To be able to easily send commands to the ITS, create the respective
wrapper functions, which take care of the ring buffer.
The first two commands we implement provide methods to map a collection
to a redistributor (aka host core) and to flush the command queue (SYNC).
Start using these commands for mapping one collection to each host CPU.
As an ITS might choose between *two* ways of addressing a redistributor,
we store both the MMIO base address as well as the processor number in
a per-CPU variable to give each ITS what it wants.
Signed-off-by: Andre Przywara <andre.przyw...@arm.com>
---
xen/arch/arm/gic-v3-its.c | 199 ++++++++++++++++++++++++++++++++++++++
xen/arch/arm/gic-v3-lpi.c | 28 ++++++
xen/arch/arm/gic-v3.c | 26 ++++-
xen/include/asm-arm/gic_v3_defs.h | 2 +
xen/include/asm-arm/gic_v3_its.h | 37 +++++++
5 files changed, 291 insertions(+), 1 deletion(-)
diff --git a/xen/arch/arm/gic-v3-its.c b/xen/arch/arm/gic-v3-its.c
index d8e978a..1ecd63b 100644
--- a/xen/arch/arm/gic-v3-its.c
+++ b/xen/arch/arm/gic-v3-its.c
@@ -19,11 +19,14 @@
*/
#include <xen/lib.h>
+#include <xen/delay.h>
#include <xen/mm.h>
#include <xen/sizes.h>
+#include <asm/gic.h>
#include <asm/gic_v3_defs.h>
#include <asm/gic_v3_its.h>
#include <asm/io.h>
+#include <asm/page.h>
#define ITS_CMD_QUEUE_SZ SZ_1M
@@ -38,6 +41,160 @@ bool gicv3_its_host_has_its(void)
return !list_empty(&host_its_list);
}
+#define BUFPTR_MASK GENMASK_ULL(19, 5)
+static int its_send_command(struct host_its *hw_its, const void *its_cmd)
+{
+ /*
+ * The command queue should actually never become full, if it does anyway
+ * and this situation is not resolved quickly, this points to a much
+ * bigger problem, probably an hardware error.
+ * So to cover the one-off case where we actually hit a full command
+ * queue, we introduce a small grace period to not give up too quickly.
+ * Given the usual multi-hundred MHz frequency the ITS usually runs with,
+ * one millisecond (for a single command) seem to be more than enough.
+ * But this value is rather arbitrarily chosen based on theoretical
+ * considerations.
+ */
+ s_time_t deadline = NOW() + MILLISECS(1);
+ uint64_t readp, writep;
+ int ret = -EBUSY;
+
+ /* No ITS commands from an interrupt handler (at the moment). */
+ ASSERT(!in_irq());
+
+ spin_lock(&hw_its->cmd_lock);
+
+ do {
+ readp = readq_relaxed(hw_its->its_base + GITS_CREADR) & BUFPTR_MASK;
+ writep = readq_relaxed(hw_its->its_base + GITS_CWRITER) & BUFPTR_MASK;
+
+ if ( ((writep + ITS_CMD_SIZE) % ITS_CMD_QUEUE_SZ) != readp )
+ {
+ ret = 0;
+ break;
+ }
+
+ /*
+ * If the command queue is full, wait for a bit in the hope it drains
+ * before giving up.
+ */
+ spin_unlock(&hw_its->cmd_lock);
+ cpu_relax();
+ udelay(1);
+ spin_lock(&hw_its->cmd_lock);
+ } while ( NOW() <= deadline );
+
+ if ( ret )
+ {
+ spin_unlock(&hw_its->cmd_lock);
+ if ( printk_ratelimit() )
+ printk(XENLOG_WARNING "host ITS: command queue full.\n");
+ return ret;
+ }
+
+ memcpy(hw_its->cmd_buf + writep, its_cmd, ITS_CMD_SIZE);
+ if ( hw_its->flags & HOST_ITS_FLUSH_CMD_QUEUE )
+ clean_and_invalidate_dcache_va_range(hw_its->cmd_buf + writep,
+ ITS_CMD_SIZE);
+ else
+ dsb(ishst);
+
+ writep = (writep + ITS_CMD_SIZE) % ITS_CMD_QUEUE_SZ;
+ writeq_relaxed(writep & BUFPTR_MASK, hw_its->its_base + GITS_CWRITER);
+
+ spin_unlock(&hw_its->cmd_lock);
+
+ return 0;
+}
+
+/* Wait for an ITS to finish processing all commands. */
+static int gicv3_its_wait_commands(struct host_its *hw_its)
+{
+ /*
+ * As there could be quite a number of commands in a queue, we will
+ * wait a bit longer than the one millisecond for a single command above.
