x86/mm/cpa: Fold cpa_flush_range() and cpa_flush_array() into a single cpa_flush...

Note that the cache flush loop in cpa_flush_*() is identical when we
use __cpa_addr(); further observe that flush_tlb_kernel_range() is a
special case of to the cpa_flush_array() TLB invalidation code.

This then means the two functions are virtually identical. Fold these
two functions into a single cpa_flush() call.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tom.StDenis@amd.com
Cc: dave.hansen@intel.com
Link: http://lkml.kernel.org/r/20181203171043.559855600@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index 12b69263e501589ad5972297ea46b777b7b0f997..85ef53b86fa0f3d53e5b59549fb87941fb25aa70 100644 (file)
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -304,51 +304,7 @@ static void cpa_flush_all(unsigned long cache)
        on_each_cpu(__cpa_flush_all, (void *) cache, 1);
 }
 
-static bool __inv_flush_all(int cache)
-{
-       BUG_ON(irqs_disabled() && !early_boot_irqs_disabled);
-
-       if (cache && !static_cpu_has(X86_FEATURE_CLFLUSH)) {
-               cpa_flush_all(cache);
-               return true;
-       }
-
-       return false;
-}
-
-static void cpa_flush_range(unsigned long start, int numpages, int cache)
-{
-       unsigned int i, level;
-       unsigned long addr;
-
-       WARN_ON(PAGE_ALIGN(start) != start);
-
-       if (__inv_flush_all(cache))
-               return;
-
-       flush_tlb_kernel_range(start, start + PAGE_SIZE * numpages);
-
-       if (!cache)
-               return;
-
-       /*
-        * We only need to flush on one CPU,
-        * clflush is a MESI-coherent instruction that
-        * will cause all other CPUs to flush the same
-        * cachelines:
-        */
-       for (i = 0, addr = start; i < numpages; i++, addr += PAGE_SIZE) {
-               pte_t *pte = lookup_address(addr, &level);
-
-               /*
-                * Only flush present addresses:
-                */
-               if (pte && (pte_val(*pte) & _PAGE_PRESENT))
-                       clflush_cache_range((void *) addr, PAGE_SIZE);
-       }
-}
-
-void __cpa_flush_array(void *data)
+void __cpa_flush_tlb(void *data)
 {
        struct cpa_data *cpa = data;
        unsigned int i;
@@ -357,33 +313,31 @@ void __cpa_flush_array(void *data)
                __flush_tlb_one_kernel(__cpa_addr(cpa, i));
 }
 
-static void cpa_flush_array(struct cpa_data *cpa, int cache)
+static void cpa_flush(struct cpa_data *data, int cache)
 {
+       struct cpa_data *cpa = data;
        unsigned int i;
 
-       if (cpa_check_flush_all(cache))
+       BUG_ON(irqs_disabled() && !early_boot_irqs_disabled);
+
+       if (cache && !static_cpu_has(X86_FEATURE_CLFLUSH)) {
+               cpa_flush_all(cache);
                return;
+       }
 
        if (cpa->numpages <= tlb_single_page_flush_ceiling)
-               on_each_cpu(__cpa_flush_array, cpa, 1);
+               on_each_cpu(__cpa_flush_tlb, cpa, 1);
        else
                flush_tlb_all();
 
        if (!cache)
                return;
 
-       /*
-        * We only need to flush on one CPU,
-        * clflush is a MESI-coherent instruction that
-        * will cause all other CPUs to flush the same
-        * cachelines:
-        */
        for (i = 0; i < cpa->numpages; i++) {
                unsigned long addr = __cpa_addr(cpa, i);
                unsigned int level;
-               pte_t *pte;
 
-               pte = lookup_address(addr, &level);
+               pte_t *pte = lookup_address(addr, &level);
 
                /*
                 * Only flush present addresses:
@@ -1698,7 +1652,6 @@ static int change_page_attr_set_clr(unsigned long *addr, int numpages,
 {
        struct cpa_data cpa;
        int ret, cache, checkalias;
-       unsigned long baddr = 0;
 
        memset(&cpa, 0, sizeof(cpa));
 
@@ -1732,11 +1685,6 @@ static int change_page_attr_set_clr(unsigned long *addr, int numpages,
                         */
                        WARN_ON_ONCE(1);
                }
-               /*
-                * Save address for cache flush. *addr is modified in the call
-                * to __change_page_attr_set_clr() below.
-                */
-               baddr = make_addr_canonical_again(*addr);
        }
 
        /* Must avoid aliasing mappings in the highmem code */
@@ -1784,11 +1732,7 @@ static int change_page_attr_set_clr(unsigned long *addr, int numpages,
                goto out;
        }
 
-       if (cpa.flags & (CPA_PAGES_ARRAY | CPA_ARRAY))
-               cpa_flush_array(&cpa, cache);
-       else
-               cpa_flush_range(baddr, numpages, cache);
-
+       cpa_flush(&cpa, cache);
 out:
        return ret;
 }
@@ -2097,18 +2041,18 @@ static int __set_memory_enc_dec(unsigned long addr, int numpages, bool enc)
        /*
         * Before changing the encryption attribute, we need to flush caches.
         */
-       cpa_flush_range(addr, numpages, 1);
+       cpa_flush(&cpa, 1);
 
        ret = __change_page_attr_set_clr(&cpa, 1);
 
        /*
-        * After changing the encryption attribute, we need to flush TLBs
-        * again in case any speculative TLB caching occurred (but no need
-        * to flush caches again).  We could just use cpa_flush_all(), but
-        * in case TLB flushing gets optimized in the cpa_flush_range()
-        * path use the same logic as above.
+        * After changing the encryption attribute, we need to flush TLBs again
+        * in case any speculative TLB caching occurred (but no need to flush
+        * caches again).  We could just use cpa_flush_all(), but in case TLB
+        * flushing gets optimized in the cpa_flush() path use the same logic
+        * as above.
         */
-       cpa_flush_range(addr, numpages, 0);
+       cpa_flush(&cpa, 0);
 
        return ret;
 }