[PATCH 3/3] powerpc/pseries/mm: call H_BLOCK_REMOVE

From: Laurent Dufour
Date: Fri Jul 27 2018 - 09:51:48 EST


This hypervisor call allows to remove up to 8 ptes with only call to tlbie.

The virtual pages must be all within the same naturally aligned 8 page
virtual address block and have the same page and segment size encodings.

Cc: "Aneesh Kumar K.V" <aneesh.kumar@xxxxxxxxxxxxx>
Cc: Nicholas Piggin <npiggin@xxxxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Laurent Dufour <ldufour@xxxxxxxxxxxxxxxxxx>
---
arch/powerpc/include/asm/hvcall.h | 1 +
arch/powerpc/platforms/pseries/lpar.c | 223 +++++++++++++++++++++++++++++++---
2 files changed, 205 insertions(+), 19 deletions(-)

diff --git a/arch/powerpc/include/asm/hvcall.h b/arch/powerpc/include/asm/hvcall.h
index 662c8347d699..e403d574651d 100644
--- a/arch/powerpc/include/asm/hvcall.h
+++ b/arch/powerpc/include/asm/hvcall.h
@@ -278,6 +278,7 @@
#define H_COP 0x304
#define H_GET_MPP_X 0x314
#define H_SET_MODE 0x31C
+#define H_BLOCK_REMOVE 0x328
#define H_CLEAR_HPT 0x358
#define H_REQUEST_VMC 0x360
#define H_RESIZE_HPT_PREPARE 0x36C
diff --git a/arch/powerpc/platforms/pseries/lpar.c b/arch/powerpc/platforms/pseries/lpar.c
index 96b8cd8a802d..41ed03245eb4 100644
--- a/arch/powerpc/platforms/pseries/lpar.c
+++ b/arch/powerpc/platforms/pseries/lpar.c
@@ -418,6 +418,73 @@ static void pSeries_lpar_hpte_invalidate(unsigned long slot, unsigned long vpn,
BUG_ON(lpar_rc != H_SUCCESS);
}

+
+/*
+ * As defined in the PAPR's section 14.5.4.1.8
+ * The control mask doesn't include the returned reference and change bit from
+ * the processed PTE.
+ */
+#define HBLKR_AVPN 0x0100000000000000UL
+#define HBLKR_CTRL_MASK 0xf800000000000000UL
+#define HBLKR_CTRL_SUCCESS 0x8000000000000000UL
+#define HBLKR_CTRL_ERRNOTFOUND 0x8800000000000000UL
+#define HBLKR_CTRL_ERRBUSY 0xa000000000000000UL
+
+/**
+ * H_BLOCK_REMOVE caller.
+ * @idx should point to the latest @param entry set with a PTEX.
+ * If PTE cannot be processed because another CPUs has already locked that
+ * group, those entries are put back in @param starting at index 1.
+ * If entries has to be retried and @retry_busy is set to true, these entries
+ * are retried until success. If @retry_busy is set to false, the returned
+ * is the number of entries yet to process.
+ */
+static unsigned long call_block_remove(unsigned long idx, unsigned long *param,
+ bool retry_busy)
+{
+ unsigned long i, rc, new_idx;
+ unsigned long retbuf[PLPAR_HCALL9_BUFSIZE];
+
+again:
+ new_idx = 0;
+ BUG_ON((idx < 2) || (idx > PLPAR_HCALL9_BUFSIZE));
+ if (idx < PLPAR_HCALL9_BUFSIZE)
+ param[idx] = HBR_END;
+
+ rc = plpar_hcall9(H_BLOCK_REMOVE, retbuf,
+ param[0], /* AVA */
+ param[1], param[2], param[3], param[4], /* TS0-7 */
+ param[5], param[6], param[7], param[8]);
+ if (rc == H_SUCCESS)
+ return 0;
+
+ BUG_ON(rc != H_PARTIAL);
+
+ /* Check that the unprocessed entries were 'not found' or 'busy' */
+ for (i = 0; i < idx-1; i++) {
+ unsigned long ctrl = retbuf[i] & HBLKR_CTRL_MASK;
+
+ if (ctrl == HBLKR_CTRL_ERRBUSY) {
+ param[++new_idx] = param[i+1];
+ continue;
+ }
+
+ BUG_ON(ctrl != HBLKR_CTRL_SUCCESS
+ && ctrl != HBLKR_CTRL_ERRNOTFOUND);
+ }
+
+ /*
+ * If there were entries found busy, retry these entries if requested,
+ * of if all the entries have to be retried.
+ */
+ if (new_idx && (retry_busy || new_idx == (PLPAR_HCALL9_BUFSIZE-1))) {
+ idx = new_idx + 1;
+ goto again;
+ }
+
+ return new_idx;
+}
+
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
/*
* Limit iterations holding pSeries_lpar_tlbie_lock to 3. We also need
@@ -425,17 +492,59 @@ static void pSeries_lpar_hpte_invalidate(unsigned long slot, unsigned long vpn,
*/
#define PPC64_HUGE_HPTE_BATCH 12

