diff mbox series

[v6,06/10] hw/intc: GICv3 redistributor ITS processing

Message ID 20210707021815.45938-7-shashi.mallela@linaro.org (mailing list archive)
State New, archived
Headers show
Series GICv3 LPI and ITS feature implementation | expand

Commit Message

Shashi Mallela July 7, 2021, 2:18 a.m. UTC
Implemented lpi processing at redistributor to get lpi config info
from lpi configuration table,determine priority,set pending state in
lpi pending table and forward the lpi to cpuif.Added logic to invoke
redistributor lpi processing with translated LPI which set/clear LPI
from ITS device as part of ITS INT,CLEAR,DISCARD command and
GITS_TRANSLATER processing.

Signed-off-by: Shashi Mallela <shashi.mallela@linaro.org>
---
 hw/intc/arm_gicv3.c                |  14 +++
 hw/intc/arm_gicv3_common.c         |   1 +
 hw/intc/arm_gicv3_cpuif.c          |   7 +-
 hw/intc/arm_gicv3_its.c            |  23 +++++
 hw/intc/arm_gicv3_redist.c         | 142 +++++++++++++++++++++++++++++
 hw/intc/gicv3_internal.h           |   9 ++
 include/hw/intc/arm_gicv3_common.h |   7 ++
 7 files changed, 201 insertions(+), 2 deletions(-)

Comments

Peter Maydell July 13, 2021, 4:45 p.m. UTC | #1
On Wed, 7 Jul 2021 at 03:18, Shashi Mallela <shashi.mallela@linaro.org> wrote:
>
> Implemented lpi processing at redistributor to get lpi config info
> from lpi configuration table,determine priority,set pending state in
> lpi pending table and forward the lpi to cpuif.Added logic to invoke
> redistributor lpi processing with translated LPI which set/clear LPI
> from ITS device as part of ITS INT,CLEAR,DISCARD command and
> GITS_TRANSLATER processing.
>
> Signed-off-by: Shashi Mallela <shashi.mallela@linaro.org>

> +
> +void gicv3_redist_update_lpi(GICv3CPUState *cs)
> +{
> +    /*
> +     * This function scans the LPI pending table and for each pending
> +     * LPI, reads the corresponding entry from LPI configuration table
> +     * to extract the priority info and determine if the current LPI
> +     * priority is lower than the last computed high priority lpi interrupt.
> +     * If yes, replace current LPI as the new high priority lpi interrupt.
> +     */
> +    AddressSpace *as = &cs->gic->dma_as;
> +    uint64_t lpipt_baddr;
> +    uint32_t pendt_size = 0;
> +    uint8_t pend;
> +    int i;
> +    uint64_t idbits;
> +
> +    idbits = MIN(FIELD_EX64(cs->gicr_propbaser, GICR_PROPBASER, IDBITS),
> +                 GICD_TYPER_IDBITS);
> +
> +    if (!(cs->gicr_ctlr & GICR_CTLR_ENABLE_LPIS) || !cs->gicr_propbaser ||
> +        !cs->gicr_pendbaser || (idbits < GICR_PROPBASER_IDBITS_THRESHOLD)) {

If you structure the loop below appropriately, you can avoid having to
explicitly check idbits against GICR_PROPBASER_IDBITS_THRESHOLD; see below.

> +        return;
> +    }
> +
> +    cs->hpplpi.prio = 0xff;
> +
> +    lpipt_baddr = cs->gicr_pendbaser & R_GICR_PENDBASER_PHYADDR_MASK;
> +
> +    /* Determine the highest priority pending interrupt among LPIs */
> +    pendt_size = (1ULL << (idbits + 1));
> +
> +    for (i = 0; i < pendt_size / 8; i++) {
> +        address_space_read(as, lpipt_baddr +
> +                (((GICV3_LPI_INTID_START + i) / 8) * sizeof(pend)),
> +                MEMTXATTRS_UNSPECIFIED, &pend, sizeof(pend));
> +
> +        if (!((1 << ((GICV3_LPI_INTID_START + i) % 8)) & pend)) {
> +            continue;
> +        }

I don't think this code is right. The pending table size includes one
bit for every interrupt ID, including the low ones below GICV3_LPID_INTID_START
(ie there's a spare 1K for IMPDEF purposes at the start). Here the
loop is iterating through the whole pending table with 'i' a byte
offset into it -- but then when we calculate the address to read we
add GICV3_LPI_INTID_START to it. The loop body seems to be written
as if 'i' is an intid, but the for() is not doing that.

