1  // SPDX-License-Identifier: GPL-2.0
2  /*
3  **  linux/amiga/chipram.c
4  **
5  **      Modified 03-May-94 by Geert Uytterhoeven <geert@linux-m68k.org>
6  **          - 64-bit aligned allocations for full AGA compatibility
7  **
8  **	Rewritten 15/9/2000 by Geert to use resource management
9  */
10  
11  #include <linux/types.h>
12  #include <linux/kernel.h>
13  #include <linux/mm.h>
14  #include <linux/init.h>
15  #include <linux/ioport.h>
16  #include <linux/slab.h>
17  #include <linux/string.h>
18  #include <linux/module.h>
19  
20  #include <asm/atomic.h>
21  #include <asm/page.h>
22  #include <asm/amigahw.h>
23  
24  unsigned long amiga_chip_size;
25  EXPORT_SYMBOL(amiga_chip_size);
26  
27  static struct resource chipram_res = {
28  	.name = "Chip RAM", .start = CHIP_PHYSADDR
29  };
30  static atomic_t chipavail;
31  
32  
amiga_chip_init(void)33  void __init amiga_chip_init(void)
34  {
35  	if (!AMIGAHW_PRESENT(CHIP_RAM))
36  		return;
37  
38  	chipram_res.end = CHIP_PHYSADDR + amiga_chip_size - 1;
39  	request_resource(&iomem_resource, &chipram_res);
40  
41  	atomic_set(&chipavail, amiga_chip_size);
42  }
43  
44  
amiga_chip_alloc(unsigned long size,const char * name)45  void *amiga_chip_alloc(unsigned long size, const char *name)
46  {
47  	struct resource *res;
48  	void *p;
49  
50  	res = kzalloc(sizeof(struct resource), GFP_KERNEL);
51  	if (!res)
52  		return NULL;
53  
54  	res->name = name;
55  	p = amiga_chip_alloc_res(size, res);
56  	if (!p) {
57  		kfree(res);
58  		return NULL;
59  	}
60  
61  	return p;
62  }
63  EXPORT_SYMBOL(amiga_chip_alloc);
64  
65  
66  	/*
67  	 *  Warning:
68  	 *  amiga_chip_alloc_res is meant only for drivers that need to
69  	 *  allocate Chip RAM before kmalloc() is functional. As a consequence,
70  	 *  those drivers must not free that Chip RAM afterwards.
71  	 */
72  
amiga_chip_alloc_res(unsigned long size,struct resource * res)73  void *amiga_chip_alloc_res(unsigned long size, struct resource *res)
74  {
75  	int error;
76  
77  	/* round up */
78  	size = PAGE_ALIGN(size);
79  
80  	pr_debug("amiga_chip_alloc_res: allocate %lu bytes\n", size);
81  	error = allocate_resource(&chipram_res, res, size, 0, UINT_MAX,
82  				  PAGE_SIZE, NULL, NULL);
83  	if (error < 0) {
84  		pr_err("amiga_chip_alloc_res: allocate_resource() failed %d!\n",
85  		       error);
86  		return NULL;
87  	}
88  
89  	atomic_sub(size, &chipavail);
90  	pr_debug("amiga_chip_alloc_res: returning %pR\n", res);
91  	return ZTWO_VADDR(res->start);
92  }
93  
amiga_chip_free(void * ptr)94  void amiga_chip_free(void *ptr)
95  {
96  	unsigned long start = ZTWO_PADDR(ptr);
97  	struct resource *res;
98  	unsigned long size;
99  
100  	res = lookup_resource(&chipram_res, start);
101  	if (!res) {
102  		pr_err("amiga_chip_free: trying to free nonexistent region at "
103  		       "%p\n", ptr);
104  		return;
105  	}
106  
107  	size = resource_size(res);
108  	pr_debug("amiga_chip_free: free %lu bytes at %p\n", size, ptr);
109  	atomic_add(size, &chipavail);
110  	release_resource(res);
111  	kfree(res);
112  }
113  EXPORT_SYMBOL(amiga_chip_free);
114  
115  
amiga_chip_avail(void)116  unsigned long amiga_chip_avail(void)
117  {
118  	unsigned long n = atomic_read(&chipavail);
119  
120  	pr_debug("amiga_chip_avail : %lu bytes\n", n);
121  	return n;
122  }
123  EXPORT_SYMBOL(amiga_chip_avail);
124  
125