[PATCH v2 5/6] PCI: hv: Use hv_hvcall_*() to set up hypercall arguments

[mhkelley58@gmail.com]

From: Michael Kelley <mhklinux@outlook.com>

Update hypercall call sites to use the new hv_hvcall_*() functions
to set up hypercall arguments. Since these functions zero the
fixed portion of input memory, remove now redundant calls to memset().

Signed-off-by: Michael Kelley <mhklinux@outlook.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
---

Notes:
    Changes in v2:
    * In hv_arch_irq_unmask(), added check of the number of computed banks
      in the hv_vpset against the batch_size. Since an hv_vpset currently
      represents a maximum of 4096 CPUs, the hv_vpset size does not exceed
      512 bytes and there should always be sufficent space. But do the
      check just in case something changes. [Nuno Das Neves]

 drivers/pci/controller/pci-hyperv.c | 18 ++++++++----------
 include/hyperv/hvgdk_mini.h         |  2 +-
 2 files changed, 9 insertions(+), 11 deletions(-)

diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c
index ac27bda5ba26..82ac0e09943b 100644
--- a/drivers/pci/controller/pci-hyperv.c
+++ b/drivers/pci/controller/pci-hyperv.c
@@ -622,7 +622,7 @@ static void hv_arch_irq_unmask(struct irq_data *data)
 	struct pci_dev *pdev;
 	unsigned long flags;
 	u32 var_size = 0;
-	int cpu, nr_bank;
+	int cpu, nr_bank, batch_size;
 	u64 res;
 
 	dest = irq_data_get_effective_affinity_mask(data);
@@ -638,8 +638,8 @@ static void hv_arch_irq_unmask(struct irq_data *data)
 
 	local_irq_save(flags);
 
-	params = *this_cpu_ptr(hyperv_pcpu_input_arg);
-	memset(params, 0, sizeof(*params));
+	batch_size = hv_hvcall_in_array(&params, sizeof(*params),
+					sizeof(params->int_target.vp_set.bank_contents[0]));
 	params->partition_id = HV_PARTITION_ID_SELF;
 	params->int_entry.source = HV_INTERRUPT_SOURCE_MSI;
 	params->int_entry.msi_entry.address.as_uint32 = int_desc->address & 0xffffffff;
@@ -671,7 +671,7 @@ static void hv_arch_irq_unmask(struct irq_data *data)
 		nr_bank = cpumask_to_vpset(&params->int_target.vp_set, tmp);
 		free_cpumask_var(tmp);
 
-		if (nr_bank <= 0) {
+		if (nr_bank <= 0 || nr_bank > batch_size) {
 			res = 1;
 			goto out;
 		}
@@ -1034,11 +1034,9 @@ static void hv_pci_read_mmio(struct device *dev, phys_addr_t gpa, int size, u32
 
 	/*
 	 * Must be called with interrupts disabled so it is safe
-	 * to use the per-cpu input argument page.  Use it for
-	 * both input and output.
+	 * to use the per-cpu argument page.
 	 */
-	in = *this_cpu_ptr(hyperv_pcpu_input_arg);
-	out = *this_cpu_ptr(hyperv_pcpu_input_arg) + sizeof(*in);
+	hv_hvcall_inout(&in, sizeof(*in), &out, sizeof(*out));
 	in->gpa = gpa;
 	in->size = size;
 
@@ -1067,9 +1065,9 @@ static void hv_pci_write_mmio(struct device *dev, phys_addr_t gpa, int size, u32
 
 	/*
 	 * Must be called with interrupts disabled so it is safe
-	 * to use the per-cpu input argument memory.
+	 * to use the per-cpu argument page.
 	 */
-	in = *this_cpu_ptr(hyperv_pcpu_input_arg);
+	hv_hvcall_in_array(&in, sizeof(*in), sizeof(in->data[0]));
 	in->gpa = gpa;
 	in->size = size;
 	switch (size) {
diff --git a/include/hyperv/hvgdk_mini.h b/include/hyperv/hvgdk_mini.h
index 70e5d7ee40c8..cb25ac1e3ac5 100644
--- a/include/hyperv/hvgdk_mini.h
+++ b/include/hyperv/hvgdk_mini.h
@@ -1342,7 +1342,7 @@ struct hv_mmio_write_input {
 	u64 gpa;
 	u32 size;
 	u32 reserved;
-	u8 data[HV_HYPERCALL_MMIO_MAX_DATA_LENGTH];
+	u8 data[];
 } __packed;
 
 #endif /* _HV_HVGDK_MINI_H */
-- 
2.25.1