[patch RFC 03/15] x86/mm/highmem: Use generic kmap atomic implementation

Thomas Gleixner
2020-09-19T09:50:14Z

Convert X86 to the generic kmap atomic implementation.

Make the iomap_atomic() naming convention consistent while at it.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
arch/x86/Kconfig | 3 +-
arch/x86/include/asm/fixmap.h | 1
arch/x86/include/asm/highmem.h | 12 ++++++--
arch/x86/include/asm/iomap.h | 17 ++++++-----
arch/x86/mm/highmem_32.c | 59 -----------------------------------------
arch/x86/mm/init_32.c | 15 ----------
arch/x86/mm/iomap_32.c | 58 ++--------------------------------------
include/linux/io-mapping.h | 2 -
8 files changed, 25 insertions(+), 142 deletions(-)

--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -14,10 +14,11 @@ config X86_32
select ARCH_WANT_IPC_PARSE_VERSION
select CLKSRC_I8253
select CLONE_BACKWARDS
+ select GENERIC_VDSO_32
select HAVE_DEBUG_STACKOVERFLOW
+ select KMAP_ATOMIC_GENERIC
select MODULES_USE_ELF_REL
select OLD_SIGACTION
- select GENERIC_VDSO_32

config X86_64
def_bool y
--- a/arch/x86/include/asm/fixmap.h
+++ b/arch/x86/include/asm/fixmap.h
@@ -151,7 +151,6 @@ extern void reserve_top_address(unsigned

extern int fixmaps_set;

-extern pte_t *kmap_pte;
extern pte_t *pkmap_page_table;

void __native_set_fixmap(enum fixed_addresses idx, pte_t pte);
--- a/arch/x86/include/asm/highmem.h
+++ b/arch/x86/include/asm/highmem.h
@@ -58,11 +58,17 @@ extern unsigned long highstart_pfn, high
#define PKMAP_NR(virt) ((virt-PKMAP_BASE) >> PAGE_SHIFT)
#define PKMAP_ADDR(nr) (PKMAP_BASE + ((nr) << PAGE_SHIFT))

-void *kmap_atomic_pfn(unsigned long pfn);
-void *kmap_atomic_prot_pfn(unsigned long pfn, pgprot_t prot);
-
#define flush_cache_kmaps() do { } while (0)

+#define arch_kmap_temp_post_map(vaddr, pteval) \
+ arch_flush_lazy_mmu_mode()
+
+#define arch_kmap_temp_post_unmap(vaddr) \
+ do { \
+ flush_tlb_one_kernel((vaddr)); \
+ arch_flush_lazy_mmu_mode(); \
+ } while (0)
+
extern void add_highpages_with_active_regions(int nid, unsigned long start_pfn,
unsigned long end_pfn);

--- a/arch/x86/include/asm/iomap.h
+++ b/arch/x86/include/asm/iomap.h
@@ -9,19 +9,20 @@
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/uaccess.h>
+#include <linux/highmem.h>
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>

-void __iomem *
-iomap_atomic_prot_pfn(unsigned long pfn, pgprot_t prot);
+void __iomem *iomap_atomic_pfn_prot(unsigned long pfn, pgprot_t prot);

-void
-iounmap_atomic(void __iomem *kvaddr);
+static inline void iounmap_atomic(void __iomem *vaddr)
+{
+ kunmap_atomic_indexed((void __force *)vaddr);
+ preempt_enable();
+}

-int
-iomap_create_wc(resource_size_t base, unsigned long size, pgprot_t *prot);
+int iomap_create_wc(resource_size_t base, unsigned long size, pgprot_t *prot);

-void
-iomap_free(resource_size_t base, unsigned long size);
+void iomap_free(resource_size_t base, unsigned long size);

#endif /* _ASM_X86_IOMAP_H */
--- a/arch/x86/mm/highmem_32.c
+++ b/arch/x86/mm/highmem_32.c
@@ -4,65 +4,6 @@
#include <linux/swap.h> /* for totalram_pages */
#include <linux/memblock.h>

