From 6d146aefbaa5c5dff0c2e9d81e90e5112ded284e Mon Sep 17 00:00:00 2001 From: Jake Oshins Date: Tue, 5 Apr 2016 10:22:55 -0700 Subject: drivers:hv: Record MMIO range in use by frame buffer Later in the boot sequence, we need to figure out which memory ranges can be given out to various paravirtual drivers. The hyperv_fb driver should, ideally, be placed right on top of the frame buffer, without some other device getting plopped on top of this range in the meantime. Recording this now allows that to be guaranteed. Signed-off-by: Jake Oshins Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman --- drivers/hv/vmbus_drv.c | 37 ++++++++++++++++++++++++++++++++++++- 1 file changed, 36 insertions(+), 1 deletion(-) (limited to 'drivers/hv') diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c index dfc6149ccc93..eaa5c3b7fd8a 100644 --- a/drivers/hv/vmbus_drv.c +++ b/drivers/hv/vmbus_drv.c @@ -41,6 +41,7 @@ #include #include #include +#include #include "hyperv_vmbus.h" static struct acpi_device *hv_acpi_dev; @@ -101,6 +102,8 @@ static struct notifier_block hyperv_panic_block = { .notifier_call = hyperv_panic_event, }; +static const char *fb_mmio_name = "fb_range"; +static struct resource *fb_mmio; struct resource *hyperv_mmio; DEFINE_SEMAPHORE(hyperv_mmio_lock); @@ -1091,6 +1094,12 @@ static int vmbus_acpi_remove(struct acpi_device *device) struct resource *next_res; if (hyperv_mmio) { + if (fb_mmio) { + __release_region(hyperv_mmio, fb_mmio->start, + resource_size(fb_mmio)); + fb_mmio = NULL; + } + for (cur_res = hyperv_mmio; cur_res; cur_res = next_res) { next_res = cur_res->sibling; kfree(cur_res); @@ -1100,6 +1109,30 @@ static int vmbus_acpi_remove(struct acpi_device *device) return 0; } +static void vmbus_reserve_fb(void) +{ + int size; + /* + * Make a claim for the frame buffer in the resource tree under the + * first node, which will be the one below 4GB. The length seems to + * be underreported, particularly in a Generation 1 VM. So start out + * reserving a larger area and make it smaller until it succeeds. + */ + + if (screen_info.lfb_base) { + if (efi_enabled(EFI_BOOT)) + size = max_t(__u32, screen_info.lfb_size, 0x800000); + else + size = max_t(__u32, screen_info.lfb_size, 0x4000000); + + for (; !fb_mmio && (size >= 0x100000); size >>= 1) { + fb_mmio = __request_region(hyperv_mmio, + screen_info.lfb_base, size, + fb_mmio_name, 0); + } + } +} + /** * vmbus_allocate_mmio() - Pick a memory-mapped I/O range. * @new: If successful, supplied a pointer to the @@ -1261,8 +1294,10 @@ static int vmbus_acpi_add(struct acpi_device *device) if (ACPI_FAILURE(result)) continue; - if (hyperv_mmio) + if (hyperv_mmio) { + vmbus_reserve_fb(); break; + } } ret_val = 0; -- cgit v1.2.3