diff options
author | David Hildenbrand <david@redhat.com> | 2020-06-25 17:00:29 +0200 |
---|---|---|
committer | Heiko Carstens <heiko.carstens@de.ibm.com> | 2020-07-01 20:00:49 +0200 |
commit | f05f62d04271faa265c7a4f75638ebc380d182fa (patch) | |
tree | a31cdfd4d9a36ed3bdddf6eac505a81fea1cc443 /arch/s390/mm | |
parent | 66a049b764a71dc32031b7b533f98fc0299e6e11 (diff) |
s390/vmem: get rid of memory segment list
I can't come up with a satisfying reason why we still need the memory
segment list. We used to represent in the list:
- boot memory
- standby memory added via add_memory()
- loaded dcss segments
When loading/unloading dcss segments, we already track them in a
separate list and check for overlaps
(arch/s390/mm/extmem.c:segment_overlaps_others()) when loading segments.
The overlap check was introduced for some segments in
commit b2300b9efe1b ("[S390] dcssblk: add >2G DCSSs support and stacked
contiguous DCSSs support.")
and was extended to cover all dcss segments in
commit ca57114609d1 ("s390/extmem: remove code for 31 bit addressing
mode").
Although I doubt that overlaps with boot memory and standby memory
are relevant, let's reshuffle the checks in load_segment() to request
the resource first. This will bail out in case we have overlaps with
other resources (esp. boot memory and standby memory). The order
is now different compared to segment_unload() and segment_unload(), but
that should not matter.
This smells like a leftover from ancient times, let's get rid of it. We
can now convert vmem_remove_mapping() into a void function - everybody
ignored the return value already.
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20200625150029.45019-1-david@redhat.com>
Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Tested-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> [DCSS]
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Diffstat (limited to 'arch/s390/mm')
-rw-r--r-- | arch/s390/mm/extmem.c | 25 | ||||
-rw-r--r-- | arch/s390/mm/vmem.c | 115 |
2 files changed, 20 insertions, 120 deletions
diff --git a/arch/s390/mm/extmem.c b/arch/s390/mm/extmem.c index 9e0aa7aa03ba..105c09282f8c 100644 --- a/arch/s390/mm/extmem.c +++ b/arch/s390/mm/extmem.c @@ -313,15 +313,10 @@ __segment_load (char *name, int do_nonshared, unsigned long *addr, unsigned long goto out_free; } - rc = vmem_add_mapping(seg->start_addr, seg->end - seg->start_addr + 1); - - if (rc) - goto out_free; - seg->res = kzalloc(sizeof(struct resource), GFP_KERNEL); if (seg->res == NULL) { rc = -ENOMEM; - goto out_shared; + goto out_free; } seg->res->flags = IORESOURCE_BUSY | IORESOURCE_MEM; seg->res->start = seg->start_addr; @@ -335,12 +330,17 @@ __segment_load (char *name, int do_nonshared, unsigned long *addr, unsigned long if (rc == SEG_TYPE_SC || ((rc == SEG_TYPE_SR || rc == SEG_TYPE_ER) && !do_nonshared)) seg->res->flags |= IORESOURCE_READONLY; + + /* Check for overlapping resources before adding the mapping. */ if (request_resource(&iomem_resource, seg->res)) { rc = -EBUSY; - kfree(seg->res); - goto out_shared; + goto out_free_resource; } + rc = vmem_add_mapping(seg->start_addr, seg->end - seg->start_addr + 1); + if (rc) + goto out_resource; + if (do_nonshared) diag_cc = dcss_diag(&loadnsr_scode, seg->dcss_name, &start_addr, &end_addr); @@ -351,14 +351,14 @@ __segment_load (char *name, int do_nonshared, unsigned long *addr, unsigned long dcss_diag(&purgeseg_scode, seg->dcss_name, &dummy, &dummy); rc = diag_cc; - goto out_resource; + goto out_mapping; } if (diag_cc > 1) { pr_warn("Loading DCSS %s failed with rc=%ld\n", name, end_addr); rc = dcss_diag_translate_rc(end_addr); dcss_diag(&purgeseg_scode, seg->dcss_name, &dummy, &dummy); - goto out_resource; + goto out_mapping; } seg->start_addr = start_addr; seg->end = end_addr; @@ -377,11 +377,12 @@ __segment_load (char *name, int do_nonshared, unsigned long *addr, unsigned long (void*) seg->end, segtype_string[seg->vm_segtype]); } goto out; + out_mapping: + vmem_remove_mapping(seg->start_addr, seg->end - seg->start_addr + 1); out_resource: release_resource(seg->res); + out_free_resource: kfree(seg->res); - out_shared: - vmem_remove_mapping(seg->start_addr, seg->end - seg->start_addr + 1); out_free: kfree(seg); out: diff --git a/arch/s390/mm/vmem.c b/arch/s390/mm/vmem.c index 8b6282cf7d13..3b9e71654c37 100644 --- a/arch/s390/mm/vmem.c +++ b/arch/s390/mm/vmem.c @@ -20,14 +20,6 @@ static DEFINE_MUTEX(vmem_mutex); -struct memory_segment { - struct list_head list; - unsigned long start; - unsigned long size; -}; - -static LIST_HEAD(mem_segs); - static void __ref *vmem_alloc_pages(unsigned int order) { unsigned long size = PAGE_SIZE << order; @@ -300,94 +292,25 @@ void vmemmap_free(unsigned long start, unsigned long end, { } -/* - * Add memory segment to the segment list if it doesn't overlap with - * an already present segment. - */ -static int insert_memory_segment(struct memory_segment *seg) -{ - struct memory_segment *tmp; - - if (seg->start + seg->size > VMEM_MAX_PHYS || - seg->start + seg->size < seg->start) - return -ERANGE; - - list_for_each_entry(tmp, &mem_segs, list) { - if (seg->start >= tmp->start + tmp->size) - continue; - if (seg->start + seg->size <= tmp->start) - continue; - return -ENOSPC; - } - list_add(&seg->list, &mem_segs); - return 0; -} - -/* - * Remove memory segment from the segment list. - */ -static void remove_memory_segment(struct memory_segment *seg) -{ - list_del(&seg->list); -} - -static void __remove_shared_memory(struct memory_segment *seg) +void vmem_remove_mapping(unsigned long start, unsigned long size) { - remove_memory_segment(seg); - vmem_remove_range(seg->start, seg->size); -} - -int vmem_remove_mapping(unsigned long start, unsigned long size) -{ - struct memory_segment *seg; - int ret; - mutex_lock(&vmem_mutex); - - ret = -ENOENT; - list_for_each_entry(seg, &mem_segs, list) { - if (seg->start == start && seg->size == size) - break; - } - - if (seg->start != start || seg->size != size) - goto out; - - ret = 0; - __remove_shared_memory(seg); - kfree(seg); -out: + vmem_remove_range(start, size); mutex_unlock(&vmem_mutex); - return ret; } int vmem_add_mapping(unsigned long start, unsigned long size) { - struct memory_segment *seg; int ret; - mutex_lock(&vmem_mutex); - ret = -ENOMEM; - seg = kzalloc(sizeof(*seg), GFP_KERNEL); - if (!seg) - goto out; - seg->start = start; - seg->size = size; - - ret = insert_memory_segment(seg); - if (ret) - goto out_free; + if (start + size > VMEM_MAX_PHYS || + start + size < start) + return -ERANGE; + mutex_lock(&vmem_mutex); ret = vmem_add_mem(start, size); if (ret) - goto out_remove; - goto out; - -out_remove: - __remove_shared_memory(seg); -out_free: - kfree(seg); -out: + vmem_remove_range(start, size); mutex_unlock(&vmem_mutex); return ret; } @@ -421,27 +344,3 @@ void __init vmem_map_init(void) pr_info("Write protected kernel read-only data: %luk\n", (unsigned long)(__end_rodata - _stext) >> 10); } - -/* - * Convert memblock.memory to a memory segment list so there is a single - * list that contains all memory segments. - */ -static int __init vmem_convert_memory_chunk(void) -{ - struct memblock_region *reg; - struct memory_segment *seg; - - mutex_lock(&vmem_mutex); - for_each_memblock(memory, reg) { - seg = kzalloc(sizeof(*seg), GFP_KERNEL); - if (!seg) - panic("Out of memory...\n"); - seg->start = reg->base; - seg->size = reg->size; - insert_memory_segment(seg); - } - mutex_unlock(&vmem_mutex); - return 0; -} - -core_initcall(vmem_convert_memory_chunk); |