[PATCH v3 06/32] irqchip/gic-v4.1: Implement the v4.1 flavour of VMAPP

Marc Zyngier
2019-12-24T11:11:45Z

The ITS VMAPP command gains some new fields with GICv4.1:
- a default doorbell, which allows a single doorbell to be used for
all the VLPIs routed to a given VPE
- a pointer to the configuration table (instead of having it in a register
that gets context switched)
- a flag indicating whether this is the first map or the last unmap for
this particular VPE
- a flag indicating whether the pending table is known to be zeroed, or not

Plumb in the new fields in the VMAPP builder, and add the map/unmap
refcounting so that the ITS can do the right thing.

Reviewed-by: Zenghui Yu <yuzenghui@huawei.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
drivers/irqchip/irq-gic-v3-its.c | 60 +++++++++++++++++++++++++++---
include/linux/irqchip/arm-gic-v4.h | 18 +++++++--
2 files changed, 69 insertions(+), 9 deletions(-)

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 15dea531c34f..e3c7d9ae0bdb 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -450,6 +450,27 @@ static void its_encode_vpt_size(struct its_cmd_block *cmd, u8 vpt_size)
its_mask_encode(&cmd->raw_cmd[3], vpt_size, 4, 0);
}

+static void its_encode_vconf_addr(struct its_cmd_block *cmd, u64 vconf_pa)
+{
+ its_mask_encode(&cmd->raw_cmd[0], vconf_pa >> 16, 51, 16);
+}
+
+static void its_encode_alloc(struct its_cmd_block *cmd, bool alloc)
+{
+ its_mask_encode(&cmd->raw_cmd[0], alloc, 8, 8);
+}
+
+static void its_encode_ptz(struct its_cmd_block *cmd, bool ptz)
+{
+ its_mask_encode(&cmd->raw_cmd[0], ptz, 9, 9);
+}
+
+static void its_encode_vmapp_default_db(struct its_cmd_block *cmd,
+ u32 vpe_db_lpi)
+{
+ its_mask_encode(&cmd->raw_cmd[1], vpe_db_lpi, 31, 0);
+}
+
static inline void its_fixup_cmd(struct its_cmd_block *cmd)
{
/* Let's fixup BE commands */
@@ -633,19 +654,45 @@ static struct its_vpe *its_build_vmapp_cmd(struct its_node *its,
struct its_cmd_block *cmd,
struct its_cmd_desc *desc)
{
- unsigned long vpt_addr;
+ unsigned long vpt_addr, vconf_addr;
u64 target;
-
- vpt_addr = virt_to_phys(page_address(desc->its_vmapp_cmd.vpe->vpt_page));
- target = desc->its_vmapp_cmd.col->target_address + its->vlpi_redist_offset;
+ bool alloc;

its_encode_cmd(cmd, GITS_CMD_VMAPP);
its_encode_vpeid(cmd, desc->its_vmapp_cmd.vpe->vpe_id);
its_encode_valid(cmd, desc->its_vmapp_cmd.valid);
+
+ if (!desc->its_vmapp_cmd.valid) {
+ if (is_v4_1(its)) {
+ alloc = !atomic_dec_return(&desc->its_vmapp_cmd.vpe->vmapp_count);
+ its_encode_alloc(cmd, alloc);
+ }
+
+ goto out;
+ }
+
+ vpt_addr = virt_to_phys(page_address(desc->its_vmapp_cmd.vpe->vpt_page));
+ target = desc->its_vmapp_cmd.col->target_address + its->vlpi_redist_offset;
+
its_encode_target(cmd, target);
its_encode_vpt_addr(cmd, vpt_addr);
its_encode_vpt_size(cmd, LPI_NRBITS - 1);

+ if (!is_v4_1(its))
+ goto out;
+
+ vconf_addr = virt_to_phys(page_address(desc->its_vmapp_cmd.vpe->its_vm->vprop_page));
+
+ alloc = !atomic_fetch_inc(&desc->its_vmapp_cmd.vpe->vmapp_count);
+
+ its_encode_alloc(cmd, alloc);
+
+ /* We can only signal PTZ when alloc==1. Why do we have two bits? */
+ its_encode_ptz(cmd, alloc);
+ its_encode_vconf_addr(cmd, vconf_addr);
+ its_encode_vmapp_default_db(cmd, desc->its_vmapp_cmd.vpe->vpe_db_lpi);
+
+out:
its_fixup_cmd(cmd);

return valid_vpe(its, desc->its_vmapp_cmd.vpe);
@@ -3493,7 +3540,10 @@ static int its_vpe_init(struct its_vpe *vpe)

vpe->vpe_id = vpe_id;
vpe->vpt_page = vpt_page;
- vpe->vpe_proxy_event = -1;
+ if (gic_rdists->has_rvpeid)
+ atomic_set(&vpe->vmapp_count, 0);
+ else
+ vpe->vpe_proxy_event = -1;

return 0;
}
diff --git a/include/linux/irqchip/arm-gic-v4.h b/include/linux/irqchip/arm-gic-v4.h
index 5dbcfc65f21e..498e523085a7 100644
--- a/include/linux/irqchip/arm-gic-v4.h
+++ b/include/linux/irqchip/arm-gic-v4.h
@@ -39,8 +39,20 @@ struct its_vpe {
irq_hw_number_t vpe_db_lpi;
/* VPE resident */
bool resident;
- /* VPE proxy mapping */
- int vpe_proxy_event;
+ union {
+ /* GICv4.0 implementations */
+ struct {
+ /* VPE proxy mapping */
+ int vpe_proxy_event;
+ /* Implementation Defined Area Invalid */
+ bool idai;
+ };
+ /* GICv4.1 implementations */
+ struct {
+ atomic_t vmapp_count;
+ };
+ };
+
/*
* This collection ID is used to indirect the target
* redistributor for this VPE. The ID itself isn't involved in
@@ -49,8 +61,6 @@ struct its_vpe {
u16 col_idx;
/* Unique (system-wide) VPE identifier */
u16 vpe_id;
- /* Implementation Defined Area Invalid */
- bool idai;
/* Pending VLPIs on schedule out? */
bool pending_last;
};
--
2.20.1