2 * Copyright (c) 2015, Sony Mobile Communications AB.
3 * Copyright (c) 2012-2013, The Linux Foundation. All rights reserved.
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 and
7 * only version 2 as published by the Free Software Foundation.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
15 #include <linux/hwspinlock.h>
17 #include <linux/module.h>
19 #include <linux/of_address.h>
20 #include <linux/platform_device.h>
21 #include <linux/slab.h>
22 #include <linux/soc/qcom/smem.h>
25 * The Qualcomm shared memory system is a allocate only heap structure that
26 * consists of one of more memory areas that can be accessed by the processors
29 * All systems contains a global heap, accessible by all processors in the SoC,
30 * with a table of contents data structure (@smem_header) at the beginning of
31 * the main shared memory block.
33 * The global header contains meta data for allocations as well as a fixed list
34 * of 512 entries (@smem_global_entry) that can be initialized to reference
35 * parts of the shared memory space.
38 * In addition to this global heap a set of "private" heaps can be set up at
39 * boot time with access restrictions so that only certain processor pairs can
42 * These partitions are referenced from an optional partition table
43 * (@smem_ptable), that is found 4kB from the end of the main smem region. The
44 * partition table entries (@smem_ptable_entry) lists the involved processors
45 * (or hosts) and their location in the main shared memory region.
47 * Each partition starts with a header (@smem_partition_header) that identifies
48 * the partition and holds properties for the two internal memory regions. The
49 * two regions are cached and non-cached memory respectively. Each region
50 * contain a link list of allocation headers (@smem_private_entry) followed by
53 * Items in the non-cached region are allocated from the start of the partition
54 * while items in the cached region are allocated from the end. The free area
55 * is hence the region between the cached and non-cached offsets.
58 * To synchronize allocations in the shared memory heaps a remote spinlock must
59 * be held - currently lock number 3 of the sfpb or tcsr is used for this on all
65 * Item 3 of the global heap contains an array of versions for the various
66 * software components in the SoC. We verify that the boot loader version is
67 * what the expected version (SMEM_EXPECTED_VERSION) as a sanity check.
69 #define SMEM_ITEM_VERSION 3
70 #define SMEM_MASTER_SBL_VERSION_INDEX 7
71 #define SMEM_EXPECTED_VERSION 11
74 * The first 8 items are only to be allocated by the boot loader while
75 * initializing the heap.
77 #define SMEM_ITEM_LAST_FIXED 8
79 /* Highest accepted item number, for both global and private heaps */
80 #define SMEM_ITEM_COUNT 512
82 /* Processor/host identifier for the application processor */
83 #define SMEM_HOST_APPS 0
85 /* Max number of processors/hosts in a system */
86 #define SMEM_HOST_COUNT 9
89 * struct smem_proc_comm - proc_comm communication struct (legacy)
90 * @command: current command to be executed
91 * @status: status of the currently requested command
92 * @params: parameters to the command
94 struct smem_proc_comm
{
101 * struct smem_global_entry - entry to reference smem items on the heap
102 * @allocated: boolean to indicate if this entry is used
103 * @offset: offset to the allocated space
104 * @size: size of the allocated space, 8 byte aligned
105 * @aux_base: base address for the memory region used by this unit, or 0 for
106 * the default region. bits 0,1 are reserved
108 struct smem_global_entry
{
112 __le32 aux_base
; /* bits 1:0 reserved */
114 #define AUX_BASE_MASK 0xfffffffc
117 * struct smem_header - header found in beginning of primary smem region
118 * @proc_comm: proc_comm communication interface (legacy)
119 * @version: array of versions for the various subsystems
120 * @initialized: boolean to indicate that smem is initialized
121 * @free_offset: index of the first unallocated byte in smem
122 * @available: number of bytes available for allocation
123 * @reserved: reserved field, must be 0
124 * toc: array of references to items
127 struct smem_proc_comm proc_comm
[4];
133 struct smem_global_entry toc
[SMEM_ITEM_COUNT
];
137 * struct smem_ptable_entry - one entry in the @smem_ptable list
138 * @offset: offset, within the main shared memory region, of the partition
139 * @size: size of the partition
140 * @flags: flags for the partition (currently unused)
141 * @host0: first processor/host with access to this partition
142 * @host1: second processor/host with access to this partition
