diff options
Diffstat (limited to 'arch/s390/mm')
-rw-r--r-- | arch/s390/mm/init.c | 2 | ||||
-rw-r--r-- | arch/s390/mm/maccess.c | 67 | ||||
-rw-r--r-- | arch/s390/mm/vmem.c | 85 |
3 files changed, 116 insertions, 38 deletions
diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c index 6a0ac00d5a42..7b6873ac99d1 100644 --- a/arch/s390/mm/init.c +++ b/arch/s390/mm/init.c @@ -38,7 +38,7 @@ #include <asm/kfence.h> #include <asm/ptdump.h> #include <asm/dma.h> -#include <asm/lowcore.h> +#include <asm/abs_lowcore.h> #include <asm/tlb.h> #include <asm/tlbflush.h> #include <asm/sections.h> diff --git a/arch/s390/mm/maccess.c b/arch/s390/mm/maccess.c index d6d84e02f35a..b8451ddbb3d6 100644 --- a/arch/s390/mm/maccess.c +++ b/arch/s390/mm/maccess.c @@ -15,6 +15,7 @@ #include <asm/asm-extable.h> #include <asm/ctl_reg.h> #include <asm/io.h> +#include <asm/abs_lowcore.h> #include <asm/stacktrace.h> static notrace long s390_kernel_write_odd(void *dst, const void *src, size_t size) @@ -148,46 +149,20 @@ int memcpy_real(void *dest, unsigned long src, size_t count) } /* - * Copy memory in absolute mode (kernel to kernel) + * Find CPU that owns swapped prefix page */ -void memcpy_absolute(void *dest, void *src, size_t count) -{ - unsigned long cr0, flags, prefix; - - flags = arch_local_irq_save(); - __ctl_store(cr0, 0, 0); - __ctl_clear_bit(0, 28); /* disable lowcore protection */ - prefix = store_prefix(); - if (prefix) { - local_mcck_disable(); - set_prefix(0); - memcpy(dest, src, count); - set_prefix(prefix); - local_mcck_enable(); - } else { - memcpy(dest, src, count); - } - __ctl_load(cr0, 0, 0); - arch_local_irq_restore(flags); -} - -/* - * Check if physical address is within prefix or zero page - */ -static int is_swapped(phys_addr_t addr) +static int get_swapped_owner(phys_addr_t addr) { phys_addr_t lc; int cpu; - if (addr < sizeof(struct lowcore)) - return 1; for_each_online_cpu(cpu) { lc = virt_to_phys(lowcore_ptr[cpu]); if (addr > lc + sizeof(struct lowcore) - 1 || addr < lc) continue; - return 1; + return cpu; } - return 0; + return -1; } /* @@ -200,17 +175,35 @@ void *xlate_dev_mem_ptr(phys_addr_t addr) { void *ptr = phys_to_virt(addr); void *bounce = ptr; + struct lowcore *abs_lc; + unsigned long flags; unsigned long size; + int this_cpu, cpu; cpus_read_lock(); - preempt_disable(); - if (is_swapped(addr)) { - size = PAGE_SIZE - (addr & ~PAGE_MASK); - bounce = (void *) __get_free_page(GFP_ATOMIC); - if (bounce) - memcpy_absolute(bounce, ptr, size); + this_cpu = get_cpu(); + if (addr >= sizeof(struct lowcore)) { + cpu = get_swapped_owner(addr); + if (cpu < 0) + goto out; + } + bounce = (void *)__get_free_page(GFP_ATOMIC); + if (!bounce) + goto out; + size = PAGE_SIZE - (addr & ~PAGE_MASK); + if (addr < sizeof(struct lowcore)) { + abs_lc = get_abs_lowcore(&flags); + ptr = (void *)abs_lc + addr; + memcpy(bounce, ptr, size); + put_abs_lowcore(abs_lc, flags); + } else if (cpu == this_cpu) { + ptr = (void *)(addr - virt_to_phys(lowcore_ptr[cpu])); + memcpy(bounce, ptr, size); + } else { + memcpy(bounce, ptr, size); } - preempt_enable(); +out: + put_cpu(); cpus_read_unlock(); return bounce; } diff --git a/arch/s390/mm/vmem.c b/arch/s390/mm/vmem.c index c2583f921ca8..203ba2bfea59 100644 --- a/arch/s390/mm/vmem.c +++ b/arch/s390/mm/vmem.c @@ -561,6 +561,91 @@ int vmem_add_mapping(unsigned long start, unsigned long size) } /* + * Allocate new or return existing page-table entry, but do not map it + * to any physical address. If missing, allocate segment- and region- + * table entries along. Meeting a large segment- or region-table entry + * while traversing is an error, since the function is expected to be + * called against virtual regions reserverd for 4KB mappings only. + */ +static pte_t *vmem_get_alloc_pte(unsigned long addr) +{ + pte_t *ptep = NULL; + pgd_t *pgd; + p4d_t *p4d; + pud_t *pud; + pmd_t *pmd; + pte_t *pte; + + pgd = pgd_offset_k(addr); + if (pgd_none(*pgd)) { + p4d = vmem_crst_alloc(_REGION2_ENTRY_EMPTY); + if (!p4d) + goto out; + pgd_populate(&init_mm, pgd, p4d); + } + p4d = p4d_offset(pgd, addr); + if (p4d_none(*p4d)) { + pud = vmem_crst_alloc(_REGION3_ENTRY_EMPTY); + if (!pud) + goto out; + p4d_populate(&init_mm, p4d, pud); + } + pud = pud_offset(p4d, addr); + if (pud_none(*pud)) { + pmd = vmem_crst_alloc(_SEGMENT_ENTRY_EMPTY); + if (!pmd) + goto out; + pud_populate(&init_mm, pud, pmd); + } else if (WARN_ON_ONCE(pud_large(*pud))) { + goto out; + } + pmd = pmd_offset(pud, addr); + if (pmd_none(*pmd)) { + pte = vmem_pte_alloc(); + if (!pte) + goto out; + pmd_populate(&init_mm, pmd, pte); + } else if (WARN_ON_ONCE(pmd_large(*pmd))) { + goto out; + } + ptep = pte_offset_kernel(pmd, addr); +out: + return ptep; +} + +int vmem_map_4k_page(unsigned long addr, unsigned long phys, pgprot_t prot) +{ + pte_t *ptep, pte; + int rc = 0; + + if (!IS_ALIGNED(addr, PAGE_SIZE)) + return -EINVAL; + mutex_lock(&vmem_mutex); + ptep = vmem_get_alloc_pte(addr); + if (!ptep) { + rc = -ENOMEM; + goto out; + } + __ptep_ipte(addr, ptep, 0, 0, IPTE_GLOBAL); + pte = mk_pte_phys(phys, prot); + set_pte(ptep, pte); +out: + mutex_unlock(&vmem_mutex); + return rc; +} + +void vmem_unmap_4k_page(unsigned long addr) +{ + pte_t *ptep; + + mutex_lock(&vmem_mutex); + ptep = virt_to_kpte(addr); + __ptep_ipte(addr, ptep, 0, 0, IPTE_GLOBAL); + pte_clear(&init_mm, addr, ptep); + mutex_unlock(&vmem_mutex); +} + +/* * map whole physical memory to virtual memory (identity mapping) * we reserve enough space in the vmalloc area for vmemmap to hotplug * additional memory segments. |