imsic_init() is introduced to parse device tree node, which has the following
bindings [2], and based on the parsed information update IMSIC configuration
which is stored in imsic_cfg.
The following helpers are introduces for imsic_init() usage:
- imsic_parse_node() parses IMSIC node from DTS
- imsic_get_parent_hartid() returns the hart ( CPU ) ID of the given device
tree node.
This patch is based on the code from [1].
Since Microchip originally developed imsic.{c,h}, an internal discussion with
them led to the decision to use the MIT license.
[1]
https://gitlab.com/xen-project/people/olkur/xen/-/commit/0b1a94f2bc3bb1a81cd26bb75f0bf578f84cb4d4
[2]
https://elixir.bootlin.com/linux/v6.12/source/Documentation/devicetree/bindings/interrupt-controller/riscv,imsics.yaml
Co-developed-by: Romain Caritey <romain.cari...@microchip.com>
Signed-off-by: Oleksii Kurochko <oleksii.kuroc...@gmail.com>
---
Changes in V3:
- Drop year in imsic.h in copyrights.
- Correct identation in imsic_parse_node() and imsic_init()
where for imsic_cfg.base_addr a mask is applied.
- Use unsigned int istead of uint32_t for local variable nr_parent_irqs,
index, nr_handlers in imsic_init().
- Fix a leakage of ealiers successfull allocations in case if imsic_init()
returns with an error.
- Excess blank in printk() message: "%s: unable to parse MMIO regset %d\n".
- Introduce hartid_to_cpuid() and use it in the check:
if ( hardid_to_cpuid(cpuid) >= num_possible_cpus() )
in imsic_init().
- Use "%u" for unsigned int in printk(...).
- Fix for loop condition: nr_mmios -> "j < nr_mmios".
- [imsic_init()] Drop usage of j in nested loop. It is enough to have only
index.
- Change 0x%lx to %#lx for formatting of an address in printk().
- [imsic_init()] Rename local variable cpuid to hartid.
- s/imsic_get_parent_cpuid/imsic_get_parent_hartid, s/cpuid/hartid for an
imsic_get_parent_hartid()'s argument.
- Declare cpus member of struct imsic_mmios as cpumask_t.
- [imsic_init()] Allocate imsic_mmios.cpus by using of alloc_cpumask_var().
- [imsic_init()] Use cpumask_set_cpu() instead of bitmap_set().
- [imsic_parse_node()] add check for correctness of "interrupt-extended"
property.
- [imsic_parse_node()] Use dt_node_name() or dt_full_node_name() instead of
derefence of struct dt_node.
- [imsic_parse_node()] Add cleanup label and update 'rc = XXX; goto cleanup'
instead of 'return rc' as now we have to cleanup dynamically allocated
irq_range
array.
- Add comments above imsic_init() and imsic_parse_node().
- s/xen/arch/riscv/imsic.h/xen/arch/riscv/include/asm/imsic.h in the comment of
imsic.h.
---
Changes in V2:
- Drop years in copyrights.
- s/riscv_of_processor_hartid/dt_processor_cpuid.
- s/imsic_get_parent_hartid/imsic_get_parent_hartid.
Rename argument hartid to cpuid.
Make node argument const.
Return res instead of -EINVAL for the failure case of dt_processor_cpuid().
Drop local variable hart and use cpuid argument instead.
Drop useless return res;
- imsic_parse_node() changes:
- Make node argument const.
- Check the return value of dt_property_read_u32() directly instead of
saving it to rc variable.
- Update tmp usage, use short form "-=".
- Update a check (imsic_cfg.nr_ids >= IMSIC_MAX_ID) to (imsic_cfg.nr_ids >
IMSIC_MAX_ID)
as IMSIC_MAX_ID is changed to maximum valid value, not just the firsr
out-of-range.
- Use `rc` to return value instead of explicitly use -EINVAL.
- Use do {} while() to find number of MMIO register sets.
- Set IMSIC_MAX_ID to 2047 (maximum possible IRQ number).
- imsic_init() changes:
- Use unsigned int in for's expression1.
- s/xfree/XFEE.
- Allocate msi and cpus array dynamically.
- Drop forward declaration before declaration of imsic_get_config() in
asm/imsic.h
as it is not used as parameter type.
- Align declaration of imisic_init with defintion.
- s/harts/cpus in imisic_mmios.
Also, change type from bool harts[NR_CPUS] to unsigned long *cpus.
- Allocate msi member of imsic_config dynamically to save some memory.
- Code style fixes.
- Update the commit message.