143 * @reserved: reserved entries for later use
145 struct smem_ptable_entry
{
155 * struct smem_ptable - partition table for the private partitions
156 * @magic: magic number, must be SMEM_PTABLE_MAGIC
157 * @version: version of the partition table
158 * @num_entries: number of partitions in the table
159 * @reserved: for now reserved entries
160 * @entry: list of @smem_ptable_entry for the @num_entries partitions
167 struct smem_ptable_entry entry
[];
170 static const u8 SMEM_PTABLE_MAGIC
[] = { 0x24, 0x54, 0x4f, 0x43 }; /* "$TOC" */
173 * struct smem_partition_header - header of the partitions
174 * @magic: magic number, must be SMEM_PART_MAGIC
175 * @host0: first processor/host with access to this partition
176 * @host1: second processor/host with access to this partition
177 * @size: size of the partition
178 * @offset_free_uncached: offset to the first free byte of uncached memory in
180 * @offset_free_cached: offset to the first free byte of cached memory in this
182 * @reserved: for now reserved entries
184 struct smem_partition_header
{
189 __le32 offset_free_uncached
;
190 __le32 offset_free_cached
;
194 static const u8 SMEM_PART_MAGIC
[] = { 0x24, 0x50, 0x52, 0x54 };
197 * struct smem_private_entry - header of each item in the private partition
198 * @canary: magic number, must be SMEM_PRIVATE_CANARY
199 * @item: identifying number of the smem item
200 * @size: size of the data, including padding bytes
201 * @padding_data: number of bytes of padding of data
202 * @padding_hdr: number of bytes of padding between the header and the data
203 * @reserved: for now reserved entry
205 struct smem_private_entry
{
206 u16 canary
; /* bytes are the same so no swapping needed */
208 __le32 size
; /* includes padding bytes */
213 #define SMEM_PRIVATE_CANARY 0xa5a5
216 * struct smem_region - representation of a chunk of memory used for smem
217 * @aux_base: identifier of aux_mem base
218 * @virt_base: virtual base address of memory with this aux_mem identifier
219 * @size: size of the memory region
223 void __iomem
*virt_base
;
228 * struct qcom_smem - device data for the smem device
229 * @dev: device pointer
230 * @hwlock: reference to a hwspinlock
231 * @partitions: list of pointers to partitions affecting the current
233 * @num_regions: number of @regions
234 * @regions: list of the memory regions defining the shared memory
239 struct hwspinlock
*hwlock
;
241 struct smem_partition_header
*partitions
[SMEM_HOST_COUNT
];
243 unsigned num_regions
;
244 struct smem_region regions
[0];
247 static struct smem_private_entry
*
248 phdr_to_last_private_entry(struct smem_partition_header
*phdr
)
252 return p
+ le32_to_cpu(phdr
->offset_free_uncached
);
255 static void *phdr_to_first_cached_entry(struct smem_partition_header
*phdr
)
259 return p
+ le32_to_cpu(phdr
->offset_free_cached
);
262 static struct smem_private_entry
*
263 phdr_to_first_private_entry(struct smem_partition_header
*phdr
)
267 return p
+ sizeof(*phdr
);
270 static struct smem_private_entry
*
271 private_entry_next(struct smem_private_entry
*e
)
275 return p
+ sizeof(*e
) + le16_to_cpu(e
->padding_hdr
) +
276 le32_to_cpu(e
->size
);
279 static void *entry_to_item(struct smem_private_entry
*e
)
283 return p
+ sizeof(*e
) + le16_to_cpu(e
->padding_hdr
);
286 /* Pointer to the one and only smem handle */
287 static struct qcom_smem
*__smem
;
289 /* Timeout (ms) for the trylock of remote spinlocks */
290 #define HWSPINLOCK_TIMEOUT 1000
292 static int qcom_smem_alloc_private(struct qcom_smem
*smem
,
297 struct smem_partition_header
*phdr
;
298 struct smem_private_entry
*hdr
, *end
;
302 phdr
= smem
->partitions
[host
];
303 hdr
= phdr_to_first_private_entry(phdr
);
304 end
= phdr_to_last_private_entry(phdr
);
305 cached
= phdr_to_first_cached_entry(phdr
);
308 if (hdr
->canary
!= SMEM_PRIVATE_CANARY
) {
310 "Found invalid canary in host %d partition\n",
315 if (le16_to_cpu(hdr
->item
) == item
)
318 hdr
= private_entry_next(hdr
);
321 /* Check that we don't grow into the cached region */
322 alloc_size
= sizeof(*hdr
) + ALIGN(size
, 8);
323 if ((void *)hdr
+ alloc_size
>= cached
) {
324 dev_err(smem
->dev
, "Out of memory\n");
328 hdr
->canary
= SMEM_PRIVATE_CANARY
;
329 hdr
->item
= cpu_to_le16(item
);
330 hdr
->size
= cpu_to_le32(ALIGN(size
, 8));
331 hdr
->padding_data
= cpu_to_le16(le32_to_cpu(hdr
->size
) - size
);
332 hdr
->padding_hdr
= 0;
335 * Ensure the header is written before we advance the free offset, so
336 * that remote processors that does not take the remote spinlock still
337 * gets a consistent view of the linked list.
