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author | James Hogan <jhogan@kernel.org> | 2017-10-24 15:14:50 +0300 |
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committer | James Hogan <jhogan@kernel.org> | 2018-02-22 14:07:36 +0300 |
commit | 298910619d13e9c04680e923fef1e5bbc1790d10 (patch) | |
tree | 4af1534934f3a9e9de88f0732aad8fae987dbbc0 | |
parent | bb6fb6dfcc17cddac11ac295861f7608194447a7 (diff) | |
download | linux-298910619d13e9c04680e923fef1e5bbc1790d10.tar.xz |
docs: Remove metag docs
Now that arch/metag/ has been removed, remove Meta architecture specific
documentation from the Documentation/ directory.
Signed-off-by: James Hogan <jhogan@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-metag@vger.kernel.org
Cc: linux-doc@vger.kernel.org
-rw-r--r-- | Documentation/00-INDEX | 2 | ||||
-rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 4 | ||||
-rw-r--r-- | Documentation/devicetree/bindings/metag/meta.txt | 30 | ||||
-rw-r--r-- | Documentation/metag/00-INDEX | 4 | ||||
-rw-r--r-- | Documentation/metag/kernel-ABI.txt | 256 |
5 files changed, 0 insertions, 296 deletions
diff --git a/Documentation/00-INDEX b/Documentation/00-INDEX index 7f3a0728ccf2..eae1e7193f50 100644 --- a/Documentation/00-INDEX +++ b/Documentation/00-INDEX @@ -276,8 +276,6 @@ memory-hotplug.txt - Hotpluggable memory support, how to use and current status. men-chameleon-bus.txt - info on MEN chameleon bus. -metag/ - - directory with info about Linux on Meta architecture. mic/ - Intel Many Integrated Core (MIC) architecture device driver. mips/ diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 1d1d53f85ddd..30a8d0635898 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -1347,10 +1347,6 @@ If specified, z/VM IUCV HVC accepts connections from listed z/VM user IDs only. - hwthread_map= [METAG] Comma-separated list of Linux cpu id to - hardware thread id mappings. - Format: <cpu>:<hwthread> - keep_bootcon [KNL] Do not unregister boot console at start. This is only useful for debugging when something happens in the window diff --git a/Documentation/devicetree/bindings/metag/meta.txt b/Documentation/devicetree/bindings/metag/meta.txt deleted file mode 100644 index f4457f57ab08..000000000000 --- a/Documentation/devicetree/bindings/metag/meta.txt +++ /dev/null @@ -1,30 +0,0 @@ -* Meta Processor Binding - -This binding specifies what properties must be available in the device tree -representation of a Meta Processor Core, which is the root node in the tree. - -Required properties: - - - compatible: Specifies the compatibility list for the Meta processor. - The type shall be <string> and the value shall include "img,meta". - -Optional properties: - - - clocks: Clock consumer specifiers as described in - Documentation/devicetree/bindings/clock/clock-bindings.txt - - - clock-names: Clock consumer names as described in - Documentation/devicetree/bindings/clock/clock-bindings.txt. - -Clocks are identified by name. Valid clocks are: - - - "core": The Meta core clock from which the Meta timers are derived. - -* Examples - -/ { - compatible = "toumaz,tz1090", "img,meta"; - - clocks = <&meta_core_clk>; - clock-names = "core"; -}; diff --git a/Documentation/metag/00-INDEX b/Documentation/metag/00-INDEX deleted file mode 100644 index db11c513bd5c..000000000000 --- a/Documentation/metag/00-INDEX +++ /dev/null @@ -1,4 +0,0 @@ -00-INDEX - - this file -kernel-ABI.txt - - Documents metag ABI details diff --git a/Documentation/metag/kernel-ABI.txt b/Documentation/metag/kernel-ABI.txt deleted file mode 100644 index 628216603198..000000000000 --- a/Documentation/metag/kernel-ABI.txt +++ /dev/null @@ -1,256 +0,0 @@ - ========================== - KERNEL ABIS FOR METAG ARCH - ========================== - -This document describes the Linux ABIs for the metag architecture, and has the -following sections: - - (*) Outline of registers - (*) Userland registers - (*) Kernel registers - (*) System call ABI - (*) Calling conventions - - -==================== -OUTLINE OF REGISTERS -==================== - -The main Meta core registers are arranged in units: - - UNIT Type DESCRIPTION GP EXT PRIV GLOBAL - ======= ======= =============== ======= ======= ======= ======= - CT Special Control unit - D0 General Data unit 0 0-7 8-15 16-31 16-31 - D1 General Data unit 1 0-7 8-15 16-31 