---
xen/arch/riscv/Makefile | 1 +
xen/arch/riscv/imsic.c | 354 +++++++++++++++++++++++++++++
xen/arch/riscv/include/asm/imsic.h | 65 ++++++
xen/arch/riscv/include/asm/smp.h | 13 ++
4 files changed, 433 insertions(+)
create mode 100644 xen/arch/riscv/imsic.c
create mode 100644 xen/arch/riscv/include/asm/imsic.h
diff --git a/xen/arch/riscv/Makefile b/xen/arch/riscv/Makefile
index a1c145c506..e2b8aa42c8 100644
--- a/xen/arch/riscv/Makefile
+++ b/xen/arch/riscv/Makefile
@@ -2,6 +2,7 @@ obj-y += aplic.o
obj-y += cpufeature.o
obj-$(CONFIG_EARLY_PRINTK) += early_printk.o
obj-y += entry.o
+obj-y += imsic.o
obj-y += intc.o
obj-y += irq.o
obj-y += mm.o
diff --git a/xen/arch/riscv/imsic.c b/xen/arch/riscv/imsic.c
new file mode 100644
index 0000000000..9f8b492e97
--- /dev/null
+++ b/xen/arch/riscv/imsic.c
@@ -0,0 +1,354 @@
+/* SPDX-License-Identifier: MIT */
+
+/*
+ * xen/arch/riscv/imsic.c
+ *
+ * RISC-V Incoming MSI Controller support
+ *
+ * (c) Microchip Technology Inc.
+ * (c) Vates
+ */
+
+#include <xen/bitops.h>
+#include <xen/const.h>
+#include <xen/cpumask.h>
+#include <xen/device_tree.h>
+#include <xen/errno.h>
+#include <xen/init.h>
+#include <xen/macros.h>
+#include <xen/smp.h>
+#include <xen/spinlock.h>
+#include <xen/xmalloc.h>
+
+#include <asm/imsic.h>
+
+static struct imsic_config imsic_cfg;
+
+/* Callers aren't expected to changed imsic_cfg so return const. */
+const struct imsic_config *imsic_get_config(void)
+{
+ return &imsic_cfg;
+}
+
+static int __init imsic_get_parent_hartid(const struct dt_device_node *node,
+ unsigned int index,
+ unsigned long *hartid)
+{
+ int res;
+ struct dt_phandle_args args;
+
+ res = dt_parse_phandle_with_args(node, "interrupts-extended",
+ "#interrupt-cells", index, &args);
+ if ( !res )
+ res = dt_processor_hartid(args.np->parent, hartid);
+
+ return res;
+}
+
+/*
+ * Parses IMSIC DT node.
+ *
+ * Returns 0 if initialization is successful, a negative value on failure,
+ * or IRQ_M_EXT if the IMSIC node corresponds to a machine-mode IMSIC,
+ * which should be ignored by the hypervisor.
+ */
+static int imsic_parse_node(const struct dt_device_node *node,
+ unsigned int *nr_parent_irqs)
+{
+ int rc;
+ unsigned int tmp;
+ paddr_t base_addr;
+ uint32_t *irq_range;
+
+ *nr_parent_irqs = dt_number_of_irq(node);
+ if ( !*nr_parent_irqs )
+ panic("%s: irq_num can be 0. Check %s node\n", __func__,
+ dt_node_full_name(node));
+
+ irq_range = xzalloc_array(uint32_t, *nr_parent_irqs * 2);
+ if ( !irq_range )
+ panic("%s: irq_range[] allocation failed\n", __func__);
+
+ if ( (rc = dt_property_read_u32_array(node, "interrupts-extended",
+ irq_range, *nr_parent_irqs * 2)) )
+ panic("%s: unable to find interrupt-extended in %s node: %d\n",
+ __func__, dt_node_full_name(node), rc);
+
+ if ( irq_range[1] == IRQ_M_EXT )
+ {
+ /* Machine mode imsic node, ignore it. */
+ rc = IRQ_M_EXT;
+ goto cleanup;
+ }
+
+ /* Check that interrupts-extended property is well-formed. */
+ for ( unsigned int i = 2; i < (*nr_parent_irqs * 2); i += 2 )
+ {
+ if ( irq_range[i + 1] != irq_range[1] )
+ panic("%s: mode[%d] != %d\n", __func__, i + 1, irq_range[1]);
+ }