340 le32_add_cpu(&phdr
->offset_free_uncached
, alloc_size
);
345 static int qcom_smem_alloc_global(struct qcom_smem
*smem
,
349 struct smem_header
*header
;
350 struct smem_global_entry
*entry
;
352 if (WARN_ON(item
>= SMEM_ITEM_COUNT
))
355 header
= smem
->regions
[0].virt_base
;
356 entry
= &header
->toc
[item
];
357 if (entry
->allocated
)
360 size
= ALIGN(size
, 8);
361 if (WARN_ON(size
> le32_to_cpu(header
->available
)))
364 entry
->offset
= header
->free_offset
;
365 entry
->size
= cpu_to_le32(size
);
368 * Ensure the header is consistent before we mark the item allocated,
369 * so that remote processors will get a consistent view of the item
370 * even though they do not take the spinlock on read.
373 entry
->allocated
= cpu_to_le32(1);
375 le32_add_cpu(&header
->free_offset
, size
);
376 le32_add_cpu(&header
->available
, -size
);
382 * qcom_smem_alloc() - allocate space for a smem item
383 * @host: remote processor id, or -1
384 * @item: smem item handle
385 * @size: number of bytes to be allocated
387 * Allocate space for a given smem item of size @size, given that the item is
390 int qcom_smem_alloc(unsigned host
, unsigned item
, size_t size
)
396 return -EPROBE_DEFER
;
398 if (item
< SMEM_ITEM_LAST_FIXED
) {
400 "Rejecting allocation of static entry %d\n", item
);
404 ret
= hwspin_lock_timeout_irqsave(__smem
->hwlock
,
410 if (host
< SMEM_HOST_COUNT
&& __smem
->partitions
[host
])
411 ret
= qcom_smem_alloc_private(__smem
, host
, item
, size
);
413 ret
= qcom_smem_alloc_global(__smem
, item
, size
);
415 hwspin_unlock_irqrestore(__smem
->hwlock
, &flags
);
419 EXPORT_SYMBOL(qcom_smem_alloc
);
421 static void *qcom_smem_get_global(struct qcom_smem
*smem
,
425 struct smem_header
*header
;
426 struct smem_region
*area
;
427 struct smem_global_entry
*entry
;
431 if (WARN_ON(item
>= SMEM_ITEM_COUNT
))
432 return ERR_PTR(-EINVAL
);
434 header
= smem
->regions
[0].virt_base
;
435 entry
= &header
->toc
[item
];
436 if (!entry
->allocated
)
437 return ERR_PTR(-ENXIO
);
439 aux_base
= le32_to_cpu(entry
->aux_base
) & AUX_BASE_MASK
;
441 for (i
= 0; i
< smem
->num_regions
; i
++) {
442 area
= &smem
->regions
[i
];
444 if (area
->aux_base
== aux_base
|| !aux_base
) {
446 *size
= le32_to_cpu(entry
->size
);
447 return area
->virt_base
+ le32_to_cpu(entry
->offset
);
451 return ERR_PTR(-ENOENT
);
454 static void *qcom_smem_get_private(struct qcom_smem
*smem
,
459 struct smem_partition_header
*phdr
;
460 struct smem_private_entry
*e
, *end
;
462 phdr
= smem
->partitions
[host
];
463 e
= phdr_to_first_private_entry(phdr
);
464 end
= phdr_to_last_private_entry(phdr
);
467 if (e
->canary
!= SMEM_PRIVATE_CANARY
) {
469 "Found invalid canary in host %d partition\n",
471 return ERR_PTR(-EINVAL
);
474 if (le16_to_cpu(e
->item
) == item
) {
476 *size
= le32_to_cpu(e
->size
) -
477 le16_to_cpu(e
->padding_data
);
479 return entry_to_item(e
);
482 e
= private_entry_next(e
);
485 return ERR_PTR(-ENOENT
);
489 * qcom_smem_get() - resolve ptr of size of a smem item
490 * @host: the remote processor, or -1
491 * @item: smem item handle
492 * @size: pointer to be filled out with size of the item
494 * Looks up smem item and returns pointer to it. Size of smem
495 * item is returned in @size.
