ARM: GICv3 ITS: allocate device and collection table

Each ITS maps a pair of a DeviceID (for instance derived from a PCI
b/d/f triplet) and an EventID (the MSI payload or interrupt ID) to a
pair of LPI number and collection ID, which points to the target CPU.
This mapping is stored in the device and collection tables, which software
has to provide for the ITS to use.
Allocate the required memory and hand it over to the ITS.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Reviewed-by: Julien Grall <julien.grall@arm.com>

diff --git a/xen/arch/arm/gic-v3-its.c b/xen/arch/arm/gic-v3-its.c
index 02988662606556f18222f0ebfafe4ef53e637841..27b41adc2fefc5f394305d7c2e252f18de9b6c63 100644 (file)
--- a/xen/arch/arm/gic-v3-its.c
+++ b/xen/arch/arm/gic-v3-its.c
@@ -35,9 +35,109 @@ bool gicv3_its_host_has_its(void)
     return !list_empty(&host_its_list);
 }
 
+#define BASER_ATTR_MASK                                           \
+        ((0x3UL << GITS_BASER_SHAREABILITY_SHIFT)               | \
+         (0x7UL << GITS_BASER_OUTER_CACHEABILITY_SHIFT)         | \
+         (0x7UL << GITS_BASER_INNER_CACHEABILITY_SHIFT))
+#define BASER_RO_MASK   (GENMASK(58, 56) | GENMASK(52, 48))
+
+/* Check that the physical address can be encoded in the PROPBASER register. */
+static bool check_baser_phys_addr(void *vaddr, unsigned int page_bits)
+{
+    paddr_t paddr = virt_to_maddr(vaddr);
+
+    return (!(paddr & ~GENMASK(page_bits < 16 ? 47 : 51, page_bits)));
+}
+
+static uint64_t encode_baser_phys_addr(paddr_t addr, unsigned int page_bits)
+{
+    uint64_t ret = addr & GENMASK(47, page_bits);
+
+    if ( page_bits < 16 )
+        return ret;
+
+    /* For 64K pages address bits 51-48 are encoded in bits 15-12. */
+    return ret | ((addr & GENMASK(51, 48)) >> (48 - 12));
+}
+
+/* The ITS BASE registers work with page sizes of 4K, 16K or 64K. */
+#define BASER_PAGE_BITS(sz) ((sz) * 2 + 12)
+
+static int its_map_baser(void __iomem *basereg, uint64_t regc,
+                         unsigned int nr_items)
+{
+    uint64_t attr, reg;
+    unsigned int entry_size = GITS_BASER_ENTRY_SIZE(regc);
+    unsigned int pagesz = 2;    /* try 64K pages first, then go down. */
+    unsigned int table_size;
+    void *buffer;
+
+    attr  = GIC_BASER_InnerShareable << GITS_BASER_SHAREABILITY_SHIFT;
+    attr |= GIC_BASER_CACHE_SameAsInner << GITS_BASER_OUTER_CACHEABILITY_SHIFT;
+    attr |= GIC_BASER_CACHE_RaWaWb << GITS_BASER_INNER_CACHEABILITY_SHIFT;
+
+    /*
+     * Setup the BASE register with the attributes that we like. Then read
+     * it back and see what sticks (page size, cacheability and shareability
+     * attributes), retrying if necessary.
+     */
+retry:
+    table_size = ROUNDUP(nr_items * entry_size, BIT(BASER_PAGE_BITS(pagesz)));
+    /* The BASE registers support at most 256 pages. */
+    table_size = min(table_size, 256U << BASER_PAGE_BITS(pagesz));
+
+    buffer = _xzalloc(table_size, BIT(BASER_PAGE_BITS(pagesz)));
+    if ( !buffer )
+        return -ENOMEM;
+
+    if ( !check_baser_phys_addr(buffer, BASER_PAGE_BITS(pagesz)) )
+    {
+        xfree(buffer);
+        return -ERANGE;
+    }
+
+    reg  = attr;
+    reg |= (pagesz << GITS_BASER_PAGE_SIZE_SHIFT);
+    reg |= (table_size >> BASER_PAGE_BITS(pagesz)) - 1;
+    reg |= regc & BASER_RO_MASK;
+    reg |= GITS_VALID_BIT;
+    reg |= encode_baser_phys_addr(virt_to_maddr(buffer),
+                                  BASER_PAGE_BITS(pagesz));
+
+    writeq_relaxed(reg, basereg);
+    regc = readq_relaxed(basereg);
+
+    /* The host didn't like our attributes, just use what it returned. */
+    if ( (regc & BASER_ATTR_MASK) != attr )
+    {
+        /* If we can't map it shareable, drop cacheability as well. */
+        if ( (regc & GITS_BASER_SHAREABILITY_MASK) == GIC_BASER_NonShareable )
+        {
+            regc &= ~GITS_BASER_INNER_CACHEABILITY_MASK;
+            writeq_relaxed(regc, basereg);
+        }
+        attr = regc & BASER_ATTR_MASK;
+    }
+    if ( (regc & GITS_BASER_INNER_CACHEABILITY_MASK) <= GIC_BASER_CACHE_nC )
+        clean_and_invalidate_dcache_va_range(buffer, table_size);
+
+    /* If the host accepted our page size, we are done. */
+    if ( ((regc >> GITS_BASER_PAGE_SIZE_SHIFT) & 0x3UL) == pagesz )
+        return 0;
+
+    xfree(buffer);
+
+    if ( pagesz-- > 0 )
+        goto retry;
+
+    /* None of the page sizes was accepted, give up */
+    return -EINVAL;
+}
+
 static int gicv3_its_init_single_its(struct host_its *hw_its)
 {
     uint64_t reg;
+    int i, ret;
 