+ * Again this value is based on theoretical considerations, actually the
+ * command queue should drain much faster.
+ */
+ s_time_t deadline = NOW() + MILLISECS(100);
+ uint64_t readp, writep;
+
+ do {
+ spin_lock(&hw_its->cmd_lock);
+ readp = readq_relaxed(hw_its->its_base + GITS_CREADR) & BUFPTR_MASK;
+ writep = readq_relaxed(hw_its->its_base + GITS_CWRITER) & BUFPTR_MASK;
+ spin_unlock(&hw_its->cmd_lock);
+
+ if ( readp == writep )
+ return 0;
+
+ cpu_relax();
+ udelay(1);
+ } while ( NOW() <= deadline );
+
+ return -ETIMEDOUT;
+}
+
+static uint64_t encode_rdbase(struct host_its *hw_its, unsigned int cpu,
+ uint64_t reg)
+{
+ reg &= ~GENMASK_ULL(51, 16);
+
+ reg |= gicv3_get_redist_address(cpu, hw_its->flags & HOST_ITS_USES_PTA);
+
+ return reg;
+}
+
+static int its_send_cmd_sync(struct host_its *its, unsigned int cpu)
+{
+ uint64_t cmd[4];
+
+ cmd[0] = GITS_CMD_SYNC;
+ cmd[1] = 0x00;
+ cmd[2] = encode_rdbase(its, cpu, 0x0);
+ cmd[3] = 0x00;
+
+ return its_send_command(its, cmd);
+}
+
+static int its_send_cmd_mapc(struct host_its *its, uint32_t collection_id,
+ unsigned int cpu)
+{
+ uint64_t cmd[4];
+
+ cmd[0] = GITS_CMD_MAPC;
+ cmd[1] = 0x00;
+ cmd[2] = encode_rdbase(its, cpu, collection_id);
+ cmd[2] |= GITS_VALID_BIT;
+ cmd[3] = 0x00;
+
+ return its_send_command(its, cmd);
+}
+
+/* Set up the (1:1) collection mapping for the given host CPU. */
+int gicv3_its_setup_collection(unsigned int cpu)
+{
+ struct host_its *its;
+ int ret;
+
+ list_for_each_entry(its, &host_its_list, entry)
+ {
+ ret = its_send_cmd_mapc(its, cpu, cpu);
+ if ( ret )
+ return ret;
+
+ ret = its_send_cmd_sync(its, cpu);
+ if ( ret )
+ return ret;
+
+ ret = gicv3_its_wait_commands(its);
+ if ( ret )
+ return ret;
+ }
+
+ return 0;
+}
+
#define BASER_ATTR_MASK \
((0x3UL << GITS_BASER_SHAREABILITY_SHIFT) | \
(0x7UL << GITS_BASER_OUTER_CACHEABILITY_SHIFT) | \
@@ -182,6 +339,41 @@ retry:
return -EINVAL;
}
+/*
+ * Before an ITS gets initialized, it should be in a quiescent state, where
+ * all outstanding commands and transactions have finished.
+ * So if the ITS is already enabled, turn it off and wait for all outstanding
+ * operations to get processed by polling the QUIESCENT bit.
+ */
+static int gicv3_disable_its(struct host_its *hw_its)
+{
+ uint32_t reg;
+ /*
+ * As we also need to wait for the command queue to drain, we use the same
+ * (arbitrary) timeout value as above for gicv3_its_wait_commands().