+
+ if ( !dt_property_read_u32(node, "riscv,guest-index-bits",
+ &imsic_cfg.guest_index_bits) )
+ imsic_cfg.guest_index_bits = 0;
+ tmp = BITS_PER_LONG - IMSIC_MMIO_PAGE_SHIFT;
+ if ( tmp < imsic_cfg.guest_index_bits )
+ {
+ printk(XENLOG_ERR "%s: guest index bits too big\n",
+ dt_node_name(node));
+ rc = -ENOENT;
+ goto cleanup;
+ }
+
+ /* Find number of HART index bits */
+ if ( !dt_property_read_u32(node, "riscv,hart-index-bits",
+ &imsic_cfg.hart_index_bits) )
+ {
+ /* Assume default value */
+ imsic_cfg.hart_index_bits = fls(*nr_parent_irqs);
+ if ( BIT(imsic_cfg.hart_index_bits, UL) < *nr_parent_irqs )
+ imsic_cfg.hart_index_bits++;
+ }
+ tmp -= imsic_cfg.guest_index_bits;
+ if ( tmp < imsic_cfg.hart_index_bits )
+ {
+ printk(XENLOG_ERR "%s: HART index bits too big\n",
+ dt_node_name(node));
+ rc = -ENOENT;
+ goto cleanup;
+ }
+
+ /* Find number of group index bits */
+ if ( !dt_property_read_u32(node, "riscv,group-index-bits",
+ &imsic_cfg.group_index_bits) )
+ imsic_cfg.group_index_bits = 0;
+ tmp -= imsic_cfg.hart_index_bits;
+ if ( tmp < imsic_cfg.group_index_bits )
+ {
+ printk(XENLOG_ERR "%s: group index bits too big\n",
+ dt_node_name(node));
+ rc = -ENOENT;
+ goto cleanup;
+ }
+
+ /* Find first bit position of group index */
+ tmp = IMSIC_MMIO_PAGE_SHIFT * 2;
+ if ( !dt_property_read_u32(node, "riscv,group-index-shift",
+ &imsic_cfg.group_index_shift) )
+ imsic_cfg.group_index_shift = tmp;
+ if ( imsic_cfg.group_index_shift < tmp )
+ {
+ printk(XENLOG_ERR "%s: group index shift too small\n",
+ dt_node_name(node));
+ rc = -ENOENT;
+ goto cleanup;
+ }
+ tmp = imsic_cfg.group_index_bits + imsic_cfg.group_index_shift - 1;
+ if ( tmp >= BITS_PER_LONG )
+ {
+ printk(XENLOG_ERR "%s: group index shift too big\n",
+ dt_node_name(node));
+ rc = -EINVAL;
+ goto cleanup;
+ }
+
+ /* Find number of interrupt identities */
+ if ( !dt_property_read_u32(node, "riscv,num-ids", &imsic_cfg.nr_ids) )
+ {
+ printk(XENLOG_ERR "%s: number of interrupt identities not found\n",
+ node->name);
+ rc = -ENOENT;
+ goto cleanup;
+ }
+
+ if ( (imsic_cfg.nr_ids < IMSIC_MIN_ID) ||
+ (imsic_cfg.nr_ids > IMSIC_MAX_ID) ||
+ ((imsic_cfg.nr_ids & IMSIC_MIN_ID) != IMSIC_MIN_ID) )
+ {
+ printk(XENLOG_ERR "%s: invalid number of interrupt identities\n",
+ node->name);
+ rc = -EINVAL;
+ goto cleanup;
+ }
+
+ /* Compute base address */
+ imsic_cfg.nr_mmios = 0;
+ rc = dt_device_get_address(node, imsic_cfg.nr_mmios, &base_addr, NULL);
+ if ( rc )
+ {
+ printk(XENLOG_ERR "%s: first MMIO resource not found: %d\n",
+ dt_node_name(node), rc);
+ goto cleanup;
+ }
+
+ imsic_cfg.base_addr = base_addr;
+ imsic_cfg.base_addr &= ~(BIT(imsic_cfg.guest_index_bits +
+ imsic_cfg.hart_index_bits +
+ IMSIC_MMIO_PAGE_SHIFT, UL) - 1);
+ imsic_cfg.base_addr &= ~((BIT(imsic_cfg.group_index_bits, UL) - 1) <<
+ imsic_cfg.group_index_shift);
+
+ /* Find number of MMIO register sets */
+ do {
+ imsic_cfg.nr_mmios++;
+ } while ( !dt_device_get_address(node, imsic_cfg.nr_mmios, &base_addr,
NULL) );
+
+ cleanup:
+ xfree(irq_range);
+
+ return rc;
+}
+
+/*
+ * Initialize the imsic_cfg structure based on the IMSIC DT node.