-void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
-{
- unsigned long vaddr;
- int idx, type;
-
- type = kmap_atomic_idx_push();
- idx = type + KM_TYPE_NR*smp_processor_id();
- vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
- BUG_ON(!pte_none(*(kmap_pte-idx)));
- set_pte(kmap_pte-idx, mk_pte(page, prot));
- arch_flush_lazy_mmu_mode();
-
- return (void *)vaddr;
-}
-EXPORT_SYMBOL(kmap_atomic_high_prot);
-
-/*
- * This is the same as kmap_atomic() but can map memory that doesn't
- * have a struct page associated with it.
- */
-void *kmap_atomic_pfn(unsigned long pfn)
-{
- return kmap_atomic_prot_pfn(pfn, kmap_prot);
-}
-EXPORT_SYMBOL_GPL(kmap_atomic_pfn);
-
-void kunmap_atomic_high(void *kvaddr)
-{
- unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
-
- if (vaddr >= __fix_to_virt(FIX_KMAP_END) &&
- vaddr <= __fix_to_virt(FIX_KMAP_BEGIN)) {
- int idx, type;
-
- type = kmap_atomic_idx();
- idx = type + KM_TYPE_NR * smp_processor_id();
-
-#ifdef CONFIG_DEBUG_HIGHMEM
- WARN_ON_ONCE(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
-#endif
- /*
- * Force other mappings to Oops if they'll try to access this
- * pte without first remap it. Keeping stale mappings around
- * is a bad idea also, in case the page changes cacheability
- * attributes or becomes a protected page in a hypervisor.
- */
- kpte_clear_flush(kmap_pte-idx, vaddr);
- kmap_atomic_idx_pop();
- arch_flush_lazy_mmu_mode();
- }
-#ifdef CONFIG_DEBUG_HIGHMEM
- else {
- BUG_ON(vaddr < PAGE_OFFSET);
- BUG_ON(vaddr >= (unsigned long)high_memory);
- }
-#endif
-}
-EXPORT_SYMBOL(kunmap_atomic_high);
-
void __init set_highmem_pages_init(void)
{
struct zone *zone;
--- a/arch/x86/mm/init_32.c
+++ b/arch/x86/mm/init_32.c
@@ -394,19 +394,6 @@ kernel_physical_mapping_init(unsigned lo
return last_map_addr;
}

-pte_t *kmap_pte;
-
-static void __init kmap_init(void)
-{
- unsigned long kmap_vstart;
-
- /*
- * Cache the first kmap pte:
- */
- kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN);
- kmap_pte = virt_to_kpte(kmap_vstart);
-}
-
#ifdef CONFIG_HIGHMEM
static void __init permanent_kmaps_init(pgd_t *pgd_base)
{
@@ -712,8 +699,6 @@ void __init paging_init(void)

__flush_tlb_all();

- kmap_init();
-
/*
* NOTE: at this point the bootmem allocator is fully available.
*/
--- a/arch/x86/mm/iomap_32.c
+++ b/arch/x86/mm/iomap_32.c
@@ -44,28 +44,7 @@ void iomap_free(resource_size_t base, un
}
EXPORT_SYMBOL_GPL(iomap_free);

-void *kmap_atomic_prot_pfn(unsigned long pfn, pgprot_t prot)
-{
- unsigned long vaddr;
- int idx, type;
-
- preempt_disable();
- pagefault_disable();
-
- type = kmap_atomic_idx_push();
- idx = type + KM_TYPE_NR * smp_processor_id();
- vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
- set_pte(kmap_pte - idx, pfn_pte(pfn, prot));
- arch_flush_lazy_mmu_mode();
-
- return (void *)vaddr;
-}
-
-/*
- * Map 'pfn' using protections 'prot'
- */
-void __iomem *
-iomap_atomic_prot_pfn(unsigned long pfn, pgprot_t prot)
+void __iomem *iomap_atomic_pfn_prot(unsigned long pfn, pgprot_t prot)
{
/*
* For non-PAT systems, translate non-WB request to UC- just in
@@ -81,36 +60,7 @@ iomap_atomic_prot_pfn(unsigned long pfn,
/* Filter out unsupported __PAGE_KERNEL* bits: */
pgprot_val(prot) &= __default_kernel_pte_mask;

- return (void __force __iomem *) kmap_atomic_prot_pfn(pfn, prot);
-}
-EXPORT_SYMBOL_GPL(iomap_atomic_prot_pfn);
-
-void
-iounmap_atomic(void __iomem *kvaddr)
-{
- unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
-
- if (vaddr >= __fix_to_virt(FIX_KMAP_END) &&
- vaddr <= __fix_to_virt(FIX_KMAP_BEGIN)) {
- int idx, type;
-
- type = kmap_atomic_idx();
- idx = type + KM_TYPE_NR * smp_processor_id();
-
-#ifdef CONFIG_DEBUG_HIGHMEM
- WARN_ON_ONCE(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
-#endif
- /*
- * Force other mappings to Oops if they'll try to access this
- * pte without first remap it. Keeping stale mappings around
- * is a bad idea also, in case the page changes cacheability
- * attributes or becomes a protected page in a hypervisor.
- */
- kpte_clear_flush(kmap_pte-idx, vaddr);
- kmap_atomic_idx_pop();
- }
-
- pagefault_enable();
- preempt_enable();
+ preempt_disable();
+ return (void __force __iomem *)kmap_atomic_pfn_prot(pfn, prot);
}
-EXPORT_SYMBOL_GPL(iounmap_atomic);
+EXPORT_SYMBOL_GPL(iomap_atomic_pfn_prot);
--- a/include/linux/io-mapping.h
+++ b/include/linux/io-mapping.h
@@ -69,7 +69,7 @@ io_mapping_map_atomic_wc(struct io_mappi

BUG_ON(offset >= mapping->size);
phys_addr = mapping->base + offset;
- return iomap_atomic_prot_pfn(PHYS_PFN(phys_addr), mapping->prot);
+ return iomap_atomic_pfn_prot(PHYS_PFN(phys_addr), mapping->prot);
}

static inline void