/* Public domain. */

#include <linux/types.h>
#include <linux/ioport.h>
#include <linux/pci.h>
#include <drm/intel/i915_drm.h>
#include "i915_drv.h"

struct resource intel_graphics_stolen_res = DEFINE_RES_MEM(0, 0);

bus_addr_t
gen3_stolen_base(struct drm_i915_private *dev_priv)
{
        uint32_t bsm = pci_conf_read(dev_priv->pc, dev_priv->tag,
            INTEL_BSM);
        return bsm & INTEL_BSM_MASK;
}

bus_addr_t
gen11_stolen_base(struct drm_i915_private *dev_priv)
{
        uint64_t bsm = pci_conf_read(dev_priv->pc, dev_priv->tag,
            INTEL_GEN11_BSM_DW0);
        bsm &= INTEL_BSM_MASK;
        bsm |= (uint64_t)pci_conf_read(dev_priv->pc, dev_priv->tag,
            INTEL_GEN11_BSM_DW1) << 32;
        return bsm;
}

bus_size_t
i830_stolen_size(struct drm_i915_private *dev_priv)
{
        uint16_t gmch_ctl, gms;

        pci_read_config_word(dev_priv->gmch.pdev, I830_GMCH_CTRL,
            &gmch_ctl);
        gms = gmch_ctl & I830_GMCH_GMS_MASK;

        switch (gms) {
        case I830_GMCH_GMS_STOLEN_512:
                return 512 * 1024;
        case I830_GMCH_GMS_STOLEN_1024:
                return 1 * 1024 * 1024;
        case I830_GMCH_GMS_STOLEN_8192:
                return 8 * 1024 * 1024;
        }

        return 0;
}

bus_size_t
gen3_stolen_size(struct drm_i915_private *dev_priv)
{
        uint16_t gmch_ctl, gms;

        pci_read_config_word(dev_priv->gmch.pdev, I830_GMCH_CTRL,
            &gmch_ctl);
        gms = gmch_ctl & I855_GMCH_GMS_MASK;

        switch (gms) {
        case I855_GMCH_GMS_STOLEN_1M:
                return 1 * 1024 * 1024;
        case I855_GMCH_GMS_STOLEN_4M:
                return 4 * 1024 * 1024;
        case I855_GMCH_GMS_STOLEN_8M:
                return 8 * 1024 * 1024;
        case I855_GMCH_GMS_STOLEN_16M:
                return 16 * 1024 * 1024;
        case I855_GMCH_GMS_STOLEN_32M:
                return 32 * 1024 * 1024;
        case I915_GMCH_GMS_STOLEN_48M:
                return 48 * 1024 * 1024;
        case I915_GMCH_GMS_STOLEN_64M:
                return 64 * 1024 * 1024;
        case G33_GMCH_GMS_STOLEN_128M:
                return 128 * 1024 * 1024;
        case G33_GMCH_GMS_STOLEN_256M:
                return 256 * 1024 * 1024;
        case INTEL_GMCH_GMS_STOLEN_96M:
                return 96 * 1024 * 1024;
        case INTEL_GMCH_GMS_STOLEN_160M:
                return 160 * 1024 * 1024;
        case INTEL_GMCH_GMS_STOLEN_224M:
                return 224 * 1024 * 1024;
        case INTEL_GMCH_GMS_STOLEN_352M:
                return 352 * 1024 * 1024;
        }

        return 0;
}

bus_size_t
gen6_stolen_size(struct drm_i915_private *dev_priv)
{
        struct pci_dev *pdev = dev_priv->drm.pdev;
        uint16_t gmch_ctl, gms;

        pci_read_config_word(pdev, SNB_GMCH_CTRL, &gmch_ctl);
        gms = (gmch_ctl >> SNB_GMCH_GMS_SHIFT) & SNB_GMCH_GMS_MASK;

        return gms * (32 * 1024 * 1024);
}

bus_size_t
chv_stolen_size(struct drm_i915_private *dev_priv)
{
        struct pci_dev *pdev = dev_priv->drm.pdev;
        uint16_t gmch_ctl, gms;