     hw_its->its_base = ioremap_nocache(hw_its->addr, hw_its->size);
     if ( !hw_its->its_base )
@@ -48,6 +148,38 @@ static int gicv3_its_init_single_its(struct host_its *hw_its)
     hw_its->evid_bits = GITS_TYPER_EVENT_ID_BITS(reg);
     hw_its->itte_size = GITS_TYPER_ITT_SIZE(reg);
 
+    for ( i = 0; i < GITS_BASER_NR_REGS; i++ )
+    {
+        void __iomem *basereg = hw_its->its_base + GITS_BASER0 + i * 8;
+        unsigned int type;
+
+        reg = readq_relaxed(basereg);
+        type = (reg & GITS_BASER_TYPE_MASK) >> GITS_BASER_TYPE_SHIFT;
+        switch ( type )
+        {
+        case GITS_BASER_TYPE_NONE:
+            continue;
+        case GITS_BASER_TYPE_DEVICE:
+            ret = its_map_baser(basereg, reg, BIT(hw_its->devid_bits));
+            if ( ret )
+                return ret;
+            break;
+        case GITS_BASER_TYPE_COLLECTION:
+            ret = its_map_baser(basereg, reg, num_possible_cpus());
+            if ( ret )
+                return ret;
+            break;
+        /* In case this is a GICv4, provide a (dummy) vPE table as well. */
+        case GITS_BASER_TYPE_VCPU:
+            ret = its_map_baser(basereg, reg, 1);
+            if ( ret )
+                return ret;
+            break;
+        default:
+            continue;
+        }
+    }
+
     return 0;
 }
 

diff --git a/xen/include/asm-arm/gic_v3_its.h b/xen/include/asm-arm/gic_v3_its.h
index d1382c11a0dee7208bfe948d7d3153ab62d9e277..c0256223f1d32e42ed0a9eb2192c92a7f9c55dbc 100644 (file)
--- a/xen/include/asm-arm/gic_v3_its.h
+++ b/xen/include/asm-arm/gic_v3_its.h
@@ -37,6 +37,11 @@
 #define GITS_BASER7                     0x138
 
 /* Register bits */
+#define GITS_VALID_BIT                  BIT(63)
+
+#define GITS_CTLR_QUIESCENT             BIT(31)
+#define GITS_CTLR_ENABLE                BIT(0)
+
 #define GITS_TYPER_DEVIDS_SHIFT         13
 #define GITS_TYPER_DEVIDS_MASK          (0x1fUL << GITS_TYPER_DEVIDS_SHIFT)
 #define GITS_TYPER_DEVICE_ID_BITS(r)    (((r & GITS_TYPER_DEVIDS_MASK) >> \
@@ -52,6 +57,28 @@
 #define GITS_TYPER_ITT_SIZE(r)          ((((r) & GITS_TYPER_ITT_SIZE_MASK) >> \
                                                  GITS_TYPER_ITT_SIZE_SHIFT) + 1)
 
+#define GITS_BASER_INDIRECT             BIT(62)
+#define GITS_BASER_INNER_CACHEABILITY_SHIFT        59
+#define GITS_BASER_TYPE_SHIFT           56
+#define GITS_BASER_TYPE_MASK            (7ULL << GITS_BASER_TYPE_SHIFT)
+#define GITS_BASER_OUTER_CACHEABILITY_SHIFT        53
+#define GITS_BASER_TYPE_NONE            0UL
+#define GITS_BASER_TYPE_DEVICE          1UL
+#define GITS_BASER_TYPE_VCPU            2UL
+#define GITS_BASER_TYPE_CPU             3UL
+#define GITS_BASER_TYPE_COLLECTION      4UL
+#define GITS_BASER_TYPE_RESERVED5       5UL
+#define GITS_BASER_TYPE_RESERVED6       6UL
+#define GITS_BASER_TYPE_RESERVED7       7UL
+#define GITS_BASER_ENTRY_SIZE_SHIFT     48
+#define GITS_BASER_ENTRY_SIZE(reg)                                       \
+                        (((reg >> GITS_BASER_ENTRY_SIZE_SHIFT) & 0x1f) + 1)
+#define GITS_BASER_SHAREABILITY_SHIFT   10
+#define GITS_BASER_PAGE_SIZE_SHIFT      8
+#define GITS_BASER_SHAREABILITY_MASK   (0x3ULL << GITS_BASER_SHAREABILITY_SHIFT)
+#define GITS_BASER_OUTER_CACHEABILITY_MASK   (0x7ULL << GITS_BASER_OUTER_CACHEABILITY_SHIFT)
+#define GITS_BASER_INNER_CACHEABILITY_MASK   (0x7ULL << GITS_BASER_INNER_CACHEABILITY_SHIFT)
+
 #include <xen/device_tree.h>
 
 /* data structure for each hardware ITS */