Also, you read a byte of pending information, which tells you about
the pending state of 8 interrupts, but you only call
gicv3_redist_check_lpi_priority() for one of them.

> +
> +        gicv3_redist_check_lpi_priority(cs, GICV3_LPI_INTID_START + i);
> +    }

I think you probably want to structure the loop something like this:

for (offset = GICV3_LPI_INTID_START / 8; offset < pendt_size / 8; offset++) {
    read the byte at lpipt_baddr + offset;
    while (byte) {
        bit = ctz32(byte);
        gicv3_redist_check_lpi_priority(cs, offset * 8 + bit);
        byte &= ~(1 << bit);
    }
}

(this is why you don't need to explicitly check GICR_PROPBASER_IDBITS_THRESHOLD:
if idbits is too low then the loop condition is just always false and we
don't check any pending bits.)


> +}
> +
> +void gicv3_redist_lpi_pending(GICv3CPUState *cs, int irq, int level)
> +{
> +    /*
> +     * This function updates the pending bit in lpi pending table for
> +     * the irq being activated or deactivated.
> +     */
> +    AddressSpace *as = &cs->gic->dma_as;
> +    uint64_t lpipt_baddr;
> +    bool ispend = false;
> +    uint8_t pend;
> +
> +    /*
> +     * get the bit value corresponding to this irq in the
> +     * lpi pending table
> +     */
> +    lpipt_baddr = cs->gicr_pendbaser & R_GICR_PENDBASER_PHYADDR_MASK;
> +
> +    address_space_read(as, lpipt_baddr + ((irq / 8) * sizeof(pend)),
> +                       MEMTXATTRS_UNSPECIFIED, &pend, sizeof(pend));
> +
> +    ispend = extract32(pend, irq % 8, 1);
> +
> +    /* no change in the value of pending bit, return */
> +    if (ispend == level) {
> +        return;
> +    }
> +    pend = deposit32(pend, irq % 8, 1, level ? 1 : 0);
> +
> +    address_space_write(as, lpipt_baddr + ((irq / 8) * sizeof(pend)),
> +                        MEMTXATTRS_UNSPECIFIED, &pend, sizeof(pend));
> +
> +    /*
> +     * check if this LPI is better than the current hpplpi, if yes
> +     * just set hpplpi.prio and .irq without doing a full rescan
> +     */
> +    if (level) {
> +        gicv3_redist_check_lpi_priority(cs, irq);
> +    } else {
> +        if (irq == cs->hpplpi.irq) {
> +            gicv3_redist_update_lpi(cs);
> +        }
> +    }
> +}
> +
> +void gicv3_redist_process_lpi(GICv3CPUState *cs, int irq, int level)
> +{
> +    uint64_t idbits;
> +
> +    idbits = MIN(FIELD_EX64(cs->gicr_propbaser, GICR_PROPBASER, IDBITS),
> +                 GICD_TYPER_IDBITS);

You should ignore irq values less than GICV3_LPI_INTID_START here.
(We checked when we put the map into the ITE but this is an easy
way to get rid of the 1023 special case.)

> +
> +    if (!(cs->gicr_ctlr & GICR_CTLR_ENABLE_LPIS) || !cs->gicr_propbaser ||
> +         !cs->gicr_pendbaser || (idbits < GICR_PROPBASER_IDBITS_THRESHOLD) ||

You don't need to explicitly look for "idbits <
GICR_PROPBASER_IDBITS_THRESHOLD":
if that is true then the irq will always be greater than the maximum imposed by
idbits and we'll throw it out that way.

> +         (irq > (1ULL << (idbits + 1)))) {

This is off by one -- 1 << (bitcount) is not the largest permitted intID,
it is one greater than that.