        pci_read_config_word(pdev, SNB_GMCH_CTRL, &gmch_ctl);
        gms = (gmch_ctl >> SNB_GMCH_GMS_SHIFT) & SNB_GMCH_GMS_MASK;

        if (gms < 0x11)
                return gms * (32 * 1024 * 1024);
        else if (gms < 0x17)
                return (gms - 0x11) * (4 * 1024 * 1024) + (8 * 1024 * 1024);
        else
                return (gms - 0x17) + (4 * 1024 * 1024) + (36 * 1024 * 1024);
}

bus_size_t
gen8_stolen_size(struct drm_i915_private *dev_priv)
{
        struct pci_dev *pdev = dev_priv->drm.pdev;
        uint16_t gmch_ctl, gms;

        pci_read_config_word(pdev, SNB_GMCH_CTRL, &gmch_ctl);
        gms = (gmch_ctl >> BDW_GMCH_GMS_SHIFT) & BDW_GMCH_GMS_MASK;

        return gms * (32 * 1024 * 1024);
}

bus_size_t
gen9_stolen_size(struct drm_i915_private *dev_priv)
{
        struct pci_dev *pdev = dev_priv->drm.pdev;
        uint16_t gmch_ctl, gms;

        pci_read_config_word(pdev, SNB_GMCH_CTRL, &gmch_ctl);
        gms = (gmch_ctl >> BDW_GMCH_GMS_SHIFT) & BDW_GMCH_GMS_MASK;
        if (gms < 0xf0)
                return gms * (32 * 1024 * 1024);
        else
                return (gms - 0xf0) * (4 * 1024 * 1024) + (4 * 1024 * 1024);
}

void
intel_init_stolen_res(struct drm_i915_private *dev_priv)
{
        bus_addr_t stolen_base = 0;
        bus_size_t stolen_size = 0;

#ifdef notyet
        if (IS_I830(dev_priv))
                stolen_base  = i830_stolen_base(dev_priv);
        else if (IS_I845G(dev_priv))
                stolen_base  = i845_stolen_base(dev_priv);
        else if (IS_I85X(dev_priv))
                stolen_base  = i85x_stolen_base(dev_priv);
        else if (IS_I865G(dev_priv))
                stolen_base  = i865_stolen_base(dev_priv);
#endif

        if (GRAPHICS_VER(dev_priv) >= 3 && GRAPHICS_VER(dev_priv) < 11)
                stolen_base  = gen3_stolen_base(dev_priv);
        else if (GRAPHICS_VER(dev_priv) == 11 || GRAPHICS_VER(dev_priv) == 12)
                stolen_base = gen11_stolen_base(dev_priv);

        if (IS_I830(dev_priv) || IS_I845G(dev_priv))
                stolen_size = i830_stolen_size(dev_priv);
        else if (IS_I85X(dev_priv) || IS_I865G(dev_priv) ||
            (GRAPHICS_VER(dev_priv) >= 3 && GRAPHICS_VER(dev_priv) <= 5))
                stolen_size = gen3_stolen_size(dev_priv);
        else if (IS_CHERRYVIEW(dev_priv))
                stolen_size = chv_stolen_size(dev_priv);
        else if (GRAPHICS_VER(dev_priv) >= 6 && GRAPHICS_VER(dev_priv) < 8)
                stolen_size = gen6_stolen_size(dev_priv);
        else if (GRAPHICS_VER(dev_priv) == 8)
                stolen_size = gen8_stolen_size(dev_priv);
        else if (GRAPHICS_VER(dev_priv) >= 9 && GRAPHICS_VER(dev_priv) <= 12)
                stolen_size = gen9_stolen_size(dev_priv);

        if (stolen_base == 0 || stolen_size == 0)
                return;

        intel_graphics_stolen_res.start = stolen_base;
        intel_graphics_stolen_res.end = stolen_base + stolen_size - 1;
}