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x86,percpu: generalize lpage first chunk allocator

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Generalize and move x86 setup_pcpu_lpage() into
pcpu_lpage_first_chunk().  setup_pcpu_lpage() now is a simple wrapper
around the generalized version.  Other than taking size parameters and
using arch supplied callbacks to allocate/free/map memory,
pcpu_lpage_first_chunk() is identical to the original implementation.

This simplifies arch code and will help converting more archs to
dynamic percpu allocator.

While at it, factor out pcpu_calc_fc_sizes() which is common to
pcpu_embed_first_chunk() and pcpu_lpage_first_chunk().

[ Impact: code reorganization and generalization ]

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Tejun Heo
2009-07-04 08:10:59 +09:00
parent 8f05a6a65d
commit 8c4bfc6e88
5 changed files with 244 additions and 171 deletions
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169
arch/x86/kernel/setup_percpu.c
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@@ -137,44 +137,21 @@ static void __init pcpu_fc_free(void *ptr, size_t size)
}
/*
* Large page remap allocator
*
* This allocator uses PMD page as unit. A PMD page is allocated for
* each cpu and each is remapped into vmalloc area using PMD mapping.
* As PMD page is quite large, only part of it is used for the first
* chunk. Unused part is returned to the bootmem allocator.
*
* So, the PMD pages are mapped twice - once to the physical mapping
* and to the vmalloc area for the first percpu chunk. The double
* mapping does add one more PMD TLB entry pressure but still is much
* better than only using 4k mappings while still being NUMA friendly.
* Large page remapping allocator
*/
#ifdef CONFIG_NEED_MULTIPLE_NODES
struct pcpul_ent {
unsigned int cpu;
void *ptr;
};
static size_t pcpul_size;
static struct pcpul_ent *pcpul_map;
static struct vm_struct pcpul_vm;
static struct page * __init pcpul_get_page(unsigned int cpu, int pageno)
static void __init pcpul_map(void *ptr, size_t size, void *addr)
{
size_t off = (size_t)pageno << PAGE_SHIFT;
pmd_t *pmd, pmd_v;
if (off >= pcpul_size)
return NULL;
return virt_to_page(pcpul_map[cpu].ptr + off);
pmd = populate_extra_pmd((unsigned long)addr);
pmd_v = pfn_pmd(page_to_pfn(virt_to_page(ptr)), PAGE_KERNEL_LARGE);
set_pmd(pmd, pmd_v);
}
static ssize_t __init setup_pcpu_lpage(size_t static_size, bool chosen)
{
size_t map_size, dyn_size;
unsigned int cpu;
int i, j;
ssize_t ret;
size_t reserve = PERCPU_MODULE_RESERVE + PERCPU_DYNAMIC_RESERVE;
if (!chosen) {
size_t vm_size = VMALLOC_END - VMALLOC_START;
@@ -198,134 +175,10 @@ static ssize_t __init setup_pcpu_lpage(size_t static_size, bool chosen)
return -EINVAL;
}
/*
* Currently supports only single page. Supporting multiple
* pages won't be too difficult if it ever becomes necessary.
*/
pcpul_size = PFN_ALIGN(static_size + PERCPU_MODULE_RESERVE +
PERCPU_DYNAMIC_RESERVE);
if (pcpul_size > PMD_SIZE) {
pr_warning("PERCPU: static data is larger than large page, "
"can't use large page\n");
return -EINVAL;
}
dyn_size = pcpul_size - static_size - PERCPU_FIRST_CHUNK_RESERVE;
/* allocate pointer array and alloc large pages */