+ */
+ s_time_t deadline = NOW() + MILLISECS(100);
+
+ reg = readl_relaxed(hw_its->its_base + GITS_CTLR);
+ if ( !(reg & GITS_CTLR_ENABLE) && (reg & GITS_CTLR_QUIESCENT) )
+ return 0;
+
+ writel_relaxed(reg & ~GITS_CTLR_ENABLE, hw_its->its_base + GITS_CTLR);
+
+ do {
+ reg = readl_relaxed(hw_its->its_base + GITS_CTLR);
+ if ( reg & GITS_CTLR_QUIESCENT )
+ return 0;
+
+ cpu_relax();
+ udelay(1);
+ } while ( NOW() <= deadline );
+
+ printk(XENLOG_ERR "ITS@%lx not quiescent.\n", hw_its->addr);
+
+ return -ETIMEDOUT;
+}
+
static int gicv3_its_init_single_its(struct host_its *hw_its)
{
uint64_t reg;
@@ -191,10 +383,17 @@ static int gicv3_its_init_single_its(struct host_its
*hw_its)
if ( !hw_its->its_base )
return -ENOMEM;
+ ret = gicv3_disable_its(hw_its);
+ if ( ret )
+ return ret;
+
reg = readq_relaxed(hw_its->its_base + GITS_TYPER);
hw_its->devid_bits = GITS_TYPER_DEVICE_ID_BITS(reg);
hw_its->evid_bits = GITS_TYPER_EVENT_ID_BITS(reg);
hw_its->itte_size = GITS_TYPER_ITT_SIZE(reg);
+ if ( reg & GITS_TYPER_PTA )
+ hw_its->flags |= HOST_ITS_USES_PTA;
+ spin_lock_init(&hw_its->cmd_lock);
for ( i = 0; i < GITS_BASER_NR_REGS; i++ )
{
diff --git a/xen/arch/arm/gic-v3-lpi.c b/xen/arch/arm/gic-v3-lpi.c
index 7f99ec6..9d3df7f 100644
--- a/xen/arch/arm/gic-v3-lpi.c
+++ b/xen/arch/arm/gic-v3-lpi.c
@@ -45,6 +45,8 @@ static struct {
} lpi_data;
struct lpi_redist_data {
+ paddr_t redist_addr;
+ unsigned int redist_id;
void *pending_table;
};
@@ -52,6 +54,32 @@ static DEFINE_PER_CPU(struct lpi_redist_data, lpi_redist);
#define MAX_NR_HOST_LPIS (lpi_data.max_host_lpi_ids - LPI_OFFSET)
+/*
+ * An ITS can refer to redistributors in two ways: either by an ID (possibly
+ * the CPU number) or by its MMIO address. This is a hardware implementation
+ * choice, so we have to cope with both approaches. The GICv3 code calculates
+ * both values and calls this function to let the ITS store them when it's
+ * later required to provide them. This is done in a per-CPU variable.
+ */
+void gicv3_set_redist_address(paddr_t address, unsigned int redist_id)
+{
+ this_cpu(lpi_redist).redist_addr = address;
+ this_cpu(lpi_redist).redist_id = redist_id;
+}
+
+/*
+ * Returns a redistributor's ID (either as an address or as an ID).
+ * This must be (and is) called only after it has been setup by the above
+ * function.
+ */
+uint64_t gicv3_get_redist_address(unsigned int cpu, bool use_pta)
+{
+ if ( use_pta )
+ return per_cpu(lpi_redist, cpu).redist_addr & GENMASK_ULL(51, 16);
+ else
+ return per_cpu(lpi_redist, cpu).redist_id << 16;
+}
+
static int gicv3_lpi_allocate_pendtable(uint64_t *reg)
{
uint64_t val;
diff --git a/xen/arch/arm/gic-v3.c b/xen/arch/arm/gic-v3.c
index 54d2235..a559e5e 100644
--- a/xen/arch/arm/gic-v3.c
+++ b/xen/arch/arm/gic-v3.c
@@ -665,8 +665,25 @@ static int __init gicv3_populate_rdist(void)
if ( typer & GICR_TYPER_PLPIS )
{
+ paddr_t rdist_addr;
+ unsigned int procnum;
int ret;
+ /*
+ * The ITS refers to redistributors either by their
physical
+ * address or by their ID. Which one to use is an ITS
+ * choice. So determine those two values here (which we
+ * can do only here in GICv3 code) and tell the
+ * ITS code about it, so it can use them later to be able
+ * to address those redistributors accordingly.