16-31 - A0 General Address unit 0 0-3 4-7 8-15 8-15 - A1 General Address unit 1 0-3 4-7 8-15 8-15 - PC Special PC unit 0 1 - PORT Special Ports - TR Special Trigger unit 0-7 - TT Special Trace unit 0-5 - FX General FP unit 0-15 - -GP registers form part of the main context. - -Extended context registers (EXT) may not be present on all hardware threads and -can be context switched if support is enabled and the appropriate bits are set -in e.g. the D0.8 register to indicate what extended state to preserve. - -Global registers are shared between threads and are privilege protected. - -See arch/metag/include/asm/metag_regs.h for definitions relating to core -registers and the fields and bits they contain. See the TRMs for further details -about special registers. - -Several special registers are preserved in the main context, these are the -interesting ones: - - REG (ALIAS) PURPOSE - ======================= =============================================== - CT.1 (TXMODE) Processor mode bits (particularly for DSP) - CT.2 (TXSTATUS) Condition flags and LSM_STEP (MGET/MSET step) - CT.3 (TXRPT) Branch repeat counter - PC.0 (PC) Program counter - -Some of the general registers have special purposes in the ABI and therefore -have aliases: - - D0 REG (ALIAS) PURPOSE D1 REG (ALIAS) PURPOSE - =============== =============== =============== ======================= - D0.0 (D0Re0) 32bit result D1.0 (D1Re0) Top half of 64bit result - D0.1 (D0Ar6) Argument 6 D1.1 (D1Ar5) Argument 5 - D0.2 (D0Ar4) Argument 4 D1.2 (D1Ar3) Argument 3 - D0.3 (D0Ar2) Argument 2 D1.3 (D1Ar1) Argument 1 - D0.4 (D0FrT) Frame temp D1.4 (D1RtP) Return pointer - D0.5 Call preserved D1.5 Call preserved - D0.6 Call preserved D1.6 Call preserved - D0.7 Call preserved D1.7 Call preserved - - A0 REG (ALIAS) PURPOSE A1 REG (ALIAS) PURPOSE - =============== =============== =============== ======================= - A0.0 (A0StP) Stack pointer A1.0 (A1GbP) Global base pointer - A0.1 (A0FrP) Frame pointer A1.1 (A1LbP) Local base pointer - A0.2 A1.2 - A0.3 A1.3 - - -================== -USERLAND REGISTERS -================== - -All the general purpose D0, D1, A0, A1 registers are preserved when entering the -kernel (including asynchronous events such as interrupts and timer ticks) except -the following which have special purposes in the ABI: - - REGISTERS WHEN STATUS PURPOSE - =============== ======= =============== =============================== - D0.8 DSP Preserved ECH, determines what extended - DSP state to preserve. - A0.0 (A0StP) ALWAYS Preserved Stack >= A0StP may be clobbered - at any time by the creation of a - signal frame. - A1.0 (A1GbP) SMP Clobbered Used as temporary for loading - kernel stack pointer and saving - core context. - A0.15 !SMP Protected Stores kernel stack pointer. - A1.15 ALWAYS Protected Stores kernel base pointer. - -On UP A0.15 is used to store the kernel stack pointer for storing the userland -context. A0.15 is global between hardware threads though which means it cannot -be used on SMP for this purpose. Since no protected local registers are -available A1GbP is reserved for use as a temporary to allow a percpu stack -pointer to be loaded for storing the rest of the context. - - -================ -KERNEL REGISTERS -================ - -When in the kernel the following registers have special purposes in the ABI: - - REGISTERS WHEN STATUS PURPOSE - =============== ======= =============== =============================== - A0.0 (A0StP) ALWAYS Preserved Stack >= A0StP may be clobbered - at any time by the creation of - an irq signal frame. - A1.0 (A1GbP) ALWAYS Preserved Reserved (kernel base pointer). - - -=============== -SYSTEM CALL ABI -=============== - -When a system call is made, the following registers are effective: - - REGISTERS CALL RETURN - =============== ======================= =============================== - D0.0 (D0Re0) Return value (or -errno) - D1.0 (D1Re0) System call number Clobbered - D0.1 (D0Ar6) Syscall arg #6 Preserved - D1.1 (D1Ar5) Syscall arg #5 Preserved - D0.2 (D0Ar4) Syscall arg #4 Preserved - D1.2 (D1Ar3) Syscall arg #3 Preserved - D0.3 (D0Ar2) Syscall arg #2 Preserved - D1.3 (D1Ar1) Syscall arg #1 Preserved - -Due to the limited number of argument registers and some system calls with badly -aligned 64-bit arguments, 64-bit values are always packed