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authorMarc Zyngier <marc.zyngier@arm.com>2016-04-26 11:06:12 +0100
committerChristoffer Dall <christoffer.dall@linaro.org>2016-05-20 15:39:49 +0200
commit4493b1c4866a03963a35be7d157c911a617a3694 (patch)
tree612e202d4d5c4f9536d38637b7b1f7afafbe6b85 /virt/kvm/arm/vgic/vgic-mmio.h
parent90eee56c5f9081686035972dfcddfd6c85cafdf9 (diff)
downloadlinux-stericsson-4493b1c4866a03963a35be7d157c911a617a3694.tar.gz
KVM: arm/arm64: vgic-new: Add MMIO handling framework
Add an MMIO handling framework to the VGIC emulation: Each register is described by its offset, size (or number of bits per IRQ, if applicable) and the read/write handler functions. We provide initialization macros to describe each GIC register later easily. Separate dispatch functions for read and write accesses are connected to the kvm_io_bus framework and binary-search for the responsible register handler based on the offset address within the region. We convert the incoming data (referenced by a pointer) to the host's endianess and use pass-by-value to hand the data over to the actual handler functions. The register handler prototype and the endianess conversion are courtesy of Christoffer Dall. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Diffstat (limited to 'virt/kvm/arm/vgic/vgic-mmio.h')
-rw-r--r--virt/kvm/arm/vgic/vgic-mmio.h99
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diff --git a/virt/kvm/arm/vgic/vgic-mmio.h b/virt/kvm/arm/vgic/vgic-mmio.h
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+/*
+ * Copyright (C) 2015, 2016 ARM Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+#ifndef __KVM_ARM_VGIC_MMIO_H__
+#define __KVM_ARM_VGIC_MMIO_H__
+
+struct vgic_register_region {
+ unsigned int reg_offset;
+ unsigned int len;
+ unsigned int bits_per_irq;
+ unsigned int access_flags;
+ unsigned long (*read)(struct kvm_vcpu *vcpu, gpa_t addr,
+ unsigned int len);
+ void (*write)(struct kvm_vcpu *vcpu, gpa_t addr, unsigned int len,
+ unsigned long val);
+};
+
+extern struct kvm_io_device_ops kvm_io_gic_ops;
+
+#define VGIC_ACCESS_8bit 1
+#define VGIC_ACCESS_32bit 2
+#define VGIC_ACCESS_64bit 4
+
+/*
+ * Generate a mask that covers the number of bytes required to address
+ * up to 1024 interrupts, each represented by <bits> bits. This assumes
+ * that <bits> is a power of two.
+ */
+#define VGIC_ADDR_IRQ_MASK(bits) (((bits) * 1024 / 8) - 1)
+
+/*
+ * (addr & mask) gives us the byte offset for the INT ID, so we want to
+ * divide this with 'bytes per irq' to get the INT ID, which is given
+ * by '(bits) / 8'. But we do this with fixed-point-arithmetic and
+ * take advantage of the fact that division by a fraction equals
+ * multiplication with the inverted fraction, and scale up both the
+ * numerator and denominator with 8 to support at most 64 bits per IRQ:
+ */
+#define VGIC_ADDR_TO_INTID(addr, bits) (((addr) & VGIC_ADDR_IRQ_MASK(bits)) * \
+ 64 / (bits) / 8)
+
+/*
+ * Some VGIC registers store per-IRQ information, with a different number
+ * of bits per IRQ. For those registers this macro is used.
+ * The _WITH_LENGTH version instantiates registers with a fixed length
+ * and is mutually exclusive with the _PER_IRQ version.
+ */
+#define REGISTER_DESC_WITH_BITS_PER_IRQ(off, rd, wr, bpi, acc) \
+ { \
+ .reg_offset = off, \
+ .bits_per_irq = bpi, \
+ .len = bpi * 1024 / 8, \
+ .access_flags = acc, \
+ .read = rd, \
+ .write = wr, \
+ }
+
+#define REGISTER_DESC_WITH_LENGTH(off, rd, wr, length, acc) \
+ { \
+ .reg_offset = off, \
+ .bits_per_irq = 0, \
+ .len = length, \
+ .access_flags = acc, \
+ .read = rd, \
+ .write = wr, \
+ }
+
+int kvm_vgic_register_mmio_region(struct kvm *kvm, struct kvm_vcpu *vcpu,
+ struct vgic_register_region *reg_desc,
+ struct vgic_io_device *region,
+ int nr_irqs, bool offset_private);
+
+unsigned long vgic_data_mmio_bus_to_host(const void *val, unsigned int len);
+
+void vgic_data_host_to_mmio_bus(void *buf, unsigned int len,
+ unsigned long data);
+
+unsigned long vgic_mmio_read_raz(struct kvm_vcpu *vcpu,
+ gpa_t addr, unsigned int len);
+
+unsigned long vgic_mmio_read_rao(struct kvm_vcpu *vcpu,
+ gpa_t addr, unsigned int len);
+
+void vgic_mmio_write_wi(struct kvm_vcpu *vcpu, gpa_t addr,
+ unsigned int len, unsigned long val);
+
+#endif