+ *
+ * Returns 0 if initialization is successful, a negative value on failure,
+ * or IRQ_M_EXT if the IMSIC node corresponds to a machine-mode IMSIC,
+ * which should be ignored by the hypervisor.
+ */
+int __init imsic_init(const struct dt_device_node *node)
+{
+ int rc;
+ unsigned long reloff, hartid;
+ unsigned int nr_parent_irqs, index, nr_handlers = 0;
+ paddr_t base_addr;
+ unsigned int nr_mmios;
+
+ /* Parse IMSIC node */
+ rc = imsic_parse_node(node, &nr_parent_irqs);
+ /*
+ * If machine mode imsic node => ignore it.
+ * If rc < 0 => parsing of IMSIC DT node failed.
+ */
+ if ( (rc == IRQ_M_EXT) || rc )
+ return rc;
+
+ nr_mmios = imsic_cfg.nr_mmios;
+
+ /* Allocate MMIO resource array */
+ imsic_cfg.mmios = xzalloc_array(struct imsic_mmios, nr_mmios);
+ if ( !imsic_cfg.mmios )
+ {
+ rc = -ENOMEM;
+ goto imsic_init_err;
+ }
+
+ imsic_cfg.msi = xzalloc_array(struct imsic_msi, nr_parent_irqs);
+ if ( !imsic_cfg.msi )
+ {
+ rc = -ENOMEM;
+ goto imsic_init_err;
+ }
+
+ /* Check MMIO register sets */
+ for ( unsigned int i = 0; i < nr_mmios; i++ )
+ {
+ if ( !alloc_cpumask_var(&imsic_cfg.mmios[i].cpus) )
+ {
+ rc = -ENOMEM;
+ goto imsic_init_err;
+ }
+
+ rc = dt_device_get_address(node, i, &imsic_cfg.mmios[i].base_addr,
+ &imsic_cfg.mmios[i].size);
+ if ( rc )
+ {
+ printk(XENLOG_ERR "%s: unable to parse MMIO regset %u\n",
+ node->name, i);
+ goto imsic_init_err;
+ }
+
+ base_addr = imsic_cfg.mmios[i].base_addr;
+ base_addr &= ~(BIT(imsic_cfg.guest_index_bits +
+ imsic_cfg.hart_index_bits +
+ IMSIC_MMIO_PAGE_SHIFT, UL) - 1);
+ base_addr &= ~((BIT(imsic_cfg.group_index_bits, UL) - 1) <<
+ imsic_cfg.group_index_shift);
+ if ( base_addr != imsic_cfg.base_addr )
+ {
+ rc = -EINVAL;
+ printk(XENLOG_ERR "%s: address mismatch for regset %u\n",
+ node->name, i);
+ goto imsic_init_err;
+ }
+ }
+
+ /* Configure handlers for target CPUs */
+ for ( unsigned int i = 0; i < nr_parent_irqs; i++ )
+ {
+ unsigned long xen_cpuid;
+
+ rc = imsic_get_parent_hartid(node, i, &hartid);
+ if ( rc )
+ {
+ printk(XENLOG_WARNING "%s: cpu ID for parent irq%u not found\n",
+ node->name, i);
+ continue;
+ }
+
+ xen_cpuid = hartid_to_cpuid(hartid);
+
+ if ( xen_cpuid >= num_possible_cpus() )
+ {
+ printk(XENLOG_WARNING "%s: unsupported cpu ID=%lu for parent
irq%u\n",
+ node->name, hartid, i);
+ continue;
+ }
+
+ /* Find MMIO location of MSI page */
+ reloff = i * BIT(imsic_cfg.guest_index_bits, UL) * IMSIC_MMIO_PAGE_SZ;
+ for ( index = 0; index < nr_mmios; index++ )
+ {
+ if ( reloff < imsic_cfg.mmios[index].size )
+ break;
+
+ /*
+ * MMIO region size may not be aligned to
+ * BIT(global->guest_index_bits) * IMSIC_MMIO_PAGE_SZ
+ * if holes are present.