> +        return;
> +    }
> +
> +    /* set/clear the pending bit for this irq */
> +    gicv3_redist_lpi_pending(cs, irq, level);
> +
> +    gicv3_redist_update(cs);
> +}

thanks
-- PMM
diff mbox series

Patch

diff --git a/hw/intc/arm_gicv3.c b/hw/intc/arm_gicv3.c
index d63f8af604..3f24707838 100644
--- a/hw/intc/arm_gicv3.c
+++ b/hw/intc/arm_gicv3.c
@@ -165,6 +165,16 @@  static void gicv3_redist_update_noirqset(GICv3CPUState *cs)
         cs->hppi.grp = gicv3_irq_group(cs->gic, cs, cs->hppi.irq);
     }
 
+    if ((cs->gicr_ctlr & GICR_CTLR_ENABLE_LPIS) && cs->gic->lpi_enable &&
+        (cs->hpplpi.prio != 0xff)) {
+        if (irqbetter(cs, cs->hpplpi.irq, cs->hpplpi.prio)) {
+            cs->hppi.irq = cs->hpplpi.irq;
+            cs->hppi.prio = cs->hpplpi.prio;
+            cs->hppi.grp = cs->hpplpi.grp;
+            seenbetter = true;
+        }
+    }
+
     /* If the best interrupt we just found would preempt whatever
      * was the previous best interrupt before this update, then
      * we know it's definitely the best one now.
@@ -339,9 +349,13 @@  static void gicv3_set_irq(void *opaque, int irq, int level)
 
 static void arm_gicv3_post_load(GICv3State *s)
 {
+    int i;
     /* Recalculate our cached idea of the current highest priority
      * pending interrupt, but don't set IRQ or FIQ lines.
      */
+    for (i = 0; i < s->num_cpu; i++) {
+        gicv3_redist_update_lpi(&s->cpu[i]);
+    }
     gicv3_full_update_noirqset(s);
     /* Repopulate the cache of GICv3CPUState pointers for target CPUs */
     gicv3_cache_all_target_cpustates(s);
diff --git a/hw/intc/arm_gicv3_common.c b/hw/intc/arm_gicv3_common.c
index 53dea2a775..223db16fec 100644
--- a/hw/intc/arm_gicv3_common.c
+++ b/hw/intc/arm_gicv3_common.c
@@ -435,6 +435,7 @@  static void arm_gicv3_common_reset(DeviceState *dev)
         memset(cs->gicr_ipriorityr, 0, sizeof(cs->gicr_ipriorityr));
 
         cs->hppi.prio = 0xff;
+        cs->hpplpi.prio = 0xff;
 
         /* State in the CPU interface must *not* be reset here, because it
          * is part of the CPU's reset domain, not the GIC device's.
diff --git a/hw/intc/arm_gicv3_cpuif.c b/hw/intc/arm_gicv3_cpuif.c
index 3e0641aff9..184b92e7de 100644
--- a/hw/intc/arm_gicv3_cpuif.c
+++ b/hw/intc/arm_gicv3_cpuif.c
@@ -899,10 +899,12 @@  static void icc_activate_irq(GICv3CPUState *cs, int irq)
         cs->gicr_iactiver0 = deposit32(cs->gicr_iactiver0, irq, 1, 1);
         cs->gicr_ipendr0 = deposit32(cs->gicr_ipendr0, irq, 1, 0);
         gicv3_redist_update(cs);
-    } else {
+    } else if (irq < GICV3_LPI_INTID_START) {
         gicv3_gicd_active_set(cs->gic, irq);
         gicv3_gicd_pending_clear(cs->gic, irq);
         gicv3_update(cs->gic, irq, 1);
+    } else {
+        gicv3_redist_lpi_pending(cs, irq, 0);
     }
 }
 
@@ -1318,7 +1320,8 @@  static void icc_eoir_write(CPUARMState *env, const ARMCPRegInfo *ri,
     trace_gicv3_icc_eoir_write(is_eoir0 ? 0 : 1,
                                gicv3_redist_affid(cs), value);
 
