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authorCatalin Marinas <catalin.marinas@arm.com>2020-07-31 18:09:50 +0100
committerCatalin Marinas <catalin.marinas@arm.com>2020-07-31 18:09:50 +0100
commit18aa3bd58b1428d1927fe11f85ad444423d4fc59 (patch)
tree40171776fd498d9ae9378c9559fcada83c92ee17 /arch/arm64/include/asm/tlbflush.h
parent4557062da7ebfa9236af83fcb4323a1838ae533e (diff)
parentd1d3aa98b1d4826a19adfefb69b96142a0cac633 (diff)
downloadlinux-18aa3bd58b1428d1927fe11f85ad444423d4fc59.tar.bz2
Merge branch 'for-next/tlbi' into for-next/core
* for-next/tlbi: : Support for TTL (translation table level) hint in the TLB operations arm64: tlb: Use the TLBI RANGE feature in arm64 arm64: enable tlbi range instructions arm64: tlb: Detect the ARMv8.4 TLBI RANGE feature arm64: tlb: don't set the ttl value in flush_tlb_page_nosync arm64: Shift the __tlbi_level() indentation left arm64: tlb: Set the TTL field in flush_*_tlb_range arm64: tlb: Set the TTL field in flush_tlb_range tlb: mmu_gather: add tlb_flush_*_range APIs arm64: Add tlbi_user_level TLB invalidation helper arm64: Add level-hinted TLB invalidation helper arm64: Document SW reserved PTE/PMD bits in Stage-2 descriptors arm64: Detect the ARMv8.4 TTL feature
Diffstat (limited to 'arch/arm64/include/asm/tlbflush.h')
-rw-r--r--arch/arm64/include/asm/tlbflush.h177
1 files changed, 162 insertions, 15 deletions
diff --git a/arch/arm64/include/asm/tlbflush.h b/arch/arm64/include/asm/tlbflush.h
index bc3949064725..d493174415db 100644
--- a/arch/arm64/include/asm/tlbflush.h
+++ b/arch/arm64/include/asm/tlbflush.h
@@ -10,6 +10,7 @@
#ifndef __ASSEMBLY__
+#include <linux/bitfield.h>
#include <linux/mm_types.h>
#include <linux/sched.h>
#include <asm/cputype.h>
@@ -60,6 +61,102 @@
})
/*
+ * Get translation granule of the system, which is decided by
+ * PAGE_SIZE. Used by TTL.
+ * - 4KB : 1
+ * - 16KB : 2
+ * - 64KB : 3
+ */
+#define TLBI_TTL_TG_4K 1
+#define TLBI_TTL_TG_16K 2
+#define TLBI_TTL_TG_64K 3
+
+static inline unsigned long get_trans_granule(void)
+{
+ switch (PAGE_SIZE) {
+ case SZ_4K:
+ return TLBI_TTL_TG_4K;
+ case SZ_16K:
+ return TLBI_TTL_TG_16K;
+ case SZ_64K:
+ return TLBI_TTL_TG_64K;
+ default:
+ return 0;
+ }
+}
+
+/*
+ * Level-based TLBI operations.
+ *
+ * When ARMv8.4-TTL exists, TLBI operations take an additional hint for
+ * the level at which the invalidation must take place. If the level is
+ * wrong, no invalidation may take place. In the case where the level
+ * cannot be easily determined, a 0 value for the level parameter will
+ * perform a non-hinted invalidation.
+ *
+ * For Stage-2 invalidation, use the level values provided to that effect
+ * in asm/stage2_pgtable.h.
+ */
+#define TLBI_TTL_MASK GENMASK_ULL(47, 44)
+
+#define __tlbi_level(op, addr, level) do { \
+ u64 arg = addr; \
+ \
+ if (cpus_have_const_cap(ARM64_HAS_ARMv8_4_TTL) && \
+ level) { \
+ u64 ttl = level & 3; \
+ ttl |= get_trans_granule() << 2; \
+ arg &= ~TLBI_TTL_MASK; \
+ arg |= FIELD_PREP(TLBI_TTL_MASK, ttl); \
+ } \
+ \
+ __tlbi(op, arg); \
+} while(0)
+
+#define __tlbi_user_level(op, arg, level) do { \
+ if (arm64_kernel_unmapped_at_el0()) \
+ __tlbi_level(op, (arg | USER_ASID_FLAG), level); \
+} while (0)
+
+/*
+ * This macro creates a properly formatted VA operand for the TLB RANGE.
+ * The value bit assignments are:
+ *
+ * +----------+------+-------+-------+-------+----------------------+
+ * | ASID | TG | SCALE | NUM | TTL | BADDR |
+ * +-----------------+-------+-------+-------+----------------------+
+ * |63 48|47 46|45 44|43 39|38 37|36 0|
+ *
+ * The address range is determined by below formula:
+ * [BADDR, BADDR + (NUM + 1) * 2^(5*SCALE + 1) * PAGESIZE)
+ *
+ */
+#define __TLBI_VADDR_RANGE(addr, asid, scale, num, ttl) \
+ ({ \
+ unsigned long __ta = (addr) >> PAGE_SHIFT; \
+ __ta &= GENMASK_ULL(36, 0); \
+ __ta |= (unsigned long)(ttl) << 37; \
+ __ta |= (unsigned long)(num) << 39; \
+ __ta |= (unsigned long)(scale) << 44; \
+ __ta |= get_trans_granule() << 46; \
+ __ta |= (unsigned long)(asid) << 48; \
+ __ta; \
+ })
+
+/* These macros are used by the TLBI RANGE feature. */
+#define __TLBI_RANGE_PAGES(num, scale) \
+ ((unsigned long)((num) + 1) << (5 * (scale) + 1))
+#define MAX_TLBI_RANGE_PAGES __TLBI_RANGE_PAGES(31, 3)
+
+/*
+ * Generate 'num' values from -1 to 30 with -1 rejected by the
+ * __flush_tlb_range() loop below.