497 void *qcom_smem_get(unsigned host
, unsigned item
, size_t *size
)
501 void *ptr
= ERR_PTR(-EPROBE_DEFER
);
506 ret
= hwspin_lock_timeout_irqsave(__smem
->hwlock
,
512 if (host
< SMEM_HOST_COUNT
&& __smem
->partitions
[host
])
513 ptr
= qcom_smem_get_private(__smem
, host
, item
, size
);
515 ptr
= qcom_smem_get_global(__smem
, item
, size
);
517 hwspin_unlock_irqrestore(__smem
->hwlock
, &flags
);
522 EXPORT_SYMBOL(qcom_smem_get
);
525 * qcom_smem_get_free_space() - retrieve amount of free space in a partition
526 * @host: the remote processor identifying a partition, or -1
528 * To be used by smem clients as a quick way to determine if any new
529 * allocations has been made.
531 int qcom_smem_get_free_space(unsigned host
)
533 struct smem_partition_header
*phdr
;
534 struct smem_header
*header
;
538 return -EPROBE_DEFER
;
540 if (host
< SMEM_HOST_COUNT
&& __smem
->partitions
[host
]) {
541 phdr
= __smem
->partitions
[host
];
542 ret
= le32_to_cpu(phdr
->offset_free_cached
) -
543 le32_to_cpu(phdr
->offset_free_uncached
);
545 header
= __smem
->regions
[0].virt_base
;
546 ret
= le32_to_cpu(header
->available
);
551 EXPORT_SYMBOL(qcom_smem_get_free_space
);
553 static int qcom_smem_get_sbl_version(struct qcom_smem
*smem
)
558 versions
= qcom_smem_get_global(smem
, SMEM_ITEM_VERSION
, &size
);
559 if (IS_ERR(versions
)) {
560 dev_err(smem
->dev
, "Unable to read the version item\n");
564 if (size
< sizeof(unsigned) * SMEM_MASTER_SBL_VERSION_INDEX
) {
565 dev_err(smem
->dev
, "Version item is too small\n");
569 return le32_to_cpu(versions
[SMEM_MASTER_SBL_VERSION_INDEX
]);
572 static int qcom_smem_enumerate_partitions(struct qcom_smem
*smem
,
575 struct smem_partition_header
*header
;
576 struct smem_ptable_entry
*entry
;
577 struct smem_ptable
*ptable
;
578 unsigned remote_host
;
579 u32 version
, host0
, host1
;
582 ptable
= smem
->regions
[0].virt_base
+ smem
->regions
[0].size
- SZ_4K
;
583 if (memcmp(ptable
->magic
, SMEM_PTABLE_MAGIC
, sizeof(ptable
->magic
)))
586 version
= le32_to_cpu(ptable
->version
);
589 "Unsupported partition header version %d\n", version
);
593 for (i
= 0; i
< le32_to_cpu(ptable
->num_entries
); i
++) {
594 entry
= &ptable
->entry
[i
];
595 host0
= le16_to_cpu(entry
->host0
);
596 host1
= le16_to_cpu(entry
->host1
);
598 if (host0
!= local_host
&& host1
!= local_host
)
601 if (!le32_to_cpu(entry
->offset
))
604 if (!le32_to_cpu(entry
->size
))
607 if (host0
== local_host
)
612 if (remote_host
>= SMEM_HOST_COUNT
) {
614 "Invalid remote host %d\n",
619 if (smem
->partitions
[remote_host
]) {
621 "Already found a partition for host %d\n",
626 header
= smem
->regions
[0].virt_base
+ le32_to_cpu(entry
->offset
);
627 host0
= le16_to_cpu(header
->host0
);
628 host1
= le16_to_cpu(header
->host1
);
630 if (memcmp(header
->magic
, SMEM_PART_MAGIC
,
631 sizeof(header
->magic
))) {
633 "Partition %d has invalid magic\n", i
);
637 if (host0
!= local_host
&& host1
!= local_host
) {
639 "Partition %d hosts are invalid\n", i
);