-    if (irq >= cs->gic->num_irq) {
+    if ((irq >= cs->gic->num_irq) &&
+        !(cs->gic->lpi_enable && (irq >= GICV3_LPI_INTID_START))) {
         /* This handles two cases:
          * 1. If software writes the ID of a spurious interrupt [ie 1020-1023]
          * to the GICC_EOIR, the GIC ignores that write.
diff --git a/hw/intc/arm_gicv3_its.c b/hw/intc/arm_gicv3_its.c
index bf92a8d0f1..20f85a3759 100644
--- a/hw/intc/arm_gicv3_its.c
+++ b/hw/intc/arm_gicv3_its.c
@@ -226,6 +226,7 @@  static MemTxResult process_its_cmd(GICv3ITSState *s, uint64_t value,
     bool ite_valid = false;
     uint64_t cte = 0;
     bool cte_valid = false;
+    uint64_t rdbase;
     IteEntry ite;
 
     if (cmd == NONE) {
@@ -287,6 +288,18 @@  static MemTxResult process_its_cmd(GICv3ITSState *s, uint64_t value,
          * Current implementation only supports rdbase == procnum
          * Hence rdbase physical address is ignored
          */
+        rdbase = (cte & GITS_CTE_RDBASE_PROCNUM_MASK) >> 1U;
+
+        if (rdbase > s->gicv3->num_cpu) {
+            return res;
+        }
+
+        if ((cmd == CLEAR) || (cmd == DISCARD)) {
+            gicv3_redist_process_lpi(&s->gicv3->cpu[rdbase], pIntid, 0);
+        } else {
+            gicv3_redist_process_lpi(&s->gicv3->cpu[rdbase], pIntid, 1);
+        }
+
         if (cmd == DISCARD) {
             memset(&ite, 0 , sizeof(ite));
             /* remove mapping from interrupt translation table */
@@ -605,6 +618,7 @@  static void process_cmdq(GICv3ITSState *s)
     AddressSpace *as = &s->gicv3->dma_as;
     MemTxResult res = MEMTX_OK;
     uint8_t cmd;
+    int i;
 
     if (!(s->ctlr & ITS_CTLR_ENABLED)) {
         return;
@@ -666,6 +680,15 @@  static void process_cmdq(GICv3ITSState *s)
             break;
         case GITS_CMD_INV:
         case GITS_CMD_INVALL:
+            /*
+             * Current implementation doesn't cache any ITS tables,
+             * but the calculated lpi priority information. We only
+             * need to trigger lpi priority re-calculation to be in
+             * sync with LPI config table or pending table changes.
+             */
+            for (i = 0; i < s->gicv3->num_cpu; i++) {
+                gicv3_redist_update_lpi(&s->gicv3->cpu[i]);
+            }
             break;
         default:
             break;
diff --git a/hw/intc/arm_gicv3_redist.c b/hw/intc/arm_gicv3_redist.c
index fc3d95dcc6..061b4e1ad2 100644
--- a/hw/intc/arm_gicv3_redist.c
+++ b/hw/intc/arm_gicv3_redist.c
@@ -254,6 +254,9 @@  static MemTxResult gicr_writel(GICv3CPUState *cs, hwaddr offset,
         if (cs->gicr_typer & GICR_TYPER_PLPIS) {
             if (value & GICR_CTLR_ENABLE_LPIS) {
                 cs->gicr_ctlr |= GICR_CTLR_ENABLE_LPIS;
+                /* Check for any pending interr in pending table */
+                gicv3_redist_update_lpi(cs);
+                gicv3_redist_update(cs);
             } else {
                 cs->gicr_ctlr &= ~GICR_CTLR_ENABLE_LPIS;
             }
@@ -532,6 +535,145 @@  MemTxResult gicv3_redist_write(void *opaque, hwaddr offset, uint64_t data,
     return r;
 }
 