map_size = PFN_ALIGN(num_possible_cpus() * sizeof(pcpul_map[0]));
pcpul_map = alloc_bootmem(map_size);
for_each_possible_cpu(cpu) {
pcpul_map[cpu].cpu = cpu;
pcpul_map[cpu].ptr = pcpu_alloc_bootmem(cpu, PMD_SIZE,
PMD_SIZE);
if (!pcpul_map[cpu].ptr) {
pr_warning("PERCPU: failed to allocate large page "
"for cpu%u\n", cpu);
goto enomem;
}
/*
* Only use pcpul_size bytes and give back the rest.
*
* Ingo: The 2MB up-rounding bootmem is needed to make
* sure the partial 2MB page is still fully RAM - it's
* not well-specified to have a PAT-incompatible area
* (unmapped RAM, device memory, etc.) in that hole.
*/
free_bootmem(__pa(pcpul_map[cpu].ptr + pcpul_size),
PMD_SIZE - pcpul_size);
memcpy(pcpul_map[cpu].ptr, __per_cpu_load, static_size);
}
/* allocate address and map */
pcpul_vm.flags = VM_ALLOC;
pcpul_vm.size = num_possible_cpus() * PMD_SIZE;
vm_area_register_early(&pcpul_vm, PMD_SIZE);
for_each_possible_cpu(cpu) {
pmd_t *pmd, pmd_v;
pmd = populate_extra_pmd((unsigned long)pcpul_vm.addr +
cpu * PMD_SIZE);
pmd_v = pfn_pmd(page_to_pfn(virt_to_page(pcpul_map[cpu].ptr)),
PAGE_KERNEL_LARGE);
set_pmd(pmd, pmd_v);
}
/* we're ready, commit */
pr_info("PERCPU: Remapped at %p with large pages, static data "
"%zu bytes\n", pcpul_vm.addr, static_size);
ret = pcpu_setup_first_chunk(pcpul_get_page, static_size,
PERCPU_FIRST_CHUNK_RESERVE, dyn_size,
PMD_SIZE, pcpul_vm.addr, NULL);
/* sort pcpul_map array for pcpu_lpage_remapped() */
for (i = 0; i < num_possible_cpus() - 1; i++)
for (j = i + 1; j < num_possible_cpus(); j++)
if (pcpul_map[i].ptr > pcpul_map[j].ptr) {
struct pcpul_ent tmp = pcpul_map[i];
pcpul_map[i] = pcpul_map[j];
pcpul_map[j] = tmp;
}
return ret;
enomem:
for_each_possible_cpu(cpu)
if (pcpul_map[cpu].ptr)
free_bootmem(__pa(pcpul_map[cpu].ptr), pcpul_size);
free_bootmem(__pa(pcpul_map), map_size);
return -ENOMEM;
}
/**
* pcpu_lpage_remapped - determine whether a kaddr is in pcpul recycled area
* @kaddr: the kernel address in question
*
* Determine whether @kaddr falls in the pcpul recycled area. This is
* used by pageattr to detect VM aliases and break up the pcpu PMD
* mapping such that the same physical page is not mapped under
* different attributes.
*
* The recycled area is always at the tail of a partially used PMD
* page.
*
* RETURNS:
* Address of corresponding remapped pcpu address if match is found;
* otherwise, NULL.
*/
void *pcpu_lpage_remapped(void *kaddr)
{
void *pmd_addr = (void *)((unsigned long)kaddr & PMD_MASK);
unsigned long offset = (unsigned long)kaddr & ~PMD_MASK;
int left = 0, right = num_possible_cpus() - 1;
int pos;
/* pcpul in use at all? */
if (!pcpul_map)
return NULL;
/* okay, perform binary search */
while (left <= right) {
pos = (left + right) / 2;
if (pcpul_map[pos].ptr < pmd_addr)
left = pos + 1;
else if (pcpul_map[pos].ptr > pmd_addr)
right = pos - 1;
else {
/* it shouldn't be in the area for the first chunk */
WARN_ON(offset < pcpul_size);
return pcpul_vm.addr +
pcpul_map[pos].cpu * PMD_SIZE + offset;
}
}
return NULL;
return pcpu_lpage_first_chunk(static_size, PERCPU_FIRST_CHUNK_RESERVE,
reserve - PERCPU_FIRST_CHUNK_RESERVE,
PMD_SIZE,
pcpu_fc_alloc, pcpu_fc_free, pcpul_map);
}
#else
static ssize_t __init setup_pcpu_lpage(size_t static_size, bool chosen)