[Xen-devel] [PATCH v6 4/6] xen/arm: zynqmp: implement zynqmp_eemi

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

From: "Edgar E. Iglesias" <edgar.iglesias@xxxxxxxxxx>

From: Edgar E. Iglesias <edgar.iglesias@xxxxxxxxxx>

zynqmp_eemi uses the defined functions and structs to decide whether to
make a call to the firmware, or to simply return a predefined value.

Signed-off-by: Edgar E. Iglesias <edgar.iglesias@xxxxxxxxxx>
Signed-off-by: Stefano Stabellini <stefanos@xxxxxxxxxx>
---
Changes in v6:
- mmio_access removal moved to previous patch
- forward to firmware mandatory smc32 calls
- check that the function id belongs to the right range before
  proceeding
- basic is_hardware_domain implementation for domain_has_node_access and
  domain_has_reset_access

Changes in v5:
- remove mmio_access handling

Changes in v4:
- add #include as needed
- improve comment
- code style
---
 xen/arch/arm/platforms/xilinx-zynqmp-eemi.c | 180 +++++++++++++++++++++++++++-
 1 file changed, 179 insertions(+), 1 deletion(-)

diff --git a/xen/arch/arm/platforms/xilinx-zynqmp-eemi.c 
b/xen/arch/arm/platforms/xilinx-zynqmp-eemi.c
index 369bb3f..e0456ae 100644
--- a/xen/arch/arm/platforms/xilinx-zynqmp-eemi.c
+++ b/xen/arch/arm/platforms/xilinx-zynqmp-eemi.c
@@ -17,11 +17,189 @@
  */
 
 #include <asm/regs.h>
+#include <xen/sched.h>
+#include <asm/smccc.h>
 #include <asm/platforms/xilinx-zynqmp-eemi.h>
 