+ */
+ rdist_addr = gicv3.rdist_regions[i].base;
+ rdist_addr += ptr - gicv3.rdist_regions[i].map_base;
+ procnum = (typer & GICR_TYPER_PROC_NUM_MASK);
+ procnum >>= GICR_TYPER_PROC_NUM_SHIFT;
+
+ gicv3_set_redist_address(rdist_addr, procnum);
+
ret = gicv3_lpi_init_rdist(ptr);
if ( ret && ret != -ENODEV )
{
@@ -704,7 +721,7 @@ static int __init gicv3_populate_rdist(void)
static int gicv3_cpu_init(void)
{
- int i;
+ int i, ret;
uint32_t priority;
/* Register ourselves with the rest of the world */
@@ -714,6 +731,13 @@ static int gicv3_cpu_init(void)
if ( gicv3_enable_redist() )
return -ENODEV;
+ if ( gicv3_its_host_has_its() )
+ {
+ ret = gicv3_its_setup_collection(smp_processor_id());
+ if ( ret )
+ return ret;
+ }
+
/* Set priority on PPI and SGI interrupts */
priority = (GIC_PRI_IPI << 24 | GIC_PRI_IPI << 16 | GIC_PRI_IPI << 8 |
GIC_PRI_IPI);
diff --git a/xen/include/asm-arm/gic_v3_defs.h
b/xen/include/asm-arm/gic_v3_defs.h
index 6f02bb0..b7e5a47 100644
--- a/xen/include/asm-arm/gic_v3_defs.h
+++ b/xen/include/asm-arm/gic_v3_defs.h
@@ -103,6 +103,8 @@
#define GICR_TYPER_PLPIS (1U << 0)
#define GICR_TYPER_VLPIS (1U << 1)
#define GICR_TYPER_LAST (1U << 4)
+#define GICR_TYPER_PROC_NUM_SHIFT 8
+#define GICR_TYPER_PROC_NUM_MASK (0xffff << GICR_TYPER_PROC_NUM_SHIFT)
/* For specifying the inner cacheability type only */
#define GIC_BASER_CACHE_nCnB 0ULL
diff --git a/xen/include/asm-arm/gic_v3_its.h b/xen/include/asm-arm/gic_v3_its.h
index a68ccf3..7d7ec32 100644
--- a/xen/include/asm-arm/gic_v3_its.h
+++ b/xen/include/asm-arm/gic_v3_its.h
@@ -42,6 +42,7 @@
#define GITS_CTLR_QUIESCENT BIT(31)
#define GITS_CTLR_ENABLE BIT(0)
+#define GITS_TYPER_PTA BIT_ULL(19)
#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) >> \
@@ -86,9 +87,26 @@
#define GITS_CBASER_SIZE_MASK 0xff
+/* ITS command definitions */
+#define ITS_CMD_SIZE 32
+
+#define GITS_CMD_MOVI 0x01
+#define GITS_CMD_INT 0x03
+#define GITS_CMD_CLEAR 0x04
+#define GITS_CMD_SYNC 0x05
+#define GITS_CMD_MAPD 0x08
+#define GITS_CMD_MAPC 0x09
+#define GITS_CMD_MAPTI 0x0a
+#define GITS_CMD_MAPI 0x0b
+#define GITS_CMD_INV 0x0c
+#define GITS_CMD_INVALL 0x0d
+#define GITS_CMD_MOVALL 0x0e
+#define GITS_CMD_DISCARD 0x0f
+
#include <xen/device_tree.h>
#define HOST_ITS_FLUSH_CMD_QUEUE (1U << 0)
+#define HOST_ITS_USES_PTA (1U << 1)
/* data structure for each hardware ITS */
struct host_its {
@@ -100,6 +118,7 @@ struct host_its {
unsigned int devid_bits;
unsigned int evid_bits;
unsigned int itte_size;
+ spinlock_t cmd_lock;
void *cmd_buf;
unsigned int flags;
};
@@ -120,6 +139,13 @@ int gicv3_lpi_init_rdist(void __iomem * rdist_base);
int gicv3_lpi_init_host_lpis(unsigned int host_lpi_bits);
int gicv3_its_init(void);
+/* Store the physical address and ID for each redistributor as read from DT. */
+void gicv3_set_redist_address(paddr_t address, unsigned int redist_id);
+uint64_t gicv3_get_redist_address(unsigned int cpu, bool use_pta);
+
+/* Map a collection for this host CPU to each host ITS. */
+int gicv3_its_setup_collection(unsigned int cpu);
+
#else
static LIST_HEAD(host_its_list);
@@ -148,6 +174,17 @@ static inline int gicv3_its_init(void)
return 0;
}
+static inline void gicv3_set_redist_address(paddr_t address,
+ unsigned int redist_id)
+{
+}
+
+static inline int gicv3_its_setup_collection(unsigned int cpu)
+{
+ /* We should never get here without an ITS. */
+ BUG();
+}
+
#endif /* CONFIG_HAS_ITS */
#endif
--
2.8.2
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