diff options
Diffstat (limited to 'arch/x86/xen/p2m.c')
| -rw-r--r-- | arch/x86/xen/p2m.c | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c index 7c735b730acd..b52d3e17e2c1 100644 --- a/arch/x86/xen/p2m.c +++ b/arch/x86/xen/p2m.c @@ -70,6 +70,7 @@ #include <linux/memblock.h> #include <linux/slab.h> #include <linux/vmalloc.h> +#include <linux/acpi.h> #include <asm/cache.h> #include <asm/setup.h> @@ -80,6 +81,7 @@ #include <asm/xen/hypervisor.h> #include <xen/balloon.h> #include <xen/grant_table.h> +#include <xen/hvc-console.h> #include "xen-ops.h" @@ -792,6 +794,102 @@ int clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops, return ret; } +/* Remapped non-RAM areas */ +#define NR_NONRAM_REMAP 4 +static struct nonram_remap { + phys_addr_t maddr; + phys_addr_t paddr; + size_t size; +} xen_nonram_remap[NR_NONRAM_REMAP] __ro_after_init; +static unsigned int nr_nonram_remap __ro_after_init; + +/* + * Do the real remapping of non-RAM regions as specified in the + * xen_nonram_remap[] array. + * In case of an error just crash the system. + */ +void __init xen_do_remap_nonram(void) +{ + unsigned int i; + unsigned int remapped = 0; + const struct nonram_remap *remap = xen_nonram_remap; + unsigned long pfn, mfn, end_pfn; + + for (i = 0; i < nr_nonram_remap; i++) { + end_pfn = PFN_UP(remap->paddr + remap->size); + pfn = PFN_DOWN(remap->paddr); + mfn = PFN_DOWN(remap->maddr); + while (pfn < end_pfn) { + if (!set_phys_to_machine(pfn, mfn)) + panic("Failed to set p2m mapping for pfn=%lx mfn=%lx\n", + pfn, mfn); + + pfn++; + mfn++; + remapped++; + } + + remap++; + } + + pr_info("Remapped %u non-RAM page(s)\n", remapped); +} + +#ifdef CONFIG_ACPI +/* + * Xen variant of acpi_os_ioremap() taking potentially remapped non-RAM + * regions into account. + * Any attempt to map an area crossing a remap boundary will produce a + * WARN() splat. + * phys is related to remap->maddr on input and will be rebased to remap->paddr. + */ +static void __iomem *xen_acpi_os_ioremap(acpi_physical_address phys, + acpi_size size) +{ + unsigned int i; + const struct nonram_remap *remap = xen_nonram_remap; + + for (i = 0; i < nr_nonram_remap; i++) { + if (phys + size > remap->maddr && + phys < remap->maddr + remap->size) { + WARN_ON(phys < remap->maddr || + phys + size > remap->maddr + remap->size); + phys += remap->paddr - remap->maddr; + break; + } + } + + return x86_acpi_os_ioremap(phys, size); +} +#endif /* CONFIG_ACPI */ + +/* + * Add a new non-RAM remap entry. + * In case of no free entry found, just crash the system. + */ +void __init xen_add_remap_nonram(phys_addr_t maddr, phys_addr_t paddr, + unsigned long size) +{ + BUG_ON((maddr & ~PAGE_MASK) != (paddr & ~PAGE_MASK)); + + if (nr_nonram_remap == NR_NONRAM_REMAP) { + xen_raw_console_write("Number of required E820 entry remapping actions exceed maximum value\n"); + BUG(); + } + +#ifdef CONFIG_ACPI + /* Switch to the Xen acpi_os_ioremap() variant. */ + if (nr_nonram_remap == 0) + acpi_os_ioremap = xen_acpi_os_ioremap; +#endif + + xen_nonram_remap[nr_nonram_remap].maddr = maddr; + xen_nonram_remap[nr_nonram_remap].paddr = paddr; + xen_nonram_remap[nr_nonram_remap].size = size; + + nr_nonram_remap++; +} + #ifdef CONFIG_XEN_DEBUG_FS #include <linux/debugfs.h> static int p2m_dump_show(struct seq_file *m, void *v) |