From 8f21814292cbfc2efe407c61171f041c821c69e3 Mon Sep 17 00:00:00 2001 From: Ivan Baravy Date: Thu, 11 Jun 2020 13:23:44 +0000 Subject: [PATCH] Move slab allocator code from bus/usb/memory.inc to core/slab.inc. git-svn-id: svn://kolibrios.org@8037 a494cfbc-eb01-0410-851d-a64ba20cac60 --- kernel/trunk/bus/usb/hccommon.inc | 4 +- kernel/trunk/bus/usb/memory.inc | 112 +------------------------- kernel/trunk/core/slab.inc | 125 ++++++++++++++++++++++++++++++ kernel/trunk/kernel32.inc | 1 + 4 files changed, 129 insertions(+), 113 deletions(-) create mode 100644 kernel/trunk/core/slab.inc diff --git a/kernel/trunk/bus/usb/hccommon.inc b/kernel/trunk/bus/usb/hccommon.inc index 76ca9abb95..90eacfab5f 100644 --- a/kernel/trunk/bus/usb/hccommon.inc +++ b/kernel/trunk/bus/usb/hccommon.inc @@ -20,8 +20,8 @@ usb_hc_func: dd usb_wakeup_if_needed dd usb_subscribe_control dd usb_subscription_done - dd usb_allocate_common - dd usb_free_common + dd slab_alloc + dd slab_free dd usb_td_to_virt dd usb_init_transfer dd usb_undo_tds diff --git a/kernel/trunk/bus/usb/memory.inc b/kernel/trunk/bus/usb/memory.inc index 128459d8b8..1a68336ac8 100644 --- a/kernel/trunk/bus/usb/memory.inc +++ b/kernel/trunk/bus/usb/memory.inc @@ -13,117 +13,7 @@ $Revision$ ; * memory blocks should be properly aligned ; * memory blocks should not cross page boundary ; Hardware layer allocates fixed-size blocks. -; Thus, the specific allocator is quite easy to write: -; allocate one page, split into blocks, maintain the single-linked -; list of all free blocks in each page. - -; Note: size must be a multiple of required alignment. - -; Data for one pool: dd pointer to the first page, MUTEX lock. - -; Allocator for fixed-size blocks: allocate a block. -; [ebx-4] = pointer to the first page, ebx = pointer to MUTEX structure. -proc usb_allocate_common - push edi ; save used register to be stdcall -virtual at esp - dd ? ; saved edi - dd ? ; return address -.size dd ? -end virtual -; 1. Take the lock. - mov ecx, ebx - call mutex_lock -; 2. Find the first allocated page with a free block, if any. -; 2a. Initialize for the loop. - mov edx, ebx -.pageloop: -; 2b. Get the next page, keeping the current in eax. - mov eax, edx - mov edx, [edx-4] -; 2c. If there is no next page, we're out of luck; go to 4. - test edx, edx - jz .newpage - add edx, 0x1000 -@@: -; 2d. Get the pointer to the first free block on this page. -; If there is no free block, continue to 2b. - mov eax, [edx-8] - test eax, eax - jz .pageloop -; 2e. Get the pointer to the next free block. - mov ecx, [eax] -; 2f. Update the pointer to the first free block from eax to ecx. -; Normally [edx-8] still contains eax, if so, atomically set it to ecx -; and proceed to 3. -; However, the price of simplicity of usb_free_common (in particular, it -; doesn't take the lock) is that [edx-8] could (rarely) be changed while -; we processed steps 2d+2e. If so, return to 2d and retry. - lock cmpxchg [edx-8], ecx - jnz @b -.return: -; 3. Release the lock taken in step 1 and return. - push eax - mov ecx, ebx - call mutex_unlock - pop eax - pop edi ; restore used register to be stdcall - ret 4 -.newpage: -; 4. Allocate a new page. - push eax - stdcall kernel_alloc, 0x1000 - pop edx -; If failed, say something to the debug board and return zero. - test eax, eax - jz .nomemory -; 5. Add the new page to the tail of list of allocated pages. - mov [edx-4], eax -; 6. Initialize two service dwords in the end of page: -; first free block is (start of page) + (block size) -; (we will return first block at (start of page), so consider it allocated), -; no next page. - mov edx, eax - lea edi, [eax+0x1000-8] - add edx, [.size] - mov [edi], edx - and dword [edi+4], 0 -; 7. All blocks starting from edx are free; join them in a single-linked list. -@@: - mov ecx, edx - add edx, [.size] - mov [ecx], edx - cmp edx, edi - jbe @b - sub ecx, [.size] - and dword [ecx], 0 -; 8. Return (start of page). - jmp .return -.nomemory: - dbgstr 'no memory for USB descriptor' - xor eax, eax - jmp .return -endp - -; Allocator for fixed-size blocks: free a block. -proc usb_free_common - push ecx edx -virtual at esp - rd 2 ; saved registers - dd ? ; return address -.block dd ? -end virtual -; Insert the given block to the head of free blocks in this page. - mov ecx, [.block] - mov edx, ecx - or edx, 0xFFF -@@: - mov eax, [edx+1-8] - mov [ecx], eax - lock cmpxchg [edx+1-8], ecx - jnz @b - pop edx ecx - ret 4 -endp +; Thus, hardware layer uses the system slab allocator. ; Helper procedure: translate physical address in ecx ; of some transfer descriptor to linear address. diff --git a/kernel/trunk/core/slab.inc b/kernel/trunk/core/slab.inc new file mode 100644 index 0000000000..2b70509afe --- /dev/null +++ b/kernel/trunk/core/slab.inc @@ -0,0 +1,125 @@ +;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; +;; ;; +;; Copyright (C) KolibriOS team 2013-2015. All rights reserved. ;; +;; Distributed under terms of the GNU General Public License ;; +;; ;; +;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; + +$Revision$ + +; Memory management for slab structures. +; The allocator meets special requirements: +; * memory blocks are properly aligned +; * memory blocks do not cross page boundary +; The allocator manages fixed-size blocks. +; Thus, the specific allocator works as follows: +; allocate one page, split into blocks, maintain the single-linked +; list of all free blocks in each page. + +; Note: size must be a multiple of required alignment. + +; Data for one pool: dd pointer to the first page, MUTEX lock. + +; Allocator for fixed-size blocks: allocate a block. +; [ebx-4] = pointer to the first page, ebx = pointer to MUTEX structure. +proc slab_alloc + push edi ; save used register to be stdcall +virtual at esp + dd ? ; saved edi + dd ? ; return address +.size dd ? +end virtual +; 1. Take the lock. + mov ecx, ebx + call mutex_lock +; 2. Find the first allocated page with a free block, if any. +; 2a. Initialize for the loop. + mov edx, ebx +.pageloop: +; 2b. Get the next page, keeping the current in eax. + mov eax, edx + mov edx, [edx-4] +; 2c. If there is no next page, we're out of luck; go to 4. + test edx, edx + jz .newpage + add edx, 0x1000 +@@: +; 2d. Get the pointer to the first free block on this page. +; If there is no free block, continue to 2b. + mov eax, [edx-8] + test eax, eax + jz .pageloop +; 2e. Get the pointer to the next free block. + mov ecx, [eax] +; 2f. Update the pointer to the first free block from eax to ecx. +; Normally [edx-8] still contains eax, if so, atomically set it to ecx +; and proceed to 3. +; However, the price of simplicity of slab_free (in particular, it doesn't take +; the lock) is that [edx-8] could (rarely) be changed while we processed steps +; 2d+2e. If so, return to 2d and retry. + lock cmpxchg [edx-8], ecx + jnz @b +.return: +; 3. Release the lock taken in step 1 and return. + push eax + mov ecx, ebx + call mutex_unlock + pop eax + pop edi ; restore used register to be stdcall + ret 4 +.newpage: +; 4. Allocate a new page. + push eax + stdcall kernel_alloc, 0x1000 + pop edx +; If failed, say something to the debug board and return zero. + test eax, eax + jz .nomemory +; 5. Add the new page to the tail of list of allocated pages. + mov [edx-4], eax +; 6. Initialize two service dwords in the end of page: +; first free block is (start of page) + (block size) +; (we will return first block at (start of page), so consider it allocated), +; no next page. + mov edx, eax + lea edi, [eax+0x1000-8] + add edx, [.size] + mov [edi], edx + and dword [edi+4], 0 +; 7. All blocks starting from edx are free; join them in a single-linked list. +@@: + mov ecx, edx + add edx, [.size] + mov [ecx], edx + cmp edx, edi + jbe @b + sub ecx, [.size] + and dword [ecx], 0 +; 8. Return (start of page). + jmp .return +.nomemory: + dbgstr 'no memory for slab allocation' + xor eax, eax + jmp .return +endp + +; Allocator for fixed-size blocks: free a block. +proc slab_free + push ecx edx +virtual at esp + rd 2 ; saved registers + dd ? ; return address +.block dd ? +end virtual +; Insert the given block to the head of free blocks in this page. + mov ecx, [.block] + mov edx, ecx + or edx, 0xFFF +@@: + mov eax, [edx+1-8] + mov [ecx], eax + lock cmpxchg [edx+1-8], ecx + jnz @b + pop edx ecx + ret 4 +endp diff --git a/kernel/trunk/kernel32.inc b/kernel/trunk/kernel32.inc index 3dc4488605..071d2a04f1 100644 --- a/kernel/trunk/kernel32.inc +++ b/kernel/trunk/kernel32.inc @@ -26,6 +26,7 @@ include "core/irq.inc" ; interrupt handling functions include "core/apic.inc" include "core/timers.inc" include "core/clipboard.inc" +include "core/slab.inc" include "posix/posix.inc"