in consecutive -arguments, even if this is contrary to the normal calling conventions (where the -two halves would go in a matching pair of data registers). - -For example fadvise64_64 usually has the signature: - - long sys_fadvise64_64(i32 fd, i64 offs, i64 len, i32 advice); - -But for metag fadvise64_64 is wrapped so that the 64-bit arguments are packed: - - long sys_fadvise64_64_metag(i32 fd, i32 offs_lo, - i32 offs_hi, i32 len_lo, - i32 len_hi, i32 advice) - -So the arguments are packed in the registers like this: - - D0 REG (ALIAS) VALUE D1 REG (ALIAS) VALUE - =============== =============== =============== ======================= - D0.1 (D0Ar6) advice D1.1 (D1Ar5) hi(len) - D0.2 (D0Ar4) lo(len) D1.2 (D1Ar3) hi(offs) - D0.3 (D0Ar2) lo(offs) D1.3 (D1Ar1) fd - - -=================== -CALLING CONVENTIONS -=================== - -These calling conventions apply to both user and kernel code. The stack grows -from low addresses to high addresses in the metag ABI. The stack pointer (A0StP) -should always point to the next free address on the stack and should at all -times be 64-bit aligned. The following registers are effective at the point of a -call: - - REGISTERS CALL RETURN - =============== ======================= =============================== - D0.0 (D0Re0) 32bit return value - D1.0 (D1Re0) Upper half of 64bit return value - D0.1 (D0Ar6) 32bit argument #6 Clobbered - D1.1 (D1Ar5) 32bit argument #5 Clobbered - D0.2 (D0Ar4) 32bit argument #4 Clobbered - D1.2 (D1Ar3) 32bit argument #3 Clobbered - D0.3 (D0Ar2) 32bit argument #2 Clobbered - D1.3 (D1Ar1) 32bit argument #1 Clobbered - D0.4 (D0FrT) Clobbered - D1.4 (D1RtP) Return pointer Clobbered - D{0-1}.{5-7} Preserved - A0.0 (A0StP) Stack pointer Preserved - A1.0 (A0GbP) Preserved - A0.1 (A0FrP) Frame pointer Preserved - A1.1 (A0LbP) Preserved - A{0-1},{2-3} Clobbered - -64-bit arguments are placed in matching pairs of registers (i.e. the same -register number in both D0 and D1 units), with the least significant half in D0 -and the most significant half in D1, leaving a gap where necessary. Further -arguments are stored on the stack in reverse order (earlier arguments at higher -addresses): - - ADDRESS 0 1 2 3 4 5 6 7 - =============== ===== ===== ===== ===== ===== ===== ===== ===== - A0StP --> - A0StP-0x08 32bit argument #8 32bit argument #7 - A0StP-0x10 32bit argument #10 32bit argument #9 - -Function prologues tend to look a bit like this: - - /* If frame pointer in use, move it to frame temp register so it can be - easily pushed onto stack */ - MOV D0FrT,A0FrP - - /* If frame pointer in use, set it to stack pointer */ - ADD A0FrP,A0StP,#0 - - /* Preserve D0FrT, D1RtP, D{0-1}.{5-7} on stack, incrementing A0StP */ - MSETL [A0StP++],D0FrT,D0.5,D0.6,D0.7 - - /* Allocate some stack space for local variables */ - ADD A0StP,A0StP,#0x10 - -At this point the stack would look like this: - - ADDRESS 0 1 2 3 4 5 6 7 - =============== ===== ===== ===== ===== ===== ===== ===== ===== - A0StP --> - A0StP-0x08 - A0StP-0x10 - A0StP-0x18 Old D0.7 Old D1.7 - A0StP-0x20 Old D0.6 Old D1.6 - A0StP-0x28 Old D0.5 Old D1.5 - A0FrP --> Old A0FrP (frame ptr) Old D1RtP (return ptr) - A0FrP-0x08 32bit argument #8 32bit argument #7 - A0FrP-0x10 32bit argument #10 32bit argument #9 - -Function epilogues tend to differ depending on the use of a frame pointer. An -example of a frame pointer epilogue: - - /* Restore D0FrT, D1RtP, D{0-1}.{5-7} from stack, incrementing A0FrP */ - MGETL D0FrT,D0.5,D0.6,D0.7,[A0FrP++] - /* Restore stack pointer to where frame pointer was before increment */ - SUB A0StP,A0FrP,#0x20 - /* Restore frame pointer from frame temp */ - MOV A0FrP,D0FrT - /* Return to caller via restored return pointer */ - MOV PC,D1RtP - -If the function hasn't touched the frame pointer, MGETL cannot be safely used -with A0StP as it always increments and that would expose the stack to clobbering -by interrupts (kernel) or signals (user). Therefore it's common to see the MGETL -split into separate GETL instructions: - - /* Restore D0FrT, D1RtP, D{0-1}.{5-7} from stack */ - GETL D0FrT,D1RtP,[A0StP+#-0x30] - GETL D0.5,D1.5,[A0StP+#-0x28] - GETL D0.6,D1.6,[A0StP+#-0x20] - GETL D0.7,D1.7,[A0StP+#-0x18] - /* Restore stack pointer */ - SUB A0StP,A0StP,#0x30 - /* Return to caller via restored return pointer */ - MOV PC,D1RtP |