-static void __pSeries_lpar_hugepage_invalidate(unsigned long *slot,
- unsigned long *vpn, int count,
- int psize, int ssize)
+static void hugepage_block_invalidate(unsigned long *slot, unsigned long *vpn,
+ int count, int psize, int ssize)
{
unsigned long param[PLPAR_HCALL9_BUFSIZE];
- int i = 0, pix = 0, rc;
- unsigned long flags = 0;
- int lock_tlbie = !mmu_has_feature(MMU_FTR_LOCKLESS_TLBIE);
+ unsigned long shift, current_vpgb, vpgb;
+ int i, pix = 0;

- if (lock_tlbie)
- spin_lock_irqsave(&pSeries_lpar_tlbie_lock, flags);
+ shift = mmu_psize_defs[psize].shift;
+
+ for (i = 0; i < count; i++) {
+ /*
+ * Shifting 3 bits more on the right to get a
+ * 8 pages aligned virtual addresse.
+ */
+ vpgb = (vpn[i] >> (shift - VPN_SHIFT + 3));
+ if (!pix || vpgb != current_vpgb) {
+ /*
+ * Need to start a new 8 pages block, flush
+ * the current one if needed.
+ */
+ if (pix)
+ (void)call_block_remove(pix, param, true);
+ current_vpgb = vpgb;
+ param[0] = hpte_encode_avpn(vpn[i], psize, ssize);
+ pix = 1;
+ }
+
+ param[pix++] = HBR_REQUEST | HBLKR_AVPN | slot[i];
+ if (pix == PLPAR_HCALL9_BUFSIZE) {
+ pix = call_block_remove(pix, param, false);
+ /*
+ * pix = 0 means that all the entries were
+ * removed, we can start a new block.
+ * Otherwise, this means that there are entries
+ * to retry, and pix points to latest one, so
+ * we should increment it and try to continue
+ * the same block.
+ */
+ if (!pix)
+ current_vpgb = 0;
+ else
+ pix++;
+ }
+ }
+ if (pix)
+ (void)call_block_remove(pix, param, true);
+}
+
+static void hugepage_bulk_invalidate(unsigned long *slot, unsigned long *vpn,
+ int count, int psize, int ssize)
+{
+ unsigned long param[PLPAR_HCALL9_BUFSIZE];
+ int i = 0, pix = 0, rc;