643 if (host0
!= remote_host
&& host1
!= remote_host
) {
645 "Partition %d hosts are invalid\n", i
);
649 if (header
->size
!= entry
->size
) {
651 "Partition %d has invalid size\n", i
);
655 if (le32_to_cpu(header
->offset_free_uncached
) > le32_to_cpu(header
->size
)) {
657 "Partition %d has invalid free pointer\n", i
);
661 smem
->partitions
[remote_host
] = header
;
667 static int qcom_smem_map_memory(struct qcom_smem
*smem
, struct device
*dev
,
668 const char *name
, int i
)
670 struct device_node
*np
;
674 np
= of_parse_phandle(dev
->of_node
, name
, 0);
676 dev_err(dev
, "No %s specified\n", name
);
680 ret
= of_address_to_resource(np
, 0, &r
);
685 smem
->regions
[i
].aux_base
= (u32
)r
.start
;
686 smem
->regions
[i
].size
= resource_size(&r
);
687 smem
->regions
[i
].virt_base
= devm_ioremap_wc(dev
, r
.start
, resource_size(&r
));
688 if (!smem
->regions
[i
].virt_base
)
694 static int qcom_smem_probe(struct platform_device
*pdev
)
696 struct smem_header
*header
;
697 struct qcom_smem
*smem
;
705 if (of_find_property(pdev
->dev
.of_node
, "qcom,rpm-msg-ram", NULL
))
708 array_size
= num_regions
* sizeof(struct smem_region
);
709 smem
= devm_kzalloc(&pdev
->dev
, sizeof(*smem
) + array_size
, GFP_KERNEL
);
713 smem
->dev
= &pdev
->dev
;
714 smem
->num_regions
= num_regions
;
716 ret
= qcom_smem_map_memory(smem
, &pdev
->dev
, "memory-region", 0);
720 if (num_regions
> 1 && (ret
= qcom_smem_map_memory(smem
, &pdev
->dev
,
721 "qcom,rpm-msg-ram", 1)))
724 header
= smem
->regions
[0].virt_base
;
725 if (le32_to_cpu(header
->initialized
) != 1 ||
726 le32_to_cpu(header
->reserved
)) {
727 dev_err(&pdev
->dev
, "SMEM is not initialized by SBL\n");
731 version
= qcom_smem_get_sbl_version(smem
);
732 if (version
>> 16 != SMEM_EXPECTED_VERSION
) {
733 dev_err(&pdev
->dev
, "Unsupported SMEM version 0x%x\n", version
);
737 ret
= qcom_smem_enumerate_partitions(smem
, SMEM_HOST_APPS
);
741 hwlock_id
= of_hwspin_lock_get_id(pdev
->dev
.of_node
, 0);
743 if (hwlock_id
!= -EPROBE_DEFER
)
744 dev_err(&pdev
->dev
, "failed to retrieve hwlock\n");
748 smem
->hwlock
= hwspin_lock_request_specific(hwlock_id
);
757 static int qcom_smem_remove(struct platform_device
*pdev
)
759 hwspin_lock_free(__smem
->hwlock
);
765 static const struct of_device_id qcom_smem_of_match
[] = {
766 { .compatible
= "qcom,smem" },
769 MODULE_DEVICE_TABLE(of
, qcom_smem_of_match
);
771 static struct platform_driver qcom_smem_driver
= {
772 .probe
= qcom_smem_probe
,
773 .remove
= qcom_smem_remove
,
776 .of_match_table
= qcom_smem_of_match
,
777 .suppress_bind_attrs
= true,
781 static int __init
qcom_smem_init(void)
783 return platform_driver_register(&qcom_smem_driver
);
785 arch_initcall(qcom_smem_init
);
787 static void __exit
qcom_smem_exit(void)
789 platform_driver_unregister(&qcom_smem_driver
);
791 module_exit(qcom_smem_exit
)
793 MODULE_AUTHOR("Bjorn Andersson <bjorn.andersson@sonymobile.com>");
794 MODULE_DESCRIPTION("Qualcomm Shared Memory Manager");
795 MODULE_LICENSE("GPL v2");