+/*
+ * EEMI firmware API:
+ * https://www.xilinx.com/support/documentation/user_guides/ug1200-eemi-api.pdf
+ *
+ * Power domain node_ids identify the area of effect of the power
+ * management operations. They are the first parameter passed to power
+ * management EEMI calls.
+ *
+ * Reset IDs identify the area of effect of a reset operation. They are
+ * the first parameter passed to reset EEMI calls.
+ *
+ * For now, let the hardware domain access to all power domain nodes and
+ * all reset lines. In the future, we'll check for ownership of
+ * resources by specific virtual machines.
+ */
+static inline bool domain_has_node_access(struct domain *d, uint32_t nodeid)
+{
+       return is_hardware_domain(d);
+}
+
+static inline bool domain_has_reset_access(struct domain *d, uint32_t rst)
+{
+       return is_hardware_domain(d);
+}
+
 bool zynqmp_eemi(struct cpu_user_regs *regs)
 {
-    return false;
+    struct arm_smccc_res res;
+    uint32_t fid = get_user_reg(regs, 0);
+    uint32_t nodeid;
+    unsigned int pm_fn;
+    enum pm_ret_status ret;
+
+    /* Check for the mandatory SMC32 functions first */
+    switch ( fid )
+    {
+        case ARM_SMCCC_CALL_COUNT_FID(SIP):
+        case ARM_SMCCC_CALL_UID_FID(SIP):
+        case ARM_SMCCC_REVISION_FID(SIP):
+            goto forward_to_fw;
+        default:
+            break;
+    }
+
+    /* EEMI calls are SMC64 SIP Fast Calls */
+    if ( !(fid & ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL,
+                                    ARM_SMCCC_CONV_64,
+                                    ARM_SMCCC_OWNER_SIP,
+                                    0x0)) )
+    {
+        ret = ARM_SMCCC_NOT_SUPPORTED;
+        goto done;
+    }
+
+    nodeid = get_user_reg(regs, 1);
+    pm_fn = fid & 0xFFFF;
+
+    switch ( pm_fn )
+    {
+    /*
+     * We can't allow CPUs to suspend without Xen knowing about it.
+     * We accept but ignore the request and wait for the guest to issue
+     * a WFI or PSCI call which Xen will trap and act accordingly upon.
+     */
+    case PM_SELF_SUSPEND:
+        ret = XST_PM_SUCCESS;
+        goto done;
+
+    case PM_GET_NODE_STATUS:
+    /* API for PUs.  */
+    case PM_REQ_SUSPEND:
+    case PM_FORCE_POWERDOWN:
+    case PM_ABORT_SUSPEND:
+    case PM_REQ_WAKEUP:
+    case PM_SET_WAKEUP_SOURCE:
+    /* API for slaves.  */
+    case PM_REQ_NODE:
+    case PM_RELEASE_NODE:
+    case PM_SET_REQUIREMENT:
+    case PM_SET_MAX_LATENCY:
+        if ( !domain_has_node_access(current->domain, nodeid) )
+        {
+            gprintk(XENLOG_WARNING,
+                    "zynqmp-pm: fn=%u No access to node %u\n", pm_fn, nodeid);
+            ret = XST_PM_NO_ACCESS;
+            goto done;
+        }
+        goto forward_to_fw;
+
+    case PM_RESET_ASSERT:
+    case PM_RESET_GET_STATUS:
+        if ( !domain_has_reset_access(current->domain, nodeid) )
+        {
+            gprintk(XENLOG_WARNING,
+                    "zynqmp-pm: fn=%u No access to reset %u\n", pm_fn, nodeid);
+            ret = XST_PM_NO_ACCESS;
+            goto done;
+        }
+        goto forward_to_fw;
+
+    /* These calls are safe and always allowed.  */
+    case ZYNQMP_SIP_SVC_CALL_COUNT:
+    case ZYNQMP_SIP_SVC_UID:
+    case ZYNQMP_SIP_SVC_VERSION:
+    case PM_GET_TRUSTZONE_VERSION:
+    case PM_GET_API_VERSION:
+    case PM_GET_CHIPID:
+        goto forward_to_fw;
+
+    /* No MMIO access is allowed from non-secure domains */
+    case PM_MMIO_WRITE:
+    case PM_MMIO_READ:
+        gprintk(XENLOG_WARNING,
+                "zynqmp-pm: fn=%u No MMIO access to %u\n", pm_fn, nodeid);
+        ret = XST_PM_NO_ACCESS;
+        goto done;
+
+    /* Exclusive to the hardware domain.  */
+    case PM_INIT:
+    case PM_SET_CONFIGURATION:
+    case PM_FPGA_LOAD:
+    case PM_FPGA_GET_STATUS:
+    case PM_SECURE_SHA:
+    case PM_SECURE_RSA:
+    case PM_PINCTRL_SET_FUNCTION:
+    case PM_PINCTRL_REQUEST:
+    case PM_PINCTRL_RELEASE:
+    case PM_PINCTRL_GET_FUNCTION:
+    case PM_PINCTRL_CONFIG_PARAM_GET:
+    case PM_PINCTRL_CONFIG_PARAM_SET:
+    case PM_IOCTL:
+    case PM_QUERY_DATA:
+    case PM_CLOCK_ENABLE:
+    case PM_CLOCK_DISABLE:
+    case PM_CLOCK_GETSTATE:
+    case PM_CLOCK_GETDIVIDER:
+    case PM_CLOCK_SETDIVIDER:
+    case PM_CLOCK_SETRATE:
+    case PM_CLOCK_GETRATE:
+    case PM_CLOCK_SETPARENT:
+    case PM_CLOCK_GETPARENT:
+        if ( !is_hardware_domain(current->domain) )
+        {
+            gprintk(XENLOG_WARNING, "eemi: fn=%u No access", pm_fn);
+            ret = XST_PM_NO_ACCESS;
+            goto done;
+        }
+        goto forward_to_fw;
+
+    /* These calls are never allowed.  */
+    case PM_SYSTEM_SHUTDOWN:
+        ret = XST_PM_NO_ACCESS;
+        goto done;
+
+    default:
+        gprintk(XENLOG_WARNING, "zynqmp-pm: Unhandled PM Call: %u\n", fid);
+        return false;
+    }
+
+forward_to_fw:
+    arm_smccc_1_1_smc(get_user_reg(regs, 0),
+                      get_user_reg(regs, 1),
+                      get_user_reg(regs, 2),
+                      get_user_reg(regs, 3),
+                      get_user_reg(regs, 4),
+                      get_user_reg(regs, 5),
+                      get_user_reg(regs, 6),
+                      get_user_reg(regs, 7),
+                      &res);
+
+    set_user_reg(regs, 0, res.a0);
+    set_user_reg(regs, 1, res.a1);
+    set_user_reg(regs, 2, res.a2);
+    set_user_reg(regs, 3, res.a3);
+    return true;
+
+done:
+    set_user_reg(regs, 0, ret);
+    return true;
 }
 
 /*
-- 
1.9.1


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