+static void gicv3_redist_check_lpi_priority(GICv3CPUState *cs, int irq)
+{
+    AddressSpace *as = &cs->gic->dma_as;
+    uint64_t lpict_baddr;
+    uint8_t lpite;
+    uint8_t prio;
+
+    lpict_baddr = cs->gicr_propbaser & R_GICR_PROPBASER_PHYADDR_MASK;
+
+    address_space_read(as, lpict_baddr + ((irq - GICV3_LPI_INTID_START) *
+                       sizeof(lpite)), MEMTXATTRS_UNSPECIFIED, &lpite,
+                       sizeof(lpite));
+
+    if (!(lpite & LPI_CTE_ENABLED)) {
+        return;
+    }
+
+    if (cs->gic->gicd_ctlr & GICD_CTLR_DS) {
+        prio = lpite & LPI_PRIORITY_MASK;
+    } else {
+        prio = ((lpite & LPI_PRIORITY_MASK) >> 1) | 0x80;
+    }
+
+    if ((prio < cs->hpplpi.prio) ||
+        ((prio == cs->hpplpi.prio) && (irq <= cs->hpplpi.irq))) {
+        cs->hpplpi.irq = irq;
+        cs->hpplpi.prio = prio;
+        /* LPIs are always non-secure Grp1 interrupts */
+        cs->hpplpi.grp = GICV3_G1NS;
+    }
+}
+
+void gicv3_redist_update_lpi(GICv3CPUState *cs)
+{
+    /*
+     * This function scans the LPI pending table and for each pending
+     * LPI, reads the corresponding entry from LPI configuration table
+     * to extract the priority info and determine if the current LPI
+     * priority is lower than the last computed high priority lpi interrupt.
+     * If yes, replace current LPI as the new high priority lpi interrupt.
+     */
+    AddressSpace *as = &cs->gic->dma_as;
+    uint64_t lpipt_baddr;
+    uint32_t pendt_size = 0;
+    uint8_t pend;
+    int i;
+    uint64_t idbits;
+
+    idbits = MIN(FIELD_EX64(cs->gicr_propbaser, GICR_PROPBASER, IDBITS),
+                 GICD_TYPER_IDBITS);
+
+    if (!(cs->gicr_ctlr & GICR_CTLR_ENABLE_LPIS) || !cs->gicr_propbaser ||
+        !cs->gicr_pendbaser || (idbits < GICR_PROPBASER_IDBITS_THRESHOLD)) {
+        return;
+    }
+
+    cs->hpplpi.prio = 0xff;
+
+    lpipt_baddr = cs->gicr_pendbaser & R_GICR_PENDBASER_PHYADDR_MASK;
+
+    /* Determine the highest priority pending interrupt among LPIs */
+    pendt_size = (1ULL << (idbits + 1));
+
+    for (i = 0; i < pendt_size / 8; i++) {
+        address_space_read(as, lpipt_baddr +
+                (((GICV3_LPI_INTID_START + i) / 8) * sizeof(pend)),
+                MEMTXATTRS_UNSPECIFIED, &pend, sizeof(pend));
+
+        if (!((1 << ((GICV3_LPI_INTID_START + i) % 8)) & pend)) {
+            continue;
+        }
+
+        gicv3_redist_check_lpi_priority(cs, GICV3_LPI_INTID_START + i);
+    }
+}
+
+void gicv3_redist_lpi_pending(GICv3CPUState *cs, int irq, int level)
+{
+    /*
+     * This function updates the pending bit in lpi pending table for
+     * the irq being activated or deactivated.
+     */
+    AddressSpace *as = &cs->gic->dma_as;
+    uint64_t lpipt_baddr;
+    bool ispend = false;
+    uint8_t pend;
+
+    /*
+     * get the bit value corresponding to this irq in the
+     * lpi pending table
+     */
+    lpipt_baddr = cs->gicr_pendbaser & R_GICR_PENDBASER_PHYADDR_MASK;
+
+    address_space_read(as, lpipt_baddr + ((irq / 8) * sizeof(pend)),
+                       MEMTXATTRS_UNSPECIFIED, &pend, sizeof(pend));
+
+    ispend = extract32(pend, irq % 8, 1);
+
+    /* no change in the value of pending bit, return */
+    if (ispend == level) {
+        return;
+    }
+    pend = deposit32(pend, irq % 8, 1, level ? 1 : 0);
+
+    address_space_write(as, lpipt_baddr + ((irq / 8) * sizeof(pend)),
+                        MEMTXATTRS_UNSPECIFIED, &pend, sizeof(pend));
+
+    /*
+     * check if this LPI is better than the current hpplpi, if yes
+     * just set hpplpi.prio and .irq without doing a full rescan
+     */
+    if (level) {
+        gicv3_redist_check_lpi_priority(cs, irq);
+    } else {
+        if (irq == cs->hpplpi.irq) {
+            gicv3_redist_update_lpi(cs);
+        }
+    }
+}
+
+void gicv3_redist_process_lpi(GICv3CPUState *cs, int irq, int level)
+{
+    uint64_t idbits;
+
+    idbits = MIN(FIELD_EX64(cs->gicr_propbaser, GICR_PROPBASER, IDBITS),
+                 GICD_TYPER_IDBITS);
+
+    if (!(cs->gicr_ctlr & GICR_CTLR_ENABLE_LPIS) || !cs->gicr_propbaser ||
+         !cs->gicr_pendbaser || (idbits < GICR_PROPBASER_IDBITS_THRESHOLD) ||
+         (irq > (1ULL << (idbits + 1)))) {
+        return;
+    }
+
+    /* set/clear the pending bit for this irq */
+    gicv3_redist_lpi_pending(cs, irq, level);
+
+    gicv3_redist_update(cs);
+}
+
 void gicv3_redist_set_irq(GICv3CPUState *cs, int irq, int level)
 {
     /* Update redistributor state for a change in an external PPI input line */
diff --git a/hw/intc/gicv3_internal.h b/hw/intc/gicv3_internal.h
index b27e25dea3..fbd99a576c 100644
--- a/hw/intc/gicv3_internal.h
+++ b/hw/intc/gicv3_internal.h
@@ -140,6 +140,8 @@  FIELD(GICR_PENDBASER, PHYADDR, 16, 36)
 FIELD(GICR_PENDBASER, OUTERCACHE, 56, 3)
 FIELD(GICR_PENDBASER, PTZ, 62, 1)
 
