mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-26 10:49:33 +00:00
![Christophe Leroy](/assets/img/avatar_default.png)
ioremap does things differently depending on whether SLAB is available or not at different levels. Try to separate the early path from the beginning. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/3acd2dbe04b04f111475e7a59f2b6f2ab9b95ab6.1566309263.git.christophe.leroy@c-s.fr
113 lines
2.6 KiB
C
113 lines
2.6 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
|
|
|
|
#include <linux/io.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/vmalloc.h>
|
|
|
|
/**
|
|
* Low level function to establish the page tables for an IO mapping
|
|
*/
|
|
void __iomem *__ioremap_at(phys_addr_t pa, void *ea, unsigned long size, pgprot_t prot)
|
|
{
|
|
int ret;
|
|
unsigned long va = (unsigned long)ea;
|
|
|
|
/* We don't support the 4K PFN hack with ioremap */
|
|
if (pgprot_val(prot) & H_PAGE_4K_PFN)
|
|
return NULL;
|
|
|
|
if ((ea + size) >= (void *)IOREMAP_END) {
|
|
pr_warn("Outside the supported range\n");
|
|
return NULL;
|
|
}
|
|
|
|
WARN_ON(pa & ~PAGE_MASK);
|
|
WARN_ON(((unsigned long)ea) & ~PAGE_MASK);
|
|
WARN_ON(size & ~PAGE_MASK);
|
|
|
|
if (slab_is_available()) {
|
|
ret = ioremap_page_range(va, va + size, pa, prot);
|
|
if (ret)
|
|
unmap_kernel_range(va, size);
|
|
} else {
|
|
ret = early_ioremap_range(va, pa, size, prot);
|
|
}
|
|
|
|
if (ret)
|
|
return NULL;
|
|
|
|
return (void __iomem *)ea;
|
|
}
|
|
EXPORT_SYMBOL(__ioremap_at);
|
|
|
|
/**
|
|
* Low level function to tear down the page tables for an IO mapping. This is
|
|
* used for mappings that are manipulated manually, like partial unmapping of
|
|
* PCI IOs or ISA space.
|
|
*/
|
|
void __iounmap_at(void *ea, unsigned long size)
|
|
{
|
|
WARN_ON(((unsigned long)ea) & ~PAGE_MASK);
|
|
WARN_ON(size & ~PAGE_MASK);
|
|
|
|
unmap_kernel_range((unsigned long)ea, size);
|
|
}
|
|
EXPORT_SYMBOL(__iounmap_at);
|
|
|
|
void __iomem *__ioremap_caller(phys_addr_t addr, unsigned long size,
|
|
pgprot_t prot, void *caller)
|
|
{
|
|
phys_addr_t paligned, offset;
|
|
void __iomem *ret;
|
|
int err;
|
|
|
|
/* We don't support the 4K PFN hack with ioremap */
|
|
if (pgprot_val(prot) & H_PAGE_4K_PFN)
|
|
return NULL;
|
|
|
|
/*
|
|
* Choose an address to map it to. Once the vmalloc system is running,
|
|
* we use it. Before that, we map using addresses going up from
|
|
* ioremap_bot. vmalloc will use the addresses from IOREMAP_BASE
|
|
* through ioremap_bot.
|
|
*/
|
|
paligned = addr & PAGE_MASK;
|
|
offset = addr & ~PAGE_MASK;
|
|
size = PAGE_ALIGN(addr + size) - paligned;
|
|
|
|
if (size == 0 || paligned == 0)
|
|
return NULL;
|
|
|
|
if (slab_is_available())
|
|
return do_ioremap(paligned, offset, size, prot, caller);
|
|
|
|
err = early_ioremap_range(ioremap_bot, paligned, size, prot);
|
|
if (err)
|
|
return NULL;
|
|
|
|
ret = (void __iomem *)ioremap_bot + offset;
|
|
ioremap_bot += size;
|
|
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Unmap an IO region and remove it from vmalloc'd list.
|
|
* Access to IO memory should be serialized by driver.
|
|
*/
|
|
void iounmap(volatile void __iomem *token)
|
|
{
|
|
void *addr;
|
|
|
|
if (!slab_is_available())
|
|
return;
|
|
|
|
addr = (void *)((unsigned long __force)PCI_FIX_ADDR(token) & PAGE_MASK);
|
|
|
|
if ((unsigned long)addr < ioremap_bot) {
|
|
pr_warn("Attempt to iounmap early bolted mapping at 0x%p\n", addr);
|
|
return;
|
|
}
|
|
vunmap(addr);
|
|
}
|
|
EXPORT_SYMBOL(iounmap);
|