+ */
+ reloff -= ROUNDUP(imsic_cfg.mmios[index].size,
+ BIT(imsic_cfg.guest_index_bits, UL) * IMSIC_MMIO_PAGE_SZ);
+ }
+
+ if ( index == nr_mmios )
+ {
+ printk(XENLOG_WARNING "%s: MMIO not found for parent irq%u\n",
+ node->name, i);
+ continue;
+ }
+
+ if ( !IS_ALIGNED(imsic_cfg.msi[xen_cpuid].base_addr + reloff,
PAGE_SIZE) )
+ {
+ printk(XENLOG_WARNING "%s: MMIO address %#lx is not aligned on a
page\n",
+ node->name, imsic_cfg.msi[xen_cpuid].base_addr + reloff);
+ imsic_cfg.msi[xen_cpuid].offset = 0;
+ imsic_cfg.msi[xen_cpuid].base_addr = 0;
+ continue;
+ }
+
+ cpumask_set_cpu(xen_cpuid, imsic_cfg.mmios[index].cpus);
+
+ imsic_cfg.msi[xen_cpuid].base_addr = imsic_cfg.mmios[index].base_addr;
+ imsic_cfg.msi[xen_cpuid].offset = reloff;
+
+ nr_handlers++;
+ }
+
+ if ( !nr_handlers )
+ {
+ printk(XENLOG_ERR "%s: No CPU handlers found\n", node->name);
+ rc = -ENODEV;
+ goto imsic_init_err;
+ }
+
+ return 0;
+
+ imsic_init_err:
+ for ( unsigned int i = 0; i < nr_mmios; i++ )
+ free_cpumask_var(imsic_cfg.mmios[i].cpus);
+ XFREE(imsic_cfg.mmios);
+ XFREE(imsic_cfg.msi);
+
+ return rc;
+}
diff --git a/xen/arch/riscv/include/asm/imsic.h
b/xen/arch/riscv/include/asm/imsic.h
new file mode 100644
index 0000000000..0d17881884
--- /dev/null
+++ b/xen/arch/riscv/include/asm/imsic.h
@@ -0,0 +1,65 @@
+/* SPDX-License-Identifier: MIT */
+
+/*
+ * xen/arch/riscv/include/asm/imsic.h
+ *
+ * RISC-V Incoming MSI Controller support
+ *
+ * (c) Microchip Technology Inc.
+ */
+
+#ifndef ASM__RISCV__IMSIC_H
+#define ASM__RISCV__IMSIC_H
+
+#include <xen/types.h>
+
+#define IMSIC_MMIO_PAGE_SHIFT 12
+#define IMSIC_MMIO_PAGE_SZ (1UL << IMSIC_MMIO_PAGE_SHIFT)
+
+#define IMSIC_MIN_ID 63
+#define IMSIC_MAX_ID 2047
+
+struct imsic_msi {
+ paddr_t base_addr;
+ unsigned long offset;
+};
+
+struct imsic_mmios {
+ paddr_t base_addr;
+ unsigned long size;
+ cpumask_var_t cpus;
+};
+
+struct imsic_config {
+ /* Base address */
+ paddr_t base_addr;
+
+ /* Bits representing Guest index, HART index, and Group index */
+ unsigned int guest_index_bits;
+ unsigned int hart_index_bits;
+ unsigned int group_index_bits;
+ unsigned int group_index_shift;
+
+ /* IMSIC phandle */
+ unsigned int phandle;
+
+ /* Number of parent irq */
+ unsigned int nr_parent_irqs;
+
+ /* Number off interrupt identities */
+ unsigned int nr_ids;
+
+ /* MMIOs */
+ unsigned int nr_mmios;
+ struct imsic_mmios *mmios;
+
+ /* MSI */
+ struct imsic_msi *msi;
+};
+
+struct dt_device_node;
+int imsic_init(const struct dt_device_node *node);
+
+const struct imsic_config *imsic_get_config(void);
+
+#endif /* ASM__RISCV__IMSIC_H */
diff --git a/xen/arch/riscv/include/asm/smp.h b/xen/arch/riscv/include/asm/smp.h
index eb58b6576b..33ee5ec06b 100644
--- a/xen/arch/riscv/include/asm/smp.h
+++ b/xen/arch/riscv/include/asm/smp.h
@@ -3,6 +3,7 @@
#define ASM__RISCV__SMP_H
#include <xen/cpumask.h>
+#include <xen/macros.h>
#include <xen/percpu.h>
#include <asm/current.h>
@@ -18,6 +19,18 @@ static inline unsigned long cpuid_to_hartid(unsigned long
cpuid)
return pcpu_info[cpuid].hart_id;
}
+static inline unsigned long hartid_to_cpuid(unsigned long hartid)
+{
+ for ( unsigned int cpuid = 0; cpuid < ARRAY_SIZE(pcpu_info); cpuid++ )
+ {
+ if ( hartid == cpuid_to_hartid(cpuid) )
+ return cpuid;
+ }
+
+ /* hartid isn't valid for some reason */
+ return NR_CPUS;
+}
+
static inline void set_cpuid_to_hartid(unsigned long cpuid,
unsigned long hartid)
{
--
2.49.0