+ */
+#define TLBI_RANGE_MASK GENMASK_ULL(4, 0)
+#define __TLBI_RANGE_NUM(pages, scale) \
+ ((((pages) >> (5 * (scale) + 1)) & TLBI_RANGE_MASK) - 1)
+
+/*
* TLB Invalidation
* ================
*
@@ -179,34 +276,83 @@ static inline void flush_tlb_page(struct vm_area_struct *vma,
static inline void __flush_tlb_range(struct vm_area_struct *vma,
unsigned long start, unsigned long end,
- unsigned long stride, bool last_level)
+ unsigned long stride, bool last_level,
+ int tlb_level)
{
+ int num = 0;
+ int scale = 0;
unsigned long asid = ASID(vma->vm_mm);
unsigned long addr;
+ unsigned long pages;
start = round_down(start, stride);
end = round_up(end, stride);
+ pages = (end - start) >> PAGE_SHIFT;
- if ((end - start) >= (MAX_TLBI_OPS * stride)) {
+ /*
+ * When not uses TLB range ops, we can handle up to
+ * (MAX_TLBI_OPS - 1) pages;
+ * When uses TLB range ops, we can handle up to
+ * (MAX_TLBI_RANGE_PAGES - 1) pages.
+ */
+ if ((!system_supports_tlb_range() &&
+ (end - start) >= (MAX_TLBI_OPS * stride)) ||
+ pages >= MAX_TLBI_RANGE_PAGES) {
flush_tlb_mm(vma->vm_mm);
return;
}
- /* Convert the stride into units of 4k */
- stride >>= 12;
+ dsb(ishst);
- start = __TLBI_VADDR(start, asid);
- end = __TLBI_VADDR(end, asid);
+ /*
+ * When the CPU does not support TLB range operations, flush the TLB
+ * entries one by one at the granularity of 'stride'. If the the TLB
+ * range ops are supported, then:
+ *
+ * 1. If 'pages' is odd, flush the first page through non-range
+ * operations;
+ *
+ * 2. For remaining pages: the minimum range granularity is decided
+ * by 'scale', so multiple range TLBI operations may be required.
+ * Start from scale = 0, flush the corresponding number of pages
+ * ((num+1)*2^(5*scale+1) starting from 'addr'), then increase it
+ * until no pages left.
+ *
+ * Note that certain ranges can be represented by either num = 31 and
+ * scale or num = 0 and scale + 1. The loop below favours the latter
+ * since num is limited to 30 by the __TLBI_RANGE_NUM() macro.
+ */
+ while (pages > 0) {
+ if (!system_supports_tlb_range() ||
+ pages % 2 == 1) {
+ addr = __TLBI_VADDR(start, asid);
+ if (last_level) {
+ __tlbi_level(vale1is, addr, tlb_level);
+ __tlbi_user_level(vale1is, addr, tlb_level);
+ } else {
+ __tlbi_level(vae1is, addr, tlb_level);
+ __tlbi_user_level(vae1is, addr, tlb_level);
+ }
+ start += stride;
+ pages -= stride >> PAGE_SHIFT;
+ continue;
+ }
- dsb(ishst);
- for (addr = start; addr < end; addr += stride) {
- if (last_level) {
- __tlbi(vale1is, addr);
- __tlbi_user(vale1is, addr);
- } else {
- __tlbi(vae1is, addr);
- __tlbi_user(vae1is, addr);
+ num = __TLBI_RANGE_NUM(pages, scale);
+ if (num >= 0) {
+ addr = __TLBI_VADDR_RANGE(start, asid, scale,
+ num, tlb_level);
+ if (last_level) {
+ __tlbi(rvale1is, addr);
+ __tlbi_user(rvale1is, addr);
+ } else {
+ __tlbi(rvae1is, addr);
+ __tlbi_user(rvae1is, addr);
+ }
+ start += __TLBI_RANGE_PAGES(num, scale) << PAGE_SHIFT;
+ pages -= __TLBI_RANGE_PAGES(num, scale);
}
+ scale++;
}
dsb(ish);
}
@@ -217,8 +363,9 @@ static inline void flush_tlb_range(struct vm_area_struct *vma,
/*
* We cannot use leaf-only invalidation here, since we may be invalidating
* table entries as part of collapsing hugepages or moving page tables.
+ * Set the tlb_level to 0 because we can not get enough information here.
*/
- __flush_tlb_range(vma, start, end, PAGE_SIZE, false);
+ __flush_tlb_range(vma, start, end, PAGE_SIZE, false, 0);
}
static inline void flush_tlb_kernel_range(unsigned long start, unsigned long end)