + -------- --- -------- --- + 4K: 64K 2M 32M 1G + 16K: 2M 32M 1G + 64K: 2M 512M 16G diff --git a/Documentation/arm64/silicon-errata.txt b/Documentation/arm64/silicon-errata.txt index 3b2f2dd82225..76ccded8b74c 100644 --- a/Documentation/arm64/silicon-errata.txt +++ b/Documentation/arm64/silicon-errata.txt @@ -56,6 +56,7 @@ stable kernels. | ARM | Cortex-A72 | #853709 | N/A | | ARM | Cortex-A73 | #858921 | ARM64_ERRATUM_858921 | | ARM | Cortex-A55 | #1024718 | ARM64_ERRATUM_1024718 | +| ARM | Cortex-A76 | #1188873 | ARM64_ERRATUM_1188873 | | ARM | MMU-500 | #841119,#826419 | N/A | | | | | | | Cavium | ThunderX ITS | #22375, #24313 | CAVIUM_ERRATUM_22375 | diff --git a/Documentation/arm64/sve.txt b/Documentation/arm64/sve.txt index f128f736b4a5..7169a0ec41d8 100644 --- a/Documentation/arm64/sve.txt +++ b/Documentation/arm64/sve.txt @@ -200,7 +200,7 @@ prctl(PR_SVE_SET_VL, unsigned long arg) thread. * Changing the vector length causes all of P0..P15, FFR and all bits of - Z0..V31 except for Z0 bits [127:0] .. Z31 bits [127:0] to become + Z0..Z31 except for Z0 bits [127:0] .. Z31 bits [127:0] to become unspecified. Calling PR_SVE_SET_VL with vl equal to the thread's current vector length, or calling PR_SVE_SET_VL with the PR_SVE_SET_VL_ONEXEC flag, does not constitute a change to the vector length for this purpose. @@ -500,7 +500,7 @@ References [2] arch/arm64/include/uapi/asm/ptrace.h AArch64 Linux ptrace ABI definitions -[3] linux/Documentation/arm64/cpu-feature-registers.txt +[3] Documentation/arm64/cpu-feature-registers.txt [4] ARM IHI0055C http://infocenter.arm.com/help/topic/com.arm.doc.ihi0055c/IHI0055C_beta_aapcs64.pdf |