+#define GICR_PROPBASER_IDBITS_THRESHOLD          0xd
+
 #define ICC_CTLR_EL1_CBPR           (1U << 0)
 #define ICC_CTLR_EL1_EOIMODE        (1U << 1)
 #define ICC_CTLR_EL1_PMHE           (1U << 6)
@@ -305,6 +307,9 @@  FIELD(GITS_TYPER, CIL, 36, 1)
 
 #define L1TABLE_ENTRY_SIZE         8
 
+#define LPI_CTE_ENABLED          TABLE_ENTRY_VALID_MASK
+#define LPI_PRIORITY_MASK         0xfc
+
 #define GITS_CMDQ_ENTRY_SIZE               32
 #define NUM_BYTES_IN_DW                     8
 
@@ -398,6 +403,7 @@  FIELD(MAPC, RDBASE, 16, 32)
  * Valid = 1 bit,RDBase = 36 bits(considering max RDBASE)
  */
 #define GITS_CTE_SIZE                 (0x8ULL)
+#define GITS_CTE_RDBASE_PROCNUM_MASK  MAKE_64BIT_MASK(1, RDBASE_PROCNUM_LENGTH)
 
 /* Special interrupt IDs */
 #define INTID_SECURE 1020
@@ -456,6 +462,9 @@  MemTxResult gicv3_redist_write(void *opaque, hwaddr offset, uint64_t data,
                                unsigned size, MemTxAttrs attrs);
 void gicv3_dist_set_irq(GICv3State *s, int irq, int level);
 void gicv3_redist_set_irq(GICv3CPUState *cs, int irq, int level);
+void gicv3_redist_process_lpi(GICv3CPUState *cs, int irq, int level);
+void gicv3_redist_lpi_pending(GICv3CPUState *cs, int irq, int level);
+void gicv3_redist_update_lpi(GICv3CPUState *cs);
 void gicv3_redist_send_sgi(GICv3CPUState *cs, int grp, int irq, bool ns);
 void gicv3_init_cpuif(GICv3State *s);
 
diff --git a/include/hw/intc/arm_gicv3_common.h b/include/hw/intc/arm_gicv3_common.h
index c1348cc60a..aa4f0d6770 100644
--- a/include/hw/intc/arm_gicv3_common.h
+++ b/include/hw/intc/arm_gicv3_common.h
@@ -204,6 +204,13 @@  struct GICv3CPUState {
      * real state above; it doesn't need to be migrated.
      */
     PendingIrq hppi;
+
+    /*
+     * Cached information recalculated from LPI tables
+     * in guest memory
+     */
+    PendingIrq hpplpi;
+
     /* This is temporary working state, to avoid a malloc in gicv3_update() */
     bool seenbetter;
 };