// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries. */

#include <linux/gunyah.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/pgtable.h>
#include <linux/memblock.h>
#include <linux/of_fdt.h>
#include <linux/libfdt.h>
#include <linux/virtio_balloon.h>

#include <asm/hypervisor.h>

#define ADDRSPACE_INFO_AREA_ROOTVM_ADDRSPACE_CAP ((uint16_t)0)
struct addrspace_info_area_rootvm_addrspace_cap {
	u64 addrspace_cap;
	u32 rights;
	u32 res0;
};

static u64 our_addrspace_capid;

static int gunyah_mmio_guard_ioremap_hook(phys_addr_t phys, size_t size, pgprot_t *prot)
{
	pteval_t protval = pgprot_val(*prot);
	int ret;

	/*
	 * We only expect MMIO emulation for regions mapped with device
	 * attributes.
	 */
	if (protval != PROT_DEVICE_nGnRE && protval != PROT_DEVICE_nGnRnE)
		return 0;

	ret = gunyah_hypercall_addrspc_configure_vmmio_range(our_addrspace_capid,
				phys, size, GUNYAH_ADDRSPACE_VMMIO_CONFIGURE_OP_ADD_RANGE);

	if (ret == GUNYAH_ERROR_UNIMPLEMENTED || ret == GUNYAH_ERROR_BUSY
			|| ret == GUNYAH_ERROR_CSPACE_INSUF_RIGHTS)
		/* Gunyah would have configured VMMIO via DT */
		ret = GUNYAH_ERROR_OK;

	return gunyah_error_remap(ret);
}

#ifdef CONFIG_VIRTIO_BALLOON_HYP_OPS
static void gunyah_page_relinquish(struct page *page,  unsigned int nr)
{
	/* Release page to Host, so unlock and sanitize */
	u64 flags = BIT_ULL(GUNYAH_ADDRSPC_MODIFY_FLAG_UNLOCK_BIT) |
			BIT_ULL(GUNYAH_ADDRSPC_MODIFY_FLAG_SANITIZE_BIT);
	phys_addr_t phys, end;
	int ret = 0;

	phys = page_to_phys(page);
	end = phys + PAGE_SIZE * nr;

	while (phys < end) {
		ret = gunyah_hypercall_addrspc_modify_pages(our_addrspace_capid,
				phys, PAGE_SIZE, flags);
		if (ret)
			pr_err_ratelimited("Failed to relinquish page: %016llx %d\n", phys, ret);

		phys += PAGE_SIZE;
	}

}

static void gunyah_post_page_relinquish_tlb_inv(void)
{
	/* Release page to Host, so unlock and sanitize */
	int ret = 0;

	ret = gunyah_hypercall_addrspc_modify_pages(our_addrspace_capid, 0, 0, 0);
	if (ret)
		pr_err_ratelimited("Failed to flush tlb: %d\n", ret);
}

static struct virtio_balloon_hyp_ops gunyah_virtio_balloon_hyp_ops = {
	.page_relinquish = gunyah_page_relinquish,
	.post_page_relinquish_tlb_inv = gunyah_post_page_relinquish_tlb_inv
};

#endif

static int __init gunyah_guest_init(void)
{
	struct addrspace_info_area_rootvm_addrspace_cap *info;
	size_t size;

	info = gunyah_get_info(GUNYAH_INFO_OWNER_ROOTVM, ADDRSPACE_INFO_AREA_ROOTVM_ADDRSPACE_CAP,
											&size);
	if (IS_ERR(info))
		return PTR_ERR(info);

	if (size != sizeof(*info))
		return -EINVAL;

	our_addrspace_capid = info->addrspace_cap;

	arm64_ioremap_prot_hook_register(&gunyah_mmio_guard_ioremap_hook);
#ifdef CONFIG_VIRTIO_BALLOON_HYP_OPS
	virtio_balloon_hyp_ops = &gunyah_virtio_balloon_hyp_ops;
#endif
	return 0;
}
core_initcall_sync(gunyah_guest_init);

static int __init gunyah_map_restricted_dma(char *unused)
{
	const void *fdt = initial_boot_params;
	int resv, off, len;
	const __be32 *reg, *p;
	phys_addr_t base, size;

	if (!fdt)
		return 0;

	resv = fdt_path_offset(fdt, "/reserved-memory");
	if (resv < 0)
		return 0;

	for (off = fdt_first_subnode(fdt, resv); off >= 0; off = fdt_next_subnode(fdt, off)) {
		if (of_flat_dt_is_compatible(off, "restricted-dma-pool"))
			break;
	}

	if (off < 0)
		return 0;

	if (fdt_getprop(fdt, off, "no-map", &len))
		return 0;

	reg = fdt_getprop(fdt, off, "reg", &len);
	if (!reg)
		return 0;

	p = reg;
	base = dt_mem_next_cell(dt_root_addr_cells, &p);
	size = dt_mem_next_cell(dt_root_size_cells, &p);
	if (!size)
		return 0;

	/* Make it mappable by the direct map; reserved-memory scan will reserve it */
	memblock_add(base, size);

	pr_debug("%s: added %pa..%pa to memblock.memory\n", __func__,
		&base, &(phys_addr_t){ base + size - 1 });
	return 0;
}
early_param("reset_devices", gunyah_map_restricted_dma);