mini kalloc change

.clang-format

@@ -79,7 +79,7 @@ AllowShortCaseLabelsOnASingleLine: false
 AllowShortCompoundRequirementOnASingleLine: true
 AllowShortEnumsOnASingleLine: true
 AllowShortFunctionsOnASingleLine: All
-AllowShortIfStatementsOnASingleLine: Never
+AllowShortIfStatementsOnASingleLine: WithoutElse
 AllowShortLambdasOnASingleLine: All
 AllowShortLoopsOnASingleLine: false
 AllowShortNamespacesOnASingleLine: false
@@ -171,7 +171,7 @@ IndentExternBlock: AfterExternBlock
 IndentGotoLabels: true
 IndentPPDirectives: None
 IndentRequiresClause: true
-IndentWidth:     2
+IndentWidth:     8
 IndentWrappedFunctionNames: false
 InsertBraces:    false
 InsertNewlineAtEOF: false
@@ -216,7 +216,7 @@ PenaltyBreakTemplateDeclaration: 10
 PenaltyExcessCharacter: 1000000
 PenaltyIndentedWhitespace: 0
 PenaltyReturnTypeOnItsOwnLine: 60
-PointerAlignment: Right
+PointerAlignment: Left
 PPIndentWidth:   -1
 QualifierAlignment: Leave
 ReferenceAlignment: Pointer
@@ -284,7 +284,7 @@ StatementMacros:
   - QT_REQUIRE_VERSION
 TableGenBreakInsideDAGArg: DontBreak
 TabWidth:        8
-UseTab:          Never
+UseTab:          Always
 VerilogBreakBetweenInstancePorts: true
 WhitespaceSensitiveMacros:
   - BOOST_PP_STRINGIZE

TODO

@@ -22,7 +22,7 @@ Low-Level Hardware & Interrupts
 Memory Management
 [x] Physical memory manager (Bitmap or Buddy)
 [x] Paging (Recursive or Offset mapping)
-[ ] Kernel heap (kmalloc/kfree - Linked list or Slab)
+[-] Kernel heap (kmalloc/kfree - Linked list or Slab)
 [ ] Memory mapped I/O (MMIO) API for drivers
 [ ] VMM: Shared memory regions (For IPC/Framebuffers)
 [ ] VMM: Copy-on-Write (COW) support (Optional but good)

docs/memory-management.txt

@@ -48,3 +48,19 @@ A pointer to allocated memory or NULL.
 **Parameters**
 * `size_t count` - 
 
+**Description**
+This function allocates memory for `count` elements each of `size` bytes, zeroed-out memory.
+
+**Returns**
+A pointer to allocated memory or NULL.
+
+`void* kfree(void* p)`
+******************************************
+**Parameters**
+* `void* p` - 
+
+**Description**
+This function frees memory previously allocated using `k[m,z,c]alloc()`
+
+**Returns**
+Nothing

kernel/include/kmalloc.h

@@ -0,0 +1,63 @@
+#ifndef _KMALLOC_H
+#define _KMALLOC_H
+
+#include "types.h"
+
+// This function allocates size bytes of contiguous memory.
+// Returns a pointer to allocated memory or NULL.
+void* kmalloc(size_t size);
+
+// This function allocates size bytes of contiguous, zeroed-out memory.
+// Returns a pointer to allocated memory or NULL.
+void* kzalloc(size_t size);
+
+// This function allocates memory for count elements each of size bytes,
+// zeroed-out memory. Returns a pointer to allocated memory or NULL.
+void* kcalloc(size_t count, size_t size);
+
+// powers of 2
+#define KMALLOC_MAX_SIZE 17
+
+union per_cpu_freelist_cache {
+	void* freelists[KMALLOC_MAX_SIZE];
+	struct {
+		void* kmalloc_8;
+		void* kmalloc_16;
+		void* kmalloc_32;
+		void* kmalloc_64;
+		void* kmalloc_128;
+		void* kmalloc_256;
+		void* kmalloc_512;
+		void* kmalloc_1024;
+		void* kmalloc_2048;
+		void* kmalloc_4096;
+		void* kmalloc_8192;
+		void* kmalloc_16384;
+		void* kmalloc_32768;
+		void* kmalloc_65536;
+		void* kmalloc_131072;
+	};
+};
+
+union partial_list {
+	void* freelists[KMALLOC_MAX_SIZE];
+	struct {
+		void* kmalloc_8;
+		void* kmalloc_16;
+		void* kmalloc_32;
+		void* kmalloc_64;
+		void* kmalloc_128;
+		void* kmalloc_256;
+		void* kmalloc_512;
+		void* kmalloc_1024;
+		void* kmalloc_2048;
+		void* kmalloc_4096;
+		void* kmalloc_8192;
+		void* kmalloc_16384;
+		void* kmalloc_32768;
+		void* kmalloc_65536;
+		void* kmalloc_131072;
+	};
+};
+
+#endif

kernel/src/kmalloc.c

@@ -0,0 +1,52 @@
+#include "types.h"
+#include <kmalloc.h>
+#include <string.h>
+// this file contains SLUB inspired HEAP allocator
+
+// TODO this will be an allocated array later when we have APIC MADT
+union per_cpu_freelist_cache freelists_all_cpus[1];
+
+void* kcalloc(size_t count, size_t size) {
+	size_t size_to_alloc;
+	__asm__ volatile goto(".intel_syntax noprefix\n\t"
+			      "mov rax, %1\n\t"
+			      "mov rdx, %2\n\t"
+			      "mul rdx\n\t"
+			      "jo %l[overflow]\n\t"
+			      "mov %0, rax\n\t"
+			      ".att_syntax prefix\n\t"
+			      : "=r"(size_to_alloc)
+			      : "r"(count), "r"(size)
+			      : "rax", "rdx", "cc"
+			      : overflow);
+	return kzalloc(size_to_alloc);
+
+overflow:
+	return NULL;
+}
+
+void* kzalloc(size_t size) {
+	void* allocated = kmalloc(size);
+	if (!allocated) {
+		return NULL;
+	}
+	memset(allocated, 0, size);
+	return allocated;
+}
+
+void* kmalloc(size_t size) {
+	if (!size) {
+		return NULL;
+	}
+	uint32_t core_id;
+	__asm__ volatile(
+	    "rdtscp"
+	    : "=c"(core_id) // Core ID from IA32_TSC_AUX is placed in ECX
+	    :
+	    : "eax", "edx");
+
+	// freelists_all_cpus[core_id];
+	// TODO enable when we actualy know how many CPUs we have
+	if () {
+	}
+}