for (i = 0; i < count; i++) {

@@ -443,17 +552,6 @@ static void __pSeries_lpar_hugepage_invalidate(unsigned long *slot,
pSeries_lpar_hpte_invalidate(slot[i], vpn[i], psize, 0,
ssize, 0);
} else {
- param[pix] = HBR_REQUEST | HBR_AVPN | slot[i];
- param[pix+1] = hpte_encode_avpn(vpn[i], psize, ssize);
- pix += 2;
- if (pix == 8) {
- rc = plpar_hcall9(H_BULK_REMOVE, param,
- param[0], param[1], param[2],
- param[3], param[4], param[5],
- param[6], param[7]);
- BUG_ON(rc != H_SUCCESS);
- pix = 0;
- }
}
}
if (pix) {
@@ -463,6 +561,23 @@ static void __pSeries_lpar_hugepage_invalidate(unsigned long *slot,
param[6], param[7]);
BUG_ON(rc != H_SUCCESS);
}
+}
+
+static inline void __pSeries_lpar_hugepage_invalidate(unsigned long *slot,
+ unsigned long *vpn,
+ int count, int psize,
+ int ssize)
+{
+ unsigned long flags = 0;
+ int lock_tlbie = !mmu_has_feature(MMU_FTR_LOCKLESS_TLBIE);
+
+ if (lock_tlbie)
+ spin_lock_irqsave(&pSeries_lpar_tlbie_lock, flags);
+
+ if (firmware_has_feature(FW_FEATURE_BLOCK_REMOVE))
+ hugepage_block_invalidate(slot, vpn, count, psize, ssize);
+ else
+ hugepage_bulk_invalidate(slot, vpn, count, psize, ssize);

if (lock_tlbie)
spin_unlock_irqrestore(&pSeries_lpar_tlbie_lock, flags);
@@ -565,6 +680,70 @@ static inline unsigned long compute_slot(real_pte_t pte,
return slot;
}

+/**
+ * The hcall H_BLOCK_REMOVE implies that the virtual pages to processed are
+ * "all within the same naturally aligned 8 page virtual address block".
+ */
+static void do_block_remove(unsigned long number, struct ppc64_tlb_batch *batch,
+ unsigned long *param)
+{
+ unsigned long vpn;
+ unsigned long i, pix = 0;
+ unsigned long index, shift, slot, current_vpgb, vpgb;
+ real_pte_t pte;
+ int psize, ssize;
+
+ psize = batch->psize;
+ ssize = batch->ssize;
+
+ for (i = 0; i < number; i++) {
+ vpn = batch->vpn[i];
+ pte = batch->pte[i];
+ pte_iterate_hashed_subpages(pte, psize, vpn, index, shift) {
+ /*
+ * Shifting 3 bits more on the right to get a
+ * 8 pages aligned virtual addresse.
+ */
+ vpgb = (vpn >> (shift - VPN_SHIFT + 3));
+ if (!pix || vpgb != current_vpgb) {
+ /*
+ * Need to start a new 8 pages block, flush
+ * the current one if needed.
+ */
+ if (pix)
+ (void)call_block_remove(pix, param,
+ true);
+ current_vpgb = vpgb;
+ param[0] = hpte_encode_avpn(vpn, psize,
+ ssize);
+ pix = 1;
+ }
+
+ slot = compute_slot(pte, vpn, index, shift, ssize);
+ param[pix++] = HBR_REQUEST | HBLKR_AVPN | slot;
+
+ if (pix == PLPAR_HCALL9_BUFSIZE) {
+ pix = call_block_remove(pix, param, false);
+ /*
+ * pix = 0 means that all the entries were
+ * removed, we can start a new block.
+ * Otherwise, this means that there are entries
+ * to retry, and pix points to latest one, so
+ * we should increment it and try to continue
+ * the same block.
+ */
+ if (!pix)
+ current_vpgb = 0;
+ else
+ pix++;
+ }
+ } pte_iterate_hashed_end();
+ }
+
+ if (pix > 1)
+ (void)call_block_remove(pix, param, true);
+}
+
/*
* Take a spinlock around flushes to avoid bouncing the hypervisor tlbie
* lock.
@@ -584,6 +763,11 @@ static void pSeries_lpar_flush_hash_range(unsigned long number, int local)
if (lock_tlbie)
spin_lock_irqsave(&pSeries_lpar_tlbie_lock, flags);

+ if (firmware_has_feature(FW_FEATURE_BLOCK_REMOVE)) {
+ do_block_remove(number, batch, param);
+ goto out;
+ }
+
psize = batch->psize;
ssize = batch->ssize;
pix = 0;
@@ -622,6 +806,7 @@ static void pSeries_lpar_flush_hash_range(unsigned long number, int local)
BUG_ON(rc != H_SUCCESS);
}

+out:
if (lock_tlbie)
spin_unlock_irqrestore(&pSeries_lpar_tlbie_lock, flags);
}
--
2.7.4